Montoye, Alexander H K; Begum, Munni; Henning, Zachary; Pfeiffer, Karin A
2017-02-01
This study had three purposes, all related to evaluating energy expenditure (EE) prediction accuracy from body-worn accelerometers: (1) compare linear regression to linear mixed models, (2) compare linear models to artificial neural network models, and (3) compare accuracy of accelerometers placed on the hip, thigh, and wrists. Forty individuals performed 13 activities in a 90 min semi-structured, laboratory-based protocol. Participants wore accelerometers on the right hip, right thigh, and both wrists and a portable metabolic analyzer (EE criterion). Four EE prediction models were developed for each accelerometer: linear regression, linear mixed, and two ANN models. EE prediction accuracy was assessed using correlations, root mean square error (RMSE), and bias and was compared across models and accelerometers using repeated-measures analysis of variance. For all accelerometer placements, there were no significant differences for correlations or RMSE between linear regression and linear mixed models (correlations: r = 0.71-0.88, RMSE: 1.11-1.61 METs; p > 0.05). For the thigh-worn accelerometer, there were no differences in correlations or RMSE between linear and ANN models (ANN-correlations: r = 0.89, RMSE: 1.07-1.08 METs. Linear models-correlations: r = 0.88, RMSE: 1.10-1.11 METs; p > 0.05). Conversely, one ANN had higher correlations and lower RMSE than both linear models for the hip (ANN-correlation: r = 0.88, RMSE: 1.12 METs. Linear models-correlations: r = 0.86, RMSE: 1.18-1.19 METs; p < 0.05), and both ANNs had higher correlations and lower RMSE than both linear models for the wrist-worn accelerometers (ANN-correlations: r = 0.82-0.84, RMSE: 1.26-1.32 METs. Linear models-correlations: r = 0.71-0.73, RMSE: 1.55-1.61 METs; p < 0.01). For studies using wrist-worn accelerometers, machine learning models offer a significant improvement in EE prediction
Oxendale, Chelsea L; Highton, Jamie; Twist, Craig
2017-10-01
The purpose of the study was to compare measures of energy expenditure derived from indirect calorimetry and micro-technology, as well as high power and high speed activity during linear and multi-directional running. Repeated measures. Twelve university standard team sport players completed a linear and multi-directional running condition. Estimated energy expenditure, as well as time at high speed (>14.4kmh(-1)) and high power (>20Wkg(-1)) were quantified using a 10Hz micro-technology device and compared with energy expenditure derived from indirect calorimetry. Measured energy expenditure was higher during the multi-directional condition (9.0±2.0 cf. 5.9±1.4kcalmin(-1)), whereas estimated energy expenditure was higher during the linear condition (8.7±2.1 cf. 6.5±1.5kcalmin(-1)). Whilst measures of energy expenditure were strongly related (r>0.89, p<0.001), metabolic power underestimated energy expenditure by 52% (95% LoA: 20-93%) and 34% (95% LoA: 12-59%) during the multi-directional and linear condition, respectively. Time at high power was 41% (95% LoA: 4-92%) greater than time at high speed during the multi-directional condition, whereas time at high power was 5% (95% LoA: -17-9%) lower than time at high speed during the linear condition. Estimated energy expenditure and time at high metabolic power can reflect changes in internal load. However, micro-technology cannot be used to determine the energy cost of intermittent running. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Agarwal, Parul; Sambamoorthi, Usha
2015-12-01
Depression is common among individuals with osteoarthritis and leads to increased healthcare burden. The objective of this study was to examine excess total healthcare expenditures associated with depression among individuals with osteoarthritis in the US. Adults with self-reported osteoarthritis (n = 1881) were identified using data from the 2010 Medical Expenditure Panel Survey (MEPS). Among those with osteoarthritis, chi-square tests and ordinary least square regressions (OLS) were used to examine differences in healthcare expenditures between those with and without depression. Post-regression linear decomposition technique was used to estimate the relative contribution of different constructs of the Anderson's behavioral model, i.e., predisposing, enabling, need, personal healthcare practices, and external environment factors, to the excess expenditures associated with depression among individuals with osteoarthritis. All analysis accounted for the complex survey design of MEPS. Depression coexisted among 20.6 % of adults with osteoarthritis. The average total healthcare expenditures were $13,684 among adults with depression compared to $9284 among those without depression. Multivariable OLS regression revealed that adults with depression had 38.8 % higher healthcare expenditures (p < 0.001) compared to those without depression. Post-regression linear decomposition analysis indicated that 50 % of differences in expenditures among adults with and without depression can be explained by differences in need factors. Among individuals with coexisting osteoarthritis and depression, excess healthcare expenditures associated with depression were mainly due to comorbid anxiety, chronic conditions and poor health status. These expenditures may potentially be reduced by providing timely intervention for need factors or by providing care under a collaborative care model.
[Relationship between cost systems and hospital expenditure].
García-Cornejo, Beatriz; Pérez-Méndez, José A
2017-08-31
To analyze the relationship between the degree of development of hospital cost systems (CS) implemented by the regional health services (RHS) and the variation in unit cost of hospitals in Spanish National Health Service (NHS) between 2010 and 2013 and to identify other explanatory factors of this variation. A database of NHS hospitals was constructed from exclusively public sources. Using a multilevel regression model, explaining factors of the variation in unit cost (cost per weighted unit of activity [WAU]) of a sample of 170 hospitals were analyzed. The variables representative of the degree of development of CS are associated in a negative and significant way with the variation of the cost per WAU. It is observed that if a high-level development CS is used the cost variation per WAU would be reduced by close to 3.2%. There is also a negative and significant relationship between the variation in the cost per WAU and the variations in the percentage of high technology and the hospital occupancy rate. On the other hand, the variations in the average cost of personnel and in the number of workers per 100 beds are associated in a positive and significant way with the variation of the cost per WAU. In the period analysed, during which the main health expenditure adjustment was made, the control in hospital unit cost is associated not only with spending cuts but also with aspects related to their management, such as the implementation of more developed CS. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
NASA Technical Reports Server (NTRS)
Callier, Frank M.; Desoer, Charles A.
1991-01-01
The aim of this book is to provide a systematic and rigorous access to the main topics of linear state-space system theory in both the continuous-time case and the discrete-time case; and the I/O description of linear systems. The main thrusts of the work are the analysis of system descriptions and derivations of their properties, LQ-optimal control, state feedback and state estimation, and MIMO unity-feedback systems.
NASA Technical Reports Server (NTRS)
Callier, Frank M.; Desoer, Charles A.
1991-01-01
The aim of this book is to provide a systematic and rigorous access to the main topics of linear state-space system theory in both the continuous-time case and the discrete-time case; and the I/O description of linear systems. The main thrusts of the work are the analysis of system descriptions and derivations of their properties, LQ-optimal control, state feedback and state estimation, and MIMO unity-feedback systems.
Global positioning system watches for estimating energy expenditure.
Hongu, Nobuko; Orr, Barron J; Roe, Denise J; Reed, Rebecca G; Going, Scott B
2013-11-01
Global positioning system (GPS) watches have been introduced commercially, converting frequent measurements of time, location, speed (pace), and elevation into energy expenditure (EE) estimates. The purpose of this study was to compare EE estimates of 4 different GPS watches (Forerunner, Suunto, Polar, Adeo), at various walking speeds, with EE estimate from a triaxial accelerometer (RT3), which was used as a reference measure in this study. Sixteen healthy young adults completed the study. Participants wore 4 different GPS watches and an RT3 accelerometer and walked at 6-minute intervals on an outdoor track at 3 speeds (3, 5, and 7 km/hr). The statistical significance of differences in EE between the 3 watches was assessed using linear contrasts of the coefficients from the overall model. Reliability across trials for a given device was assessed using intraclass correlation coefficients as estimated in the mixed model. The GPS watches demonstrated lower reliability (intraclass correlation coefficient) across trials when compared with the RT3, particularly at the higher speed, 7 km/hr. Three GPS watches (Forerunner, Polar, and Suunto) significantly and consistently underestimated EE compared with the reference EE given by the RT3 accelerometer (average mean difference: Garmin, -50.5%; Polar, -41.7%; and Suunto, -41.7%; all p < 0.001). Results suggested that caution should be exercised when using commercial GPS watches to estimate EE in athletes during field-based testing and training.
Ultrasonic linear measurement system
NASA Technical Reports Server (NTRS)
Marshall, Scot H. (Inventor)
1991-01-01
An ultrasonic linear measurement system uses the travel time of surface waves along the perimeter of a three-dimensional curvilinear body to determine the perimeter of the curvilinear body. The system can also be used piece-wise to measure distances along plane surfaces. The system can be used to measure perimeters where use of laser light, optical means or steel tape would be extremely difficult, time consuming or impossible. It can also be used to determine discontinuities in surfaces of known perimeter or dimension.
Multihospital System Membership and Patient Treatments, Expenditures, and Outcomes
Madison, Kristin
2004-01-01
Objective To determine the relationship between hospital membership in systems and the treatments, expenditures, and outcomes of patients. Data Sources The Medicare Provider Analysis and Review dataset, for data on Medicare patients admitted to general medical-surgical hospitals between 1985 and 1998 with a diagnosis of acute myocardial infarction (AMI); the American Hospital Association Annual Survey, for data on hospitals. Study Design A multivariate regression analysis. An observation is a fee-for-service Medicare AMI patient admitted to a study hospital. Dependent variables include patient transfers, catheterizations, angioplasties or bypass surgeries, 90-day mortality, and Medicare expenditures. Independent variables include system participation, other admission hospital and patient traits, and hospital and year fixed effects. The five-part system definition incorporates the size and location of the index admission hospital and the size and distance of its partners. Principal Findings While the effects of multihospital system membership on patients are in general limited, patients initially admitted to small rural system hospitals that have big partners within 100 miles experience lower mortality rates than patients initially admitted to independent hospitals. Regression results show that to the extent system hospital patients experience differences in treatments and outcomes relative to patients of independent hospitals, these differences remain even after controlling for the admission hospital's capacity to provide cardiac services. Conclusions Multihospital system participation may affect AMI patient treatment and outcomes through factors other than cardiac service offerings. Additional investigation into the nature of these factors is warranted. PMID:15230926
Thorpe, Carolyn T; Thorpe, Joshua M; Jiang, Tao; Atkinson, Dylan; Kang, Yihuang; Schleiden, Loren J; Carpenter, Delesha M; McGregor, Julie Anne G; Hogan, Susan L
2017-08-10
The Medicare federal insurance program is the most common United States insurer of patients with systemic vasculitis (SV). We compared healthcare utilization and expenditures for Medicare beneficiaries with versus without SV. This national, retrospective study used 2010 claims and enrollment data for a 100% cohort of Medicare Part A and B beneficiaries with ≥1 claim including a diagnosis for a form of SV (n = 176,498), and a randomly selected group of non-SV beneficiaries (n = 46,561). Outcomes included annual counts of events in 16 categories of medical services (e.g., inpatient stays, physician visits, tests, and imaging events), and total annual Medicare and patient medical expenditures. We used linear regression with bootstrapped standard errors to compare utilization and expenditures by SV status, before and after matching on age and sex. Prescription drug fills and expenditures for SV (n = 95,157) and non-SV (n = 24,992) beneficiaries with Part D drug benefits were also compared. After matching, Medicare spent $11,004 more per patient in 2010 for medical services, and $773 more on prescription drugs, for SV versus non-SV beneficiaries. SV beneficiaries spent $1547 more for medical services and $211 more for prescription drugs. Except for hospice, SV beneficiaries had greater utilization of all services, including two-to-three times more dialysis events, hospital readmissions, inpatient stays, skilled nursing facility stays, and medical tests. The average Medicare beneficiary with SV incurs about double the annual healthcare expenditures compared to their non-SV counterparts, attributable to increased utilization of almost all categories of care. Published by Elsevier Inc.
[Health expenditures, income inequality, and the marginalization index in Mexico's health system].
Pinzón Florez, Carlos Eduardo; Reveiz, Ludovic; Idrovo, Alvaro J; Reyes Morales, Hortensia
2014-01-01
Evaluate the effect of the relationship among public health expenditures, income inequality, and the marginalization index on maternal and child mortality in Mexico, to determine the effect of these factors on health system performance from a technical efficiency perspective. An ecological study of 32 Mexican states. Correlations were estimated between maternal and infant mortality and public health expenditures in total per capita, federal per capita, and state per capita for the years 2000, 2005, and 2010 (Gini coefficient and marginalization index). Linear regressions were used to explore the association of these variables with health indicators in the state systems. Negative correlations were observed for the marginalization index and Gini coefficient with regard to life expectancy at birth (-0.62 and -0.28 respectively). Furthermore, there was a positive correlation of 0.59 between the marginalization index and infant mortality (P <0.05). Multiple linear regression models revealed a negative effect of the marginalization index and Gini coefficient on health out-comes. Federal funding had a positive effect on system performance in terms of health indicators. Health system reform in Mexico has had a positive impact on the country's health indicators; federal financial investment seems to be effective in this regard. Social determinants have an important effect on health system performance, and analysis using multisectoral and multidisciplinary approaches are needed in addressing them.
Malhotra, Chetna; Do, Young Kyung
2017-04-01
Improvement in overall responsiveness to people's expectations is an important goal for any health system; socioeconomic equity in responsiveness is equally important. However, it is not known if socioeconomic disparities in responsiveness can be reduced through greater public health expenditures. This article assesses the relationship of the proportion of public health expenditure over total health expenditure (PPHE) with responsiveness for poorest individuals and the difference in responsiveness between the richest and poorest individuals. We used data from six responsiveness dimensions (prompt attention, dignity, choice, clarity of information, confidentiality and quality of basic amenities) of outpatient services from World Health Survey data from 63 countries. Hierarchical Ordered Probit (HOPIT) models assessed the probability of 'very good' responsiveness in each domain among the poorest and richest individuals for each country, correcting for reporting heterogeneity through vignettes. Linear regression models were then used to assess the association between predicted probabilities from HOPIT models and PPHE, adjusting for (log) Gross Domestic Product per capita. The study findings showed that higher PPHE was associated with a higher probability of 'very good' responsiveness for each domain among the poorest individuals, and with smaller pro-rich disparities in responsiveness between the richest and poorest individuals. In conclusion, increasing PPHE may improve the responsiveness of health services for the poorest individuals and reduce disparities in responsiveness between the richest and poorest individuals.
Linear Hereditary Control Systems,
Relationships between external and internal models for systems with time lags are discussed. The use of various canonical forms for the models in solving optimal control problems is considered. (Author)
Documentation for the State Energy Price and Expenditure Data System 1970-1987: Diskettes
Not Available
1989-10-01
The State Energy Price and Expenditure Data System (SEPEDS) is the database that supports the State Energy Price and Expenditure Report 1987'' (SEPER). The SEPEDS diskettes contain annual energy price and expenditure estimated for 1970-1987. The State data are grouped with one Census Region per diskette. In addition to the States in the Region, each diskette contains data utility programs which will format the data for use by the most widely used spreadsheet and database software products.
2013-02-15
Universiti Teknikal Malaysia Melaka in Malaysia. The project was then used to partially support a new PhD student, Mr Shanon Vuglar (who is a former...method based on cascade realization of quantum systems is used and a conference and journal paper have been produced. In another approach, a method...based on singular perturbation is used and a conference and journal paper have resulted. This work was extended by the graduate student Shanon Vuglar to
Linearization of Nonlinear Systems.
1986-11-24
series. IEEE Trans. Circuits Syst., CAS-32(11):1150-1171, November 1985. [BC85b] S. Boyd and L. 0. Chua. Uniqueness of circuits and systems containing...Control and Information Sciences vol. 58, p10 1- 1 19 , June 1983. [BC85c] S. Boyd and L. 0. Chua. Volterra series for nonlinear circuits . In Proc. IEEE...ISCAS, Tokyo, June 1985. [BCD84] S. Boyd, L. 0. Chua, and C. A. Desoer . Analytical foundations of Volterra series. IMA Journal of Mathematical
Preconditioned quantum linear system algorithm.
Clader, B D; Jacobs, B C; Sprouse, C R
2013-06-21
We describe a quantum algorithm that generalizes the quantum linear system algorithm [Harrow et al., Phys. Rev. Lett. 103, 150502 (2009)] to arbitrary problem specifications. We develop a state preparation routine that can initialize generic states, show how simple ancilla measurements can be used to calculate many quantities of interest, and integrate a quantum-compatible preconditioner that greatly expands the number of problems that can achieve exponential speedup over classical linear systems solvers. To demonstrate the algorithm's applicability, we show how it can be used to compute the electromagnetic scattering cross section of an arbitrary target exponentially faster than the best classical algorithm.
Identification of multivariate linear systems
Griffith, J.M.
1981-01-01
This paper considers the problem of modeling multivariate linear systems where noisy output measurements are the only available data. The techniques presented are valid for a class of canonical forms. Results from several simulations demonstrate the capability for structure and parameter estimation.
Systems of Inhomogeneous Linear Equations
NASA Astrophysics Data System (ADS)
Scherer, Philipp O. J.
Many problems in physics and especially computational physics involve systems of linear equations which arise e.g. from linearization of a general nonlinear problem or from discretization of differential equations. If the dimension of the system is not too large standard methods like Gaussian elimination or QR decomposition are sufficient. Systems with a tridiagonal matrix are important for cubic spline interpolation and numerical second derivatives. They can be solved very efficiently with a specialized Gaussian elimination method. Practical applications often involve very large dimensions and require iterative methods. Convergence of Jacobi and Gauss-Seidel methods is slow and can be improved by relaxation or over-relaxation. An alternative for large systems is the method of conjugate gradients.
ERIC Educational Resources Information Center
Foley, Arthur P.; Massey, Ted W.
The fifth annual financial report of West Virginia's state system of higher education is presented by the Board of Regents. Current operating revenue and expenditures for fiscal year 1974-75 are given, including trend data pertaining to total revenues and expenditures for fiscal years 1971-72 through 1974-75. Operating revenue and expenditures are…
Uei, Shu-Lin; Tsai, Chung-Hung; Kuo, Yu-Ming
2016-04-29
Telehealth cost analysis has become a crucial issue for governments in recent years. In this study, we examined cases of metabolic syndrome in Hualien County, Taiwan. This research adopted the framework proposed by Marchand to establish a study process. In addition, descriptive statistics, a t test, analysis of variance, and regression analysis were employed to analyze 100 questionnaires. The results of the t$ test revealed significant differences in medical health expenditure, number of clinical visits for medical treatment, average amount of time spent commuting to clinics, amount of time spent undergoing medical treatment, and average number of people accompanying patients to medical care facilities or assisting with other tasks in the past one month, indicating that offering telehealth care services can reduce health expenditure. The statistical analysis results revealed that customer satisfaction has a positive effect on reducing health expenditure. Therefore, this study proves that telehealth care systems can effectively reduce health expenditure and directly improve customer satisfaction with medical treatment.
THE RESPONSE OF DRUG EXPENDITURE TO NON-LINEAR CONTRACT DESIGN: EVIDENCE FROM MEDICARE PART D.
Einav, Liran; Finkelstein, Amy; Schrimpf, Paul
2015-05-01
We study the demand response to non-linear price schedules using data on insurance contracts and prescription drug purchases in Medicare Part D. We exploit the kink in individuals' budget set created by the famous "donut hole," where insurance becomes discontinuously much less generous on the margin, to provide descriptive evidence of the drug purchase response to a price increase. We then specify and estimate a simple dynamic model of drug use that allows us to quantify the spending response along the entire non-linear budget set. We use the model for counterfactual analysis of the increase in spending from "filling" the donut hole, as will be required by 2020 under the Affordable Care Act. In our baseline model, which considers spending decisions within a single year, we estimate that "filling" the donut hole will increase annual drug spending by about $150, or about 8 percent. About one-quarter of this spending increase reflects "anticipatory" behavior, coming from beneficiaries whose spending prior to the policy change would leave them short of reaching the donut hole. We also present descriptive evidence of cross-year substitution of spending by individuals who reach the kink, which motivates a simple extension to our baseline model that allows - in a highly stylized way - for individuals to engage in such cross year substitution. Our estimates from this extension suggest that a large share of the $150 drug spending increase could be attributed to cross-year substitution, and the net increase could be as little as $45 per year.
THE RESPONSE OF DRUG EXPENDITURE TO NON-LINEAR CONTRACT DESIGN: EVIDENCE FROM MEDICARE PART D*
Einav, Liran; Finkelstein, Amy; Schrimpf, Paul
2016-01-01
We study the demand response to non-linear price schedules using data on insurance contracts and prescription drug purchases in Medicare Part D. We exploit the kink in individuals’ budget set created by the famous “donut hole,” where insurance becomes discontinuously much less generous on the margin, to provide descriptive evidence of the drug purchase response to a price increase. We then specify and estimate a simple dynamic model of drug use that allows us to quantify the spending response along the entire non-linear budget set. We use the model for counterfactual analysis of the increase in spending from “filling” the donut hole, as will be required by 2020 under the Affordable Care Act. In our baseline model, which considers spending decisions within a single year, we estimate that “filling” the donut hole will increase annual drug spending by about $150, or about 8 percent. About one-quarter of this spending increase reflects “anticipatory” behavior, coming from beneficiaries whose spending prior to the policy change would leave them short of reaching the donut hole. We also present descriptive evidence of cross-year substitution of spending by individuals who reach the kink, which motivates a simple extension to our baseline model that allows – in a highly stylized way – for individuals to engage in such cross year substitution. Our estimates from this extension suggest that a large share of the $150 drug spending increase could be attributed to cross-year substitution, and the net increase could be as little as $45 per year. PMID:26769984
Narine, L
2000-01-01
In order to gain further insight into the system factors responsible for changes in the health workforce, this study undertook an empirical examination of the determinants of the size of the health workforce and overall health expenditures across fifteen OECD countries. Specifically, using the latest release of OECD data, the analysis estimated and evaluated the effects of variables such as the proportion of female physicians and the elderly, expenditures on ambulatory care, enrollment levels in training programs, level of public financing, and per capita income on the size of the health workforce and level of health spending between 1970-1991. The findings of this study help to place the problem of the changing health workforce within the context of the complexity of health systems. It confirms any understanding of what accounts for changes in the size of the health labor force and expenditures require disentangling the effects of variables which needs to be taken into account when considering health system reforms.
Conditions for Stabilizability of Linear Switched Systems
NASA Astrophysics Data System (ADS)
Minh, Vu Trieu
2011-06-01
This paper investigates some conditions that can provide stabilizability for linear switched systems with polytopic uncertainties via their closed loop linear quadratic state feedback regulator. The closed loop switched systems can stabilize unstable open loop systems or stable open loop systems but in which there is no solution for a common Lyapunov matrix. For continuous time switched linear systems, we show that if there exists solution in an associated Riccati equation for the closed loop systems sharing one common Lyapunov matrix, the switched linear systems are stable. For the discrete time switched systems, we derive a Linear Matrix Inequality (LMI) to calculate a common Lyapunov matrix and solution for the stable closed loop feedback systems. These closed loop linear quadratic state feedback regulators guarantee the global asymptotical stability for any switched linear systems with any switching signal sequence.
Linear control design for guaranteed stability of uncertain linear systems
NASA Technical Reports Server (NTRS)
Yedavalli, R. K.
1986-01-01
In this paper, a linear control design algorithm based on the elemental perturbation bounds developed recently is presented for a simple second order linear uncertain system satisfying matching conditions. The proposed method is compared with Guaranteed Cost Control (GCC), Multistep Guaranteed Cost Control (MGCC) and the Matching Condition (MC) methods and is shown to give guaranteed stability with lesser values for the control gains than some of the existing methods for the example considered.
Controlling coexisting attractors of an impacting system via linear augmentation
NASA Astrophysics Data System (ADS)
Liu, Yang; Páez Chávez, Joseph
2017-06-01
This paper studies the control of coexisting attractors in an impacting system via a recently developed control law based on linear augmentation. Special attention is given to two control issues in the framework of multistable engineering systems, namely, the switching between coexisting attractors without altering the system's main parameters and the avoidance of grazing-induced chaotic responses. The effectiveness of the proposed control scheme is confirmed numerically for the case of a periodically excited, soft impact oscillator. Our analysis shows how path-following techniques for non-smooth systems can be used in order to determine the optimal control parameters in terms of energy expenditure due to the control signal and transient behavior of the control error, which can be applied to a broad range of engineering problems.
Expenditure and Employment Data for the Criminal Justice System, 1969-70.
ERIC Educational Resources Information Center
National Inst. of Law Enforcement and Criminal Justice (Dept. of Justice/LEAA), Washington, DC.
Specific data relating to public expenditure and employment for the criminal justice system in the United States are presented in tabular form in this annual survey report. Comprehensive data are supplied in 29 tables for the Federal Government, each of the 50 state governments, city, county, and other local subdivisions of government. Data are…
ERIC Educational Resources Information Center
Blond, David L.
The Defense Economic Impact Modeling System (DEIMS) analyzes the economic effect of defense expenditures on the United States economy by using a consistent, reliable framework of economic models and government policy assumptions. Planning information on defense requirements is also provided to private sector firms. The DEIMS allows the Department…
Linear quadratic optimal control for symmetric systems
NASA Technical Reports Server (NTRS)
Lewis, J. H.; Martin, C. F.
1983-01-01
Special symmetries are present in many control problems. This paper addresses the problem of determining linear-quadratic optimal control problems whose solutions preserve the symmetry of the initial linear control system.
Parametric Identification of Systems Via Linear Operators.
1978-09-01
A general parametric identification /approximation model is developed for the black box identification of linear time invariant systems in terms of... parametric identification techniques derive from the general model as special cases associated with a particular linear operator. Some possible
Huguier, Michel
2012-10-01
Healthcare expenditure is divided between medical infrastructure and individual patient management. Total healthcare costs in France amount to roughly 175 billion euros, financed through public health insurance (77%), private insurance (14%), and individual expenditure (9%). The principal expenditures are for hospitalization (44%), community medical, dental and paramedical care (28%), drugs (20%) and miscellaneous resources (8%). The main factors of rising costs are medical progress and aging. More controllable costs include healthcare provision, the level of reimbursement, public education and information, and physician training. France devotes 9.2% of its gross national product to healthcare, compared to 7-8% in Sweden, Germany and the United Kingdom, representing a diference of about 18 billion euros. In France there is a chronic imbalance between resources and expenditure, creating a cumulative budget deficit of about 100 billlion euros. Major efforts must be made to improve efficiency, and it will be necessary to choose between preserving our healthcare system or our financial system. If the latter is prioritized, healthcare will inevitably deteriorate.
An Approach to Forecasting Health Expenditures, with Application to the U.S. Medicare System
Lee, Ronald; Miller, Timothy
2002-01-01
Objective To quantify uncertainty in forecasts of health expenditures. Study Design Stochastic time series models are estimated for historical variations in fertility, mortality, and health spending per capita in the United States, and used to generate stochastic simulations of the growth of Medicare expenditures. Individual health spending is modeled to depend on the number of years until death. Data Sources/Study Setting A simple accounting model is developed for forecasting health expenditures, using the U.S. Medicare system as an example. Principal Findings Medicare expenditures are projected to rise from 2.2 percent of GDP (gross domestic product) to about 8 percent of GDP by 2075. This increase is due in equal measure to increasing health spending per beneficiary and to population aging. The traditional projection method constructs high, medium, and low scenarios to assess uncertainty, an approach that has many problems. Using stochastic forecasting, we find a 95 percent probability that Medicare spending in 2075 will fall between 4 percent and 18 percent of GDP, indicating a wide band of uncertainty. Although there is substantial uncertainty about future mortality decline, it contributed little to uncertainty about future Medicare spending, since lower mortality both raises the number of elderly, tending to raise spending, and is associated with improved health of the elderly, tending to reduce spending. Uncertainty about fertility, by contrast, leads to great uncertainty about the future size of the labor force, and therefore adds importantly to uncertainty about the health-share of GDP. In the shorter term, the major source of uncertainty is health spending per capita. Conclusions History is a valuable guide for quantifying our uncertainty about future health expenditures. The probabilistic model we present has several advantages over the high–low scenario approach to forecasting. It indicates great uncertainty about future Medicare expenditures relative
Hartke, Patricia L.; Vermeulen, Lee C.; Hoffman, James M.; Shah, Nilay D.; Doloresco, Fred; Suda, Katie J.; Li, Edward C.; Matusiak, Linda M.; Hunkler, Robert J.
2015-01-01
Purpose To evaluate the accuracy of the forecast of drug expenditures in nonfederal hospitals and clinics published annually in the American Journal of Health-System Pharmacy (AJHP) compared to the drug expenditure forecasts produced annually by the Centers for Medicare and Medicaid Services (CMS). Methods The forecasted drug expenditure growth published in AJHP for nonfederal hospitals (for the years 2003 to 2013) and clinics (for the years 2004 to 2013) was compared to the actual growth each year. The actual and forecasted growth published by CMS was analyzed for the years 2003 to 2012. The mean absolute error (MAE) and directional accuracy for the AJHP forecasts for nonfederal hospitals and clinics, and for the CMS forecasts, were determined and compared. Results Actual growth was within the forecasted range in 2 of 11 years for nonfederal hospitals, and in 3 of 10 years for clinics. The forecasts were directionally accurate 27.3% and 60.0% of the time for nonfederal hospitals and clinics, respectively. The MAE for the nonfederal hospital and clinic drug expenditure forecasts were 2.0 and 4.7 percentage points, respectively. The CMS forecasts were directionally accurate 70% of the time, and the MAE was 2.2 percentage points and was not statistically different than the AJHP forecasts. Conclusion The forecasts published annually in AJHP have comparable accuracy that by CMS for predicting prescription expenditure growth. The forecast paper provides an overview of current trends, which must be combined with local information to accurately forecast institutional drug expenditures. PMID:26386105
2013-01-01
Background China's health system reform launched in early 2000s has achieved better coverage of health insurance and significantly increased the use of healthcare for vast majority of Chinese population. This study was to examine changes in the structure of total health expenditures in China in 2000–2011, and to investigate the financial burden of healthcare placed on its population, particularly between urban and rural areas and across different socio-economic development regions. Methods Health expenditures data came from the China National Health Accounts study in 1990–2011, and other data used to calculate the financial burden of healthcare were from China Statistical Yearbook and China Population Statistical Yearbook. Total health expenditures were divided into government and social expenditure, and out-of-pocket payment. The financial burden of healthcare was estimated as out-of-pocket payment per capita as a percentage of annual household living consumption expenditure per capita. Results Between 2000 and 2011, total health expenditures in China increased from Chinese yuan 319 to 1888 (United States dollars 51 to 305), with average annual increase of 17.4%. Government and social health expenditure increased rapidly being 22.9% and 18.8% of average annual growth rate, respectively. The share of out-of-pocket payment in total health expenditure for the urban population declined from 53% in 2005 to 36% in 2011, but had only a slight decrease for the rural population from 53% to 50%. Out-of-pocket payment, as a percentage of annual household living consumption, has continued to rise, particularly in the rural population from the less developed region (6.1% in 2000 to 8.8% in 2011). Conclusions The rapid increase of public funding to subsidize health insurance in China, as part of the reform strategy, did not mitigate the out-of-pocket payment for healthcare over the past decade. Financial burden of healthcare on the rural population increased. Affordability
Long, Qian; Xu, Ling; Bekedam, Henk; Tang, Shenglan
2013-06-13
China's health system reform launched in early 2000s has achieved better coverage of health insurance and significantly increased the use of healthcare for vast majority of Chinese population. This study was to examine changes in the structure of total health expenditures in China in 2000-2011, and to investigate the financial burden of healthcare placed on its population, particularly between urban and rural areas and across different socio-economic development regions. Health expenditures data came from the China National Health Accounts study in 1990-2011, and other data used to calculate the financial burden of healthcare were from China Statistical Yearbook and China Population Statistical Yearbook. Total health expenditures were divided into government and social expenditure, and out-of-pocket payment. The financial burden of healthcare was estimated as out-of-pocket payment per capita as a percentage of annual household living consumption expenditure per capita. Between 2000 and 2011, total health expenditures in China increased from Chinese yuan 319 to 1888 (United States dollars 51 to 305), with average annual increase of 17.4%. Government and social health expenditure increased rapidly being 22.9% and 18.8% of average annual growth rate, respectively. The share of out-of-pocket payment in total health expenditure for the urban population declined from 53% in 2005 to 36% in 2011, but had only a slight decrease for the rural population from 53% to 50%. Out-of-pocket payment, as a percentage of annual household living consumption, has continued to rise, particularly in the rural population from the less developed region (6.1% in 2000 to 8.8% in 2011). The rapid increase of public funding to subsidize health insurance in China, as part of the reform strategy, did not mitigate the out-of-pocket payment for healthcare over the past decade. Financial burden of healthcare on the rural population increased. Affordability among the rural households with sick
Linear systems, and ARMA- and Fliess models
NASA Astrophysics Data System (ADS)
Lomadze, Vakhtang; Khurram Zafar, M.
2010-10-01
Linear (dynamical) systems are central objects of study (in linear system theory), and ARMA- and Fliess models are two very important classes of models that are used to represent them. This article is concerned with the question of what is a relation between them (in case of higher dimensions). It is shown that the category of linear systems, the 'weak' category of ARMA-models and the category of Fliess models are equivalent to each other.
Per Pupil Expenditures and Academic Achievement in Georgia School Systems
ERIC Educational Resources Information Center
van Beurden, Krista
2011-01-01
Student achievement and public school funding are national concerns. Federal, state, and local funding vary across the nation and within systems in each state. In the past several years, Georgia school systems have faced austerity cuts by the state legislature and governor, and function with less money while trying to improve student achievement…
The role of the endocannabinoid system in the regulation of energy expenditure.
Cavuoto, Paul; Wittert, Gary A
2009-02-01
Endocannabinoids, a lipid-derived signaling system, regulate appetite and motivation to eat via effects in the hypothalamus and nucleus accumbens. Not all the effects of endocannabinoids on fat mass can be explained by the regulation of food intake alone. Endocannabinoids and their receptors are located in areas of the central nervous system and multiple peripheral tissues involved in the regulation of intermediary metabolism and energy expenditure. In addition to regulating food intake by both central and peripherally mediated effects, endocannabinoids modify glucose and lipid metabolism so as to promote energy storage via lipogenesis and reduce energy expenditure. The endocannabinoid system appears to be overactive in obesity and may serve to maintain fat mass and underlies some of the metabolic consequences of obesity. Inhibition of the cannabinoid type-1 receptor ameliorates the effects of endocannabinoids on food intake and energy metabolism; lipogenesis is inhibited, lipolysis, fatty acid oxidation and glucose uptake increase.
Contoyannis, Paul; Hurley, Jeremiah; Grootendorst, Paul; Jeon, Sung-Hee; Tamblyn, Robyn
2005-09-01
The price elasticity of demand for prescription drugs is a crucial parameter of interest in designing pharmaceutical benefit plans. Estimating the elasticity using micro-data, however, is challenging because insurance coverage that includes deductibles, co-insurance provisions and maximum expenditure limits create a non-linear price schedule, making price endogenous (a function of drug consumption). In this paper we exploit an exogenous change in cost-sharing within the Quebec (Canada) public Pharmacare program to estimate the price elasticity of expenditure for drugs using IV methods. This approach corrects for the endogeneity of price and incorporates the concept of a 'rational' consumer who factors into consumption decisions the price they expect to face at the margin given their expected needs. The IV method is adapted from an approach developed in the public finance literature used to estimate income responses to changes in tax schedules. The instrument is based on the price an individual would face under the new cost-sharing policy if their consumption remained at the pre-policy level. Our preferred specification leads to expenditure elasticities that are in the low range of previous estimates (between -0.12 and -0.16). Naïve OLS estimates are between 1 and 4 times these magnitudes.
Stabilization of nonlinear systems using linear observers
NASA Technical Reports Server (NTRS)
Strane, R. E.; Vogt, W. G.
1974-01-01
It is shown that a linear observer can always be employed to stabilize a nonlinear system which contains a true Popov type nonlinearity in the closed interval from 0 to k, where k is finite, provided the nonlinear function and a completely observable output of the linear portion are available as inputs to the observer. Taking into consideration the case in which a completely observable output is not available from the linear portion, stabilization is shown to be possible if the original linear approximation of the system is asymptotically stable.
Bertoldi, Andréa D; Barros, Aluísio J D; Camargo, Aline Lins; Hallal, Pedro C; Vandoros, Sotiris; Wagner, Anita; Ross-Degnan, Dennis
2011-05-01
We sought to investigate, across different socioeconomic groups, the proportion of household medicine expenses that were paid by households and the proportion paid by the Brazilian national health system. We carried out a survey in Porto Alegre, Brazil, that included 2988 individuals of all ages. We defined 2 expenditure variables: "out-of-pocket medicines value" (the sum of retail prices of all medicines used by family members within the previous 15 days and paid for out of pocket) and "free medicines value" (a similar definition for medicines obtained without charge). In 2003, the Brazilian national health system provided, free of charge, 78% of the monetary value of medicines reported (79% in the bottom wealth quintile and 32% in the top 2 quintiles). The mean out-of-pocket expense for medicines was 6 times greater among the top wealth quintiles compared with those in lower quintiles, but free medicines constituted a 3-times-greater proportion of potential expenditures for medicines among the bottom quintile than among the top 2 quintiles. Free provision of medicines seems to be saving substantial amounts of medicine expenditures for poor people in Brazil.
Barros, Aluísio J. D.; Camargo, Aline Lins; Hallal, Pedro C.; Vandoros, Sotiris; Wagner, Anita; Ross-Degnan, Dennis
2011-01-01
Objectives. We sought to investigate, across different socioeconomic groups, the proportion of household medicine expenses that were paid by households and the proportion paid by the Brazilian national health system. Methods. We carried out a survey in Porto Alegre, Brazil, that included 2988 individuals of all ages. We defined 2 expenditure variables: “out-of-pocket medicines value” (the sum of retail prices of all medicines used by family members within the previous 15 days and paid for out of pocket) and “free medicines value” (a similar definition for medicines obtained without charge). Results. In 2003, the Brazilian national health system provided, free of charge, 78% of the monetary value of medicines reported (79% in the bottom wealth quintile and 32% in the top 2 quintiles). The mean out-of-pocket expense for medicines was 6 times greater among the top wealth quintiles compared with those in lower quintiles, but free medicines constituted a 3-times-greater proportion of potential expenditures for medicines among the bottom quintile than among the top 2 quintiles. Conclusions. Free provision of medicines seems to be saving substantial amounts of medicine expenditures for poor people in Brazil. PMID:20724692
Systems of Linear Equations on a Spreadsheet.
ERIC Educational Resources Information Center
Bosch, William W.; Strickland, Jeff
1998-01-01
The Optimizer in Quattro Pro and the Solver in Excel software programs make solving linear and nonlinear optimization problems feasible for business mathematics students. Proposes ways in which the Optimizer or Solver can be coaxed into solving systems of linear equations. (ASK)
Isolators Including Main Spring Linear Guide Systems
NASA Technical Reports Server (NTRS)
Goold, Ryan (Inventor); Buchele, Paul (Inventor); Hindle, Timothy (Inventor); Ruebsamen, Dale Thomas (Inventor)
2017-01-01
Embodiments of isolators, such as three parameter isolators, including a main spring linear guide system are provided. In one embodiment, the isolator includes first and second opposing end portions, a main spring mechanically coupled between the first and second end portions, and a linear guide system extending from the first end portion, across the main spring, and toward the second end portion. The linear guide system expands and contracts in conjunction with deflection of the main spring along the working axis, while restricting displacement and rotation of the main spring along first and second axes orthogonal to the working axis.
Stochastic stability properties of jump linear systems
NASA Technical Reports Server (NTRS)
Feng, Xiangbo; Loparo, Kenneth A.; Ji, Yuandong; Chizeck, Howard J.
1992-01-01
Jump linear systems are defined as a family of linear systems with randomly jumping parameters (usually governed by a Markov jump process) and are used to model systems subject to failures or changes in structure. The authors study stochastic stability properties in jump linear systems and the relationship among various moment and sample path stability properties. It is shown that all second moment stability properties are equivalent and are sufficient for almost sure sample path stability, and a testable necessary and sufficient condition for second moment stability is derived. The Lyapunov exponent method for the study of almost sure sample stability is discussed, and a theorem which characterizes the Lyapunov exponents of jump linear systems is presented.
Estimability And Regulability Of Linear Systems
NASA Technical Reports Server (NTRS)
Baram, Yoram; Kailath, Thomas
1990-01-01
Report presents two new properties of systems characterized by linear state space models (e.g., dynamical systems and associated control systems): estimability and regulability. Provides criteria for reductions of errors and cost functions in control systems. Useful in design of optimal controllers and estimators.
Molla, Azaher Ali; Chi, Chunhuei; Mondaca, Alicia Lorena Núñez
2017-01-31
Predictors of high out-of-pocket household healthcare expenditure are essential for creating effective health system finance policy. In Bangladesh, 63.3% of health expenditure is out-of-pocket and born by households. It is imperative to know what determines household health expenditure. This study aims to investigate the predicting factors of high out-of-pocket household healthcare expenditure targeting to put forward policy recommendations on equity in financial burden. Bangladesh household income and expenditure survey 2010 provides data for this study. Predictors of high out-of-pocket household healthcare expenditure were analyzed using multiple linear regressions. We have modeled non-linear relationship using logarithmic form of linear regression. Heteroscedasticity and multicollinearity were checked using Breusch-Pagan/Cook-Weishberg and VIF tests. Normality of the residuals was checked using Kernel density curve. We applied required adjustment for survey data, so that standard errors and parameters estimation are valid. Presence of chronic disease and household income were found to be the most influential and statistically significant (p < 0.001) predictors of high household healthcare expenditure. Households in rural areas spend 7% less than urban dwellers. The results show that a 100% increase in female members in a family leads to a 2% decrease in household health expenditure. Household income, health shocks in families, and family size are other statistically significant predictors of household healthcare expenditure. Proportion of elderly and under-five members in the family show some positive influence on health expenditure, though statistically nonsignificant. The findings call for emphasizing prevention of chronic diseases, as it is a strong predictor of household health expenditure. Innovative insurance scheme needs to be devised to prevent household from being impoverished due to health shocks in the family. Policy makers are urged to design an
Simulation of linear mechanical systems
NASA Technical Reports Server (NTRS)
Sirlin, S. W.
1993-01-01
A dynamics and controls analyst is typically presented with a structural dynamics model and must perform various input/output tests and design control laws. The required time/frequency simulations need to be done many times as models change and control designs evolve. This paper examines some simple ways that open and closed loop frequency and time domain simulations can be done using the special structure of the system equations usually available. Routines were developed to run under Pro-Matlab in a mixture of the Pro-Matlab interpreter and FORTRAN (using the .mex facility). These routines are often orders of magnitude faster than trying the typical 'brute force' approach of using built-in Pro-Matlab routines such as bode. This makes the analyst's job easier since not only does an individual run take less time, but much larger models can be attacked, often allowing the whole model reduction step to be eliminated.
Design And Analysis Of Linear Control Systems
NASA Technical Reports Server (NTRS)
Jamison, John W.
1991-01-01
Package of five computer programs developed to assist in design and analysis of linear control systems by use of root-locus and frequency-response methods. Package written in FORTRAN (BODE, TPEAK) and BASIC (LOCUS, KTUNE, and POLYROOT).
Final focus systems for linear colliders
Erickson, R.A.
1987-11-01
The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs. (LEW)
Design And Analysis Of Linear Control Systems
NASA Technical Reports Server (NTRS)
Jamison, John W.
1991-01-01
Package of five computer programs developed to assist in design and analysis of linear control systems by use of root-locus and frequency-response methods. Package written in FORTRAN (BODE, TPEAK) and BASIC (LOCUS, KTUNE, and POLYROOT).
Recursive inversion of externally defined linear systems
NASA Technical Reports Server (NTRS)
Bach, Ralph E., Jr.; Baram, Yoram
1988-01-01
The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problems of system identification and compensation.
Digital simulation of stiff linear dynamic systems.
NASA Technical Reports Server (NTRS)
Holland, L. D.; Walsh, J. R., Jr.; Kerr, J. H.
1972-01-01
A method is derived for digital computer simulation of linear time-invariant systems when the insignificant eigenvalues involved in such systems are eliminated by an ALSAP root removal technique. The method is applied to a thirteenth-order dynamic system representing a passive RLC network.
A program for identification of linear systems
NASA Technical Reports Server (NTRS)
Buell, J.; Kalaba, R.; Ruspini, E.; Yakush, A.
1971-01-01
A program has been written for the identification of parameters in certain linear systems. These systems appear in biomedical problems, particularly in compartmental models of pharmacokinetics. The method presented here assumes that some of the state variables are regularly modified by jump conditions. This simulates administration of drugs following some prescribed drug regime. Parameters are identified by a least-square fit of the linear differential system to a set of experimental observations. The method is especially suited when the interval of observation of the system is very long.
Aircraft engine mathematical model - linear system approach
NASA Astrophysics Data System (ADS)
Rotaru, Constantin; Roateşi, Simona; Cîrciu, Ionicǎ
2016-06-01
This paper examines a simplified mathematical model of the aircraft engine, based on the theory of linear and nonlinear systems. The dynamics of the engine was represented by a linear, time variant model, near a nominal operating point within a finite time interval. The linearized equations were expressed in a matrix form, suitable for the incorporation in the MAPLE program solver. The behavior of the engine was included in terms of variation of the rotational speed following a deflection of the throttle. The engine inlet parameters can cover a wide range of altitude and Mach numbers.
Coprime factorizations in stable linear systems
NASA Technical Reports Server (NTRS)
Desoer, Charles A.; Gundes, A. Nazli; Kabuli, M. Guntekin
1988-01-01
A block-diagonal linear (not necessarily time-invariant) map P with a right-coprime factorization ND-1 (or a left-coprime factorization D-1N) is considered. It is shown that the individual blocks in P have right-coprime factorizations (left-coprime factorizations, respectively) if and only if the denominator map D has a special block-triangular structure. This condition is applied to the stable linear feedback system S(P1,P2).
Estimability and regulability of linear systems
NASA Technical Reports Server (NTRS)
Baram, Yoram; Kailath, Thomas
1987-01-01
A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. These properties, which are shown to be dual, are different from the well known observability and controllability properties of linear systems. Necessary and sufficient conditions for estimability and regulability are derived for time variant and time invariant systems, in discrete and continuous time.
Estimability and regulability of linear systems
NASA Technical Reports Server (NTRS)
Baram, Yoram; Kailath, Thomas
1987-01-01
A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. These properties, which are are shown to be dual, are different from the well known observability and controllability properties of linear systems. Necessary and sufficient conditions for estimability and regulability are derived for time variant and time invariant systems, in discrete and continuous time.
Finite solutions of fully fuzzy linear system
NASA Astrophysics Data System (ADS)
Malkawi, Ghassan; Ahmad, Nazihah; Ibrahim, Haslinda
2014-12-01
The solution of Fully Fuzzy Linear System (FFLS) is normally categorized as unique, finite and infinitely many solutions. However, in the case of more than one solution, the finite or alternative solution is not detected when linear programming is considered. Therefore this paper aims to provide a method of using min-max system and absolute system to append new concept for the consistency of FFLS, which is called finite solution of FFLS, where the FFLS have more than two solutions, and not only an infinite solution.
System interaction with linear and nonlinear characteristics
Lin, C.W. ); Tseng, W.S. )
1991-01-01
This book is covered under some of the following topics: seismic margins in piping systems, vibrational power flow in a cylindrical shell, inelastic pipework dynamics and aseismic design, an efficient method for dynamic analysis of a linearly elastic piping system with nonlinear supports.
The linear regulator problem for parabolic systems
NASA Technical Reports Server (NTRS)
Banks, H. T.; Kunisch, K.
1983-01-01
An approximation framework is presented for computation (in finite imensional spaces) of Riccati operators that can be guaranteed to converge to the Riccati operator in feedback controls for abstract evolution systems in a Hilbert space. It is shown how these results may be used in the linear optimal regulator problem for a large class of parabolic systems.
Hecht, Timm; Bundscherer, Anika C; Lassen, Christoph L; Lindenberg, Nicole; Graf, Bernhard M; Ittner, Karl-Peter; Wiese, Christoph H R
2015-08-01
Estimate the expenditure of computer-related worktime resulting from the use of clinical decision support systems (CDSS) to prevent adverse drug reactions (ADR) among patients undergoing chronic pain therapy and compare the employed check systems with respect to performance and practicability. Data were collected retrospectively from 113 medical records of patients under chronic pain therapy during 2012/2013. Patient-specific medications were checked for potential drug-drug interactions (DDI) using two publicly available CDSS, Apotheken Umschau (AU) and Medscape (MS), and a commercially available CDSS AiDKlinik® (AID). The time needed to analyze patient pharmacotherapy for DDIs was taken with a stopwatch. Measurements included the time needed for running the analysis and printing the results. CDSS were compared with respect to the expenditure of time and usability. Only patient pharmacotherapies with at least two prescribed drugs and fitting the criteria of the corresponding CDSS were analyzed. Additionally, a qualitative evaluation of the used check systems was performed, employing a questionnaire asking five pain physicians to compare and rate the performance and practicability of the three CDSSs. The AU tool took a total of 3:55:45 h with an average of 0:02:32 h for 93 analyzed patient regimens and led to the discovery of 261 DDIs. Using the Medscape interaction checker required a total of 1:28:35 h for 38 patients with an average of 0:01:58 h and a yield of 178 interactions. The CDSS AID required a total of 3:12:27 h for 97 patients with an average time of analysis of 0:01:59 h and the discovery of 170 DDIs. According to the pain physicians the CDSS AID was chosen as the preferred tool. Applying a CDSS to examine a patients drug regimen for potential DDIs causes an average extra expenditure of work time of 2:09 min, which extends patient treatment time by 25 % on average. Nevertheless, the authors believe that the extra expenditure of time employing a CDSS is
Executive function, episodic memory, and Medicare expenditures.
Bender, Alex C; Austin, Andrea M; Grodstein, Francine; Bynum, Julie P W
2017-07-01
We examined the relationship between health care expenditures and cognition, focusing on differences across cognitive systems defined by global cognition, executive function, or episodic memory. We used linear regression models to compare annual health expenditures by cognitive status in 8125 Nurses' Health Study participants who completed a cognitive battery and were enrolled in Medicare parts A and B. Adjusting for demographics and comorbidity, executive impairment was associated with higher total annual expenditures of $1488 per person (P < .01) compared with those without impairment. No association for episodic memory impairment was found. Expenditures exhibited a linear relationship with executive function, but not episodic memory ($584 higher for every 1 standard deviation decrement in executive function; P < .01). Impairment in executive function is specifically and linearly associated with higher health care expenditures. Focusing on management strategies that address early losses in executive function may be effective in reducing costly services. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
Controllability of non-linear biochemical systems.
Ervadi-Radhakrishnan, Anandhi; Voit, Eberhard O
2005-07-01
Mathematical methods of biochemical pathway analysis are rapidly maturing to a point where it is possible to provide objective rationale for the natural design of metabolic systems and where it is becoming feasible to manipulate these systems based on model predictions, for instance, with the goal of optimizing the yield of a desired microbial product. So far, theory-based metabolic optimization techniques have mostly been applied to steady-state conditions or the minimization of transition time, using either linear stoichiometric models or fully kinetic models within biochemical systems theory (BST). This article addresses the related problem of controllability, where the task is to steer a non-linear biochemical system, within a given time period, from an initial state to some target state, which may or may not be a steady state. For this purpose, BST models in S-system form are transformed into affine non-linear control systems, which are subjected to an exact feedback linearization that permits controllability through independent variables. The method is exemplified with a small glycolytic-glycogenolytic pathway that had been analyzed previously by several other authors in different contexts.
Conduction cooling systems for linear accelerator cavities
Kephart, Robert
2017-05-02
A conduction cooling system for linear accelerator cavities. The system conducts heat from the cavities to a refrigeration unit using at least one cavity cooler interconnected with a cooling connector. The cavity cooler and cooling connector are both made from solid material having a very high thermal conductivity of approximately 1.times.10.sup.4 W m.sup.-1 K.sup.-1 at temperatures of approximately 4 degrees K. This allows for very simple and effective conduction of waste heat from the linear accelerator cavities to the cavity cooler, along the cooling connector, and thence to the refrigeration unit.
Dual-range linearized transimpedance amplifier system
Wessendorf, Kurt O.
2010-11-02
A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).
Feedback linearization application for LLRF control system
Kwon, S.; Regan, A.; Wang, Y.M.; Rohlev, T.
1998-12-31
The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory will serve as the prototype for the low energy section of Acceleration Production of Tritium (APT) accelerator. This paper addresses the problem of the LLRF control system for LEDA. The authors propose a control law which is based on exact feedback linearization coupled with gain scheduling which reduces the effect of the deterministic klystron cathode voltage ripple that is due to harmonics of the high voltage power supply and achieves tracking of desired set points. Also, they propose an estimator of the ripple and its time derivative and the estimates based feedback linearization controller.
Estimability and Regulability of Linear Systems
NASA Technical Reports Server (NTRS)
Baram, Yoram; Kailath, Thomas
1988-01-01
A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. Estimability and regulability are shown to be dual properties, equivalent to the nonreducibility of the Kalman filter and of the optimal linear quadratic regulator, respectively.
Hwang, Bosun; Han, Jonghee; Choi, Jong Min; Park, Kwang Suk
2008-11-01
The purpose of this study was to develop an unobtrusive energy expenditure (EE) measurement system using an infrared (IR) sensor-based activity monitoring system to measure indoor activities and to estimate individual quantitative EE. IR-sensor activation counts were measured with a Bluetooth-based monitoring system and the standard EE was calculated using an established regression equation. Ten male subjects participated in the experiment and three different EE measurement systems (gas analyzer, accelerometer, IR sensor) were used simultaneously in order to determine the regression equation and evaluate the performance. As a standard measurement, oxygen consumption was simultaneously measured by a portable metabolic system (Metamax 3X, Cortex, Germany). A single room experiment was performed to develop a regression model of the standard EE measurement from the proposed IR sensor-based measurement system. In addition, correlation and regression analyses were done to compare the performance of the IR system with that of the Actigraph system. We determined that our proposed IR-based EE measurement system shows a similar correlation to the Actigraph system with the standard measurement system.
Golinelli, Davide; Toscano, Fabrizio; Bucci, Andrea; Lenzi, Jacopo; Fantini, Maria Pia; Nante, Nicola; Messina, Gabriele
2017-08-21
The sustainability of healthcare systems is a topic of major interest. During periods of economic instability, policy makers typically reallocate resources and execute linear cuts in different areas of public spending, including healthcare. The aim of this paper was to examine whether and how per capita public healthcare expenditure (PHE) in the Italian regions was related to the all-cause mortality rate (MR) between 1999 and 2013 and to determine which expenditure item most affected mortality in the short and very short term. We conducted a pooled cross-sectional time series study. Secondary data were extracted from 'Health for All', a database released periodically by the Italian National Institute of Statistics. PHE is subdivided into directly provided services (DPS), pharmaceutical care, general practitioner care, specialist medical care, privately delivered hospital care, other privately delivered medical services, and psychiatric support and rehabilitation. We used a fixed-effects regression to assess the effects of PHE items on the MR after controlling for a number of socioeconomic and supply variables. Higher spending on DPS was associated with a lower MR. Other expenditure variables were not significantly associated with the MR. The results highlight the importance of medical services and goods provided directly by public services (i.e. hospital-based general and specialized wards and offices, emergency departments, etc.). DPS represents the driving force of the system and should be considered a determinant of the health of the Italian population. Our results suggest that the context and financing methods of a healthcare system should be carefully analysed before linear cuts are made or resources are reallocated.
Lectures on algebraic system theory: Linear systems over rings
NASA Technical Reports Server (NTRS)
Kamen, E. W.
1978-01-01
The presentation centers on four classes of systems that can be treated as linear systems over a ring. These are: (1) discrete-time systems over a ring of scalars such as the integers; (2) continuous-time systems containing time delays; (3) large-scale discrete-time systems; and (4) time-varying discrete-time systems.
Minimal Solution of Singular LR Fuzzy Linear Systems
Nikuie, M.; Ahmad, M. Z.
2014-01-01
In this paper, the singular LR fuzzy linear system is introduced. Such systems are divided into two parts: singular consistent LR fuzzy linear systems and singular inconsistent LR fuzzy linear systems. The capability of the generalized inverses such as Drazin inverse, pseudoinverse, and {1}-inverse in finding minimal solution of singular consistent LR fuzzy linear systems is investigated. PMID:24737977
Minimal solution of singular LR fuzzy linear systems.
Nikuie, M; Ahmad, M Z
2014-01-01
In this paper, the singular LR fuzzy linear system is introduced. Such systems are divided into two parts: singular consistent LR fuzzy linear systems and singular inconsistent LR fuzzy linear systems. The capability of the generalized inverses such as Drazin inverse, pseudoinverse, and {1}-inverse in finding minimal solution of singular consistent LR fuzzy linear systems is investigated.
Identifiability of linear systems in physical coordinates
NASA Technical Reports Server (NTRS)
Su, Tzu-Jeng; Juang, Jer-Nan
1992-01-01
Identifiability of linear, time-invariant systems in physical coordinates is discussed. It is shown that identification of the system matrix in physical coordinates can be accomplished by determining a transformation matrix that relates the physical locations of actuators and sensors to the test-data-derived input and output matrices. For systems with symmetric matrices, the solution of a constrained optimization problem is used to characterize all the possible solutions of the transformation matrix. Conditions for the existence of a unique transformation matrix are established easily from the explicit form of the solutions. For systems with limited inputs and outputs, the question about which part of the system can be uniquely identified is also answered. A simple mass-spring system is used to verify the conclusions of this study.
Recursive Inversion Of Externally Defined Linear Systems
NASA Technical Reports Server (NTRS)
Bach, Ralph E., Jr.; Baram, Yoram
1992-01-01
Technical memorandum discusses mathematical technique described in "Recursive Inversion by Finite-Impulse-Response Filters" (ARC-12247). Technique is recursive algorithm yielding finite-impulse-response approximation of unknown single-input/single-output, causal, time-invariant, linear, real system, response of which is sequence of impulses. Useful in such diverse applications as medical diagnoses, identification of military targets, geophysical exploration, and nondestructive testing.
Nested observer for linear hybrid dynamical systems
Abdi, M.; Bensalah, H.; Cherki, B.
2009-03-05
The synthesis of observers for linear hybrid dynamical systems ''HDS,'' is significant from the point of view of the applications (control, diagnoses...); it is still, largely open. We proposed a new approach inspired from a new method of identification, where we could obtain better results with respect to discrimination between the discrete states in conflicts and time necessary to this latter. The results of the suggested technique proved to be satisfactory.
Recursive Inversion Of Externally Defined Linear Systems
NASA Technical Reports Server (NTRS)
Bach, Ralph E., Jr.; Baram, Yoram
1992-01-01
Technical memorandum discusses mathematical technique described in "Recursive Inversion by Finite-Impulse-Response Filters" (ARC-12247). Technique is recursive algorithm yielding finite-impulse-response approximation of unknown single-input/single-output, causal, time-invariant, linear, real system, response of which is sequence of impulses. Useful in such diverse applications as medical diagnoses, identification of military targets, geophysical exploration, and nondestructive testing.
Non-linear dynamic compensation system
NASA Technical Reports Server (NTRS)
Lin, Yu-Hwan (Inventor); Lurie, Boris J. (Inventor)
1992-01-01
A non-linear dynamic compensation subsystem is added in the feedback loop of a high precision optical mirror positioning control system to smoothly alter the control system response bandwidth from a relatively wide response bandwidth optimized for speed of control system response to a bandwidth sufficiently narrow to reduce position errors resulting from the quantization noise inherent in the inductosyn used to measure mirror position. The non-linear dynamic compensation system includes a limiter for limiting the error signal within preselected limits, a compensator for modifying the limiter output to achieve the reduced bandwidth response, and an adder for combining the modified error signal with the difference between the limited and unlimited error signals. The adder output is applied to control system motor so that the system response is optimized for accuracy when the error signal is within the preselected limits, optimized for speed of response when the error signal is substantially beyond the preselected limits and smoothly varied therebetween as the error signal approaches the preselected limits.
Linear relationships in systems with non linear kinetics.
Fagiolino, P; Savio, E; Stareczek, S
1991-01-01
The elimination rate of drug from a capacity-limited one-compartment model can be expressed by equation (1): [formula: see text] Traditionally equation (1) was linearized according to equation (2): [formula: see text] Here, an alternative linear relationships between concentration and the area under the curve of C/(Km + c]) is proposed: [formula: see text] By iteration of Km into equation (3) until the statistic of analysis of variance for the regression is maximized, both Km and Vmax can be obtained. Several cases were considered: a) Intravenous bolus (single dose): Km (mg/L), Vmax (mg/L h), Vd (L) and V (mg/h) can be estimated. b) Extravascular administration (single dose): by the method of residuals it is possible to make additional estimations of FD/Vd (mg/L) and Ka (1/h). c) Bioequivalence studies: with parameters obtained at single dose, the simulated levels at steady-state are considered for the bioequivalence assessments. d) Km, Vmax estimation with two (C,t) points (single dose): double iteration (Km values and interpolated fictitious third points) are needed. e) Multiple dose: [formula: see text] If t2-t1 = T (interval of administration) it is possible to calculate operatives Km, Vmax, FD/Vd and to estimate Css (steady-state concentration). C1 and C2 correspond to different intervals. All the areas were calculated by the trapezoidal rule.
Jang, Yongwon; Jung, M; Kang, Jaemin; Chan Kim, Hee
2005-01-01
The measurement of the amount of energy utilized during physical activity has generated considerable interests from various groups ranging from exercise physiologists to nutritionists and fitness center workers. To date, however, the existing energy expenditure estimation methods are not so reliable and compact. In this paper, we propose a new method for accurately and easily estimating energy expenditure during physical activity with a novel algorithm. This method involves acquiring acceleration signals through a 15-channel whole-body segment acceleration measurement system and then estimating the calories expended using a newly developed algorithm. The results of 3 subjects' experiments were compared with a commercially available mask type indirect calorimeter and a 9-axis accelerometry-based calorimeter. The results demonstrate that the proposed method provides a new and reliable way to estimate human energy expenditure during physical activity.
NASA Astrophysics Data System (ADS)
Komatsu, Kazuo; Takata, Hitoshi
2012-11-01
In this paper, we consider an observer design by using a formal linearization based on Fourier expansion for nonlinear dynamic and measurement systems. A non-linear dynamic system is given by a nonlinear ordinary differential equation, and a measurement sysetm is done by a nonlinear equation. Defining a linearization function which consists of the trigonometric functions considered up to the higher-order, a nonlinear dynamic system is transformed into an augmented linear one with respect to this linearization function by using Fourier expansion. Introducing an augmented measurement vector which consists of polynomials of measurement data, a measurement equation is transformed into an augmented linear one with respect to the linearization function in the same way. To these augmented linearized systems, a linear estimation theory is applied to design a new non-linear observer.
A scaling theory for linear systems
NASA Technical Reports Server (NTRS)
Brockett, R. W.; Krishnaprasad, P. S.
1980-01-01
A theory of scaling for rational (transfer) functions in terms of transformation groups is developed. Two different four-parameter scaling groups which play natural roles in studying linear systems are identified and the effect of scaling on Fisher information and related statistical measures in system identification are studied. The scalings considered include change of time scale, feedback, exponential scaling, magnitude scaling, etc. The scaling action of the groups studied is tied to the geometry of transfer functions in a rather strong way as becomes apparent in the examination of the invariants of scaling. As a result, the scaling process also provides new insight into the parameterization question for rational functions.
Robust observer for uncertain linear quantum systems
Yamamoto, Naoki
2006-09-15
In the theory of quantum dynamical filtering, one of the biggest issues is that the underlying system dynamics represented by a quantum stochastic differential equation must be known exactly in order that the corresponding filter provides an optimal performance; however, this assumption is generally unrealistic. Therefore, in this paper, we consider a class of linear quantum systems subjected to time-varying norm-bounded parametric uncertainties and then propose a robust observer such that the variance of the estimation error is guaranteed to be within a certain bound. Although in the linear case much of classical control theory can be applied to quantum systems, the quantum robust observer obtained in this paper does not have a classical analog due to the system's specific structure with respect to the uncertainties. Moreover, by considering a typical quantum control problem, we show that the proposed robust observer is fairly robust against a parametric uncertainty of the system even when the other estimators--the optimal Kalman filter and risk-sensitive observer--fail in the estimation.
Flexible least squares for approximately linear systems
NASA Astrophysics Data System (ADS)
Kalaba, Robert; Tesfatsion, Leigh
1990-10-01
A probability-free multicriteria approach is presented to the problem of filtering and smoothing when prior beliefs concerning dynamics and measurements take an approximately linear form. Consideration is given to applications in the social and biological sciences, where obtaining agreement among researchers regarding probability relations for discrepancy terms is difficult. The essence of the proposed flexible-least-squares (FLS) procedure is the cost-efficient frontier, a curve in a two-dimensional cost plane which provides an explicit and systematic way to determine the efficient trade-offs between the separate costs incurred for dynamic and measurement specification errors. The FLS estimates show how the state vector could have evolved over time in a manner minimally incompatible with the prior dynamic and measurement specifications. A FORTRAN program for implementing the FLS filtering and smoothing procedure for approximately linear systems is provided.
Sparks, S Andy; Orme, Duncan; Mc Naughton, Lars R
2013-05-01
This study aimed to assess the effect of portable gas analysis system carriage on energy expenditure (EE) during incremental treadmill running. Eight males (Mean ± SD) age 25.0 ± 9.47 y, body mass 78.5 ± 8.39 kg, completed an experimental trial (PT) during which they wore the system in a chest harness and a control trial (CT) when the system was externally supported. Each protocol consisted of 4 min stages at speeds of 0, 4, 7, 10, 12, 14 km h(-1). Increments continued until volitional exhaustion. The EE was greater (3.95 and 7.02% at 7 and 14 km h(-1) respectively) during PT (p < 0.05) but no significant differences were observed during standing, walking or VO(2max.) (4.10 ± 0.53, and 4.28 ± 0.75 l min(-1) for CT and PT respectively), HR or RPE. Portable gas analysis systems therefore only increase EE when running sub-maximally, but VO(2max) is unaffected, suggesting that using portable gas analysis systems in field-based situations is appropriate for maximal aerobic capacity measurement, but the effects of prolonged use on EE remains unclear. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Modeling of linear time-varying systems by linear time-invariant systems of lower order.
NASA Technical Reports Server (NTRS)
Nosrati, H.; Meadows, H. E.
1973-01-01
A method for modeling linear time-varying differential systems by linear time-invariant systems of lower order is proposed, extending the results obtained by Bierman (1972) by resolving such qualities as the model stability, various possible models of differing dimensions, and the uniqueness or nonuniqueness of the model coefficient matrix. In addition to the advantages cited by Heffes and Sarachik (1969) and Bierman, often by modeling a subsystem of a larger system it is possible to analyze the overall system behavior more easily, with resulting savings in computation time.
NASA Astrophysics Data System (ADS)
Aminah, Agustin Siti; Pawitan, Gandhi; Tantular, Bertho
2017-03-01
So far, most of the data published by Statistics Indonesia (BPS) as data providers for national statistics are still limited to the district level. Less sufficient sample size for smaller area levels to make the measurement of poverty indicators with direct estimation produced high standard error. Therefore, the analysis based on it is unreliable. To solve this problem, the estimation method which can provide a better accuracy by combining survey data and other auxiliary data is required. One method often used for the estimation is the Small Area Estimation (SAE). There are many methods used in SAE, one of them is Empirical Best Linear Unbiased Prediction (EBLUP). EBLUP method of maximum likelihood (ML) procedures does not consider the loss of degrees of freedom due to estimating β with β ^. This drawback motivates the use of the restricted maximum likelihood (REML) procedure. This paper proposed EBLUP with REML procedure for estimating poverty indicators by modeling the average of household expenditures per capita and implemented bootstrap procedure to calculate MSE (Mean Square Error) to compare the accuracy EBLUP method with the direct estimation method. Results show that EBLUP method reduced MSE in small area estimation.
Linear unsaturating magnetoresistance in disordered systems
NASA Astrophysics Data System (ADS)
Lai, Ying Tong; Lara, Silvia; Love, Cameron; Ramakrishnan, Navneeth; Adam, Shaffique
Theoretical works have shown that disordered systems exhibit classical magnetoresistance (MR). In this talk, we examine a variety of experimental systems that observe linear MR at high magnetic fields, including silver chalcogenides, graphene, graphite and Weyl semimetals. We show that a careful analysis of the magnitude of the MR, as well as the field strength at which the MR changes from quadratic to linear, reveal important properties of the system, such as the ratio of the root-mean-square fluctuations in the carrier density and the average carrier density. By looking at other properties such as the zero-field mobility, we show that this carrier density inhomogeneity is consistent with what is known about the microscopic impurities in these experiments. The application of this disorder-induced MR to a variety of different experimental scenarios underline the universality of these theoretical models. This work is supported by the Singapore National Research Foundation (NRF-NRFF2012-01) and the Singapore Ministry of Education and Yale-NUS College through Grant Number R-607-265-01312.
Koch, Kira Johanna; Cid Pedraza, Camilo; Schmid, Andreas
2017-05-01
Protection against financial risk due to medical spending is an explicit health guarantee within Chile's AUGE health reform. This paper seeks to analyze the degree to which out-of-pocket expenditure still expose Chilean households to financial catastrophe and impoverishment, and to explore inequalities in financial protection. A systematic literature review was conducted to identify empirical studies analyzing financial protection in Chile. The search included databases as well as grey literature, i.e. governmental and institutional webpages. The indicators are based on the conceptual framework of financial protection, as portrayed in the World Health Report 2013. We identify n=16 studies that fulfill the inclusion criteria. Empirical studies indicate that 4% of Chilean households faced catastrophic health expenditure defined as out-of-pocket expenditure exceeding 30% of household's capacity to pay, while less than 1% were pushed into poverty in 2012. In contrast to prior studies, recent data report that even publicly insured who should be fully protected from co-payments were affected by catastrophic health expenditure. Also in the private insurance system financial catastrophe is a common risk. Despite health reform efforts, financial protection is insufficient and varies to the disadvantage of the poor and vulnerable groups. More research is required to understand why current mechanisms are not as effective as expected and to enable according reforms of the insurance system. Copyright © 2017 Elsevier B.V. All rights reserved.
Linear Actuator System for the NASA Docking System
NASA Technical Reports Server (NTRS)
Dick, Brandon N.; Oesch, Christopher; Rupp, Timothy W.
2017-01-01
The Linear Actuator System (LAS) is a major sub-system within the NASA Docking System (NDS). The NDS Block 1 will be used on the Boeing Crew Space Transportation (CST-100) system to achieve docking with the International Space Station. Critical functions in the Soft Capture aspect of docking are performed by the LAS. This paper describes the general function of the LAS, the system's key requirements and technical challenges, and the development and qualification approach for the system.
Rumo, Martin; Amft, Oliver; Tröster, Gerhard; Mäder, Urs
2011-12-01
Regular physical activity (PA) is an important contributor to a healthy lifestyle. Currently, standard sensor-based methods to assess PA in field-based research rely on a single accelerometer mounted near the body's center of mass. This paper introduces a wearable system that estimates energy expenditure (EE) based on seven recognized activity types. The system was developed with data from 32 healthy subjects and consists of a chest mounted heart rate belt and two accelerometers attached to a thigh and dominant upper arm. The system was validated with 12 other subjects under restricted lab conditions and simulated free-living conditions against indirect calorimetry, as well as in subjects' habitual environments for 2 weeks against the doubly labeled water method. Our stepwise validation methodology gradually trades reference information from the lab against realistic data from the field. The average accuracy for EE estimation was 88% for restricted lab conditions, 55% for simulated free-living conditions and 87% and 91% for the estimation of average daily EE over the period of 1 and 2 weeks.
Analysis of a Linear System for Variable-Thrust Control in the Terminal Phase of Rendezvous
NASA Technical Reports Server (NTRS)
Hord, Richard A.; Durling, Barbara J.
1961-01-01
A linear system for applying thrust to a ferry vehicle in the 3 terminal phase of rendezvous with a satellite is analyzed. This system requires that the ferry thrust vector per unit mass be variable and equal to a suitable linear combination of the measured position and velocity vectors of the ferry relative to the satellite. The variations of the ferry position, speed, acceleration, and mass ratio are examined for several combinations of the initial conditions and two basic control parameters analogous to the undamped natural frequency and the fraction of critical damping. Upon making a desirable selection of one control parameter and requiring minimum fuel expenditure for given terminal-phase initial conditions, a simplified analysis in one dimension practically fixes the choice of the remaining control parameter. The system can be implemented by an automatic controller or by a pilot.
Systems tunnel linear shaped charge lightning strike
NASA Technical Reports Server (NTRS)
Cook, M.
1989-01-01
Simulated lightning strike testing of the systems tunnel linear shaped charge (LSC) was performed at the Thiokol Lightning Test Complex in Wendover, Utah, on 23 Jun. 1989. The test article consisted of a 160-in. section of the LSC enclosed within a section of the systems tunnel. The systems tunnel was bonded to a section of a solid rocket motor case. All test article components were full scale. The systems tunnel cover of the test article was subjected to three discharges (each discharge was over a different grounding strap) from the high-current generator. The LSC did not detonate. All three grounding straps debonded and violently struck the LSC through the openings in the systems tunnel floor plates. The LSC copper surface was discolored around the areas of grounding strap impact, and arcing occurred at the LSC clamps and LSC ends. This test verified that the present flight configuration of the redesigned solid rocket motor systems tunnel, when subjected to simulated lightning strikes with peak current levels within 71 percent of the worst-case lightning strike condition of NSTS-07636, is adequate to prevent LSC ignition. It is therefore recommended that the design remain unchanged.
CONTROL SYSTEM ANALYSIS FOR THE PERTURBED LINEAR ACCELERATOR RF SYSTEM
SUNG-IL KWON; AMY H. REGAN
2002-04-10
This paper addresses the modeling problem of the linear accelerator RF system in SNS. Klystrons are modeled as linear parameter varying systems. The effect of the high voltage power supply ripple on the klystron output voltage and the output phase is modeled as an additive disturbance. The cavity is modeled as a linear system and the beam current is modeled as the exogenous disturbance. The output uncertainty of the low level RF system which results from the uncertainties in the RF components and cabling is modeled as multiplicative uncertainty. Also, the feedback loop uncertainty and digital signal processing signal conditioning subsystem uncertainties are lumped together and are modeled as multiplicative uncertainty. Finally, the time delays in the loop are modeled as a lumped time delay. For the perturbed open loop system, the closed loop system performance, and stability are analyzed with the PI feedback controller.
Public health expenditure and spatial interactions in a decentralized national health system.
Costa-Font, Joan; Pons-Novell, Jordi
2007-03-01
One of the limitations of cross-country health expenditure analysis refers to the fact that the financing, the internal organization and political restraints of health care decision-making are country-specific and heterogeneous. Yet, a way through is to examine the influence of such effects in those countries that have undertaken decentralization processes. In such a setting, it is possible to examine potential expenditure spillovers across the geography of a country as well as the influence of the political ideology of regional incumbents and institutional factors on public health expenditure. This paper examines the determinants of public health expenditure within Spanish region-states (Autonomous Communities, ACs), most of them subject to similar financing structures although exhibiting significant heterogeneity as a result of the increasing decentralization, region-specific political factors along with different use of health care inputs, economic dimension and spatial interactions. Copyright (c) 2006 John Wiley & Sons, Ltd.
Stochastic robustness of linear control systems
NASA Technical Reports Server (NTRS)
Stengel, Robert F.; Ryan, Laura E.
1990-01-01
A simple numerical procedure for estimating the stochastic robustness of a linear, time-invariant system is described. Monte Carlo evaluation of the system's eigenvalues allows the probability of instability and the related stochastic root locus to be estimated. This definition of robustness is an alternative to existing deterministic definitions that address both structured and unstructured parameter variations directly. This analysis approach treats not only Gaussian parameter uncertainties but non-Gaussian cases, including uncertain-but-bounded variations. Trivial extensions of the procedure admit alternate discriminants to be considered. Thus, the probabilities that stipulated degrees of instability will be exceeded or that closed-loop roots will leave desirable regions also can be estimated. Results are particularly amenable to graphical presentation.
Linear optical response of finite systems using multishift linear system solvers
Hübener, Hannes; Giustino, Feliciano
2014-07-28
We discuss the application of multishift linear system solvers to linear-response time-dependent density functional theory. Using this technique the complete frequency-dependent electronic density response of finite systems to an external perturbation can be calculated at the cost of a single solution of a linear system via conjugate gradients. We show that multishift time-dependent density functional theory yields excitation energies and oscillator strengths in perfect agreement with the standard diagonalization of the response matrix (Casida's method), while being computationally advantageous. We present test calculations for benzene, porphin, and chlorophyll molecules. We argue that multishift solvers may find broad applicability in the context of excited-state calculations within density-functional theory and beyond.
Control of Linear Systems Over Commutative Normed Algebras with Applications.
1987-02-01
Identify by block number) System Theory, Linear Systems, Control, Systems with Time Delays, Time - Varying Systems, State- Space Models, Pole...modes for the class of linear time -varying systems. These concepts are defined in terms of a noncommutative factorization of opera- tor polynomials...classes of complex linear systems, including systems with time delays, systems with unknown parameters and time -varying systems. In the work on
Finite Hamiltonian Systems: Linear Transformations and Aberrations
NASA Astrophysics Data System (ADS)
Wolf, Kurt Bernardo
2008-11-01
In finite Hamiltonian systems, the operators of position, momentum, and energy have a finite number N of eigenvalues. These operators can be naturally realized as generators of the Lie algebra su(2), in a representation of spin j, of dimension N = 2j+1. Time evolution is rotation of a phase space sphere, whose projections perform the harmonic motion of an oscillator. The (centrally extended) group of rigid—linear—motions of this phase space is then U(2). On the other hand, N-point wavefunctions—signals—can be subject to a U(N) group of unitary matrices, containing the linear U(2); aberrations are transformations outside that subgroup. As in geometric optics, we classify the aberration multiplets by order and weight. Their action on phase space is displayed by means of a Wigner function on the sphere, to be compared with the corresponding geometric canonical transformations.
Curry, Timothy B; Somaraju, Madhuri; Hines, Casey N; Groenewald, Cornelius B; Miles, John M; Joyner, Michael J; Charkoudian, Nisha
2013-03-01
This study was designed to determine how gastric bypass affects the sympathetically-mediated component of resting energy expenditure (REE) and muscle sympathetic nerve activity (MSNA). We measured REE before and after beta-blockade in seventeen female subjects approximately three years post-gastric bypass surgery and in nineteen female obese individuals for comparison. We also measured MSNA in a subset of these subjects. The gastric bypass subjects had no change in REE after systemic beta-blockade, reflecting a lack of sympathetic support of REE, in contrast to obese subjects where REE was reduced by beta-blockade by approximately 5% (P < 0.05). The gastric bypass subjects, while still overweight (BMI = 29.3 vs 38.0 kg·m(-2) for obese subjects, P < 0.05), also had significantly lower MSNA compared to obese subjects (10.9 ± 2.3 vs. 21.9 ± 4.1 bursts·min(-1) , P < 0.05). The reasons for low MSNA and a lack of sympathetically mediated support of REE after gastric bypass are likely multifactorial and may be related to changes in insulin sensitivity, body composition, and leptin, among other factors. These findings may have important consequences for the maintenance of weight loss after gastric bypass. Longitudinal studies are needed to further explore the changes in sympathetic support of REE and if changes in MSNA or tissue responsiveness are related to the sympathetic support of REE. Copyright © 2013 The Obesity Society.
A joint-space numerical model of metabolic energy expenditure for human multibody dynamic system.
Kim, Joo H; Roberts, Dustyn
2015-09-01
Metabolic energy expenditure (MEE) is a critical performance measure of human motion. In this study, a general joint-space numerical model of MEE is derived by integrating the laws of thermodynamics and principles of multibody system dynamics, which can evaluate MEE without the limitations inherent in experimental measurements (phase delays, steady state and task restrictions, and limited range of motion) or muscle-space models (complexities and indeterminacies from excessive DOFs, contacts and wrapping interactions, and reliance on in vitro parameters). Muscle energetic components are mapped to the joint space, in which the MEE model is formulated. A constrained multi-objective optimization algorithm is established to estimate the model parameters from experimental walking data also used for initial validation. The joint-space parameters estimated directly from active subjects provide reliable MEE estimates with a mean absolute error of 3.6 ± 3.6% relative to validation values, which can be used to evaluate MEE for complex non-periodic tasks that may not be experimentally verifiable. This model also enables real-time calculations of instantaneous MEE rate as a function of time for transient evaluations. Although experimental measurements may not be completely replaced by model evaluations, predicted quantities can be used as strong complements to increase reliability of the results and yield unique insights for various applications.
System theory as applied differential geometry. [linear system
NASA Technical Reports Server (NTRS)
Hermann, R.
1979-01-01
The invariants of input-output systems under the action of the feedback group was examined. The approach used the theory of Lie groups and concepts of modern differential geometry, and illustrated how the latter provides a basis for the discussion of the analytic structure of systems. Finite dimensional linear systems in a single independent variable are considered. Lessons of more general situations (e.g., distributed parameter and multidimensional systems) which are increasingly encountered as technology advances are presented.
Curry, Timothy B.; Somaraju, Madhuri; Hines, Casey N.; Groenewald, Cornelius B.; Miles, John M.; Joyner, Michael J.; Charkoudian, Nisha
2012-01-01
Resting energy expenditure (REE) is partially dependent on the sympathetic nervous system as evidenced by the fact REE decreases during systemic beta-adrenergic blockade. It is not known how gastric bypass affects the sympathetically mediated component of REE or muscle sympathetic nerve activity (MSNA). We measured REE before and after beta-blockade in female subjects approximately three years post-gastric bypass surgery and in female obese individuals for comparison. We also measured MSNA in a subset of these subjects. The gastric bypass subjects had no change in REE after systemic beta-blockade, reflecting a lack of sympathetic support of REE, in contrast to obese subjects where REE was reduced by beta-blockade by approximately 5% (P<0.05). The gastric bypass subjects, while still overweight (BMI = 29.3 vs 38.0 kg/m2 for obese subjects, P<0.05), also had significantly lower MSNA compared to obese subjects (10.9 ± 2.3 vs. 21.9 ± 4.1 bursts/min, P<0.05). The reasons for low MSNA and a lack of sympathetically mediated support of REE after gastric bypass are likely multifactorial and may be related to changes in insulin sensitivity, body composition, and leptin, among other factors. These findings may have important consequences for the maintenance of weight loss after gastric bypass. Longitudinal studies are needed to further explore the changes in sympathetic support of REE and if changes in MSNA or tissue responsiveness are related to the sympathetic support of REE. PMID:23592656
Time-varying linear systems and the theory of non-linear waves
NASA Technical Reports Server (NTRS)
Hermann, R.
1979-01-01
The isospectral deformation of a Sturm-Liouville equation is extended to general linear time-varying systems and a method is described for determining the resulting nonlinear partial differential equations. Consideration is given to (1) isospectral deformation of I/O systems with boundary value conditions and (2) the spectral vector bundles attached to linear time-varying systems.
Generic perturbations of linear integrable Hamiltonian systems
NASA Astrophysics Data System (ADS)
Bounemoura, Abed
2016-11-01
In this paper, we investigate perturbations of linear integrable Hamiltonian systems, with the aim of establishing results in the spirit of the KAM theorem (preservation of invariant tori), the Nekhoroshev theorem (stability of the action variables for a finite but long interval of time) and Arnold diffusion (instability of the action variables). Whether the frequency of the integrable system is resonant or not, it is known that the KAM theorem does not hold true for all perturbations; when the frequency is resonant, it is the Nekhoroshev theorem that does not hold true for all perturbations. Our first result deals with the resonant case: we prove a result of instability for a generic perturbation, which implies that the KAM and the Nekhoroshev theorem do not hold true even for a generic perturbation. The case where the frequency is nonresonant is more subtle. Our second result shows that for a generic perturbation the KAM theorem holds true. Concerning the Nekhrosohev theorem, it is known that one has stability over an exponentially long (with respect to some function of ɛ -1) interval of time and that this cannot be improved for all perturbations. Our third result shows that for a generic perturbation one has stability for a doubly exponentially long interval of time. The only question left unanswered is whether one has instability for a generic perturbation (necessarily after this very long interval of time).
Linear Actuator System for the NASA Docking System
NASA Technical Reports Server (NTRS)
Dick, Brandon; Oesch, Chris
2017-01-01
The Linear Actuator System (LAS) is a major sub-system within the NASA Docking System (NDS). The NDS Block 1 will be used on the Boeing Crew Space Transportation (CST-100) system to achieve docking with the International Space Station. Critical functions in the Soft Capture aspect of docking are performed by the LAS, which implements the Soft Impact Mating and Attenuation Concept (SIMAC). This paper describes the general function of the LAS, the system's key requirements and technical challenges, and the development and qualification approach for the system.
Energy expenditure estimate by heart-rate monitor and a portable electromagnetic coils system.
Gastinger, Steven; Nicolas, Guillaume; Sorel, Anthony; Sefati, Hamid; Prioux, Jacques
2012-04-01
The aim of this article was to compare 2 portable devices (a heart-rate monitor and an electromagnetic-coil system) that evaluate 2 different physiological parameters--heart rate (HR) and ventilation (VE)--with the objective of estimating energy expenditure (EE). The authors set out to prove that VE is a more pertinent setting than HR to estimate EE during light to moderate activities (sitting and standing at rest and walking at 4, 5, and 6 km/hr). Eleven healthy men were recruited to take part in this study (27.6 ± 5.4 yr, 73.7 ± 9.7 kg). The authors determined the relationships between HR and EE and between VE and EE during light to moderate activities. They compared EE measured by indirect calorimetry (EEREF) with EE estimated by HR monitor (EEHR) and EE estimated by electromagnetic coils (EEMAG) in upright sitting and standing positions and during walking exercises. They compared EEREF with EEHR and EEMAG. The results showed no significant difference between the values of EEREF and EEMAG. However, they showed several significant differences between the values of EEREF and EEHR (for standing at rest and walking at 5 and 6 km/hr). These results showed that the electromagnetic-coil system seems to be more accurate than the HR monitor to estimate EE at rest and during exercise. Taking into consideration these results, it would be interesting to associate the parameters VE and HR to estimate EE. Furthermore, a new version of the electromagnetic-coil device was recently developed and provides the possibility to perform measurement under daily life conditions.
Linear tracking systems with applications to aircraft control system design
NASA Technical Reports Server (NTRS)
Lee, W. H.; Athans, M.; Castanon, D.; Bacchioloni, F.
1977-01-01
A class of optimal linear time invariant tracking systems, both in continuous time and discrete time, of which the number of inputs (which are restricted to be step functions) is equal to the number of system outputs, is studied. Along with derivation of equations and design procedures, two discretization schemes are presented, constraining either the control or its time derivative, to be a constant over each sampling period. Descriptions are given for the linearized model of the F-8C aircraft longitudinal dynamics, and the C* handling qualities criterion, which then serve as an illustration of the applications of these linear tracking designs. A suboptimal reduced state design is also presented. Numerical results are given for both the continuous time and discrete time designs.
Nondeterministic Noiseless Linear Amplification of Quantum Systems
NASA Astrophysics Data System (ADS)
Ralph, T. C.; Lund, A. P.
2009-04-01
We introduce the concept of non-deterministic noiseless linear amplification. We propose a linear optical realization of this transformation that could be built with current technology. We discuss the application of the device to distillation of continuous variable entanglement. We demonstrate that highly pure entanglement can be distilled from transmission over a lossy channel.
Linear stability in an extended ring system
NASA Astrophysics Data System (ADS)
Arribas, M.; Elipe, A.; Palacios, M.
2010-10-01
The planar n+1 ring body problem consists of n bodies of equal mass m uniformly distributed around a central body of mass m0. The bodies are rotating on its own plane about its center of mass with a constant angular velocity. Since Maxwell introduced the problem to understand the stability of Saturn's rings, many authors have studied and extended the problem. In particular, we proved that if forces that are functions of the mutual distances are considered the n-gon is a central configuration. Examples of this kind are the quasi-homogeneous potentials. In a previous work we analyzed the linear stability of a system where the potential of the central body is a Manev's type potential. By introducing a perturbation parameter (ɛ0) to the Newtonian potential associated with the central primary, we showed that unstable cases for the unperturbed problem, for n<=6, may become stable for some values of the perturbation. The purpose of this paper is to show that it is possible to increase the range of values of the mass parameter (μ = m/m0) and the parameter (V0) in order to render a stable configuration. In order to get it, we introduce a second perturbation term (with parameter (V1) to the Newtonian potential of the bodies in the ring. We show some results for the problem with n = 7.
Symmetric linear systems - An application of algebraic systems theory
NASA Technical Reports Server (NTRS)
Hazewinkel, M.; Martin, C.
1983-01-01
Dynamical systems which contain several identical subsystems occur in a variety of applications ranging from command and control systems and discretization of partial differential equations, to the stability augmentation of pairs of helicopters lifting a large mass. Linear models for such systems display certain obvious symmetries. In this paper, we discuss how these symmetries can be incorporated into a mathematical model that utilizes the modern theory of algebraic systems. Such systems are inherently related to the representation theory of algebras over fields. We will show that any control scheme which respects the dynamical structure either implicitly or explicitly uses the underlying algebra.
Symmetric linear systems - An application of algebraic systems theory
NASA Technical Reports Server (NTRS)
Hazewinkel, M.; Martin, C.
1983-01-01
Dynamical systems which contain several identical subsystems occur in a variety of applications ranging from command and control systems and discretization of partial differential equations, to the stability augmentation of pairs of helicopters lifting a large mass. Linear models for such systems display certain obvious symmetries. In this paper, we discuss how these symmetries can be incorporated into a mathematical model that utilizes the modern theory of algebraic systems. Such systems are inherently related to the representation theory of algebras over fields. We will show that any control scheme which respects the dynamical structure either implicitly or explicitly uses the underlying algebra.
Estimation of Energy Expenditure for Wheelchair Users Using a Physical Activity Monitoring System.
Hiremath, Shivayogi V; Intille, Stephen S; Kelleher, Annmarie; Cooper, Rory A; Ding, Dan
2016-07-01
To develop and evaluate energy expenditure (EE) estimation models for a physical activity monitoring system (PAMS) in manual wheelchair users with spinal cord injury (SCI). Cross-sectional study. University-based laboratory environment, a semistructured environment at the National Veterans Wheelchair Games, and the participants' home environments. Volunteer sample of manual wheelchair users with SCI (N=45). Participants were asked to perform 10 physical activities (PAs) of various intensities from a list. The PAMS consists of a gyroscope-based wheel rotation monitor (G-WRM) and an accelerometer device worn on the upper arm or on the wrist. Criterion EE using a portable metabolic cart and raw sensor data from PAMS were collected during each of these activities. Estimated EE using custom models for manual wheelchair users based on either the G-WRM and arm accelerometer (PAMS-Arm) or the G-WRM and wrist accelerometer (PAMS-Wrist). EE estimation performance for the PAMS-Arm (average error ± SD: -9.82%±37.03%) and PAMS-Wrist (-5.65%±32.61%) on the validation dataset indicated that both PAMS-Arm and PAMS-Wrist were able to estimate EE for a range of PAs with <10% error. Moderate to high intraclass correlation coefficients (ICCs) indicated that the EE estimated by PAMS-Arm (ICC3,1=.82, P<.05) and PAMS-Wrist (ICC3,1=.89, P<.05) are consistent with the criterion EE. Availability of PA monitors can assist wheelchair users to track PA levels, leading toward a healthier lifestyle. The new models we developed can estimate PA levels in manual wheelchair users with SCI in laboratory and community settings. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Tail suspension increases energy expenditure independently of the melanocortin system in mice.
Lew, Pei San; Wong, Davie; Yamaguchi, Takafumi; Leckstrom, Arnold; Schwartz, Jacquie; Dodd, Janice G; Mizuno, Tooru M
2009-10-01
Space travelers experience anorexia and body weight loss in a microgravity environment, and microgravity-like situations cause changes in hypothalamic activity. Hypothalamic melanocortins play a critical role in the regulation of metabolism. Therefore, we hypothesized that microgravity affects metabolism through alterations in specific hypothalamic signaling pathways, including melanocortin signaling. To address this hypothesis, the microgravity-like situation was produced by an antiorthostatic tail suspension in wild-type and agouti mice, and the effect of tail suspension on energy expenditure and hypothalamic gene expression was examined. Energy expenditure was measured using indirect calorimetry before and during the tail suspension protocol. Hypothalamic tissues were collected for gene expression analysis at the end of the 3 h tail suspension period. Tail suspension significantly increased oxygen consumption, carbon dioxide production, and heat production in wild-type mice. Tail suspension-induced increases in energy expenditure were not attenuated in agouti mice. Although tail suspension did not alter hypothalamic proopiomelanocortin (POMC) and agouti-related protein (AGRP) mRNA levels, it significantly increased hypothalamic interleukin 6 (Il-6) mRNA levels. These data are consistent with the hypothesis that microgravity increases energy expenditure and suggest that these effects are mediated through hypothalamic signaling pathways that are independent of melanocortins, but possibly used by Il-6.
Perfect decoupling of linear systems with discrete parameter uncertainties
NASA Technical Reports Server (NTRS)
Dorato, P.; Wang, S.-H.; Asher, R.
1977-01-01
A design procedure based on Gilbert's decoupling parameters for determining a fixed state feedback control law which decouples a linear system with discrete parameter uncertainties is described. Perfect decoupling conditions are established which involve a test for the existence of a solution to a system of linear equations. An actual solution of the linear equations yields the decoupling control law.
The energy expenditure of 2 Holstein cow strains in an organic grazing system.
Thanner, S; Dohme-Meier, F; Görs, S; Metges, C C; Bruckmaier, R M; Schori, F
2014-05-01
Until recently, measurements of energy expenditure (EE; herein defined as heat production) in respiration chambers did not account for the extra energy requirements of grazing dairy cows on pasture. As energy is first limiting in most pasture-based milk production systems, its efficient use is important. Therefore, the aim of the present study was to compare EE, which can be affected by differences in body weight (BW), body composition, grazing behavior, physical activity, and milk production level, in 2 Holstein cow strains. Twelve Swiss Holstein-Friesian (HCH; 616 kg of BW) and 12 New Zealand Holstein-Friesian (HNZ; 570 kg of BW) cows in the third stage of lactation were paired according to their stage of lactation and kept in a rotational, full-time grazing system without concentrate supplementation. After adaption, the daily milk yield, grass intake using the alkane double-indicator technique, nutrient digestibility, physical activity, and grazing behavior recorded by an automatic jaw movement recorder were investigated over 7d. Using the (13)C bicarbonate dilution technique in combination with an automatic blood sampling system, EE based on measured carbon dioxide production was determined in 1 cow pair per day between 0800 to 1400 h. The HCH were heavier and had a lower body condition score compared with HNZ, but the difference in BW was smaller compared with former studies. Milk production, grass intake, and nutrient digestibility did not differ between the 2 cow strains, but HCH grazed for a longer time during the 6-h measurement period and performed more grazing mastication compared with the HNZ. No difference was found between the 2 cow strains with regard to EE (291 ± 15.6 kJ) per kilogram of metabolic BW, mainly due to a high between-animal variation in EE. As efficiency and energy use are important in sustainable, pasture-based, organic milk production systems, the determining factors for EE, such as methodology, genetics, physical activity, grazing
Yoon, Jangho; Luck, Jeff
2016-12-01
This study examines the extent to which increased public mental health expenditures lead to a reduction in jail populations and computes the associated intersystem return on investment (ROI). We analyze unique panel data on 44 U.S. states and D.C. for years 2001-2009. To isolate the intersystem spillover effect, we exploit variations across states and over time within states in per capita public mental health expenditures and average daily jail inmates. Regression models control for a comprehensive set of determinants of jail incarcerations as well as unobserved determinants specific to state and year. Findings show a positive spillover benefit of increased public mental health spending on the jail system: a 10% increase in per capita public inpatient mental health expenditure on average leads to a 1.5% reduction in jail inmates. We also find that the positive intersystem externality of increased public inpatient mental health expenditure is greater when the level of community mental health spending is lower. Similarly, the intersystem spillover effect of community mental health expenditure is larger when inpatient mental health spending is lower. We compute that overall an extra dollar in public inpatient mental health expenditure by a state would yield an intersystem ROI of a quarter dollar for the jail system. There is significant cross-state variation in the intersystem ROI in both public inpatient and community mental health expenditures, and the ROI overall is greater for inpatient mental health spending than for community mental health spending.
Fazaeli, Amir Abbas; Seyedin, Hesam; Moghaddam, Abbas Vosoogh; Delavari, Alireza; Salimzadeh, H.; Varmazyar, Hasan; Fazaeli, Ali Akbar
2015-01-01
Background: Social systems are dealing with the challenge of achieving fairness in the distribution of financial burden and protecting the risk of financial loss. The purpose of this paper is to present a trend analysis for the indicators related to fairness in healthcare’s financial burden in rural and urban population of Iran during the eight years period of 2003 to 2010. Methods: We used the information gathered by statistical center of Iran through sampling processes for the household income and expenditures. The indicators of fairness in financial contribution of healthcare were calculated based on the WHO recommended methodology. The indices trend analysis of eight-year period for the rural, urban areas and the country level were computed. Results: This study shows that in Iran the fairness of financial contribution index during the eight-year period has been decreased from 0.841 in 2003 to above 0.827 in 2010 and The percentage of people with catastrophic health expenditures has been increased from 2.3% to above 3.1%. The ratio of total treatment costs to the household overall capacity to pay has been increased from 0.055 to 0.068 and from 0.072 to 0.0818 in urban and rural areas respectively. Conclusion: There is a decline in fairness of financial contribution index during the study period. While, a trend stability of the proportion of households who suffered catastrophic health expenditures was found. PMID:26156920
Fazaeli, Amir Abbas; Seyedin, Hesam; Vosoogh Moghaddam, Abbas; Delavari, Alireza; Salimzadeh, H; Varmazyar, Hasan; Fazaeli, Ali Akbar
2015-03-18
Social systems are dealing with the challenge of achieving fairness in the distribution of financial burden and protecting the risk of financial loss. The purpose of this paper is to present a trend analysis for the indicators related to fairness in healthcare's financial burden in rural and urban population of Iran during the eight years period of 2003 to 2010. We used the information gathered by statistical center of Iran through sampling processes for the household income and expenditures. The indicators of fairness in financial contribution of healthcare were calculated based on the WHO recommended methodology. The indices trend analysis of eight-year period for the rural, urban areas and the country level were computed. This study shows that in Iran the fairness of financial contribution index during the eight-year period has been decreased from 0.841 in 2003 to above 0.827 in 2010 and The percentage of people with catastrophic health expenditures has been increased from 2.3% to above 3.1%. The ratio of total treatment costs to the household overall capacity to pay has been increased from 0.055 to 0.068 and from 0.072 to 0.0818 in urban and rural areas respectively. There is a decline in fairness of financial contribution index during the study period. While, a trend stability of the proportion of households who suffered catastrophic health expenditures was found.
Polynomial compensation, inversion, and approximation of discrete time linear systems
NASA Technical Reports Server (NTRS)
Baram, Yoram
1987-01-01
The least-squares transformation of a discrete-time multivariable linear system into a desired one by convolving the first with a polynomial system yields optimal polynomial solutions to the problems of system compensation, inversion, and approximation. The polynomial coefficients are obtained from the solution to a so-called normal linear matrix equation, whose coefficients are shown to be the weighting patterns of certain linear systems. These, in turn, can be used in the recursive solution of the normal equation.
Formal modeling and verification of fractional order linear systems.
Zhao, Chunna; Shi, Likun; Guan, Yong; Li, Xiaojuan; Shi, Zhiping
2016-05-01
This paper presents a formalization of a fractional order linear system in a higher-order logic (HOL) theorem proving system. Based on the formalization of the Grünwald-Letnikov (GL) definition, we formally specify and verify the linear and superposition properties of fractional order systems. The proof provides a rigor and solid underpinnings for verifying concrete fractional order linear control systems. Our implementation in HOL demonstrates the effectiveness of our approach in practical applications.
Linear System of Equations, Matrix Inversion, and Linear Programming Using MS Excel
ERIC Educational Resources Information Center
El-Gebeily, M.; Yushau, B.
2008-01-01
In this note, we demonstrate with illustrations two different ways that MS Excel can be used to solve Linear Systems of Equation, Linear Programming Problems, and Matrix Inversion Problems. The advantage of using MS Excel is its availability and transparency (the user is responsible for most of the details of how a problem is solved). Further, we…
Linear System of Equations, Matrix Inversion, and Linear Programming Using MS Excel
ERIC Educational Resources Information Center
El-Gebeily, M.; Yushau, B.
2008-01-01
In this note, we demonstrate with illustrations two different ways that MS Excel can be used to solve Linear Systems of Equation, Linear Programming Problems, and Matrix Inversion Problems. The advantage of using MS Excel is its availability and transparency (the user is responsible for most of the details of how a problem is solved). Further, we…
Non-linear system identification in flow-induced vibration
Spanos, P.D.; Zeldin, B.A.; Lu, R.
1996-12-31
The paper introduces a method of identification of non-linear systems encountered in marine engineering applications. The non-linearity is accounted for by a combination of linear subsystems and known zero-memory non-linear transformations; an equivalent linear multi-input-single-output (MISO) system is developed for the identification problem. The unknown transfer functions of the MISO system are identified by assembling a system of linear equations in the frequency domain. This system is solved by performing the Cholesky decomposition of a related matrix. It is shown that the proposed identification method can be interpreted as a {open_quotes}Gram-Schmidt{close_quotes} type of orthogonal decomposition of the input-output quantities of the equivalent MISO system. A numerical example involving the identification of unknown parameters of flow (ocean wave) induced forces on offshore structures elucidates the applicability of the proposed method.
A Cognitive Approach to Solving Systems of Linear Equations
ERIC Educational Resources Information Center
Ramirez, Ariel A.
2009-01-01
Systems of linear equations are used in a variety of fields. Exposure to the concept of systems of equations initially occurs at the high school level and continues through college. Attempts to unearth what students understand about the solutions of linear systems have been limited. Gaps exist in our knowledge of how students understand systems…
A Cognitive Approach to Solving Systems of Linear Equations
ERIC Educational Resources Information Center
Ramirez, Ariel A.
2009-01-01
Systems of linear equations are used in a variety of fields. Exposure to the concept of systems of equations initially occurs at the high school level and continues through college. Attempts to unearth what students understand about the solutions of linear systems have been limited. Gaps exist in our knowledge of how students understand systems…
A stabilization algorithm for linear discrete constant systems
NASA Technical Reports Server (NTRS)
Armstrong, E. S.; Rublein, G. T.
1976-01-01
A procedure is derived for stabilizing linear constant discrete systems which is a discrete analog to the extended Bass algorithm for stabilizing linear constant continuous systems. The procedure offers a method for constructing a stabilizing feedback without the computational difficulty of raising the unstable open-loop response matrix to powers thus making the method attractive for high order or poorly conditioned systems.
Singular linear quadratic control problem for systems with linear and constant delay
NASA Astrophysics Data System (ADS)
Sesekin, A. N.; Andreeva, I. Yu.; Shlyakhov, A. S.
2016-12-01
This article is devoted to the singular linear-quadratic optimization problem on the trajectories of the linear non-autonomous system of differential equations with linear and constant delay. It should be noted that such task does not solve the class of integrable controls, so to ensure the existence of a solution is needed to expand the class of controls to include the control impulse components. For the problem under consideration, we have built program control containing impulse components in the initial and final moments time. This is done under certain assumptions on the functional and the right side of the control system.
Asymptotic Stability of Interconnected Passive Non-Linear Systems
NASA Technical Reports Server (NTRS)
Isidori, A.; Joshi, S. M.; Kelkar, A. G.
1999-01-01
This paper addresses the problem of stabilization of a class of internally passive non-linear time-invariant dynamic systems. A class of non-linear marginally strictly passive (MSP) systems is defined, which is less restrictive than input-strictly passive systems. It is shown that the interconnection of a non-linear passive system and a non-linear MSP system is globally asymptotically stable. The result generalizes and weakens the conditions of the passivity theorem, which requires one of the systems to be input-strictly passive. In the case of linear time-invariant systems, it is shown that the MSP property is equivalent to the marginally strictly positive real (MSPR) property, which is much simpler to check.
Self-characterization of linear and nonlinear adaptive optics systems
NASA Astrophysics Data System (ADS)
Hampton, Peter J.; Conan, Rodolphe; Keskin, Onur; Bradley, Colin; Agathoklis, Pan
2008-01-01
We present methods used to determine the linear or nonlinear static response and the linear dynamic response of an adaptive optics (AO) system. This AO system consists of a nonlinear microelectromechanical systems deformable mirror (DM), a linear tip-tilt mirror (TTM), a control computer, and a Shack-Hartmann wavefront sensor. The system is modeled using a single-input-single-output structure to determine the one-dimensional transfer function of the dynamic response of the chain of system hardware. An AO system has been shown to be able to characterize its own response without additional instrumentation. Experimentally determined models are given for a TTM and a DM.
Decentrally stabilizable linear and bilinear large-scale systems
NASA Technical Reports Server (NTRS)
Siljak, D. D.; Vukcevic, M. B.
1977-01-01
Two classes of large-scale systems are identified, which can always be stabilized by decentralized feedback control. For the class of systems composed of interconnected linear subsystems, we can choose local controllers for the subsystems to achieve stability of the overall system. The same linear feedback scheme can be used to stabilize a class of linear systems with bilinear interconnections. In this case, however, the scheme is used to establish a finite region of stability for the overall system. The stabilization algorithm is applied to the design of a control system for the Large-Space Telescope.
Electronic Non-Contacting Linear Position Measuring System
Post, Richard F.
2005-06-14
A non-contacting linear position location system employs a special transmission line to encode and transmit magnetic signals to a receiver on the object whose position is to be measured. The invention is useful as a non-contact linear locator of moving objects, e.g., to determine the location of a magnetic-levitation train for the operation of the linear-synchronous motor drive system.
A proposed method for solving fuzzy system of linear equations.
Kargar, Reza; Allahviranloo, Tofigh; Rostami-Malkhalifeh, Mohsen; Jahanshaloo, Gholam Reza
2014-01-01
This paper proposes a new method for solving fuzzy system of linear equations with crisp coefficients matrix and fuzzy or interval right hand side. Some conditions for the existence of a fuzzy or interval solution of m × n linear system are derived and also a practical algorithm is introduced in detail. The method is based on linear programming problem. Finally the applicability of the proposed method is illustrated by some numerical examples.
A Proposed Method for Solving Fuzzy System of Linear Equations
Rostami-Malkhalifeh, Mohsen; Jahanshaloo, Gholam Reza
2014-01-01
This paper proposes a new method for solving fuzzy system of linear equations with crisp coefficients matrix and fuzzy or interval right hand side. Some conditions for the existence of a fuzzy or interval solution of m × n linear system are derived and also a practical algorithm is introduced in detail. The method is based on linear programming problem. Finally the applicability of the proposed method is illustrated by some numerical examples. PMID:25215332
NASA Technical Reports Server (NTRS)
Pilkey, W. D.; Chen, Y. H.
1974-01-01
An indirect synthesis method is used in the efficient optimal design of multi-degree of freedom, multi-design element, nonlinear, transient systems. A limiting performance analysis which requires linear programming for a kinematically linear system is presented. The system is selected using system identification methods such that the designed system responds as closely as possible to the limiting performance. The efficiency is a result of the method avoiding the repetitive systems analyses accompanying other numerical optimization methods.
Processing in (linear) systems with stochastic input
NASA Astrophysics Data System (ADS)
Nutu, Catalin Silviu; Axinte, Tiberiu
2016-12-01
The paper is providing a different approach to real-world systems, such as micro and macro systems of our real life, where the man has little or no influence on the system, either not knowing the rules of the respective system or not knowing the input of the system, being thus mainly only spectator of the system's output. In such a system, the input of the system and the laws ruling the system could be only "guessed", based on intuition or previous knowledge of the analyzer of the respective system. But, as we will see in the paper, it exists also another, more theoretical and hence scientific way to approach the matter of the real-world systems, and this approach is mostly based on the theory related to Schrödinger's equation and the wave function associated with it and quantum mechanics as well. The main results of the paper are regarding the utilization of the Schrödinger's equation and related theory but also of the Quantum mechanics, in modeling real-life and real-world systems.
Linear response theory for open systems: Quantum master equation approach
NASA Astrophysics Data System (ADS)
Ban, Masashi; Kitajima, Sachiko; Arimitsu, Toshihico; Shibata, Fumiaki
2017-02-01
A linear response theory for open quantum systems is formulated by means of the time-local and time-nonlocal quantum master equations, where a relevant quantum system interacts with a thermal reservoir as well as with an external classical field. A linear response function that characterizes how a relaxation process deviates from its intrinsic process by a weak external field is obtained by extracting the linear terms with respect to the external field from the quantum master equation. It consists of four parts. One represents the linear response of a quantum system when system-reservoir correlation at an initial time and correlation between reservoir states at different times are neglected. The others are correction terms due to these effects. The linear response function is compared with the Kubo formula in the usual linear response theory. To investigate the properties of the linear response of an open quantum system, an exactly solvable model for a stochastic dephasing of a two-level system is examined. Furthermore, the method for deriving the linear response function is applied for calculating two-time correlation functions of open quantum systems. It is shown that the quantum regression theorem is not valid for open quantum systems unless their reduced time evolution is Markovian.
Petrila, John; Andel, Ross; Constantine, Robert; Robst, John
2010-05-01
The study identified expenditures related to criminal justice, health, mental health, and social welfare services over a four-year period for arrestees with serious mental illnesses in a large Florida county and characteristics of subgroups. Multiple data sets were used to identify 3,769 persons arrested in a one-year period who had serious mental illnesses. Multiple regression with all variables mutually adjusted was used to explore associations with a log of aggregate criminal justice, health, mental health, and social welfare expenditures. Aggregate expenditures were $94,957,465, with a median per person of $15,134. Individuals with the highest expenditures were at least 40 years old with a psychotic disorder, an involuntary psychiatric examination, and more arrests and mental health contacts. Medicaid enrollees had higher expenditures than nonenrollees overall but lower criminal justice expenditures. Identifying characteristics of subgroups with higher expenditures may assist policy makers and providers in designing appropriate criminal justice and treatment responses.
[The security system of SIEMENS digital linear accelerator].
Wang, Jianping
2013-03-01
The security system plays an important role to protect the safety of patients and equipment in radiotherapy. The principle and structure of three kinds of security system of the Siemens digital linear accelerator were analyzed with some examples.
Two level optimization of a redundant linear control system
NASA Technical Reports Server (NTRS)
Martin, C. F.; Harding, R. S.
1975-01-01
A linear system with two sets of controls, one primary and the other redundant, is considered. A two level optimization procedure is used to control the system and to maintain maximal availability of the primary control.
Brown, Darcy M; Dwyer, Dan B; Robertson, Samuel J; Gastin, Paul B
2016-11-01
The purpose of this study was to assess the validity of a global positioning system (GPS) tracking system to estimate energy expenditure (EE) during exercise and field-sport locomotor movements. Twenty-seven participants each completed a 90-min exercise session on an outdoor synthetic futsal pitch. During the exercise session, they wore a 5-Hz GPS unit interpolated to 15 Hz and a portable gas analyzer that acted as the criterion measure of EE. The exercise session was composed of alternating 5-minute exercise bouts of randomized walking, jogging, running, or a field-sport circuit (×3) followed by 10 min of recovery. One-way analysis of variance showed significant (P < .01) and very large underestimations between GPS metabolic power- derived EE and oxygen-consumption (VO2) -derived EE for all field-sport circuits (% difference ≈ -44%). No differences in EE were observed for the jog (7.8%) and run (4.8%), whereas very large overestimations were found for the walk (43.0%). The GPS metabolic power EE over the entire 90-min session was significantly lower (P < .01) than the VO2 EE, resulting in a moderate underestimation overall (-19%). The results of this study suggest that a GPS tracking system using the metabolic power model of EE does not accurately estimate EE in field-sport movements or over an exercise session consisting of mixed locomotor activities interspersed with recovery periods; however, is it able to provide a reasonably accurate estimation of EE during continuous jogging and running.
Singular linear-quadratic control problem for systems with linear delay
Sesekin, A. N.
2013-12-18
A singular linear-quadratic optimization problem on the trajectories of non-autonomous linear differential equations with linear delay is considered. The peculiarity of this problem is the fact that this problem has no solution in the class of integrable controls. To ensure the existence of solutions is required to expand the class of controls including controls with impulse components. Dynamical systems with linear delay are used to describe the motion of pantograph from the current collector with electric traction, biology, etc. It should be noted that for practical problems fact singularity criterion of quality is quite commonly occurring, and therefore the study of these problems is surely important. For the problem under discussion optimal programming control contained impulse components at the initial and final moments of time is constructed under certain assumptions on the functional and the right side of the control system.
Generation of chaotic attractors without equilibria via piecewise linear systems
NASA Astrophysics Data System (ADS)
Escalante-González, R. J.; Campos-Cantón, E.
In this paper, we present a mechanism of generation of a class of switched dynamical system without equilibrium points that generates a chaotic attractor. The switched dynamical systems are based on piecewise linear (PWL) systems. The theoretical results are formally given through a theorem and corollary which give necessary and sufficient conditions to guarantee that a linear affine dynamical system has no equilibria. Numerical results are in accordance with the theory.
Kaiyala, Karl J.
2014-01-01
Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit ‘local linearity.’ Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying ‘latent’ allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses. PMID:25068692
Kaiyala, Karl J
2014-01-01
Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit 'local linearity.' Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying 'latent' allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses.
A linear quadratic regulator approach to the stabilization of uncertain linear systems
NASA Technical Reports Server (NTRS)
Shieh, L. S.; Sunkel, J. W.; Wang, Y. J.
1990-01-01
This paper presents a linear quadratic regulator approach to the stabilization of uncertain linear systems. The uncertain systems under consideration are described by state equations with the presence of time-varying unknown-but-bounded uncertainty matrices. The method is based on linear quadratic regulator (LQR) theory and Liapunov stability theory. The robust stabilizing control law for a given uncertain system can be easily constructed from the symmetric positive-definite solution of the associated augmented Riccati equation. The proposed approach can be applied to matched and/or mismatched systems with uncertainty matrices in which only their matrix norms are bounded by some prescribed values and/or their entries are bounded by some prescribed constraint sets. Several numerical examples are presented to illustrate the results.
Output Synchronization of Nonidentical Linear Multiagent Systems.
Wu, Yuanqing; Su, Hongye; Shi, Peng; Lu, Renquan; Wu, Zheng-Guang
2017-01-01
In this paper, the problem of output synchronization is investigated for the heterogeneous network with an uncertain leader. It is assumed that parameter perturbations influence the nonidentical linear agents, whose outputs are controlled to track the output of an uncertain leader. Based on the hierarchical structure of the communication graph, a novel control scheme is proposed to guarantee the output synchronization. As there exist parameter uncertainties in the models of the agents, the internal model principle is used to gain robustness versus plant parameter uncertainties. Furthermore, as the precise model of the leader is also not available, the adaptive control principle is adopted to tune the parameters in the local controllers. The developed new technique is able to simultaneously handle uncertainties in the follower parameters as well as the leader parameters. The agents in the upper layers will be treated as the exosystems of the agents in the lower layers. The local controllers are constructed in a sequential order. It is shown that the output synchronization can be achieved globally asymptotically and locally exponentially. Finally, a simulation example is given to illustrate the effectiveness and potential of the theoretic results obtained.
On Optimal Feedback Control for Stationary Linear Systems
Russell, David L.
2010-04-15
We study linear-quadratic optimal control problems for finite dimensional stationary linear systems AX+BU=Z with output Y=CX+DU from the viewpoint of linear feedback solution. We interpret solutions in relation to system robustness with respect to disturbances Z and relate them to nonlinear matrix equations of Riccati type and eigenvalue-eigenvector problems for the corresponding Hamiltonian system. Examples are included along with an indication of extensions to continuous, i.e., infinite dimensional, systems, primarily of elliptic type.
Virtual Estimator for Piecewise Linear Systems Based on Observability Analysis
Morales-Morales, Cornelio; Adam-Medina, Manuel; Cervantes, Ilse; Vela-Valdés and, Luis G.; García Beltrán, Carlos Daniel
2013-01-01
This article proposes a virtual sensor for piecewise linear systems based on observability analysis that is in function of a commutation law related with the system's outpu. This virtual sensor is also known as a state estimator. Besides, it presents a detector of active mode when the commutation sequences of each linear subsystem are arbitrary and unknown. For the previous, this article proposes a set of virtual estimators that discern the commutation paths of the system and allow estimating their output. In this work a methodology in order to test the observability for piecewise linear systems with discrete time is proposed. An academic example is presented to show the obtained results. PMID:23447007
Predictors of regional Medicare expenditures for otolaryngology physician services.
Smith, Alden; Handorf, Elizabeth; Arjmand, Ellis; Lango, Miriam N
2017-06-01
To describe geographic variation in spending and evaluate regional Medicare expenditures for otolaryngologist services with population- and beneficiary-related factors, physician supply, and hospital system factors. Cross-sectional study. The average regional expenditures for otolaryngology physician services were defined as the total work relative value units (wRVUs) collected by otolaryngologists in a hospital referral region (HRR) per thousand Medicare beneficiaries in the HRR. A multivariable linear regression model tested associations with regional sociodemographics (age, sex, race, income, education), the physician and hospital bed supply, and the presence of an otolaryngology residency program. In 2012, the mean Medicare expenditure for otolaryngology provider services across HRRs was 224 wRVUs per thousand Medicare beneficiaries (standard deviation [SD] 104), ranging from 31 to 604 wRVUs per thousand Medicare beneficiaries. In 2013, the average Medicare expenditures for each HRR was highly correlated with expenditures collected in 2012 (Pearson correlation coefficient .997, P = .0001). Regional Medicare expenditures were independently and positively associated with otolaryngology, medical specialist, and hospital bed supply in the region, and were negatively associated with the supply of primary care physicians and presence of an otolaryngology residency program after adjusting for other factors. The magnitude of associations with physician supply and hospital factors was stronger than any population or Medicare beneficiary factor. Wide variations in regional Medicare expenditures for otolaryngology physician services, highly stable over 2 years, were strongly associated with regional health system factors. Changes in health policy for otolaryngology care may require coordination with other physician specialties and integrated hospital systems. NA. Laryngoscope, 127:1312-1317, 2017. © 2016 The American Laryngological, Rhinological and Otological Society
Numerical methods for control optimization in linear systems
NASA Astrophysics Data System (ADS)
Tyatyushkin, A. I.
2015-05-01
Numerical methods are considered for solving optimal control problems in linear systems, namely, terminal control problems with control and phase constraints and time-optimal control problems. Several algorithms with various computer storage requirements are proposed for solving these problems. The algorithms are intended for finding an optimal control in linear systems having certain features, for example, when the reachable set of a system has flat faces.
Complex modes and solvability of nonclassical linear systems
NASA Astrophysics Data System (ADS)
Caughey, T. K.; Ma, F.
1993-03-01
Some basic properties of nonclassical linear systems are examined to determine necessary and sufficient conditions under which nonclassical linear systems can be decoupled or become solvable in n-space. It was found that a necessary and sufficient condition under which a nonclassical system can be decoupled is for the coefficient matrices M, C, and K (where M is the mass matrix, C is the damping matrix, and K is the stiffness matrix) to be diagonalizable and pairwise commutative.
Linear decentralized systems with special structure. [for twin lift helicopters
NASA Technical Reports Server (NTRS)
Martin, C. F.
1982-01-01
Certain fundamental structures associated with linear systems having internal symmetries are outlined. It is shown that the theory of finite-dimensional algebras and their representations are closely related to such systems. It is also demonstrated that certain problems in the decentralized control of symmetric systems are equivalent to long-standing problems of linear systems theory. Even though the structure imposed arose in considering the problems of twin-lift helicopters, any large system composed of several identical intercoupled control systems can be modeled by a linear system that satisfies the constraints imposed. Internal symmetry can be exploited to yield new system-theoretic invariants and a better understanding of the way in which the underlying structure affects overall system performance.
Capacities of linear quantum optical systems
NASA Astrophysics Data System (ADS)
Lupo, Cosmo; Giovannetti, Vittorio; Pirandola, Stefano; Mancini, Stefano; Lloyd, Seth
2012-06-01
A wide variety of communication channels employ the quantized electromagnetic field to convey information. Their communication capacity crucially depends on losses associated to spatial characteristics of the channel such as diffraction and antenna design. Here we focus on the communication via a finite pupil, showing that diffraction is formally described as a memory channel. By exploiting this equivalence we then compute the communication capacity of an optical refocusing system, modeled as a converging lens. Even though loss of information originates from the finite pupil of the lens, we show that the presence of the refocusing system can substantially enhance the communication capacity. We mainly concentrate on communication of classical information, the extension to quantum information being straightforward.
The case for unified linear reference system
Espinoza, J. Jr.; Mackoy, R.D.; Fletcher, D.R.
1997-06-01
The transportation industry distinguishes its activities and data into three functionally and institutionally distinct domains. Transportation infrastructure management activities make transport links (e.g., roads, rail lines, transit routes) available for travel. In contrast, civilian and military transport operations focus on finding and using the best transport links. Each of these three transportation interest groups - transportation facility operators, civilian and military transportation users - currently collects and maintains separate, often redundant or inconsistent information concerning the location and status of the transportation system, the vehicles using the system, and the passengers and freight (or material) being conveyed. Although there has been some progress made in integrating data within each domain, little emphasis has been placed on identifying and improving the flow of information between them. Because activities initiated in one domain affect conditions in the others, defining these flows is crucial to the next generation of planners, traffic managers and customers of transportation services. For example, construction and maintenance activities affect civilian and military route choices and travel times; large scale military movements disrupt civilian travel and have potentially major effects on the infrastructure and so on. This intertwined interest in the transportation system implies the need for data integration not only within each sphere of interest but among the spheres as well. Although recent policy statements by the U.S. Departments of Transportation and Defense and ITS America indicate a desire to combine and share information resources, there are enormous technical and institutional barriers that need to be overcome.
Overweight in adolescents: implications for health expenditures.
Monheit, Alan C; Vistnes, Jessica P; Rogowski, Jeannette A
2009-03-01
We consider a compelling research question raised by the growing prevalence of overweight among adolescents: do overweight adolescents incur greater health care expenditures than adolescents of normal weight? To address this question, we use data from the Medical Expenditure Panel Survey (MEPS) and estimate a two-part, generalized linear model (GLM) of health spending. Considering separate models by gender, we find that overweight females incur $790 more in annual expenditures than those of normal weight but we find no expenditure differences by bodyweight for males. We find that mental health spending is associated with part of the disparity in expenditures for adolescent females but establishing causality between mental health problems and weight-related health expenditure differences is challenging.
Feedback linearizing control of a MIMO power system
NASA Astrophysics Data System (ADS)
Ilyes, Laszlo
Prior research has demonstrated that either the mechanical or electrical subsystem of a synchronous electric generator may be controlled using single-input single-output (SISO) nonlinear feedback linearization. This research suggests a new approach which applies nonlinear feedback linearization to a multi-input multi-output (MIMO) model of the synchronous electric generator connected to an infinite bus load model. In this way, the electrical and mechanical subsystems may be linearized and simultaneously decoupled through the introduction of a pair of auxiliary inputs. This allows well known, linear, SISO control methods to be effectively applied to the resulting systems. The derivation of the feedback linearizing control law is presented in detail, including a discussion on the use of symbolic math processing as a development tool. The linearizing and decoupling properties of the control law are validated through simulation. And finally, the robustness of the control law is demonstrated.
Decoupling in linear time-varying multivariable systems
NASA Technical Reports Server (NTRS)
Sankaran, V.
1973-01-01
The necessary and sufficient conditions for the decoupling of an m-input, m-output, linear time varying dynamical system by state variable feedback is described. The class of feedback matrices which decouple the system are illustrated. Systems which do not satisfy these results are described and systems with disturbances are considered. Some examples are illustrated to clarify the results.
Decentralization, stabilization, and estimation of large-scale linear systems
NASA Technical Reports Server (NTRS)
Siljak, D. D.; Vukcevic, M. B.
1976-01-01
In this short paper we consider three closely related aspects of large-scale systems: decentralization, stabilization, and estimation. A method is proposed to decompose a large linear system into a number of interconnected subsystems with decentralized (scalar) inputs or outputs. The procedure is preliminary to the hierarchic stabilization and estimation of linear systems and is performed on the subsystem level. A multilevel control scheme based upon the decomposition-aggregation method is developed for stabilization of input-decentralized linear systems Local linear feedback controllers are used to stabilize each decoupled subsystem, while global linear feedback controllers are utilized to minimize the coupling effect among the subsystems. Systems stabilized by the method have a tolerance to a wide class of nonlinearities in subsystem coupling and high reliability with respect to structural perturbations. The proposed output-decentralization and stabilization schemes can be used directly to construct asymptotic state estimators for large linear systems on the subsystem level. The problem of dimensionality is resolved by constructing a number of low-order estimators, thus avoiding a design of a single estimator for the overall system.
Perfect commuting-operator strategies for linear system games
NASA Astrophysics Data System (ADS)
Cleve, Richard; Liu, Li; Slofstra, William
2017-01-01
Linear system games are a generalization of Mermin's magic square game introduced by Cleve and Mittal. They show that perfect strategies for linear system games in the tensor-product model of entanglement correspond to finite-dimensional operator solutions of a certain set of non-commutative equations. We investigate linear system games in the commuting-operator model of entanglement, where Alice and Bob's measurement operators act on a joint Hilbert space, and Alice's operators must commute with Bob's operators. We show that perfect strategies in this model correspond to possibly infinite-dimensional operator solutions of the non-commutative equations. The proof is based around a finitely presented group associated with the linear system which arises from the non-commutative equations.
Complexity of Dense Linear System Solution on a Multiprocessor Ring.
1985-01-01
Lawrie and Sameh [4] present a technique for solving symmetric positive definite banded systems, which is a generalization of a method for tridiagonal...Numerical Linear Algebra, SIAM Review. 20 (1978), pp. 740-777. [4] D. Lawrie, A.H. Sameh , The Computation and Communication Complexity of a Parallel Banded...409. [7] , Parallel, Iterative Solution of Sparse Linear Systems : Models and Architectures. Technical Report 84-35, ICASE, 1984. (81 A.H. Sameh , On
Iterative algorithms for large sparse linear systems on parallel computers
NASA Technical Reports Server (NTRS)
Adams, L. M.
1982-01-01
Algorithms for assembling in parallel the sparse system of linear equations that result from finite difference or finite element discretizations of elliptic partial differential equations, such as those that arise in structural engineering are developed. Parallel linear stationary iterative algorithms and parallel preconditioned conjugate gradient algorithms are developed for solving these systems. In addition, a model for comparing parallel algorithms on array architectures is developed and results of this model for the algorithms are given.
Solution of generalized shifted linear systems with complex symmetric matrices
NASA Astrophysics Data System (ADS)
Sogabe, Tomohiro; Hoshi, Takeo; Zhang, Shao-Liang; Fujiwara, Takeo
2012-07-01
We develop the shifted COCG method [R. Takayama, T. Hoshi, T. Sogabe, S.-L. Zhang, T. Fujiwara, Linear algebraic calculation of Green's function for large-scale electronic structure theory, Phys. Rev. B 73 (165108) (2006) 1-9] and the shifted WQMR method [T. Sogabe, T. Hoshi, S.-L. Zhang, T. Fujiwara, On a weighted quasi-residual minimization strategy of the QMR method for solving complex symmetric shifted linear systems, Electron. Trans. Numer. Anal. 31 (2008) 126-140] for solving generalized shifted linear systems with complex symmetric matrices that arise from the electronic structure theory. The complex symmetric Lanczos process with a suitable bilinear form plays an important role in the development of the methods. The numerical examples indicate that the methods are highly attractive when the inner linear systems can efficiently be solved.
Recursive inversion of externally defined linear systems by FIR filters
NASA Technical Reports Server (NTRS)
Bach, Ralph E., Jr.; Baram, Yoram
1989-01-01
The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least-squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problem of system identification and compensation.
Recursive inversion of externally defined linear systems by FIR filters
NASA Technical Reports Server (NTRS)
Bach, Ralph E., Jr.; Baram, Yoram
1989-01-01
The approximate inversion of an internally unknown linear system, given by its impulse response sequence, by an inverse system having a finite impulse response, is considered. The recursive least-squares procedure is shown to have an exact initialization, based on the triangular Toeplitz structure of the matrix involved. The proposed approach also suggests solutions to the problem of system identification and compensation.
Equi-surjective systems of linear operators and applications
NASA Astrophysics Data System (ADS)
Luc, D. T.; Minh, N. B.
2008-01-01
In this paper we study a system of linear operators between finite-dimensional Euclidean spaces. Emphasis is made on unbounded systems and sufficient conditions are established for their equi-surjectivity. An application is presented in which a system of approximate Jacobian matrices is used to obtain a parametric interior mapping theorem. A multiplier rule for vector problems is also derived.
Exact linearization of the radiation-damped spin system
Rourke; Augustine
2000-02-21
Nonlinear evolution of the Landau-Lifshitz type can be exactly linearized. Special cases include the radiation-damped spin system and the superradiant system in the semiclassical regime, in the presence of time-varying driving fields. For these, the resultant linear system is simply that of a spin 1 / 2 particle, with the radiation damping rate, or superradiant characteristic time, manifested as an imaginary addition to the spin's resonance frequency. Consequently, methods from inverse scattering theory can be used to design driving fields. The behavior of these systems under stochastic excitation can be determined exactly.
Stockbridge, Erica L; Suzuki, Sumihiro; Pagán, José A
2015-01-01
Objective To estimate average incremental health care expenditures associated with chronic pain by health care service category, expanding on prior research that focused on specific pain conditions instead of general pain, excluded low levels of pain, or did not incorporate pain duration. Data Source Medical Expenditure Panel Survey (MEPS) data (2008–2011; N = 26,671). Study Design Differences in annual expenditures for adults at different levels of pain that interferes with normal work, as measured by the SF-12, were estimated using recycled predictions from two-part logit-generalized linear regression models. Principal Findings “A little bit” of chronic pain-related interference was associated with a $2,498 increase in total adjusted expenditures over no pain interference (p < .0001) and a $1,008 increase over nonchronic pain interference (p = .0001). Moderate and severe chronic pain-related interference was associated with a $3,707 and $5,804 increase in expenditures over no pain interference and a $2,218 and $4,315 increase over nonchronic interference, respectively (p < .0001). Expenditure increases were most pronounced for inpatient and hospital outpatient expenditures compared to other types of health care expenditures. Conclusions Chronic pain limitations are associated with higher health care expenditures. Results underscore the substantial cost of pain to the health care system. PMID:25424348
Stockbridge, Erica L; Suzuki, Sumihiro; Pagán, José A
2015-06-01
To estimate average incremental health care expenditures associated with chronic pain by health care service category, expanding on prior research that focused on specific pain conditions instead of general pain, excluded low levels of pain, or did not incorporate pain duration. Medical Expenditure Panel Survey (MEPS) data (2008-2011; N = 26,671). Differences in annual expenditures for adults at different levels of pain that interferes with normal work, as measured by the SF-12, were estimated using recycled predictions from two-part logit-generalized linear regression models. "A little bit" of chronic pain-related interference was associated with a $2,498 increase in total adjusted expenditures over no pain interference (p < .0001) and a $1,008 increase over nonchronic pain interference (p = .0001). Moderate and severe chronic pain-related interference was associated with a $3,707 and $5,804 increase in expenditures over no pain interference and a $2,218 and $4,315 increase over nonchronic interference, respectively (p < .0001). Expenditure increases were most pronounced for inpatient and hospital outpatient expenditures compared to other types of health care expenditures. Chronic pain limitations are associated with higher health care expenditures. Results underscore the substantial cost of pain to the health care system. © Health Research and Educational Trust.
Modal interaction in linear dynamic systems near degenerate modes
NASA Technical Reports Server (NTRS)
Afolabi, D.
1991-01-01
In various problems in structural dynamics, the eigenvalues of a linear system depend on a characteristic parameter of the system. Under certain conditions, two eigenvalues of the system approach each other as the characteristic parameter is varied, leading to modal interaction. In a system with conservative coupling, the two eigenvalues eventually repel each other, leading to the curve veering effect. In a system with nonconservative coupling, the eigenvalues continue to attract each other, eventually colliding, leading to eigenvalue degeneracy. Modal interaction is studied in linear systems with conservative and nonconservative coupling using singularity theory, sometimes known as catastrophe theory. The main result is this: eigenvalue degeneracy is a cause of instability; in systems with conservative coupling, it induces only geometric instability, whereas in systems with nonconservative coupling, eigenvalue degeneracy induces both geometric and elastic instability. Illustrative examples of mechanical systems are given.
Dynamic modeling of electrochemical systems using linear graph theory
NASA Astrophysics Data System (ADS)
Dao, Thanh-Son; McPhee, John
An electrochemical cell is a multidisciplinary system which involves complex chemical, electrical, and thermodynamical processes. The primary objective of this paper is to develop a linear graph-theoretical modeling for the dynamic description of electrochemical systems through the representation of the system topologies. After a brief introduction to the topic and a review of linear graphs, an approach to develop linear graphs for electrochemical systems using a circuitry representation is discussed, followed in turn by the use of the branch and chord transformation techniques to generate final dynamic equations governing the system. As an example, the application of linear graph theory to modeling a nickel metal hydride (NiMH) battery will be presented. Results show that not only the number of equations are reduced significantly, but also the linear graph model simulates faster compared to the original lumped parameter model. The approach presented in this paper can be extended to modeling complex systems such as an electric or hybrid electric vehicle where a battery pack is interconnected with other components in many different domains.
Switching control of linear systems subject to asymmetric actuator saturation
NASA Astrophysics Data System (ADS)
Yuan, Chengzhi; Wu, Fen
2015-01-01
In this paper, we study the saturation control problem for linear time-invariant (LTI) systems subject to asymmetric actuator saturation under a switching control framework. The LTI plant with asymmetric saturation is first transformed to an equivalent switched linear model with each subsystem subject to symmetric actuator saturation, based on which a dwell-time switching controller augmented with a controller state reset is then developed by using multiple Lyapunov functions. The controller synthesis conditions are formulated as linear matrix inequalities (LMIs), which can be solved efficiently. Simulation results are also included to illustrate the effectiveness and advantages of the proposed approach.
Alekseeva, N Iu
2011-01-01
The article presents the data related to analysis of effectiveness of budget expense in public health system of Irkutskaya oblast in 2007-2010. The results testify the accuracy and effectiveness of the strategy of ministry of health concerning the activities related to the reduction of non-effective expenditures during medical care provision to oblast population.
Robust H∞ state-feedback control for linear systems.
Chen, Hao; Zhang, Zhenzhen; Wang, Huazhang
2017-04-01
This paper investigates the problem of robust H∞ control for linear systems. First, the state-feedback closed-loop control algorithm is designed. Second, by employing the geometric progression theory, a modified augmented Lyapunov-Krasovskii functional (LKF) with the geometric integral interval is established. Then, parameter uncertainties and the derivative of the delay are flexibly described by introducing the convex combination skill. This technique can eliminate the unnecessary enlargement of the LKF derivative estimation, which gives less conservatism. In addition, the designed controller can ensure that the linear systems are globally asymptotically stable with a guaranteed H∞ performance in the presence of a disturbance input and parameter uncertainties. A liquid monopropellant rocket motor with a pressure feeding system is evaluated in a simulation example. It shows that this proposed state-feedback control approach achieves the expected results for linear systems in the sense of the prescribed H∞ performance.
Linear adaptive control of a single-tether system
NASA Technical Reports Server (NTRS)
Greene, M. E.; Carter, J. T.; Walls, J. L.
1992-01-01
A control law for a single-tether orbiting satellite system based on a reduced order linear adaptive control technique is presented. The main advantages of this technique are its design simplicity and the facts that specific system parameters and model linearization are not required when designing the controller. Two controllers are developed: one which uses only tension in the tether as control actuation and one which uses both tension and in-plane thrusters as control actuation. Both a sixth-order nonlinear and an 11th-order bead model of a tethered satellite system are used for simulation purposes, demonstrating the ability of the controller to manage an uncertain system. Retrieval and stationkeeping results using these nonlinear models and the linear adaptive controller demonstrate the feasibility of the method. The robustness of the controller with respect to parameter uncertainties is also demonstrated by changing the nonlinear model and parameters within the model without redesigning the controller.
Duality between noise and spatial resolution in linear systems.
Gureyev, Timur E; Nesterets, Yakov I; de Hoog, Frank; Schmalz, Gerd; Mayo, Sheridan C; Mohammadi, Sara; Tromba, Giuliana
2014-04-21
It is shown that in a broad class of linear systems, including general linear shift-invariant systems, the spatial resolution and the noise satisfy a duality relationship, resembling the uncertainty principle in quantum mechanics. The product of the spatial resolution and the standard deviation of output noise in such systems represents a type of phase-space volume that is invariant with respect to linear scaling of the point-spread function, and it cannot be made smaller than a certain positive absolute lower limit. A corresponding intrinsic "quality" characteristic is introduced and then evaluated for the cases of some popular imaging systems, including computed tomography, generic image convolution and phase-contrast imaging. It is shown that in the latter case the spatial resolution and the noise can sometimes be decoupled, potentially leading to a substantial increase in the imaging quality.
Geometric and asymptotic properties associated with linear switched systems
NASA Astrophysics Data System (ADS)
Chitour, Y.; Gaye, M.; Mason, P.
2015-12-01
Consider a continuous-time linear switched system on Rn associated with a compact convex set of matrices. When it is irreducible and its largest Lyapunov exponent is zero there always exists a Barabanov norm associated with the system. This paper deals with two types of issues: (a) properties of Barabanov norms such as uniqueness up to homogeneity and strict convexity; (b) asymptotic behavior of the extremal solutions of the linear switched system. Regarding Issue (a), we provide partial answers and propose four related open problems. As for Issue (b), we establish, when n = 3, a Poincaré-Bendixson theorem under a regularity assumption on the set of matrices. We then revisit a noteworthy result of N.E. Barabanov describing the asymptotic behavior of linear switched system on R3 associated with a pair of Hurwitz matrices { A , A + bcT }. After pointing out a gap in Barabanov's proof we partially recover his result by alternative arguments.
Powerful tool for design analysis of linear control systems
Maddux, Jr, A S
1982-05-10
The methods for designing linear controls for electronic or mechanical systems have been understood and put to practice. What has not been readily available to engineers, however, is a practical, quick and inexpensive method for analyzing these linear control (feedback) systems once they have been designed into the electronic or mechanical hardware. Now, the PET, manufactured by Commodore Business Machines (CBM), operating with several peripherals via the IEEE 488 Bus, brings to the engineer for about $4000 a complete set of office tools for analyzing these system designs.
LDRD final report on a unified linear reference system
Espinoza, J. Jr.; Mackoy, R.D.; Fletcher, D.R.
1997-06-01
The purpose of the project was to describe existing deficiencies in Geographic Information Systems for transportation (GIS-T) applications and prescribe solutions that would benefit the transportation community in general. After an in-depth literature search and much consultation with noted transportation experts, the need for a common linear reference system that integrated and supported the planning and operational needs of the transportation community became very apparent. The focus of the project was set on a unified linear reference system and how to go about its requirements definition, design, implementation, and promulgation to the transportation community.
Christian, B; Chattopadhyay, A
2014-06-01
To estimate dental expenditures in 2006, to analyse dental expenditures by potential explanatory factors for 2006 and to explore trends in dental expenditures from 1996-2006. Medical Expenditure Panel Survey (MEPS) data were used. T-tests and analysis of variance were used to test for significance. Multivariable linear regression analysis was conducted to identify independent predictors of dental expenditures. The trend analysis was conducted for the 11-year period, 1996-2006, on adults aged 25 years and older. Expenditures were inflation adjusted to 2006 dollars using the annual average Consumer Price Index. Data were analysed using the MEPS query tool and SASv9.2. In the 2006 MEPS sample, 8,001 adults had dental expenditures and when weighted represented about 93 million non-institutionalised adult US civilians. The mean dental expenditures for this weighted sample were $611 (sd 1,309), median $233 (inter-quartile range 466). As expected, in 2006, dental expenditures increased with age. Those adults who reported their self-perceived health status as 'excellent' were observed to have lowest dental expenditures in this category. After adjusting for other variables in the multivariable linear regression analysis of dental expenditures, age, race/ethnicity, income, geographic location, perceived health status and dental insurance coverage remained significant. Dental expenditures for 2006 were $611 (mean) and $233 (median). The time-trend showed substantial but non-uniform annual changes in real dental expenditures between 1996 and 2006.
Non-linear dynamic analysis of geared systems, part 2
NASA Technical Reports Server (NTRS)
Singh, Rajendra; Houser, Donald R.; Kahraman, Ahmet
1990-01-01
A good understanding of the steady state dynamic behavior of a geared system is required in order to design reliable and quiet transmissions. This study focuses on a system containing a spur gear pair with backlash and periodically time-varying mesh stiffness, and rolling element bearings with clearance type non-linearities. A dynamic finite element model of the linear time-invariant (LTI) system is developed. Effects of several system parameters, such as torsional and transverse flexibilities of the shafts and prime mover/load inertias, on free and force vibration characteristics are investigated. Several reduced order LTI models are developed and validated by comparing their eigen solution with the finite element model results. Several key system parameters such as mean load and damping ratio are identified and their effects on the non-linear frequency response are evaluated quantitatively. Other fundamental issues such as the dynamic coupling between non-linear modes, dynamic interactions between component non-linearities and time-varying mesh stiffness, and the existence of subharmonic and chaotic solutions including routes to chaos have also been examined in depth.
Preprocessing Inconsistent Linear System for a Meaningful Least Squares Solution
NASA Technical Reports Server (NTRS)
Sen, Syamal K.; Shaykhian, Gholam Ali
2011-01-01
Mathematical models of many physical/statistical problems are systems of linear equations. Due to measurement and possible human errors/mistakes in modeling/data, as well as due to certain assumptions to reduce complexity, inconsistency (contradiction) is injected into the model, viz. the linear system. While any inconsistent system irrespective of the degree of inconsistency has always a least-squares solution, one needs to check whether an equation is too much inconsistent or, equivalently too much contradictory. Such an equation will affect/distort the least-squares solution to such an extent that renders it unacceptable/unfit to be used in a real-world application. We propose an algorithm which (i) prunes numerically redundant linear equations from the system as these do not add any new information to the model, (ii) detects contradictory linear equations along with their degree of contradiction (inconsistency index), (iii) removes those equations presumed to be too contradictory, and then (iv) obtain the minimum norm least-squares solution of the acceptably inconsistent reduced linear system. The algorithm presented in Matlab reduces the computational and storage complexities and also improves the accuracy of the solution. It also provides the necessary warning about the existence of too much contradiction in the model. In addition, we suggest a thorough relook into the mathematical modeling to determine the reason why unacceptable contradiction has occurred thus prompting us to make necessary corrections/modifications to the models - both mathematical and, if necessary, physical.
Asymptotically optimal feedback control for a system of linear oscillators
NASA Astrophysics Data System (ADS)
Ovseevich, Alexander; Fedorov, Aleksey
2013-12-01
We consider problem of damping of an arbitrary number of linear oscillators under common bounded control. We are looking for a feedback control steering the system to the equilibrium. The obtained control is asymptotically optimal: the ratio of motion time to zero with this control to the minimum one is close to 1, if the initial energy of the system is large.
Asymptotic behavior of coupled linear systems modeling suspension bridges
NASA Astrophysics Data System (ADS)
Dell'Oro, Filippo; Giorgi, Claudio; Pata, Vittorino
2015-06-01
We consider the coupled linear system describing the vibrations of a string-beam system related to the well-known Lazer-McKenna suspension bridge model. For ɛ > 0 and k > 0, the decay properties of the solution semigroup are discussed in dependence of the nonnegative parameters γ and h, which are responsible for the damping effects.
Detail, Face C (rear), showing Interference Analysis System Linear Test ...
Detail, Face C (rear), showing Interference Analysis System Linear Test Array mounted at Level 4A - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Techinical Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA
A Methodology and Linear Model for System Planning and Evaluation.
ERIC Educational Resources Information Center
Meyer, Richard W.
1982-01-01
The two-phase effort at Clemson University to design a comprehensive library automation program is reported. Phase one was based on a version of IBM's business system planning methodology, and the second was based on a linear model designed to compare existing program systems to the phase one design. (MLW)
Feedback stabilization and control of linear neutral systems
NASA Technical Reports Server (NTRS)
Tarn, T. J.; Spong, M. W.; Ito, K.
1982-01-01
The first problem treated here is the realization and stabilization of linear neutral systems with discrete delays. It is shown that any autonomous linear neutral system with discrete delays is zero-state equivalent to an abstract linear system over a local ring of operators. Using the abstract model, the basic existence question for neutral realization is then settled. For general infinite dimensional linear systems, there is no precise analog of the finite dimensional state space isomorphism theorem. Because of this, the notion of spectral minimality must be introduced. For the case of single input-single output systems, realizations are obtained that are both minimal and spectrally minimal. Using the Cruz-Hale theory of stable D-operators, conditions are given that ensure that any poles introduced into the realization are strictly contained in the left half plane and indeed are characterized as characteristic values of the D-operator. The problem of the feedback stabilization of neutral systems is then considered using the abstract model. It is shown that, for neutral systems with commensurable delays and a stable D-operator in the sense of Cruz and Hale, Morses theorem (1976) on pole assignment over a PID implies stabilizability in the reachable case.
Parallel preconditioning for the solution of nonsymmetric banded linear systems
Amodio, P.; Mazzia, F.
1994-12-31
Many computational techniques require the solution of banded linear systems. Common examples derive from the solution of partial differential equations and of boundary value problems. In particular the authors are interested in the parallel solution of block Hessemberg linear systems Gx = f, arising from the solution of ordinary differential equations by means of boundary value methods (BVMs), even if the considered preconditioning may be applied to any block banded linear system. BVMs have been extensively investigated in the last few years and their stability properties give promising results. A new class of BVMs called Reverse Adams, which are BV-A-stable for orders up to 6, and BV-A{sub 0}-stable for orders up to 9, have been studied.
Optimal second order sliding mode control for linear uncertain systems.
Das, Madhulika; Mahanta, Chitralekha
2014-11-01
In this paper an optimal second order sliding mode controller (OSOSMC) is proposed to track a linear uncertain system. The optimal controller based on the linear quadratic regulator method is designed for the nominal system. An integral sliding mode controller is combined with the optimal controller to ensure robustness of the linear system which is affected by parametric uncertainties and external disturbances. To achieve finite time convergence of the sliding mode, a nonsingular terminal sliding surface is added with the integral sliding surface giving rise to a second order sliding mode controller. The main advantage of the proposed OSOSMC is that the control input is substantially reduced and it becomes chattering free. Simulation results confirm superiority of the proposed OSOSMC over some existing.
Miwa, M; Oishi, K; Anzai, H; Kumagai, H; Ieiri, S; Hirooka, H
2017-02-01
The estimation of energy expenditure (EE) of grazing animals is of great importance for efficient animal management on pasture. In the present study, a method is proposed to estimate EE in grazing animals based on measurements of body acceleration of animals in combination with the conventional Agricultural and Food Research Council (AFRC) energy requirement system. Three-dimensional body acceleration and heart rate were recorded for tested animals under both grazing and housing management. An acceleration index, vectorial dynamic body acceleration (VeDBA), was used to calculate activity allowance (AC) during grazing and then incorporate it into the AFRC system to estimate the EE (EE derived from VeDBA [EE]) of the grazing animals. The method was applied to 3 farm ruminant species (7 cattle, 6 goats, and 4 sheep). Energy expenditure based on heart rate (EE) was also estimated as a reference. The result showed that larger VeDBA and heart rate values were obtained under grazing management, resulting in greater EE and EE under grazing management than under housing management. There were large differences between the EE estimated from the 2 methods, where EE values were greater than EE (averages of 163.4 and 142.5% for housing and grazing management, respectively); the EE was lower than the EE, whereas the increase in EE under grazing in comparison with housing conditions was larger than that in EE. These differences may have been due to the use of an equation for estimating EE derived under laboratory conditions and due to the presence of the effects of physiological, psychological, and environmental factors in addition to physical activity being included in measurements for the heart rate method. The present method allowed us to separate activity-specific EE (i.e., AC) from overall EE, and, in fact, AC under grazing management were about twice times as large as those under housing management for farm ruminant animals. There is evidence that the conventional energy
Robot arm force control through system linearization by nonlinear feedback
NASA Technical Reports Server (NTRS)
Tarn, T. J.; Bejczy, A. K.; Yun, Xiaoping
1988-01-01
Based on a differential geometric feedback linearization technique for nonlinear time-varying systems, a dynamic force control method for robot arms is developed. It uses active force-moment measurements at the robot wrist. The controller design fully incorporate the robot-arm dynamics and is so general that it can be reduced to pure position control, hybrid position/force control, pure force control. The controller design is independent of the tasks to be performed. Computer simulations show that the controller improves the position error by a factor of ten in cases in which position errors generate force measurements. A theorem on linearization of time-varying system is also presented.
Conference on iterative methods for large linear systems
Kincaid, D.R.
1988-12-01
This conference is dedicated to providing an overview of the state of the art in the use of iterative methods for solving sparse linear systems with an eye to contributions of the past, present and future. The emphasis is on identifying current and future research directions in the mainstream of modern scientific computing. Recently, the use of iterative methods for solving linear systems has experienced a resurgence of activity as scientists attach extremely complicated three-dimensional problems using vector and parallel supercomputers. Many research advances in the development of iterative methods for high-speed computers over the past forty years are reviewed, as well as focusing on current research.
Solution of linear systems by a singular perturbation technique
NASA Technical Reports Server (NTRS)
Ardema, M. D.
1976-01-01
An approximate solution is obtained for a singularly perturbed system of initial valued, time invariant, linear differential equations with multiple boundary layers. Conditions are stated under which the approximate solution converges uniformly to the exact solution as the perturbation parameter tends to zero. The solution is obtained by the method of matched asymptotic expansions. Use of the results for obtaining approximate solutions of general linear systems is discussed. An example is considered to illustrate the method and it is shown that the formulas derived give a readily computed uniform approximation.
Conference on iterative methods for large linear systems
Kincaid, D.R.
1988-12-01
This conference is dedicated to providing an overview of the state of the art in the use of iterative methods for solving sparse linear systems with an eye to contributions of the past, present and future. The emphasis is on identifying current and future research directions in the mainstream of modern scientific computing. Recently, the use of iterative methods for solving linear systems has experienced a resurgence of activity as scientists attach extremely complicated three-dimensional problems using vector and parallel supercomputers. Many research advances in the development of iterative methods for high-speed computers over the past forty years are reviewed, as well as focusing on current research.
World military expenditures and global cardiovascular mortality.
Brenner, M Harvey
2016-02-01
Can we estimate the consequences of world military expenditures for the physical and mental health of nations that produce and purchase armaments? If anxiety and fear are promoting military expenditures, then those sentiments may well reflect poorer mental health and war-related stress as it influences cardiovascular illness rates. Further, extensive military expenditure by a society implies that other societal needs are allocated fewer resources, including nutrition, water and sanitation, health care, and economic development. We use a model focused on military expenditures to predict cardiovascular mortality in world samples of industrialized and developing countries over 2000-2011. The cardiovascular mortality model controls for economic development, smoking, body mass index, systolic blood pressure, and carbon dioxide emissions. Military expenditures as proportion of gross domestic product show significant positive relations to cardiovascular disease mortality in linear multiple regression analyses, using both cross-sectional and pooled cross-sectional time-series approaches.
Computer-aided-analysis of linear control system robustness
NASA Technical Reports Server (NTRS)
Stengel, Robert F.; Ray, Laura R.
1990-01-01
Stochastic robustness is a simple technique used to estimate the stability and performance robustness of linear, time-invariant systems. The use of high-speed graphics workstations and control system design software in stochastic robustness analysis is discussed and demonstrated. It is shown that stochastic robustness makes good use of modern computational and graphic tools, and it is easily implemented using commercial control system design and analysis software.
Stability analysis of linear fractional differential system with distributed delays
NASA Astrophysics Data System (ADS)
Veselinova, Magdalena; Kiskinov, Hristo; Zahariev, Andrey
2015-11-01
In the present work we study the Cauchy problem for linear incommensurate fractional differential system with distributed delays. For the autonomous case with distributed delays with derivatives in Riemann-Liouville or Caputo sense, we establish sufficient conditions under which the zero solution is globally asymptotic stable. The established conditions coincide with the conditions which guaranty the same result in the particular case of system with constant delays and for the case of system without delays in the commensurate case too.
Stabilization of linear distributed control systems with unbounded delay
NASA Astrophysics Data System (ADS)
Henríquez, Hernán R.; Hernández M., Eduardo
2005-07-01
In this paper we study the asymptotic stabilization of linear distributed parameter control systems with unbounded delay. Assuming that the semigroup of operators associated with the uncontrolled and nondelayed equation is compact and that the phase space is a uniform fading memory space, we characterize those systems that can be stabilized using a feedback control. As consequence we conclude that every system of this type is stabilizable with an appropriated finite dimensional control.
Colorized linear CCD data acquisition system with automatic exposure control
NASA Astrophysics Data System (ADS)
Li, Xiaofan; Sui, Xiubao
2014-11-01
Colorized linear cameras deliver superb color fidelity at the fastest line rates in the industrial inspection. It's RGB trilinear sensor eliminates image artifacts by placing a separate row of pixels for each color on a single sensor. It's advanced design minimizes distance between rows to minimize image artifacts due to synchronization. In this paper, the high-speed colorized linear CCD data acquisition system was designed take advantages of the linear CCD sensor μpd3728. The hardware and software design of the system based on FPGA is introduced and the design of the functional modules is performed. The all system is composed of CCD driver module, data buffering module, data processing module and computer interface module. The image data was transferred to computer by Camera link interface. The system which automatically adjusts the exposure time of linear CCD, is realized with a new method. The integral time of CCD can be controlled by the program. The method can automatically adjust the integration time for different illumination intensity under controlling of FPGA, and respond quickly to brightness changes. The data acquisition system is also offering programmable gains and offsets for each color. The quality of image can be improved after calibration in FPGA. The design has high expansibility and application value. It can be used in many application situations.
A linear distribution of orbits in compact planetary systems?
NASA Astrophysics Data System (ADS)
Migaszewski, Cezary; Goździewski, Krzysztof; Słonina, Mariusz
2013-11-01
We report a linear ordering of orbits in a sample of multiple extrasolar planetary systems with super-Earth planets. We selected 20 cases, mostly discovered by the Kepler mission, hosting at least four planets within ˜0.5 au. The semimajor axis an of an nth planet in each system of this sample obeys a(n) = a1 + (n - 1) Δa, where a1 is the semimajor axis of the innermost orbit and Δa is a spacing between subsequent planets, which are specific for a particular system. For instance, the Kepler-33 system hosting five super-Earth planets exhibits the relative deviations between the observed and linearly predicted semimajor axes of only a few per cent. At least half of systems in the sample fulfil the linear law with a similar accuracy. We explain the linear distribution of semimajor axes as a natural implication of multiple chains of mean-motion resonances between subsequent planets, which emerge due to planet-disc interactions and convergent migration at early stages of their evolution.
ERIC Educational Resources Information Center
DuCharme, Mike
2002-01-01
Discusses factors identified by educational facilities managers as critical to selecting roofing systems. Describes the recent trend toward considering energy conservation when selecting roofing materials. (EV)
Chapman, Michael J; Godfrey, Keith R; Chappell, Michael J; Evans, Neil D
2003-05-01
Under certain controllability and observability restrictions, two different parameterisations for a non-linear compartmental model can only have the same input-output behaviour if they differ by a locally diffeomorphic change of basis for the state space. With further restrictions, it is possible to gain valuable information with respect to identifiability via a linear analysis. Examples are presented where non-linear identifiability analyses are substantially simplified by means of an initial linear analysis. For complex models, with four or more compartments, this linear analysis can prove lengthy to perform by hand and so symbolic computation has been employed to aid this procedure.
Stabilising compensators for linear time-varying differential systems
NASA Astrophysics Data System (ADS)
Oberst, Ulrich
2016-04-01
In this paper, we describe a constructive test to decide whether a given linear time-varying (LTV) differential system admits a stabilising compensator for the control tasks of tracking, disturbance rejection or model matching and construct and parametrise all of them if at least one exists. In analogy to the linear time-invariant (LTI) case, the ring of stable rational functions, noncommutative in the LTV situation, and the Kučera-Youla parametrisation play prominent parts in the theory. We transfer Blumthaler's thesis from the LTI to the LTV case and sharpen, complete and simplify the corresponding results in the book 'Linear Time-Varying Systems' by Bourlès and Marinescu.
Experimental quantum computing to solve systems of linear equations.
Cai, X-D; Weedbrook, C; Su, Z-E; Chen, M-C; Gu, Mile; Zhu, M-J; Li, Li; Liu, Nai-Le; Lu, Chao-Yang; Pan, Jian-Wei
2013-06-07
Solving linear systems of equations is ubiquitous in all areas of science and engineering. With rapidly growing data sets, such a task can be intractable for classical computers, as the best known classical algorithms require a time proportional to the number of variables N. A recently proposed quantum algorithm shows that quantum computers could solve linear systems in a time scale of order log(N), giving an exponential speedup over classical computers. Here we realize the simplest instance of this algorithm, solving 2×2 linear equations for various input vectors on a quantum computer. We use four quantum bits and four controlled logic gates to implement every subroutine required, demonstrating the working principle of this algorithm.
Fluctuation loops in noise-driven linear dynamical systems
NASA Astrophysics Data System (ADS)
Ghanta, Akhil; Neu, John C.; Teitsworth, Stephen
2017-03-01
Understanding the spatiotemporal structure of most probable fluctuation pathways to rarely occurring states is a central problem in the study of noise-driven, nonequilibrium dynamical systems. When the underlying system does not possess detailed balance, the optimal fluctuation pathway to a particular state and relaxation pathway from that state may combine to form a looplike structure in the system phase space called a fluctuation loop. Here, fluctuation loops are studied in a linear circuit model consisting of coupled R C elements, where each element is driven by its own independent noise source. Using a stochastic Hamiltonian approach, we determine the optimal fluctuation pathways, and analytically construct corresponding fluctuation loops. To quantitatively characterize fluctuation loops, we study the time-dependent area tensor that is swept out by individual stochastic trajectories in the system phase space. At long times, the area tensor scales linearly with time, with a coefficient that precisely vanishes when the system satisfies detailed balance.
Linear monogamy of entanglement in three-qubit systems
NASA Astrophysics Data System (ADS)
Liu, Feng; Gao, Fei; Wen, Qiao-Yan
2015-11-01
For any three-qubit quantum systems ABC, Oliveira et al. numerically found that both the concurrence and the entanglement of formation (EoF) obey the linear monogamy relations in pure states. They also conjectured that the linear monogamy relations can be saturated when the focus qubit A is maximally entangled with the joint qubits BC. In this work, we prove analytically that both the concurrence and EoF obey linear monogamy relations in an arbitrary three-qubit state. Furthermore, we verify that all three-qubit pure states are maximally entangled in the bipartition A|BC when they saturate the linear monogamy relations. We also study the distribution of the concurrence and EoF. More specifically, when the amount of entanglement between A and B equals to that of A and C, we show that the sum of EoF itself saturates the linear monogamy relation, while the sum of the squared EoF is minimum. Different from EoF, the concurrence and the squared concurrence both saturate the linear monogamy relations when the entanglement between A and B equals to that of A and C.
State energy price and expenditure report 1994
1997-06-01
The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the United States. The price and expenditure estimates developed in the State Energy Price and Expenditure Data System (SEPEDS) are provided by energy source and economic sector and are published for the years 1970 through 1994. Consumption estimates used to calculate expenditures and the documentation for those estimates are taken from the State Energy Data Report 1994, Consumption Estimates (SEDR), published in October 1996. Expenditures are calculated by multiplying the price estimates by the consumption estimates, which are adjusted to remove process fuel; intermediate petroleum products; and other consumption that has no direct fuel costs, i.e., hydroelectric, geothermal, wind, solar, and photovoltaic energy sources. Documentation is included describing the development of price estimates, data sources, and calculation methods. 316 tabs.
Belkova, Yu A; Rachina, S A; Kozlov, R S; Mishchenko, V M; Pavlukov, R A; Abubakirova, A I; Berezhanskiy, B V; Eliseeva, E V; Zubareva, N A; Karpov, I A; Kopylova, I A; Palyutin, Sh Kh; Portnyagina, U S; Pribytkova, O V; Samuylo, E K
2016-01-01
The results of the systemic antimicrobials (AM) consumption and expenditures assessment in the departments of surgery of multi-profile hospitals in different regions of the Russian Federation and the Republic of Belarus in 2009-2010 based on retrospective collection and analysis of the data from the hospital expenditure notes using ATC/DDD methodology are presented. The average AM consumption and expenditure rates in the above mentioned departments varied from 24.9 DDD/100 bed-days to 61.7 DDD/100 bed-days depending on the department profile, with beta-lactams (cephalosporins and penicillins) share in the consumption being as high as 70-90%, followed by fluoroquinolones and aminoglycosides. Only 55-70% of the consumed AM belonged to the drugs of choice, whereas the improper AM consumption and expenditure rates amounted up to 10-18%. The study outputs can be used for the budget allocation and AM distribution improvement in the departments of surgery, as well as for the development and efficacy control of the local antimicrobial stewardship programs.
Recent Developments In Theory Of Balanced Linear Systems
NASA Technical Reports Server (NTRS)
Gawronski, Wodek
1994-01-01
Report presents theoretical study of some issues of controllability and observability of system represented by linear, time-invariant mathematical model of the form. x = Ax + Bu, y = Cx + Du, x(0) = xo where x is n-dimensional vector representing state of system; u is p-dimensional vector representing control input to system; y is q-dimensional vector representing output of system; n,p, and q are integers; x(0) is intial (zero-time) state vector; and set of matrices (A,B,C,D) said to constitute state-space representation of system.
Linear optimal control of continuous time chaotic systems.
Merat, Kaveh; Abbaszadeh Chekan, Jafar; Salarieh, Hassan; Alasty, Aria
2014-07-01
In this research study, chaos control of continuous time systems has been performed by using dynamic programming technique. In the first step by crossing the response orbits with a selected Poincare section and subsequently applying linear regression method, the continuous time system is converted to a discrete type. Then, by solving the Riccati equation a sub-optimal algorithm has been devised for the obtained discrete chaotic systems. In the next step, by implementing the acquired algorithm on the quantized continuous time system, the chaos has been suppressed in the Rossler and AFM systems as some case studies.
Stochastic Satbility and Performance Robustness of Linear Multivariable Systems
NASA Technical Reports Server (NTRS)
Ryan, Laurie E.; Stengel, Robert F.
1990-01-01
Stochastic robustness, a simple technique used to estimate the robustness of linear, time invariant systems, is applied to a single-link robot arm control system. Concepts behind stochastic stability robustness are extended to systems with estimators and to stochastic performance robustness. Stochastic performance robustness measures based on classical design specifications are introduced, and the relationship between stochastic robustness measures and control system design parameters are discussed. The application of stochastic performance robustness, and the relationship between performance objectives and design parameters are demonstrated by means of example. The results prove stochastic robustness to be a good overall robustness analysis method that can relate robustness characteristics to control system design parameters.
Recent Developments In Theory Of Balanced Linear Systems
NASA Technical Reports Server (NTRS)
Gawronski, Wodek
1994-01-01
Report presents theoretical study of some issues of controllability and observability of system represented by linear, time-invariant mathematical model of the form. x = Ax + Bu, y = Cx + Du, x(0) = xo where x is n-dimensional vector representing state of system; u is p-dimensional vector representing control input to system; y is q-dimensional vector representing output of system; n,p, and q are integers; x(0) is intial (zero-time) state vector; and set of matrices (A,B,C,D) said to constitute state-space representation of system.
Linear-constraint wavefront control for exoplanet coronagraphic imaging systems
NASA Astrophysics Data System (ADS)
Sun, He; Eldorado Riggs, A. J.; Kasdin, N. Jeremy; Vanderbei, Robert J.; Groff, Tyler Dean
2017-01-01
A coronagraph is a leading technology for achieving high-contrast imaging of exoplanets in a space telescope. It uses a system of several masks to modify the diffraction and achieve extremely high contrast in the image plane around target stars. However, coronagraphic imaging systems are very sensitive to optical aberrations, so wavefront correction using deformable mirrors (DMs) is necessary to avoid contrast degradation in the image plane. Electric field conjugation (EFC) and Stroke minimization (SM) are two primary high-contrast wavefront controllers explored in the past decade. EFC minimizes the average contrast in the search areas while regularizing the strength of the control inputs. Stroke minimization calculates the minimum DM commands under the constraint that a target average contrast is achieved. Recently in the High Contrast Imaging Lab at Princeton University (HCIL), a new linear-constraint wavefront controller based on stroke minimization was developed and demonstrated using numerical simulation. Instead of only constraining the average contrast over the entire search area, the new controller constrains the electric field of each single pixel using linear programming, which could led to significant increases in speed of the wavefront correction and also create more uniform dark holes. As a follow-up of this work, another linear-constraint controller modified from EFC is demonstrated theoretically and numerically and the lab verification of the linear-constraint controllers is reported. Based on the simulation and lab results, the pros and cons of linear-constraint controllers are carefully compared with EFC and stroke minimization.
Scalable Library for the Parallel Solution of Sparse Linear Systems
Jones, Mark; Plassmann, Paul E.
1993-07-14
BlockSolve is a scalable parallel software library for the solution of large sparse, symmetric systems of linear equations. It runs on a variety of parallel architectures and can easily be ported to others. BlockSovle is primarily intended for the solution of sparse linear systems that arise from physical problems having multiple degrees of freedom at each node point. For example, when the finite element method is used to solve practical problems in structural engineering, each node will typically have anywhere from 3-6 degrees of freedom associated with it. BlockSolve is written to take advantage of problems of this nature; however, it is still reasonably efficient for problems that have only one degree of freedom associated with each node, such as the three-dimensional Poisson problem. It does not require that the matrices have any particular structure other than being sparse and symmetric. BlockSolve is intended to be used within real application codes. It is designed to work best in the context of our experience which indicated that most application codes solve the same linear systems with several different right-hand sides and/or linear systems with the same structure, but different matrix values multiple times.
Robustness with observers. [linear optimal feedback control systems
NASA Technical Reports Server (NTRS)
Doyle, J. C.; Stein, G.
1979-01-01
The paper describes an adjustment procedure for observer-based linear control systems which asymptotically achieves the same loop transfer functions (and hence the same relative stability, robustness, and disturbance rejection properties) as full-state feedback control implementations. Full-state loop-transfer properties can be recovered asymptotically if the plant is minimum phase; this occurs at the expense of noise performance.
Generating Nice Linear Systems for Matrix Gaussian Elimination
ERIC Educational Resources Information Center
Homewood, L. James
2004-01-01
In this article an augmented matrix that represents a system of linear equations is called nice if a sequence of elementary row operations that reduces the matrix to row-echelon form, through matrix Gaussian elimination, does so by restricting all entries to integers in every step. Many instructors wish to use the example of matrix Gaussian…
Stabilization of linear multivariable systems by output feedback.
NASA Technical Reports Server (NTRS)
Mcbrinn, D. E.; Roy, R. J.
1972-01-01
A method is developed for improving the stability of linear multivariable systems using output feedback. The technique, which utilizes a gradient approach, has been mechanized in a digital computer program. Illustrative results are given for a seven-state two-feedback model of the Saturn V booster.
Optimal Regulator Algorithms For The Control Of Linear Systems (ORACLS)
NASA Technical Reports Server (NTRS)
Frisch, Harold P.
1990-01-01
Control theory design package offers engineer full range of subroutines to manipulate and solve Linear-Quadratic-Gaussian types of problems. ORACLS is rigorous tool, intended for multi-input and multi-output dynamic systems in both continuous and discrete form. Written in FORTRAN.
Comparative index and Sturmian theory for linear Hamiltonian systems
NASA Astrophysics Data System (ADS)
Šepitka, Peter; Šimon Hilscher, Roman
2017-01-01
The comparative index was introduced by J. Elyseeva (2007) as an efficient tool in matrix analysis, which has fundamental applications in the discrete oscillation theory. In this paper we implement the comparative index into the theory of continuous time linear Hamiltonian systems, study its properties, and apply it to obtain new Sturmian separation theorems as well as new and optimal estimates for left and right proper focal points of conjoined bases of these systems on bounded intervals. We derive our results for general possibly abnormal (or uncontrollable) linear Hamiltonian systems. The results turn out to be new even in the case of completely controllable systems. We also provide several examples, which illustrate our new theory.
Parallel/distributed direct method for solving linear systems
NASA Technical Reports Server (NTRS)
Lin, Avi
1990-01-01
A new family of parallel schemes for directly solving linear systems is presented and analyzed. It is shown that these schemes exhibit a near optimal performance and enjoy several important features: (1) For large enough linear systems, the design of the appropriate paralleled algorithm is insensitive to the number of processors as its performance grows monotonically with them; (2) It is especially good for large matrices, with dimensions large relative to the number of processors in the system; (3) It can be used in both distributed parallel computing environments and tightly coupled parallel computing systems; and (4) This set of algorithms can be mapped onto any parallel architecture without any major programming difficulties or algorithmical changes.
Design and performance of the Stanford Linear Collider Control System
Melen, R.E.
1984-10-01
The success of the Stanford Linear Collider (SLC) will be dependent upon the implementation of a very large advanced computer-based instrumentation and control system. This paper describes the architectural design of this system as well as a critique of its performance. This critique is based on experience obtained from its use in the control and monitoring of 1/3 of the SLAC linac and in support of an expensive experimental machine physics experimental program. 11 references, 3 figures.
Robust stability analysis of linear systems with parametric uncertainty
NASA Astrophysics Data System (ADS)
Zhai, Ding; Zhang, Qing-Ling; Liu, Guo-Yi
2012-09-01
This article is concerned with the problem of robust stability analysis of linear systems with uncertain parameters. By constructing an equivalent system with positive uncertain parameters and using the properties of these parameters, a new stability analysis condition is derived. Due to making use of the properties of uncertain parameters, the new proposed method has potential to give less conservative results than the existing approaches. A numerical example is given to illustrate the effectiveness of the proposed method.
A biased filter for linear discrete dynamic systems.
NASA Technical Reports Server (NTRS)
Chang, J. W.; Hoerl, A. E.; Leathrum, J. F.
1972-01-01
A recursive estimator, the ridge filter, was developed for the linear discrete dynamic estimation problem. Theorems were established to show that the ridge filter can be, on the average, closer to the expected value of the system state than the Kalman filter. On the other hand, Kalman filter, on the average, is closer to the instantaneous system state than the ridge filter. The ridge filter has been formulated in such a way that the computational features of the Kalman filter are preserved.
New timing system for the Stanford Linear Collider
Paffrath, L.; Bernstein, D.; Kang, H.; Koontz, R.; Leger, G.; Ross, M.; Pierce, W.; Wilmunder, A.
1984-11-01
In order to be able to meet the goals of the Stanford Linear Collider, a much more precise timing system had to be implemented. This paper describes the specification and design of this system, and the results obtained from its use on 1/3 of the SLAC linac. The functions of various elements are described, and a programmable delay unit (PDU) is described in detail.
Active Control of Linear Periodic System with Two Unstable Modes.
1982-12-01
tV;;;.~II.~9 - B ~ZV ~- p1 . ,,~ >. ~ ACTIVE CONTROL OF LINEAR PERIODIC SYSTEM WITH TWO UNSTABLE MODES THESIS by Gregory E. Myers, B.S.E. 2nd Lt...PERIODIC SYSTEM WITH TWO UNSTABLE MODES THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology Air University...December 1982 Approved for public release; distribution unlimited -ow PREFACE This thesis is a continuation of the work done by Yeakel in the control of
Robust fault detection observer design for linear uncertain systems
NASA Astrophysics Data System (ADS)
Wei, Xiukun; Verhaegen, Michel
2011-01-01
This article addresses the fault detection observer design issue for linear time invariant (LTI) systems with additive or multiplicative uncertainties, which are also subject to unknown disturbances. The observer design is investigated under the ℋ∞/ℋ- index framework using the generalised KYP lemma in the finite-frequency domain. Sufficient conditions for the existence of such a fault detection observer are given in terms of linear matrix inequalities (LMIs). The threshold design issue is discussed and a method for estimating the worst undetectable fault size is proposed. The effectiveness of the proposed algorithms is illustrated by numerical simulation examples.
Identification of single-input-single-output quantum linear systems
NASA Astrophysics Data System (ADS)
Levitt, Matthew; GuÅ£ǎ, Mǎdǎlin
2017-03-01
The purpose of this paper is to investigate system identification for single-input-single-output general (active or passive) quantum linear systems. For a given input we address the following questions: (1) Which parameters can be identified by measuring the output? (2) How can we construct a system realization from sufficient input-output data? We show that for time-dependent inputs, the systems which cannot be distinguished are related by symplectic transformations acting on the space of system modes. This complements a previous result of Guţă and Yamamoto [IEEE Trans. Autom. Control 61, 921 (2016), 10.1109/TAC.2015.2448491] for passive linear systems. In the regime of stationary quantum noise input, the output is completely determined by the power spectrum. We define the notion of global minimality for a given power spectrum, and characterize globally minimal systems as those with a fully mixed stationary state. We show that in the case of systems with a cascade realization, the power spectrum completely fixes the transfer function, so the system can be identified up to a symplectic transformation. We give a method for constructing a globally minimal subsystem direct from the power spectrum. Restricting to passive systems the analysis simplifies so that identifiability may be completely understood from the eigenvalues of a particular system matrix.
Capital cost expenditure of high temperature latent and sensible thermal energy storage systems
NASA Astrophysics Data System (ADS)
Jacob, Rhys; Saman, Wasim; Bruno, Frank
2017-06-01
In the following study cost estimates have been undertaken for an encapsulated phase change material (EPCM) packed bed, a packed bed thermocline and a traditional two-tank molten salt system. The effect of various heat transfer fluids (air and molten salt), system configuration (cascade vs one PCM, and direct vs indirect) and temperature difference (ΔT = 100-500 °C) on the cost estimate of the system was also investigated. Lastly, the storage system boundary was expanded to include heat exchangers, pumps and fans, and heat tracing so that a thorough cost comparison could be undertaken. The results presented in this paper provide a methodology to quickly compare various systems and configurations while providing design limits for the studied technologies.
Solving complex-valued linear systems via equivalent real formulations
DAY,DAVID M.; HEROUX,MICHAEL A.
2000-05-22
Most algorithms used in preconditioned iterative methods are generally applicable to complex valued linear systems, with real valued linear systems simply being a special case. However, most iterative solver packages available today focus exclusively on real valued systems, or deal with complex valued systems as an afterthought. One obvious approach to addressing this problem is to recast the complex problem into one of a several equivalent real forms and then use a real valued solver to solve the related system. However, well-known theoretical results showing unfavorable spectral properties for the equivalent real forms have diminished enthusiasm for this approach. At the same time, experience has shown that there are situations where using an equivalent real form can be very effective. In this paper, the authors explore this approach, giving both theoretical and experimental evidence that an equivalent real form can be useful for a number of practical situations. Furthermore, they show that by making good use of some of the advance features of modem solver packages, they can easily generate equivalent real form preconditioners that are computationally efficient and mathematically identical to their complex counterparts. Using their techniques, they are able to solve very ill-conditioned complex valued linear systems for a variety of large scale applications. However, more importantly, they shed more light on the effectiveness of equivalent real forms and more clearly delineate how and when they should be used.
Optimum Damping in a Non-Linear Base Isolation System
NASA Astrophysics Data System (ADS)
Jangid, R. S.
1996-02-01
Optimum isolation damping for minimum acceleration of a base-isolated structure subjected to earthquake ground excitation is investigated. The stochastic model of the El-Centro1940 earthquake, which preserves the non-stationary evolution of amplitude and frequency content of ground motion, is used as an earthquake excitation. The base isolated structure consists of a linear flexible shear type multi-storey building supported on a base isolation system. The resilient-friction base isolator (R-FBI) is considered as an isolation system. The non-stationary stochastic response of the system is obtained by the time dependent equivalent linearization technique as the force-deformation of the R-FBI system is non-linear. The optimum damping of the R-FBI system is obtained under important parametric variations; i.e., the coefficient of friction of the R-FBI system, the period and damping of the superstructure; the effective period of base isolation. The criterion selected for optimality is the minimization of the top floor root mean square (r.m.s.) acceleration. It is shown that the above parameters have significant effects on optimum isolation damping.
String Stability of a Linear Formation Flight Control System
NASA Technical Reports Server (NTRS)
Allen, Michael J.; Ryan, Jack; Hanson, Curtis E.; Parle, James F.
2002-01-01
String stability analysis of an autonomous formation flight system was performed using linear and nonlinear simulations. String stability is a measure of how position errors propagate from one vehicle to another in a cascaded system. In the formation flight system considered here, each i(sup th) aircraft uses information from itself and the preceding ((i-1)(sup th)) aircraft to track a commanded relative position. A possible solution for meeting performance requirements with such a system is to allow string instability. This paper explores two results of string instability and outlines analysis techniques for string unstable systems. The three analysis techniques presented here are: linear, nonlinear formation performance, and ride quality. The linear technique was developed from a worst-case scenario and could be applied to the design of a string unstable controller. The nonlinear formation performance and ride quality analysis techniques both use nonlinear formation simulation. Three of the four formation-controller gain-sets analyzed in this paper were limited more by ride quality than by performance. Formations of up to seven aircraft in a cascaded formation could be used in the presence of light gusts with this string unstable system.
Identification and robust control of linear parameter-varying systems
NASA Astrophysics Data System (ADS)
Lee, Lawton Hubert
This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear
An approximation theory for the identification of linear thermoelastic systems
NASA Technical Reports Server (NTRS)
Rosen, I. G.; Su, Chien-Hua Frank
1990-01-01
An abstract approximation framework and convergence theory for the identification of thermoelastic systems is developed. Starting from an abstract operator formulation consisting of a coupled second order hyperbolic equation of elasticity and first order parabolic equation for heat conduction, well-posedness is established using linear semigroup theory in Hilbert space, and a class of parameter estimation problems is then defined involving mild solutions. The approximation framework is based upon generic Galerkin approximation of the mild solutions, and convergence of solutions of the resulting sequence of approximating finite dimensional parameter identification problems to a solution of the original infinite dimensional inverse problem is established using approximation results for operator semigroups. An example involving the basic equations of one dimensional linear thermoelasticity and a linear spline based scheme are discussed. Numerical results indicate how the approach might be used in a study of damping mechanisms in flexible structures.
Vacuum systems of linear accelerators of the NICA injection complex
NASA Astrophysics Data System (ADS)
Kosachev, V. V.; Bazanov, A. M.; Butenko, A. V.; Galimov, A. R.; Nesterov, A. V.; Pivin, R. V.; Smirnov, A. V.
2016-12-01
The NICA project, which includes several accelerators of charged particles, is under construction in the Laboratory of High Energy Physics, Joint Institute for Nuclear Research (JINR), Dubna. Obtaining the required vacuum conditions is one of the key points in implementing the project, because reaching the required ion lifetime at all stages of particle acceleration is what determines the effective luminosity of the experiments in the long run. Currently, modernization of the vacuum system of the injection complex of the LU-20 linear accelerator of light ions, one of oldest accelerators in the JINR, is being carried out and the new HILAC linear accelerator for the acceleration of gold ions in the collider mode of the NICA complex is being installed. At the end parts of the linear accelerators, the residual gas pressure must be approximately 10-5 Pa, which is determined by the maximum amplitude of the RF electric field used for the acceleration of ions.
Breidahl, Tomas; Christensen, Michael; Jepsen, Jørgen Riis; Omland, Øyvind
2015-01-01
Previous studies of professional fishing activities have indicated that vessel movements correlate to fishermen's energy expenditure. We have previously demonstrated that even in calm weather, the heel and pitch significantly increase the fishermen's energy expenditure, ignoring the activities carried out on board. This continuation of the study goes further by exploring the relation between the exposure to the ship's movements and the fishermen's energy expenditure during various physical activities on board. Four fishermen on 2 contemporary steel trawlers recorded their work activities on an hourly basis during a 4 days fishing voyage. The energy expenditure was estimated with a body monitoring system (SenseWear Pro 3) carried as an armband, placed on the right upper arm. The vessels' movements were assessed by a gyroscope placed in the wheelhouse. The additional energy expenditure relative to the energy expenditure during sleep was recorded during activities such as navigation, fishing, and machine handling and was correlated to the vessels' recorded movements (pitch/roll). Data were analysed by linear regression. Roll and pitch were less than 10o for both vessels during the voyages. The fishermen's energy expenditure differed with the tasks undertaken and correlated with the vessels' movements, but for navigation and fishing the correlation was only significant in the highest - fourth quartile of - pitch/roll. This study has demonstrated that vessel's movements in calm weather increase the energy expenditure during navigation, fishing, and machine handling and that the relation differs in between these activities on board and rest.
Preconditioning projection methods for solving algebraic linear systems
NASA Astrophysics Data System (ADS)
García-Palomares, Ubaldo
1999-09-01
Numerical experiments have shown that projection methods are robust for solving the problem of finding a point satisfying a linear system of n variables and m equations; however, their qualities of convergence depend on certain parameters: an n n symmetric positive definite matrix M, and a vector u with m components. We are concerned here with the choice of M. Through a link with Conjugate Gradient methods we determine an expedient M. Preliminary numerical results on a hard 3D partial differential equation are highly promising. We solve a discretized system that could not be solved by conventional methods. We also give hints on how to adapt our findings to the solution of a linear system of inequalities. This is the first stage of a forthcoming research.
Applications of equivalent linearization approaches to nonlinear piping systems
Park, Y.; Hofmayer, C.; Chokshi, N.
1997-04-01
The piping systems in nuclear power plants, even with conventional snubber supports, are highly complex nonlinear structures under severe earthquake loadings mainly due to various mechanical gaps in support structures. Some type of nonlinear analysis is necessary to accurately predict the piping responses under earthquake loadings. The application of equivalent linearization approaches (ELA) to seismic analyses of nonlinear piping systems is presented. Two types of ELA`s are studied; i.e., one based on the response spectrum method and the other based on the linear random vibration theory. The test results of main steam and feedwater piping systems supported by snubbers and energy absorbers are used to evaluate the numerical accuracy and limitations.
A parallel solver for huge dense linear systems
NASA Astrophysics Data System (ADS)
Badia, J. M.; Movilla, J. L.; Climente, J. I.; Castillo, M.; Marqués, M.; Mayo, R.; Quintana-Ortí, E. S.; Planelles, J.
2011-11-01
HDSS (Huge Dense Linear System Solver) is a Fortran Application Programming Interface (API) to facilitate the parallel solution of very large dense systems to scientists and engineers. The API makes use of parallelism to yield an efficient solution of the systems on a wide range of parallel platforms, from clusters of processors to massively parallel multiprocessors. It exploits out-of-core strategies to leverage the secondary memory in order to solve huge linear systems O(100.000). The API is based on the parallel linear algebra library PLAPACK, and on its Out-Of-Core (OOC) extension POOCLAPACK. Both PLAPACK and POOCLAPACK use the Message Passing Interface (MPI) as the communication layer and BLAS to perform the local matrix operations. The API provides a friendly interface to the users, hiding almost all the technical aspects related to the parallel execution of the code and the use of the secondary memory to solve the systems. In particular, the API can automatically select the best way to store and solve the systems, depending of the dimension of the system, the number of processes and the main memory of the platform. Experimental results on several parallel platforms report high performance, reaching more than 1 TFLOP with 64 cores to solve a system with more than 200 000 equations and more than 10 000 right-hand side vectors. New version program summaryProgram title: Huge Dense System Solver (HDSS) Catalogue identifier: AEHU_v1_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHU_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 87 062 No. of bytes in distributed program, including test data, etc.: 1 069 110 Distribution format: tar.gz Programming language: Fortran90, C Computer: Parallel architectures: multiprocessors, computer clusters Operating system
Galerkin projection methods for solving multiple related linear systems
Chan, T.F.; Ng, M.; Wan, W.L.
1996-12-31
We consider using Galerkin projection methods for solving multiple related linear systems A{sup (i)}x{sup (i)} = b{sup (i)} for 1 {le} i {le} s, where A{sup (i)} and b{sup (i)} are different in general. We start with the special case where A{sup (i)} = A and A is symmetric positive definite. The method generates a Krylov subspace from a set of direction vectors obtained by solving one of the systems, called the seed system, by the CG method and then projects the residuals of other systems orthogonally onto the generated Krylov subspace to get the approximate solutions. The whole process is repeated with another unsolved system as a seed until all the systems are solved. We observe in practice a super-convergence behaviour of the CG process of the seed system when compared with the usual CG process. We also observe that only a small number of restarts is required to solve all the systems if the right-hand sides are close to each other. These two features together make the method particularly effective. In this talk, we give theoretical proof to justify these observations. Furthermore, we combine the advantages of this method and the block CG method and propose a block extension of this single seed method. The above procedure can actually be modified for solving multiple linear systems A{sup (i)}x{sup (i)} = b{sup (i)}, where A{sup (i)} are now different. We can also extend the previous analytical results to this more general case. Applications of this method to multiple related linear systems arising from image restoration and recursive least squares computations are considered as examples.
Costa, Silvia; Ogilvie, David; Dalton, Alice; Westgate, Kate; Brage, Søren; Panter, Jenna
2015-01-01
Background Active commuting may help to increase adults' physical activity levels. However, estimates of its energy cost are derived from a small number of studies which are laboratory-based or use self-reported measures. Methods Adults working in Cambridge (UK) recruited through a predominantly workplace-based strategy wore combined heart rate and movement sensors and global positioning system (GPS) devices for one week, and completed synchronous day-by-day travel diaries in 2010 and 2011. Commuting journeys were delineated using GPS data, and metabolic intensity (standard metabolic equivalents; MET) was derived and compared between journey types using mixed-effects linear regression. Results 182 commuting journeys were included in the analysis. Median intensity was 1.28 MET for car journeys; 1.67 MET for bus journeys; 4.61 MET for walking journeys; 6.44 MET for cycling journeys; 1.78 MET for journeys made by car in combination with walking; and 2.21 MET for journeys made by car in combination with cycling. The value for journeys made solely by car was significantly lower than those for all other journey types (p < 0.04). On average, 20% of the duration of journeys incorporating any active travel (equating to 8 min) was spent in moderate-to-vigorous physical activity (MVPA). Conclusions We have demonstrated how GPS and activity data from a free-living sample can be used simultaneously to provide objective estimates of commuting energy expenditure. On average, incorporating walking or cycling into longer journeys provided over half the weekly recommended activity levels from the commute alone. This may be an efficient way of achieving physical activity guidelines and improving population health. PMID:26441297
Chaos pass filter: linear response of synchronized chaotic systems.
Zeeb, Steffen; Kestler, Johannes; Kanter, Ido; Kinzel, Wolfgang
2013-04-01
The linear response of synchronized time-delayed chaotic systems to small external perturbations, i.e., the phenomenon of chaos pass filter, is investigated for iterated maps. The distribution of distances, i.e., the deviations between two synchronized chaotic units due to external perturbations on the transferred signal, is used as a measure of the linear response. It is calculated numerically and, for some special cases, analytically. Depending on the model parameters this distribution has power law tails in the region of synchronization leading to diverging moments of distances. This is a consequence of multiplicative and additive noise in the corresponding linear equations due to chaos and external perturbations. The linear response can also be quantified by the bit error rate of a transmitted binary message which perturbs the synchronized system. The bit error rate is given by an integral over the distribution of distances and is calculated analytically and numerically. It displays a complex nonmonotonic behavior in the region of synchronization. For special cases the distribution of distances has a fractal structure leading to a devil's staircase for the bit error rate as a function of coupling strength. The response to small harmonic perturbations shows resonances related to coupling and feedback delay times. A bidirectionally coupled chain of three units can completely filter out the perturbation. Thus the second moment and the bit error rate become zero.
48 CFR 47.403-3 - Disallowance of expenditures.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Disallowance of expenditures. 47.403-3 Section 47.403-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... expenditures. (a) Agencies shall disallow expenditures for U.S. Government-financed commercial international...
48 CFR 47.403-3 - Disallowance of expenditures.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Disallowance of expenditures. 47.403-3 Section 47.403-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... expenditures. (a) Agencies shall disallow expenditures for U.S. Government-financed commercial international...
48 CFR 47.403-3 - Disallowance of expenditures.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Disallowance of expenditures. 47.403-3 Section 47.403-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... expenditures. (a) Agencies shall disallow expenditures for U.S. Government-financed commercial international...
48 CFR 47.403-3 - Disallowance of expenditures.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Disallowance of expenditures. 47.403-3 Section 47.403-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... expenditures. (a) Agencies shall disallow expenditures for U.S. Government-financed commercial international...
48 CFR 47.403-3 - Disallowance of expenditures.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Disallowance of expenditures. 47.403-3 Section 47.403-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... expenditures. (a) Agencies shall disallow expenditures for U.S. Government-financed commercial...
An extended GS method for dense linear systems
NASA Astrophysics Data System (ADS)
Niki, Hiroshi; Kohno, Toshiyuki; Abe, Kuniyoshi
2009-09-01
Davey and Rosindale [K. Davey, I. Rosindale, An iterative solution scheme for systems of boundary element equations, Internat. J. Numer. Methods Engrg. 37 (1994) 1399-1411] derived the GSOR method, which uses an upper triangular matrix [Omega] in order to solve dense linear systems. By applying functional analysis, the authors presented an expression for the optimum [Omega]. Moreover, Davey and Bounds [K. Davey, S. Bounds, A generalized SOR method for dense linear systems of boundary element equations, SIAM J. Comput. 19 (1998) 953-967] also introduced further interesting results. In this note, we employ a matrix analysis approach to investigate these schemes, and derive theorems that compare these schemes with existing preconditioners for dense linear systems. We show that the convergence rate of the Gauss-Seidel method with preconditioner PG is superior to that of the GSOR method. Moreover, we define some splittings associated with the iterative schemes. Some numerical examples are reported to confirm the theoretical analysis. We show that the EGS method with preconditioner produces an extremely small spectral radius in comparison with the other schemes considered.
Coherent versus Measurement Feedback: Linear Systems Theory for Quantum Information
NASA Astrophysics Data System (ADS)
Yamamoto, Naoki
2014-10-01
To control a quantum system via feedback, we generally have two options in choosing a control scheme. One is the coherent feedback, which feeds the output field of the system, through a fully quantum device, back to manipulate the system without involving any measurement process. The other one is measurement-based feedback, which measures the output field and performs a real-time manipulation on the system based on the measurement results. Both schemes have advantages and disadvantages, depending on the system and the control goal; hence, their comparison in several situations is important. This paper considers a general open linear quantum system with the following specific control goals: backaction evasion, generation of a quantum nondemolished variable, and generation of a decoherence-free subsystem, all of which have important roles in quantum information science. Some no-go theorems are proven, clarifying that those goals cannot be achieved by any measurement-based feedback control. On the other hand, it is shown that, for each control goal there exists a coherent feedback controller accomplishing the task. The key idea to obtain all the results is system theoretic characterizations of the above three notions in terms of controllability and observability properties or transfer functions of linear systems, which are consistent with their standard definitions.
The new control system of the Saclay Linear Accelerator
Gournay, J.F.; Garreau, F.; Giraud, A.; Gourcy, G.; Rouault, J.
1985-10-01
A new control system for the Saclay Linear Accelerator is now being designed. The computer control architecture is based on 3 dedicated VME crates with MC68000 micro-processors : one crate with a disk-based operating system will run the high level application programs and the data base management facilities, another one will manage the man-machine communications and the third one will interface the system to the linac equipments. Communications between the VME microcomputers will be done through 16 bit parallel links. The software is modular and organized in specific layers, the data base is fully distributed. About 90% of the code is written in Fortran.
Essential uncontrollability of discrete linear, time-invariant, dynamical systems
NASA Technical Reports Server (NTRS)
Cliff, E. M.
1975-01-01
The concept of a 'best approximating m-dimensional subspace' for a given set of vectors in n-dimensional whole space is introduced. Such a subspace is easily described in terms of the eigenvectors of an associated Gram matrix. This technique is used to approximate an achievable set for a discrete linear time-invariant dynamical system. This approximation characterizes the part of the state space that may be reached using modest levels of control. If the achievable set can be closely approximated by a proper subspace of the whole space then the system is 'essentially uncontrollable'. The notion finds application in studies of failure-tolerant systems, and in decoupling.
Steady-state decoupling and design of linear multivariable systems
NASA Technical Reports Server (NTRS)
Thaler, G. J.
1974-01-01
A constructive criterion for decoupling the steady states of a linear time-invariant multivariable system is presented. This criterion consists of a set of inequalities which, when satisfied, will cause the steady states of a system to be decoupled. Stability analysis and a new design technique for such systems are given. A new and simple connection between single-loop and multivariable cases is found. These results are then applied to the compensation design for NASA STOL C-8A aircraft. Both steady-state decoupling and stability are justified through computer simulations.
Solving Systems of Linear Equations with a Superconducting Quantum Processor
NASA Astrophysics Data System (ADS)
Zheng, Yarui; Song, Chao; Chen, Ming-Cheng; Xia, Benxiang; Liu, Wuxin; Guo, Qiujiang; Zhang, Libo; Xu, Da; Deng, Hui; Huang, Keqiang; Wu, Yulin; Yan, Zhiguang; Zheng, Dongning; Lu, Li; Pan, Jian-Wei; Wang, H.; Lu, Chao-Yang; Zhu, Xiaobo
2017-05-01
Superconducting quantum circuits are a promising candidate for building scalable quantum computers. Here, we use a four-qubit superconducting quantum processor to solve a two-dimensional system of linear equations based on a quantum algorithm proposed by Harrow, Hassidim, and Lloyd [Phys. Rev. Lett. 103, 150502 (2009), 10.1103/PhysRevLett.103.150502], which promises an exponential speedup over classical algorithms under certain circumstances. We benchmark the solver with quantum inputs and outputs, and characterize it by nontrace-preserving quantum process tomography, which yields a process fidelity of 0.837 ±0.006 . Our results highlight the potential of superconducting quantum circuits for applications in solving large-scale linear systems, a ubiquitous task in science and engineering.
SSNN toolbox for non-linear system identification
NASA Astrophysics Data System (ADS)
Luzar, Marcel; Czajkowski, Andrzej
2015-11-01
The aim of this paper is to develop and design a State Space Neural Network toolbox for a non-linear system identification with an artificial state-space neural networks, which can be used in a model-based robust fault diagnosis and control. Such toolbox is implemented in the MATLAB environment and it uses some of its predefined functions. It is designed in the way that any non-linear multi-input multi-output system is identified and represented in the classical state-space form. The novelty of the proposed approach is that the final result of the identification process is the state, input and output matrices, not only the neural network parameters. Moreover, the toolbox is equipped with the graphical user interface, which makes it useful for the users not familiar with the neural networks theory.
Solving Systems of Linear Equations with a Superconducting Quantum Processor.
Zheng, Yarui; Song, Chao; Chen, Ming-Cheng; Xia, Benxiang; Liu, Wuxin; Guo, Qiujiang; Zhang, Libo; Xu, Da; Deng, Hui; Huang, Keqiang; Wu, Yulin; Yan, Zhiguang; Zheng, Dongning; Lu, Li; Pan, Jian-Wei; Wang, H; Lu, Chao-Yang; Zhu, Xiaobo
2017-05-26
Superconducting quantum circuits are a promising candidate for building scalable quantum computers. Here, we use a four-qubit superconducting quantum processor to solve a two-dimensional system of linear equations based on a quantum algorithm proposed by Harrow, Hassidim, and Lloyd [Phys. Rev. Lett. 103, 150502 (2009)PRLTAO0031-900710.1103/PhysRevLett.103.150502], which promises an exponential speedup over classical algorithms under certain circumstances. We benchmark the solver with quantum inputs and outputs, and characterize it by nontrace-preserving quantum process tomography, which yields a process fidelity of 0.837±0.006. Our results highlight the potential of superconducting quantum circuits for applications in solving large-scale linear systems, a ubiquitous task in science and engineering.
Ultra-Precision Linear Actuator for optical systems
NASA Astrophysics Data System (ADS)
Nalbandian, Ruben
2000-10-01
The Ultra-Precision Linear Actuator presented in this paper was developed for the Next Generation Space Telescopes' (NGST) primary mirror surface figure control. The development was a joint effort between Alson E. Hatheway, Inc (AEH) and Moog, Schaeffer Magnetics Division (SMD). The goal of this project was to demonstrate an extremely light weight, relatively high stiffness actuator capable of operating uniformly well over the range of 2- degree(s)K to 300 degree(s)K and achieving diffraction-limited performance (+/- 10 nm) in the optical band for weeks at a time, while consuming no electrical power and dissipating no heat. The essence of the design challenge was to develop a lightweight, high stiffness, low power, thermally stable linear positioning mechanism. Actuation systems with resolutions comparable to that of this design normally are operated in a closed-loop control system to compensate for any non-linearities and hysteresis inherent in their enabling technologies, such as piezoelectric and magnetostrictive transducers. These technologies require continuous application of power and therefore are not low power consumption devices. The development challenge was met through the use of Alson E. Hatheway's (AEH) patented Rubicontm elastic transducer which consists of two elastic elements; a soft spring and a stiff flexural member. Deflection of the soft spring applies a force input to the stiff flexure, which responds with a proportionally reduced output deflection. To maintain linearity, the displacements, and hence the stresses, developed in both elastic members are kept well below the elastic yield strength of the material. The AEH transducer is inherently linear and hysteresis free.
A multi-level method for sparse linear systems
Shapira, Y.
1997-09-01
A multi-level method for the solution of sparse linear systems is introduced. The definition of the method is based on data from the coefficient matrix alone. An upper bound for the condition number is available for certain symmetric positive definite (SPD) problems. Numerical experiments confirm the analysis and illustrate the efficiency of the method for diffusion problems with discontinuous coefficients with discontinuities which are not aligned with the coarse meshes.
Linear Quantum Systems: Non-Classical States and Robust Stability
2016-06-29
basic importance to develop analysis and design methods that take uncertainty into account. Specifically, in the area of robust control for linear...show that the series product, which serves as an algebraic rule for connecting state-based input–output systems, is intimately related to the...Approved for public release: distribution unlimited. 7 commutation and anticommutation relations of the underlying algebra SU(n). Refereed Conference
Linear Quantum Systems: Non-Classical States and Robust Stability
2016-06-29
basic importance to develop analysis and design methods that take uncertainty into account. Specifically, in the area of robust control for linear...We show that the series product, which serves as an algebraic rule for connecting state-based input–output systems, is intimately related to the...Approved for public release: distribution unlimited. 7 commutation and anticommutation relations of the underlying algebra SU(n). Refereed
A Constraint Generation Approach to Learning Stable Linear Dynamical Systems
2008-01-01
and † denotes the Moore - Penrose inverse . Eq. (3) asks Â to minimize the error in predicting the state at time t + 1 from the state at time t. Given...A Constraint Generation Approach to Learning Stable Linear Dynamical Systems Sajid M. Siddiqi Byron Boots Geoffrey J. Gordon January 2008...REPORT DATE JAN 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE A Constraint Generation Approach to Learning
Total Dose Effects on Error Rates in Linear Bipolar Systems
NASA Technical Reports Server (NTRS)
Buchner, Stephen; McMorrow, Dale; Bernard, Muriel; Roche, Nicholas; Dusseau, Laurent
2007-01-01
The shapes of single event transients in linear bipolar circuits are distorted by exposure to total ionizing dose radiation. Some transients become broader and others become narrower. Such distortions may affect SET system error rates in a radiation environment. If the transients are broadened by TID, the error rate could increase during the course of a mission, a possibility that has implications for hardness assurance.
AZTEC: A parallel iterative package for the solving linear systems
Hutchinson, S.A.; Shadid, J.N.; Tuminaro, R.S.
1996-12-31
We describe a parallel linear system package, AZTEC. The package incorporates a number of parallel iterative methods (e.g. GMRES, biCGSTAB, CGS, TFQMR) and preconditioners (e.g. Jacobi, Gauss-Seidel, polynomial, domain decomposition with LU or ILU within subdomains). Additionally, AZTEC allows for the reuse of previous preconditioning factorizations within Newton schemes for nonlinear methods. Currently, a number of different users are using this package to solve a variety of PDE applications.
Method of Conjugate Radii for Solving Linear and Nonlinear Systems
NASA Technical Reports Server (NTRS)
Nachtsheim, Philip R.
1999-01-01
This paper describes a method to solve a system of N linear equations in N steps. A quadratic form is developed involving the sum of the squares of the residuals of the equations. Equating the quadratic form to a constant yields a surface which is an ellipsoid. For different constants, a family of similar ellipsoids can be generated. Starting at an arbitrary point an orthogonal basis is constructed and the center of the family of similar ellipsoids is found in this basis by a sequence of projections. The coordinates of the center in this basis are the solution of linear system of equations. A quadratic form in N variables requires N projections. That is, the current method is an exact method. It is shown that the sequence of projections is equivalent to a special case of the Gram-Schmidt orthogonalization process. The current method enjoys an advantage not shared by the classic Method of Conjugate Gradients. The current method can be extended to nonlinear systems without modification. For nonlinear equations the Method of Conjugate Gradients has to be augmented with a line-search procedure. Results for linear and nonlinear problems are presented.
State feedback control of switched linear systems: An LMI approach
NASA Astrophysics Data System (ADS)
Montagner, V. F.; Leite, V. J. S.; Oliveira, R. C. L. F.; Peres, P. L. D.
2006-10-01
This paper addresses the problem of state feedback control of continuous-time switched linear systems with arbitrary switching rules. A quadratic Lyapunov function with a common matrix is used to derive a stabilizing switching control strategy that guarantees: (i) the assignment of all the eigenvalues of each linear subsystem inside a chosen circle in the left-hand half of the complex plane; (ii) a minimum disturbance attenuation level for the closed-loop switched system. The proposed design conditions are given in terms of linear matrix inequalities that encompass previous results based on quadratic stability conditions with fixed control gains. Although the quadratic stability based on a fixed Lyapunov matrix has been widely used in robust control design, the use of this condition to provide a convex design method for switching feedback gains has not been fully investigated. Numerical examples show that the switching control strategy can cope with more stringent design specifications than the fixed gain strategy, being useful to improve the performance of this class of systems.
A high linearity downconverter for digital broadcasting system
NASA Astrophysics Data System (ADS)
Songting, Li; Jiancheng, Li; Xiaochen, Gu; Hongyi, Wang; Zhaowen, Zhuang
2014-12-01
An integrated downconverter with high linearity for digital broadcasting system receivers is implemented in a 0.13 μm CMOS process with an active area of 0.1 mm2. The current-mode scheme is adopted to improve linearity performance by avoiding voltage fluctuation. A passive CMOS switching pair is utilized to improve the even-order linearity of the downconverter. A current amplifier is used to provide low input impedance which will easily lead to a wide operating bandwidth and high linearity. Moreover, a current-mode Sallen-Key low-pass filter is adopted for effective rejection of out-of-band interferers and also low input impedance. The digital-assisted DC offset calibration improves the second-order distortion of the downconverter. This design achieves a maximum gain of 40 dB and a dynamic range of 10 dB. Measured noise figure is 8.2 dB, an IIP2 of 63 dBm, an IIP3 of 17 dBm at the minimum gain of 30 dB. The downconverter consumes about 7.7 mA under a supply of 1.2 V.
Dong, Bo; Biswas, Subir; Montoye, Alexander; Pfeiffer, Karin
2014-01-01
This paper presents the implementation details, system architecture and performance of a wearable sensor network that was designed for human activity recognition and energy expenditure estimation. We also included ActiGraph GT3X+ as a popular single sensor solution for detailed comparison with the proposed wearable sensor network. Linear regression and Artificial Neural Network are implemented and tested. Through a rigorous system study and experiment, it is shown that the wearable multi-sensor network outperforms the single sensor solution in terms of energy expenditure estimation. PMID:24110325
Some generalisations of linear-graph modelling for dynamic systems
NASA Astrophysics Data System (ADS)
de Silva, Clarence W.; Pourazadi, Shahram
2013-11-01
Proper modelling of a dynamic system can benefit analysis, simulation, design, evaluation and control of the system. The linear-graph (LG) approach is suitable for modelling lumped-parameter dynamic systems. By using the concepts of graph trees, it provides a graphical representation of the system, with a direct correspondence to the physical component topology. This paper systematically extends the application of LGs to multi-domain (mixed-domain or multi-physics) dynamic systems by presenting a unified way to represent different domains - mechanical, electrical, thermal and fluid. Preservation of the structural correspondence across domains is a particular advantage of LGs when modelling mixed-domain systems. The generalisation of Thevenin and Norton equivalent circuits to mixed-domain systems, using LGs, is presented. The structure of an LG model may follow a specific pattern. Vector LGs are introduced to take advantage of such patterns, giving a general LG representation for them. Through these vector LGs, the model representation becomes simpler and rather compact, both topologically and parametrically. A new single LG element is defined to facilitate the modelling of distributed-parameter (DP) systems. Examples are presented using multi-domain systems (a motion-control system and a flow-controlled pump), a multi-body mechanical system (robot manipulator) and DP systems (structural rods) to illustrate the application and advantages of the methodologies developed in the paper.
A survey of packages for large linear systems
Wu, Kesheng; Milne, Brent
2000-02-11
This paper evaluates portable software packages for the iterative solution of very large sparse linear systems on parallel architectures. While we cannot hope to tell individual users which package will best suit their needs, we do hope that our systematic evaluation provides essential unbiased information about the packages and the evaluation process may serve as an example on how to evaluate these packages. The information contained here include feature comparisons, usability evaluations and performance characterizations. This review is primarily focused on self-contained packages that can be easily integrated into an existing program and are capable of computing solutions to very large sparse linear systems of equations. More specifically, it concentrates on portable parallel linear system solution packages that provide iterative solution schemes and related preconditioning schemes because iterative methods are more frequently used than competing schemes such as direct methods. The eight packages evaluated are: Aztec, BlockSolve,ISIS++, LINSOL, P-SPARSLIB, PARASOL, PETSc, and PINEAPL. Among the eight portable parallel iterative linear system solvers reviewed, we recommend PETSc and Aztec for most application programmers because they have well designed user interface, extensive documentation and very responsive user support. Both PETSc and Aztec are written in the C language and are callable from Fortran. For those users interested in using Fortran 90, PARASOL is a good alternative. ISIS++is a good alternative for those who prefer the C++ language. Both PARASOL and ISIS++ are relatively new and are continuously evolving. Thus their user interface may change. In general, those packages written in Fortran 77 are more cumbersome to use because the user may need to directly deal with a number of arrays of varying sizes. Languages like C++ and Fortran 90 offer more convenient data encapsulation mechanisms which make it easier to implement a clean and intuitive user
Long ion chamber systems for the SLC (Stanford Linear Collider)
Rolfe, J.; Gearhart, R.; Jacobsen, R.; Jenkins, T.; McComick, D.; Nelson, R.; Reagan, D.; Ross, M.
1989-03-01
A Panofsky Long Ion Chamber (PLIC) is essentially a gas-filled coaxial cable, and has been used to protect the Stanford Linear Accelerator from damage caused by its electron beam, and as a sensitive diagnostic tool. This old technology has been updated and has found renewed use in the SLC. PLIC systems have been installed as beam steering aids in most parts of the SLC and are a part of the system that protects the SLC from damage by errant beams in several places. 5 refs., 3 figs., 1 tab.
Beam-Based Feedback System for the International Linear Collider
NASA Astrophysics Data System (ADS)
Ivanov, Valentin
The algorithms and computer codes for linac Feedback system were developed at SLAC during 1991-2004. The efficiency of that system have been demonstrated for the SLC, CLIC, TESLA and NLC projects. International Linear Collider (ILC) has its own features. Ground motion (GM) oscillations play a dominant role here. It forced to implement a new version of the Linac Feedback Simulation Code based on the previous developments. A set of benchmark tests and realistic simulations for the whole ILC structure have been performed. The effects of different GM models, BPM resolution, time intervals, initial misalignments, a dispersion-free steering (DFS), and a quad jitter have been studied.
Critical electron binding to linear electric quadrupole systems.
Garrett, W R
2008-05-21
Results for critical quadrupolar moments for electron binding to fixed, point-charge systems are normalized, extended, and displayed in graphical forms. The influence of rotational degrees of freedom on critical binding to quadrupolar systems is examined through calculations of critical moments for electron binding to linear electric quadrupolar rotors. The results are presented for rotors covering useful ranges of size and inertial parameters. The effect of rotational degrees of freedom on critical binding is found to be less important for quadrupolar as compared to dipolar rotors.
Münster, E; Rüger, H; Ochsmann, E; Alsmann, C; Letzel, S
2010-02-01
In the past few years, the number of over-indebted private households in Germany has steadily increased and is currently estimated to have reached 3.13 million. Financial difficulties culminating in private insolvencies of the persons concerned may lead to a restrained usage of health-care services that require additional payment. For the first time ever this study has examined whether over-indebted individuals refrain from seeking medical treatment or from buying prescribed medicine because of their financial situation. The cross-sectional study covered over-indebted persons in Rhineland-Palatinate and was conducted between July 2006 and March 2007. In cooperation with 53 debt counselling agencies in Rhineland-Palatinate and in cooperation with the specialized debtor counselling centre of the Johannes Gutenberg-University of Mainz a singular, anonymous questionnaire-based survey in written form was conducted. Altogether 666 persons (51% female) between 18 and 79 years old (mean value: 41,0 years, standard deviation: 11,2 years; median: 41 years) participated in this evaluation, which amounts to a participation rate of 35.5%. The majority of participants stated to refrain from buying prescribed medication (65.2%) as well as from seeking medical advice and paying euro 10.00 own contribution (60.8%) because of their financial situation. The multivariate, binary logistic end-model showed age, family situation, insolvency proceedings, medical conditions and the self-reported attitude towards health alertness to be relevant factors of influence for both target variables. The enacted own financial contribution when seeking health care or when receiving medication in Germany might cause a discrimination of indebted persons or households with regard to health care and medical treatment. Because of the obligation of additional payment, health services are not independent of an individual's financial resources, meaning that especially destitution in expenditure affects equal
Detecting and isolating abrupt changes in linear switching systems
NASA Astrophysics Data System (ADS)
Nazari, Sohail; Zhao, Qing; Huang, Biao
2015-04-01
In this paper, a novel fault detection and isolation (FDI) method for switching linear systems is developed. All input and output signals are assumed to be corrupted with measurement noises. In the proposed method, a 'lifted' linear model named as stochastic hybrid decoupling polynomial (SHDP) is introduced. The SHDP model governs the dynamics of the switching linear system with all different modes, and is independent of the switching sequence. The error-in-variable (EIV) representation of SHDP is derived, and is used for the fault residual generation and isolation following the well-adopted local approach. The proposed FDI method can detect and isolate the fault-induced abrupt changes in switching models' parameters without estimating the switching modes. Furthermore, in this paper, the analytical expressions of the gradient vector and Hessian matrix are obtained based on the EIV SHDP formulation, so that they can be used to implement the online fault detection scheme. The performance of the proposed method is then illustrated by simulation examples.
Distributed Control of Uncertain Systems using Superpositions of Linear operators
Sanger, Terence D.
2011-01-01
Control in the natural environment is difficult in part because of uncertainty in the effect of actions. Uncertainty can be due to added motor or sensory noise, unmodeled dynamics, or quantization of sensory feedback. Biological systems are faced with further difficulties, since control must be performed by networks of cooperating neurons and neural subsystems. Here, we propose a new mathematical framework for modeling and simulation of distributed control systems operating in an uncertain environment. Stochastic Differential Operators can be derived from the stochastic differential equation describing a system, and they map the current state density into the differential of the state density. Unlike discrete-time Markov update operators, stochastic differential operators combine linearly for a large class of linear and nonlinear systems, and therefore the combined effects of multiple controllable and uncontrollable subsystems can be predicted. Design using these operators yields systems whose statistical behavior can be specified throughout state space. The relationship to Bayesian estimation and discrete-time Markov processes is described. PMID:21521040
Distributed control of uncertain systems using superpositions of linear operators.
Sanger, Terence D
2011-08-01
Control in the natural environment is difficult in part because of uncertainty in the effect of actions. Uncertainty can be due to added motor or sensory noise, unmodeled dynamics, or quantization of sensory feedback. Biological systems are faced with further difficulties, since control must be performed by networks of cooperating neurons and neural subsystems. Here, we propose a new mathematical framework for modeling and simulation of distributed control systems operating in an uncertain environment. Stochastic differential operators can be derived from the stochastic differential equation describing a system, and they map the current state density into the differential of the state density. Unlike discrete-time Markov update operators, stochastic differential operators combine linearly for a large class of linear and nonlinear systems, and therefore the combined effects of multiple controllable and uncontrollable subsystems can be predicted. Design using these operators yields systems whose statistical behavior can be specified throughout state-space. The relationship to Bayesian estimation and discrete-time Markov processes is described.
Development of a linear induction motor based artificial muscle system.
Gruber, A; Arguello, E; Silva, R
2013-01-01
We present the design of a linear induction motor based on electromagnetic interactions. The engine is capable of producing a linear movement from electricity. The design consists of stators arranged in parallel, which produce a magnetic field sufficient to displace a plunger along its axial axis. Furthermore, the winding has a shell and cap of ferromagnetic material that amplifies the magnetic field. This produces a force along the length of the motor that is similar to that of skeletal muscle. In principle, the objective is to use the engine in the development of an artificial muscle system for prosthetic applications, but it could have multiple applications, not only in the medical field, but in other industries.
Thermoelectric effects in quantum Hall systems beyond linear response
NASA Astrophysics Data System (ADS)
López, Rosa; Hwang, Sun-Yong; Sánchez, David
2014-12-01
We consider a quantum Hall system with an antidot acting as a energy dependent scatterer. In the purely charge case, we find deviations from the Wiedemann-Franz law that take place in the nonlinear regime of transport. We also discuss Peltier effects beyond linear response and describe both effects using magnetic-field asymmetric transport coefficients. For the spin case such as that arising along the helical edge states of a two-dimensional topological insulator, we investigate the generation of spin currents as a result of applied voltage and temperature differences in samples attached to ferromagnetic leads. We find that in the parallel configuration the spin current can be tuned with the leads' polarization even in the linear regime of transport. In contrast, for antiparallel magnetizations the spin currents has a strict nonlinear dependence on the the applied fields.
National health expenditures, 1993.
Levit, K R; Sensenig, A L; Cowan, C A; Lazenby, H C; McDonnell, P A; Won, D K; Sivarajan, L; Stiller, J M; Donham, C S; Stewart, M S
1994-01-01
This article presents data on health care spending for the United States, covering expenditures for various types of medical services and products and their sources of funding from 1960 to 1993. Although these statistics show a slowing in the growth of health care expenditures over the past few years, spending continues to increase faster than the overall economy. The share of the Nation's health care bill funded by the Federal Government through the Medicaid and Medicare programs steadily increased from 1991 to 1993. This significant change in the share of health expenditures funded by the public sector has caused Federal health expenditures as a share of all Federal spending to increase dramatically.
Linear system identification via an asymptotically stable observer
NASA Technical Reports Server (NTRS)
Phan, Minh; Horta, Lucas G.; Juang, Jer-Nan; Longman, Richard W.
1991-01-01
This paper presents a formulation for identification of linear multivariable systems from single or multiple sets of input-output data. The system input-output relationship is expressed in terms of an observer, which is made asymptotically stable by an embedded eigenvalue assignment procedure. The prescribed eigenvalues for the observer may be real, complex, mixed real and complex, or zero. In this formulation, the Markov parameters of the observer are identified from input-output data. The Markov parameters of the actual system are then recovered from those of the observer, and used to obtain a state space model of the system by standard realization techniques. The basic mathematical formulation is derived, and numerical examples using simulated noise-free data are presented to illustrate the proposed method.
Indirect Identification of Linear Stochastic Systems with Known Feedback Dynamics
NASA Technical Reports Server (NTRS)
Huang, Jen-Kuang; Hsiao, Min-Hung; Cox, David E.
1996-01-01
An algorithm is presented for identifying a state-space model of linear stochastic systems operating under known feedback controller. In this algorithm, only the reference input and output of closed-loop data are required. No feedback signal needs to be recorded. The overall closed-loop system dynamics is first identified. Then a recursive formulation is derived to compute the open-loop plant dynamics from the identified closed-loop system dynamics and known feedback controller dynamics. The controller can be a dynamic or constant-gain full-state feedback controller. Numerical simulations and test data of a highly unstable large-gap magnetic suspension system are presented to demonstrate the feasibility of this indirect identification method.
Frequency weighted system identification and linear quadratic controller design
NASA Technical Reports Server (NTRS)
Horta, Lucas G.; Phan, Minh; Juang, Jer-Nan; Longman, Richard W.; Sulla, Jeffrey L.
1991-01-01
Application of filters for frequency weighting of Markov parameters (pulse response functions) is described in relation to system/observer identification. The time domain identification approach recovers a model which has a pulse response weighted according to frequency. The identified model is composed of the original system and filters. The augmented system is in a form which can be used directly for frequency weighted linear quadratic controller design. Data from either single or multiple experiments can be used to recover the Markov parameters. Measured acceleration signals from a truss structure are used for system identification and the model obtained is used for frequency weighted controller design. The procedure makes the identification and controler design complementary problems.
Identification of linear systems by an asymptotically stable observer
NASA Technical Reports Server (NTRS)
Phan, Minh Q.; Horta, Lucas G.; Juang, Jer-Nan; Longman, Richard W.
1992-01-01
A formulation is presented for the identification of a linear multivariable system from single or multiple sets of input-output data. The system input-output relationship is expressed in terms of an observer, which is made asymptotically stable by an embedded eigenvalue assignment procedure. The prescribed eigenvalues for the observer may be real, complex, mixed real and complex, or zero. In this formulation, the Markov parameters of the observer are identified from input-output data. The Markov parameters of the actual system are then recovered from those of the observer and used to obtain a state space model of the system by standard realization techniques. The basic mathematical formulation is derived, and extensive numerical examples using simulated noise-free data are presented to illustrate the proposed method.
45 CFR 263.4 - When do educational expenditures count?
Code of Federal Regulations, 2011 CFR
2011-10-01
... 45 Public Welfare 2 2011-10-01 2011-10-01 false When do educational expenditures count? 263.4... do educational expenditures count? (a) Expenditures for educational activities or services count if... educational services or activities provided through the public education system do not count unless they...
Determinants and Equity Evaluation for Health Expenditure Among Patients with Rare Diseases in China
Xin, Xiao-Xiong; Zhao, Liang; Guan, Xiao-Dong; Shi, Lu-Wen
2016-01-01
Background: China has not established social security system for rare diseases. Rare diseases could easily impoverish patients and their families. Little research has studied the equity and accessibility of health services for patients with rare diseases in China. This study aimed to explore the factors that influence health expenditure of rare diseases and evaluate its equity. Methods: Questionnaire survey about living conditions and cost burden of patients with rare diseases was conducted. Individual and family information, health expenditure and reimbursement in 2014 of 982 patients were collected. The impact of medical insurance, individual sociodemographic characteristics, family characteristics, and healthcare need on total and out-of-pocket (OOP) health expenditures was analyzed through the generalized linear model. Equity of health expenditure was evaluated by both concentration index and Lorenz curve. Results: Of all the surveyed patients, 11.41% had no medical insurance and 92.10% spent money to seek medical treatment in 2014. It was suggested female (P = 0.048), over 50 years of age (P = 0.062), high-income group (P = 0.021), hospitalization (P = 0.000), and reimbursement ratio (RR) (P = 0.000) were positively correlated with total health expenditure. Diseases not needing long-term treatment (P = 0.000) was negatively correlated with total health expenditure. Over 50 years of age (P = 0.065), high-income group (P = 0.018), hospitalization (P = 0.000) and having Urban Employee Basic Medical Insurance (UEBMI) (P = 0.022) were positively correlated with OOP health expenditure. Patient or the head of the household having received higher education (P = 0.044 and P = 0.081) and reimbursement ratio (P = 0.078) were negatively correlated with OOP health expenditure. The equity evaluation found concentration indexes of health expenditure before and after reimbursement were 0.0550 and 0.0539, respectively. Conclusions: OOP health expenditure of patients with UEBMI
Xin, Xiao-Xiong; Zhao, Liang; Guan, Xiao-Dong; Shi, Lu-Wen
2016-06-20
China has not established social security system for rare diseases. Rare diseases could easily impoverish patients and their families. Little research has studied the equity and accessibility of health services for patients with rare diseases in China. This study aimed to explore the factors that influence health expenditure of rare diseases and evaluate its equity. Questionnaire survey about living conditions and cost burden of patients with rare diseases was conducted. Individual and family information, health expenditure and reimbursement in 2014 of 982 patients were collected. The impact of medical insurance, individual sociodemographic characteristics, family characteristics, and healthcare need on total and out-of-pocket (OOP) health expenditures was analyzed through the generalized linear model. Equity of health expenditure was evaluated by both concentration index and Lorenz curve. Of all the surveyed patients, 11.41% had no medical insurance and 92.10% spent money to seek medical treatment in 2014. It was suggested female (P = 0.048), over 50 years of age (P = 0.062), high-income group (P = 0.021), hospitalization (P = 0.000), and reimbursement ratio (RR) (P = 0.000) were positively correlated with total health expenditure. Diseases not needing long-term treatment (P = 0.000) was negatively correlated with total health expenditure. Over 50 years of age (P = 0.065), high-income group (P = 0.018), hospitalization (P = 0.000) and having Urban Employee Basic Medical Insurance (UEBMI) (P = 0.022) were positively correlated with OOP health expenditure. Patient or the head of the household having received higher education (P = 0.044 and P = 0.081) and reimbursement ratio (P = 0.078) were negatively correlated with OOP health expenditure. The equity evaluation found concentration indexes of health expenditure before and after reimbursement were 0.0550 and 0.0539, respectively. OOP health expenditure of patients with UEBMI was significantly more than that of
A linear signal transmission system calibration method of wideband GPR
NASA Astrophysics Data System (ADS)
Wu, Bin; Zhao, Kai; Gu, Ling-jia; Cao, Qiong; Li, Xiao-feng; Zheng, Xing-ming
2016-09-01
In VHF pulse Ground Penetrating Radar(GPR) system, the echo pass through the antenna and transmission line circuit, then reach the GPR receiver. Thus the reflection coefficient at the receiver sampling gate interface, which is at the end of the transmission line, is different from the real reflection coefficient of the media at the antenna interface, which could cause the GPR receiving error. The pulse GPR receiver is a wideband system that can't be simply described as traditional narrowband transmission line model. Since the GPR transmission circuit is a linear system, the linear transformation method could be used to analyze the characteristic of the GPR receiving system. A GPR receiver calibration method based on transmission line theory is proposed in this paper, which analyzes the relationship between the reflection coefficients of theory calculation at antenna interface and the measuring data by network analyzer at the sampling gate interface. Then the least square method is introduced to calibrate the transfer function of the GPR receiver transmission circuit. This calibration method can be useful in media quantitative inversion by GPR. When the reflection coefficient at the sampling gate is obtained, the real reflection coefficient of the media at the antenna interface can be easily determined.
Forecasting drug utilization and expenditure in a metropolitan health region
2010-01-01
Background New pharmacological therapies are challenging the healthcare systems, and there is an increasing need to assess their therapeutic value in relation to existing alternatives as well as their potential budget impact. Consequently, new models to introduce drugs in healthcare are urgently needed. In the metropolitan health region of Stockholm, Sweden, a model has been developed including early warning (horizon scanning), forecasting of drug utilization and expenditure, critical drug evaluation as well as structured programs for the introduction and follow-up of new drugs. The aim of this paper is to present the forecasting model and the predicted growth in all therapeutic areas in 2010 and 2011. Methods Linear regression analysis was applied to aggregate sales data on hospital sales and dispensed drugs in ambulatory care, including both reimbursed expenditure and patient co-payment. The linear regression was applied on each pharmacological group based on four observations 2006-2009, and the crude predictions estimated for the coming two years 2010-2011. The crude predictions were then adjusted for factors likely to increase or decrease future utilization and expenditure, such as patent expiries, new drugs to be launched or new guidelines from national bodies or the regional Drug and Therapeutics Committee. The assessment included a close collaboration with clinical, clinical pharmacological and pharmaceutical experts from the regional Drug and Therapeutics Committee. Results The annual increase in total expenditure for prescription and hospital drugs was predicted to be 2.0% in 2010 and 4.0% in 2011. Expenditures will increase in most therapeutic areas, but most predominantly for antineoplastic and immune modulating agents as well as drugs for the nervous system, infectious diseases, and blood and blood-forming organs. Conclusions The utilisation and expenditure of drugs is difficult to forecast due to uncertainties about the rate of adoption of new
State energy price and expenditure report, 1995
1998-08-01
The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the US. The estimates developed in the State Energy Price and Expenditure Data System (SEPEDS) are provided by energy source and economic sector and are published for the years 1970 through 1995. Data for all years are available on a CD-ROM and via Internet. Consumption estimates used to calculate expenditures and the documentation for those estimates are taken from the State Energy Data Report 1995, Consumption Estimates (SEDR), published in December 1997. Expenditures are calculated by multiplying the price estimates by the consumption estimates, which are adjusted to remove process fuel; intermediate petroleum products; and other consumption that has no direct fuel costs, i.e., hydroelectric, geothermal, wind, solar, and photovoltaic energy sources.
Linear systems formulation of non-paraxial scalar diffraction theory
NASA Astrophysics Data System (ADS)
Harvey, James E.
2011-10-01
Goodman's popular linear systems formulation of scalar diffraction theory includes a paraxial (small angle) approximation that severely limits the conditions under which this elegant Fourier treatment can be applied. In this paper a generalized linear systems formulation of non-paraxial scalar diffraction theory will be discussed. Diffracted radiance (not intensity or irradiance) is shown to be shift-invariant with respect to changes in incident angle only when modeled as a function of the direction cosines of the propagation vectors of the usual angular spectrum of plane waves. This revelation greatly extends the range of parameters over which simple Fourier techniques can be used to make accurate diffraction calculations. Non-paraxial diffraction grating behavior (including the Woods anomaly phenomenon) and wide-angle surface scattering effects for moderately rough surfaces at large incident and scattered angles are two diffraction phenomena that are not limited to the paraxial region and benefit greatly from this extension to Goodman's Fourier optics analysis. The resulting generalized surface scatter theory has been shown to be valid for rougher surfaces than the Rayleigh-Rice theory and for larger incident and scattered angles than the classical Beckman-Kirchhoff theory. This has enabled the development of a complete linear systems formulation of image quality, including not only diffraction effects and geometrical aberrations from residual optical design errors, but surface scatter effects from residual optical fabrication errors as well. Surface scatter effects can thus be balanced against optical design errors, allowing the derivation of optical fabrication tolerances during the design phase of a project.
Murante, Anna Maria; Seghieri, Chiara; Vainieri, Milena; Schäfer, Willemijn L A
2017-08-01
Health systems are expected to be responsive, that is to provide services that are user-oriented and respectful of people. Several surveys have tried to measure all or some of the dimensions of the responsiveness (e.g. autonomy, choice, clarity of communication, confidentiality, dignity, prompt attention, quality of basic amenities, and access to family and community support), however there is little evidence regarding the level of responsiveness of primary care (PC) systems. This work analyses the capacity of primary care systems to be responsive. Data collected from 32 PC systems were used to investigate whether a relationship exists between the responsiveness of PC systems and the PC doctor remuneration systems and domestic health expenditure. There appears to be a higher responsiveness of PC when doctors are paid via capitation than when they only receive a fee for services or a mixed payment method. In addition, countries that spend more on health services are associated with higher levels of dignity and autonomy. Quality, as measured from the patient's perspective, does not necessarily overlap with PC performance based on structure and process indicators. The results could also stimulate a new debate on the role of economic resources and PC workforce payment mechanisms in the achievement of quality goals, in this case related to the capacity of PC systems to be responsive. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Passive dynamic controllers for non-linear mechanical systems
NASA Technical Reports Server (NTRS)
Juang, Jer-Nan; Wu, Shih-Chin; Phan, Minh; Longman, Richard W.
1991-01-01
A methodology for model-independent controller design for controlling large angular motion of multi-body dynamic systems is outlined.The controlled system may consist of rigid and flexible components that undergo large rigid body motion and small elastic deformations. Control forces/torques are applied to drive the system, and at the same time suppress the vibrations due to flexibility of the components. The proposed controller consists of passive second-order systems which may be designed with little knowledge of the system parameters, even if the controlled system is non-linear. Under rather general assumptions, the passive design assures that the closed loop system has guaranteed stability properties. Unlike positive real controller design, stabilization can be accomplished without direct velocity feedback. In addition, the second-order passive design allows dynamic feedback controllers with considerable freedom to tune for desired system response, and to avoid actuator saturation. After developing the basic mathematical formulation of the design methodology, simulation results are presented to illustrate the proposed approach applied to a flexible six-degree-of-freedom manipulator.
Passive dynamic controllers for non-linear mechanical systems
NASA Technical Reports Server (NTRS)
Juang, Jer-Nan; Wu, Shih-Chin; Phan, Minh; Longman, Richard W.
1991-01-01
A methodology for model-independent controller design for controlling large angular motion of multi-body dynamic systems is outlined.The controlled system may consist of rigid and flexible components that undergo large rigid body motion and small elastic deformations. Control forces/torques are applied to drive the system, and at the same time suppress the vibrations due to flexibility of the components. The proposed controller consists of passive second-order systems which may be designed with little knowledge of the system parameters, even if the controlled system is non-linear. Under rather general assumptions, the passive design assures that the closed loop system has guaranteed stability properties. Unlike positive real controller design, stabilization can be accomplished without direct velocity feedback. In addition, the second-order passive design allows dynamic feedback controllers with considerable freedom to tune for desired system response, and to avoid actuator saturation. After developing the basic mathematical formulation of the design methodology, simulation results are presented to illustrate the proposed approach applied to a flexible six-degree-of-freedom manipulator.
Memristive non-linear system and hidden attractor
NASA Astrophysics Data System (ADS)
Saha, P.; Saha, D. C.; Ray, A.; Chowdhury, A. R.
2015-07-01
Effects of memristor on non-linear dynamical systems exhibiting chaos are analysed both form the view point of theory and experiment. It is observed that the memristive system has always fewer number of fixed points than the original one. Sometimes there is no fixed point in the memristive system. But its chaotic properties are retained. As such we have a situation known as hidden attractor because if it is a stable fixed point then the attractor does not evolve from its basin of attraction(obtained from its stable fixed point) or if there is no fixed point, the question of basin of attraction from fixed point does not arise at all [1, 2]. Our analysis gives a detailed accounts of properties related to its chaotic behavior. Important observations are also obtained with the help of electronic circuits to support the numerical simulations.
Damping Optimization for Linear Vibrating Systems Using Dimension Reduction
NASA Astrophysics Data System (ADS)
Benner, Peter; Tomljanović, Zoran; Truhar, Ninoslav
We consider a mathematical model of a linear vibrational system described by the second-order system of differential equations Mddot{x} + Ddot{x} + Kx = 0, where M, K and D are positive definite matrices, called mass, stiffness and damping, respectively. We are interested in finding an optimal damping matrix which will damp a certain part of the undamped eigenfrequencies. For this we use a minimization criterion which minimizes the average total energy of the system. This is equivalent to the minimization of the trace of the solution of a corresponding Lyapunov equation. In this paper we consider an algorithm for the efficient optimization of the damping positions based on dimension reduction techniques. Numerical results illustrate the efficiency of our approach.
Novel Approach to Linear Accelerator Superconducting Magnet System
Kashikhin, Vladimir; /Fermilab
2011-11-28
Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.
High-yield positron systems for linear colliders
Clendenin, J.E.
1989-04-01
Linear colliders, such as the SLC, are among those accelerators for which a high-yield positron source operating at the repetition rate of the accelerator is desired. The SLC, having electron energies up to 50 GeV, presents the possibility of generating positron bunches with useful charge even exceeding that of the initial electron bunch. The exact positron yield to be obtained depends on the particular capture, transport and damping system employed. Using 31 GeV electrons impinging on a W-type converter phase-space at the target to the acceptance of the capture rf section, the SLC source is capable of producing, for every electron, up to two positrons within the acceptance of the positron damping ring. The design of this source and the performance of the positron system as built are described. Also, future prospects and limitations for high-yield positron systems are discussed. 11 refs., 5 figs., 3 tabs.
Acoustic FMRI noise: linear time-invariant system model.
Rizzo Sierra, Carlos V; Versluis, Maarten J; Hoogduin, Johannes M; Duifhuis, Hendrikus Diek
2008-09-01
Functional magnetic resonance imaging (fMRI) enables sites of brain activation to be localized in human subjects. For auditory system studies, however, the acoustic noise generated by the scanner tends to interfere with the assessments of this activation. Understanding and modeling fMRI acoustic noise is a useful step to its reduction. To study acoustic noise, the MR scanner is modeled as a linear electroacoustical system generating sound pressure signals proportional to the time derivative of the input gradient currents. The transfer function of one MR scanner is determined for two different input specifications: 1) by using the gradient waveform calculated by the scanner software and 2) by using a recording of the gradient current. Up to 4 kHz, the first method is shown as reliable as the second one, and its use is encouraged when direct measurements of gradient currents are not possible. Additionally, the linear order and average damping properties of the gradient coil system are determined by impulse response analysis. Since fMRI is often based on echo planar imaging (EPI) sequences, a useful validation of the transfer function prediction ability can be obtained by calculating the acoustic output for the EPI sequence. We found a predicted sound pressure level (SPL) for the EPI sequence of 104 dB SPL compared to a measured value of 102 dB SPL. As yet, the predicted EPI pressure waveform shows similarity as well as some differences with the directly measured EPI pressure waveform.
Evaluating linear response in active systems with no perturbing field
NASA Astrophysics Data System (ADS)
Szamel, Grzegorz
2017-03-01
We present a method for the evaluation of time-dependent linear response functions for systems of active particles propelled by a persistent (colored) noise from unperturbed simulations. The method is inspired by the Malliavin weights sampling method proposed by Warren and Allen (Phys. Rev. Lett., 109 (2012) 250601) for out-of-equilibrium systems of passive Brownian particles. We illustrate our method by evaluating two linear response functions for a single active particle in an external harmonic potential. As an application, we calculate the time-dependent mobility function and an effective temperature, defined through the Einstein relation between the self-diffusion and mobility coefficients, for a system of many active particles interacting via a screened Coulomb potential. We find that this effective temperature decreases with increasing persistence time of the self-propulsion. Initially, for not too large persistence times, it changes rather slowly, but then it decreases markedly when the persistence length of the self-propelled motion becomes comparable with the particle size.
Modelling human balance using switched systems with linear feedback control
Kowalczyk, Piotr; Glendinning, Paul; Brown, Martin; Medrano-Cerda, Gustavo; Dallali, Houman; Shapiro, Jonathan
2012-01-01
We are interested in understanding the mechanisms behind and the character of the sway motion of healthy human subjects during quiet standing. We assume that a human body can be modelled as a single-link inverted pendulum, and the balance is achieved using linear feedback control. Using these assumptions, we derive a switched model which we then investigate. Stable periodic motions (limit cycles) about an upright position are found. The existence of these limit cycles is studied as a function of system parameters. The exploration of the parameter space leads to the detection of multi-stability and homoclinic bifurcations. PMID:21697168
Neighboring extremal guidance for systems with a piecewise linear control
NASA Technical Reports Server (NTRS)
Hull, David G.; Helfrich, Clifford E.
1991-01-01
The neighboring extremal feedback control law is developed for systems with a piecewise linear control for the case where the optimal control is obtained by nonlinear programming techniques. To develop the control perturbation for a given deviation from the nominal path, the second variation is minimized subject to the constraint that the final conditions be satisfied. This process leads to a feedback relationship between the control perturbation and the measured deviation from the nominal state. A simple example, the lunar launch problem, is used to demonstrate the validity of the guidance law. For model errors on the order of 5 percent, the results indicate that 5 percent errors occur in the final conditions.
Steady state decoupling and design of linear multivariable systems
NASA Technical Reports Server (NTRS)
Huang, J. Y.; Thaler, G. J.
1974-01-01
A constructive criterion for decoupling the steady states of linear multivariable systems is developed. The criterion consists of n(n-1) inequalities with the type numbers of the compensator transfer functions as the unknowns. These unknowns can be chosen to satisfy the inequalities and hence achieve a steady state decoupling scheme. It turns out that pure integrators in the loops play an important role. An extended root locus design method is then developed to take care of the stability and transient response. The overall procedure is applied to the compensation design for STOL C-8A aircraft in the approach mode.
The effect of non-linear human visual system components on linear model observers
NASA Astrophysics Data System (ADS)
Zhang, Yani; Pham, Binh T.; Eckstein, Miguel P.
2004-05-01
Linear model observers have been used successfully to predict human performance in clinically relevant visual tasks for a variety of backgrounds. On the other hand, there has been another family of models used to predict human visual detection of signals superimposed on one of two identical backgrounds (masks). These masking models usually include a number of non-linear components in the channels that reflect properties of the firing of cells in the primary visual cortex (V1). The relationship between these two traditions of models has not been extensively investigated in the context of detection in noise. In this paper, we evaluated the effect of including some of these non-linear components into a linear channelized Hotelling observer (CHO), and the associated practical implications for medical image quality evaluation. In particular, we evaluate whether the rank order evaluation of two compression algorithms (JPEG vs. JPEG 2000) is changed by inclusion of the non-linear components. The results show: a) First that the simpler linear CHO model observer outperforms CHO model with the nonlinear components investigated. b) The rank order of model observer performance for the compression algorithms did not vary when the non-linear components were included. For the present task, the results suggest that the addition of the physiologically based channel non-linearities to a channelized Hotelling might add complexity to the model observers without great impact on medical image quality evaluation.
Trends in Educational Expenditure.
ERIC Educational Resources Information Center
Burke, Gerald
This study provides an overview of expenditures for education and training by educational institutions in Australia, 1991-2001. The study used newly available data from the Australian Bureau of Statistics (ABS) and administrative data from the main sectors' reports on the size and trends in public and private education expenditures. It analyzed…
The efficient parallel iterative solution of large sparse linear systems
Jones, M.T.; Plassmann, P.E.
1992-06-01
The development of efficient, general-purpose software for the iterative solution of sparse linear systems on a parallel MIMD computer requires an interesting combination of expertise. Parallel graph heuristics, convergence analysis, and basic linear algebra implementation issues must all be considered. In this paper, we discuss how we have incorporated recent results in these areas into a general-purpose iterative solver. First, we consider two recently developed parallel graph coloring heuristics. We show how the method proposed by Luby, based on determining maximal independent sets, can be modified to run in an asynchronous manner and give aa expected running time bound for this modified heuristic. In addition, a number of graph reduction heuristics are described that are used in our implementation to improve the individual processor performance. The effect of these various graph reductions on the solution of sparse triangular systems is categorized. Finally, we discuss the performance of this solver from the perspective of two large-scale applications: a piezoelectric crystal finite-element modeling problem, and a nonlinear optimization problem to determine the minimum energy configuration of a three-dimensional, layered superconductor model.
de Deus Costa, Renata Maria; da Silva Barbosa, Rafael; Zucchi, Paola
2015-01-01
OBJECTIVE: To analyze the public expenditures of states on health care and the participation of states and the Federal District in financing the Unified Health System, better known by the acronym SUS. To develop the research, two targets were used: “to rescue expenses per government source (federal, state and municipal) during the period from 2002 to 2013” and “to rescue resource transfers from the federal SUS to the states and also to municipalities”. METHODS: This research is bibliographic, documentary and descriptive and used a quantitative approach. Data were extracted from the Information System Public Health Budget, and additional data were collected from the public managers of states, municipalities and the Federal District during the period from 2002 to 2013. Federal data from the Undersecretary of Planning and Budget (originally extracted from the Integrated System of Financial Administration of the Federal Government and available on the Budget Public Health System webpage) were also collected. RESULTS: The data revealed that during the same researched period, the Federal District has maintained the health care system budget, whereas states and municipalities have increased their budgets for the same spending. CONCLUSIONS: By analyzing the results, there is clearly a disparity regarding the investment expended by the entities of the Federation. Although municipalities and states have gradually increased their application of resources to health care, the federal state has maintained the same budget. These results reveal a bit of concern about public health funding. PMID:26017788
Solving tridiagonal linear systems on the Butterfly parallel computer
Kumar, S.P.
1989-01-01
A parallel block partitioning method to solve a tri-diagonal system of linear equations is adapted to the BBN Butterfly multiprocessor. A performance analysis of the programming experiments on the 32-node Butterfly is presented. An upper bound on the number of processors to achieve the best performance with this method is derived. The computational results verify the theoretical speedup and efficiency results of the parallel algorithm over its serial counterpart. Also included is a study comparing performance runs of the same code on the Butterfly processor with a hardware floating point unit and on one with a software floating point facility. The total parallel time of the given code is considerably reduced by making use of the hardware floating point facility whereas the speedup and efficiency of the parallel program considerably improve on the system with software floating point capability. The achieved results are shown to be within 82% to 90% of the predicted performance.
Linear theory for filtering nonlinear multiscale systems with model error
Berry, Tyrus; Harlim, John
2014-01-01
In this paper, we study filtering of multiscale dynamical systems with model error arising from limitations in resolving the smaller scale processes. In particular, the analysis assumes the availability of continuous-time noisy observations of all components of the slow variables. Mathematically, this paper presents new results on higher order asymptotic expansion of the first two moments of a conditional measure. In particular, we are interested in the application of filtering multiscale problems in which the conditional distribution is defined over the slow variables, given noisy observation of the slow variables alone. From the mathematical analysis, we learn that for a continuous time linear model with Gaussian noise, there exists a unique choice of parameters in a linear reduced model for the slow variables which gives the optimal filtering when only the slow variables are observed. Moreover, these parameters simultaneously give the optimal equilibrium statistical estimates of the underlying system, and as a consequence they can be estimated offline from the equilibrium statistics of the true signal. By examining a nonlinear test model, we show that the linear theory extends in this non-Gaussian, nonlinear configuration as long as we know the optimal stochastic parametrization and the correct observation model. However, when the stochastic parametrization model is inappropriate, parameters chosen for good filter performance may give poor equilibrium statistical estimates and vice versa; this finding is based on analytical and numerical results on our nonlinear test model and the two-layer Lorenz-96 model. Finally, even when the correct stochastic ansatz is given, it is imperative to estimate the parameters simultaneously and to account for the nonlinear feedback of the stochastic parameters into the reduced filter estimates. In numerical experiments on the two-layer Lorenz-96 model, we find that the parameters estimated online, as part of a filtering procedure
Linear operating region in the ozone dial photon counting system
NASA Technical Reports Server (NTRS)
Andrawis, Madeleine
1995-01-01
Ozone is a relatively unstable molecule found in Earth's atmosphere. An ozone molecule is made up of three atoms of oxygen. Depending on where ozone resides, it can protect or harm life on Earth. High in the atmosphere, about 15 miles up, ozone acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems. Closer to Earth, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants. Since the early 1980's, airborne lidar systems have been used for making measurements of ozone. The differential absorption lidar (DIAL) technique is used in the remote measurement of O3. This system allows the O3 to be measured as function of the range in the atmosphere. Two frequency-doubled Nd:YAG lasers are used to pump tunable dye lasers. The lasers are operating at 289 nm for the DIAL on-line wavelength of O3, and the other one is operated at 300 nm for the off-line wavelength. The DIAL wavelengths are produced in sequential laser pulses with a time separation of 300 micro s. The backscattered laser energy is collected by telescopes and measured using photon counting systems. The photon counting system measures the light signal by making use of the photon nature of light. The output pulse from the Photo-Multiplier Tube (PE), caused by a photon striking the PMT photo-cathode, is amplified and passed to a pulse height discriminator. The peak value of the pulse is compared to a reference voltage (discrimination level). If the pulse amplitude exceeds the discrimination level, the discriminator generates a standard pulse which is counted by the digital counter. Non-linearity in the system is caused by the overlapping of pulses and the finite response time of the electronics. At low count rates one expects the system to register one event for each output pulse from the PMT corresponding to a photon incident upon the
Linear operating region in the ozone dial photon counting system
NASA Technical Reports Server (NTRS)
Andrawis, Madeleine
1995-01-01
Ozone is a relatively unstable molecule found in Earth's atmosphere. An ozone molecule is made up of three atoms of oxygen. Depending on where ozone resides, it can protect or harm life on Earth. High in the atmosphere, about 15 miles up, ozone acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems. Closer to Earth, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants. Since the early 1980's, airborne lidar systems have been used for making measurements of ozone. The differential absorption lidar (DIAL) technique is used in the remote measurement of O3. This system allows the O3 to be measured as function of the range in the atmosphere. Two frequency-doubled Nd:YAG lasers are used to pump tunable dye lasers. The lasers are operating at 289 nm for the DIAL on-line wavelength of O3, and the other one is operated at 300 nm for the off-line wavelength. The DIAL wavelengths are produced in sequential laser pulses with a time separation of 300 micro s. The backscattered laser energy is collected by telescopes and measured using photon counting systems. The photon counting system measures the light signal by making use of the photon nature of light. The output pulse from the Photo-Multiplier Tube (PE), caused by a photon striking the PMT photo-cathode, is amplified and passed to a pulse height discriminator. The peak value of the pulse is compared to a reference voltage (discrimination level). If the pulse amplitude exceeds the discrimination level, the discriminator generates a standard pulse which is counted by the digital counter. Non-linearity in the system is caused by the overlapping of pulses and the finite response time of the electronics. At low count rates one expects the system to register one event for each output pulse from the PMT corresponding to a photon incident upon the
Energy and environmental analysis of a linear concentrating photovoltaic system
NASA Astrophysics Data System (ADS)
Kerzmann, Tony
The world is facing an imminent energy supply crisis. In order to sustain and increase our energy supply in an environmentally-conscious manner, it is necessary to advance renewable technologies. Despite this urgency, however, it is paramount to consider the larger environmental effects associated with using renewable energy resources. This research is meant to better understand linear concentrating photovoltaics (LCPVs) from an engineering and environmental standpoint. In order to analyze the LCPV system, a simulation and life cycle assessment (LCA) were developed. The LCPV system serves two major purposes: it produces electricity, and waste heat is collected for heating use. There are three parts to the LCPV simulation. The first part simulates the multijunction cell output so as to calculate the temperature-dependent electricity generation. The second part simulates the cell cooling and waste heat recovery system using a model consisting of heat transfer and fluid flow equations. The waste heat recovery in the LCPV system was linked to a hot water storage system, which was also modeled. Coupling the waste heat recovery simulation and the hot water storage system gives an overall integrated system that is useful for system design, optimization, and acts as a stepping stone for future multijunction cell Photovoltaic/Thermal (PV/T) systems. Finally, all of the LCPV system components were coded in Engineering Equation Solver (EES) and were used in an energy analysis under actual weather and solar conditions for the Phoenix, AZ, region. The life cycle assessment for the LCPV system allowed for an environmental analysis of the system where areas of the highest environmental impact were pinpointed. While conducting the LCA research, each component of the system was analyzed from a resource extraction, production, and use standpoint. The collective production processes of each LCPV system component were gathered into a single inventory of materials and energy flows
Linear homotopy solution of nonlinear systems of equations in geodesy
NASA Astrophysics Data System (ADS)
Paláncz, Béla; Awange, Joseph L.; Zaletnyik, Piroska; Lewis, Robert H.
2010-01-01
A fundamental task in geodesy is solving systems of equations. Many geodetic problems are represented as systems of multivariate polynomials. A common problem in solving such systems is improper initial starting values for iterative methods, leading to convergence to solutions with no physical meaning, or to convergence that requires global methods. Though symbolic methods such as Groebner bases or resultants have been shown to be very efficient, i.e., providing solutions for determined systems such as 3-point problem of 3D affine transformation, the symbolic algebra can be very time consuming, even with special Computer Algebra Systems (CAS). This study proposes the Linear Homotopy method that can be implemented easily in high-level computer languages like C++ and Fortran that are faster than CAS by at least two orders of magnitude. Using Mathematica, the power of Homotopy is demonstrated in solving three nonlinear geodetic problems: resection, GPS positioning, and affine transformation. The method enlarging the domain of convergence is found to be efficient, less sensitive to rounding of numbers, and has lower complexity compared to other local methods like Newton-Raphson.
Predictability of extremes in non-linear hierarchically organized systems
NASA Astrophysics Data System (ADS)
Kossobokov, V. G.; Soloviev, A.
2011-12-01
Understanding the complexity of non-linear dynamics of hierarchically organized systems progresses to new approaches in assessing hazard and risk of the extreme catastrophic events. In particular, a series of interrelated step-by-step studies of seismic process along with its non-stationary though self-organized behaviors, has led already to reproducible intermediate-term middle-range earthquake forecast/prediction technique that has passed control in forward real-time applications during the last two decades. The observed seismic dynamics prior to and after many mega, great, major, and strong earthquakes demonstrate common features of predictability and diverse behavior in course durable phase transitions in complex hierarchical non-linear system of blocks-and-faults of the Earth lithosphere. The confirmed fractal nature of earthquakes and their distribution in space and time implies that many traditional estimations of seismic hazard (from term-less to short-term ones) are usually based on erroneous assumptions of easy tractable analytical models, which leads to widespread practice of their deceptive application. The consequences of underestimation of seismic hazard propagate non-linearly into inflicted underestimation of risk and, eventually, into unexpected societal losses due to earthquakes and associated phenomena (i.e., collapse of buildings, landslides, tsunamis, liquefaction, etc.). The studies aimed at forecast/prediction of extreme events (interpreted as critical transitions) in geophysical and socio-economical systems include: (i) large earthquakes in geophysical systems of the lithosphere blocks-and-faults, (ii) starts and ends of economic recessions, (iii) episodes of a sharp increase in the unemployment rate, (iv) surge of the homicides in socio-economic systems. These studies are based on a heuristic search of phenomena preceding critical transitions and application of methodologies of pattern recognition of infrequent events. Any study of rare
Filtering nonlinear dynamical systems with linear stochastic models
NASA Astrophysics Data System (ADS)
Harlim, J.; Majda, A. J.
2008-06-01
An important emerging scientific issue is the real time filtering through observations of noisy signals for nonlinear dynamical systems as well as the statistical accuracy of spatio-temporal discretizations for filtering such systems. From the practical standpoint, the demand for operationally practical filtering methods escalates as the model resolution is significantly increased. For example, in numerical weather forecasting the current generation of global circulation models with resolution of 35 km has a total of billions of state variables. Numerous ensemble based Kalman filters (Evensen 2003 Ocean Dyn. 53 343-67 Bishop et al 2001 Mon. Weather Rev. 129 420-36 Anderson 2001 Mon. Weather Rev. 129 2884-903 Szunyogh et al 2005 Tellus A 57 528-45 Hunt et al 2007 Physica D 230 112-26) show promising results in addressing this issue; however, all these methods are very sensitive to model resolution, observation frequency, and the nature of the turbulent signals when a practical limited ensemble size (typically less than 100) is used. In this paper, we implement a radical filtering approach to a relatively low (40) dimensional toy model, the L-96 model (Lorenz 1996 Proc. on Predictability (ECMWF, 4-8 September 1995) pp 1-18) in various chaotic regimes in order to address the 'curse of ensemble size' for complex nonlinear systems. Practically, our approach has several desirable features such as extremely high computational efficiency, filter robustness towards variations of ensemble size (we found that the filter is reasonably stable even with a single realization) which makes it feasible for high dimensional problems, and it is independent of any tunable parameters such as the variance inflation coefficient in an ensemble Kalman filter. This radical filtering strategy decouples the problem of filtering a spatially extended nonlinear deterministic system to filtering a Fourier diagonal system of parametrized linear stochastic differential equations (Majda and Grote
Control methods to improve non-linear HVAC system operations
NASA Astrophysics Data System (ADS)
Phalak, Kaustubh Pradeep
The change of weather conditions and occupancy schedules makes heating ventilating and air-conditioning (HVAC) systems heavily dynamic. The mass and thermal inertia, nonlinear characteristics and interactions in HVAC systems make the control more complicated. As a result, some conventional control methods often cannot provide desired control performance under variable operating conditions. The purpose of this study is to develop control methods to improve the control performance of HVAC systems. This study focuses on optimizing the airflow-pressure control method of air side economizers, identifying robust building pressurization controls, developing a control method to control outdoor air and building pressure in absence of flow and pressure sensors, stabilizing the cooling coil valve operation and, return fan speed control. The improvements can be achieved by identifying and selecting a method with relatively linear performance characteristics out of the available options, applying fans rather than dampers to control building pressure, and improving the controller's stability range using cascade control method. A steady state nonlinear network model, for an air handling unit (AHU), air distribution system and conditioned space, is applied to analyze the system control performance of air-side economizers and building pressurization. The study shows that traditional controls with completely interlinked outdoor air, recirculated air, relief air dampers have the best control performance. The decoupled relief damper control may result in negative building static pressure at lower outdoor airflow ratio and excessively positive building static pressure at higher outdoor airflow ratio. On the other hand, return fan speed control has a better controllability on building pressurization. In absence of flow and pressure sensors fixed interlinked damper and linear return fan speed tracking control can maintain constant outside air ratio and positive building pressure. The
Domain walls and vortices in linearly coupled systems.
Dror, Nir; Malomed, Boris A; Zeng, Jianhua
2011-10-01
We investigate one- and two-dimensional radial domain-wall (DW) states in the system of two nonlinear-Schrödinger (NLS) or Gross-Pitaevskii (GP) equations, which are couple by linear mixing and by nonlinear XPM (cross-phase-modulation). The system has straightforward applications to two-component Bose-Einstein condensates, and to bimodal light propagation in nonlinear optics. In the former case the two components represent different hyperfine atomic states, while in the latter setting they correspond to orthogonal polarizations of light. Conditions guaranteeing the stability of flat continuous wave (CW) asymmetric bimodal states are established, followed by the study of families of the corresponding DW patterns. Approximate analytical solutions for the DWs are found near the point of the symmetry-breaking bifurcation of the CW states. An exact DW solution is produced for ratio 3:1 of the XPM and SPM (self-phase modulation) coefficients. The DWs between flat asymmetric states, which are mirror images of each other, are completely stable, and all other species of the DWs, with zero crossings in one or two components, are fully unstable. Interactions between two DWs are considered too, and an effective potential accounting for the attraction between them is derived analytically. Direct simulations demonstrate merger and annihilation of the interacting DWs. The analysis is extended for the system including single- and double-peak external potentials. Generic solutions for trapped DWs are obtained in a numerical form, and their stability is investigated. An exact stable solution is found for the DW trapped by a single-peak potential. In the 2D geometry, stable two-component vortices are found, with topological charges s=1,2,3. Radial oscillations of annular DW-shaped pulsons, with s=0,1,2, are studied too. A linear relation between the period of the oscillations and the mean radius of the DW ring is derived analytically.
Three-dimensional linear system analysis for breast tomosynthesis.
Zhao, Bo; Zhao, Wei
2008-12-01
The optimization of digital breast tomosynthesis (DBT) geometry and reconstruction is crucial for the clinical translation of this exciting new imaging technique. In the present work, the authors developed a three-dimensional (3D) cascaded linear system model for DBT to investigate the effects of detector performance, imaging geometry, and image reconstruction algorithm on the reconstructed image quality. The characteristics of a prototype DBT system equipped with an amorphous selenium flat-panel detector and filtered backprojection reconstruction were used as an example in the implementation of the linear system model. The propagation of signal and noise in the frequency domain was divided into six cascaded stages incorporating the detector performance, imaging geometry, and reconstruction filters. The reconstructed tomosynthesis imaging quality was characterized by spatial frequency dependent presampling modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) in 3D. The results showed that both MTF and NPS were affected by the angular range of the tomosynthesis scan and the reconstruction filters. For image planes parallel to the detector (in-plane), MTF at low frequencies was improved with increase in angular range. The shape of the NPS was affected by the reconstruction filters. Noise aliasing in 3D could be introduced by insufficient voxel sampling, especially in the z (slice-thickness) direction where the sampling distance (slice thickness) could be more than ten times that for in-plane images. Aliasing increases the noise at high frequencies, which causes degradation in DQE. Application of a reconstruction filter that limits the frequency components beyond the Nyquist frequency in the z direction, referred to as the slice thickness filter, eliminates noise aliasing and improves 3D DQE. The focal spot blur, which arises from continuous tube travel during tomosynthesis acquisition, could degrade DQE significantly
Domain walls and vortices in linearly coupled systems
Dror, Nir; Malomed, Boris A.; Zeng Jianhua
2011-10-15
We investigate one- and two-dimensional radial domain-wall (DW) states in the system of two nonlinear-Schroedinger (NLS) or Gross-Pitaevskii (GP) equations, which are couple by linear mixing and by nonlinear XPM (cross-phase-modulation). The system has straightforward applications to two-component Bose-Einstein condensates, and to bimodal light propagation in nonlinear optics. In the former case the two components represent different hyperfine atomic states, while in the latter setting they correspond to orthogonal polarizations of light. Conditions guaranteeing the stability of flat continuous wave (CW) asymmetric bimodal states are established, followed by the study of families of the corresponding DW patterns. Approximate analytical solutions for the DWs are found near the point of the symmetry-breaking bifurcation of the CW states. An exact DW solution is produced for ratio 3:1 of the XPM and SPM (self-phase modulation) coefficients. The DWs between flat asymmetric states, which are mirror images of each other, are completely stable, and all other species of the DWs, with zero crossings in one or two components, are fully unstable. Interactions between two DWs are considered too, and an effective potential accounting for the attraction between them is derived analytically. Direct simulations demonstrate merger and annihilation of the interacting DWs. The analysis is extended for the system including single- and double-peak external potentials. Generic solutions for trapped DWs are obtained in a numerical form, and their stability is investigated. An exact stable solution is found for the DW trapped by a single-peak potential. In the 2D geometry, stable two-component vortices are found, with topological charges s=1,2,3. Radial oscillations of annular DW-shaped pulsons, with s=0,1,2, are studied too. A linear relation between the period of the oscillations and the mean radius of the DW ring is derived analytically.
Three-dimensional linear system analysis for breast tomosynthesis
Zhao, Bo; Zhao, Wei
2008-01-01
The optimization of digital breast tomosynthesis (DBT) geometry and reconstruction is crucial for the clinical translation of this exciting new imaging technique. In the present work, the authors developed a three-dimensional (3D) cascaded linear system model for DBT to investigate the effects of detector performance, imaging geometry, and image reconstruction algorithm on the reconstructed image quality. The characteristics of a prototype DBT system equipped with an amorphous selenium flat-panel detector and filtered backprojection reconstruction were used as an example in the implementation of the linear system model. The propagation of signal and noise in the frequency domain was divided into six cascaded stages incorporating the detector performance, imaging geometry, and reconstruction filters. The reconstructed tomosynthesis imaging quality was characterized by spatial frequency dependent presampling modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) in 3D. The results showed that both MTF and NPS were affected by the angular range of the tomosynthesis scan and the reconstruction filters. For image planes parallel to the detector (in-plane), MTF at low frequencies was improved with increase in angular range. The shape of the NPS was affected by the reconstruction filters. Noise aliasing in 3D could be introduced by insufficient voxel sampling, especially in the z (slice-thickness) direction where the sampling distance (slice thickness) could be more than ten times that for in-plane images. Aliasing increases the noise at high frequencies, which causes degradation in DQE. Application of a reconstruction filter that limits the frequency components beyond the Nyquist frequency in the z direction, referred to as the slice thickness filter, eliminates noise aliasing and improves 3D DQE. The focal spot blur, which arises from continuous tube travel during tomosynthesis acquisition, could degrade DQE significantly
Locally weighted linear combination in a vector geographic information system
NASA Astrophysics Data System (ADS)
Carter, Brad; Rinner, Claus
2014-07-01
Weighted linear combination is a multi-criteria decision analysis technique that can be used by decision-makers to select an optimal location from a collection of alternative locations. Its local form takes into account the range of attribute values within a user-defined neighbourhood in accordance with the range-sensitivity principle. This research explores locally weighted linear combination in a vector-based geographic information system. A custom application in ArcGIS 10 allows the user to select a neighbourhood definition from a standard set including contiguity, distance, and k-nearest neighbours, for which local weights are generated. A case study on vulnerability to heat-related illness in Toronto is used to illustrate the technique. The impact of local weighting on the heat vulnerability index is examined using visual analysis of the spatial patterns of heat vulnerability under the global and local approaches, as well as the sensitivity of the local approach to the selected neighbourhood definition. A trade-off analysis of the local weights is also presented. The combination of socio-demographic and environmental determinants in a locally weighted index results in patterns of heat vulnerability that could support targeted hot weather response at a micro-geographic level within urban neighbourhoods.
Versatile Low Level RF System For Linear Accelerators
Potter, James M.
2011-06-01
The Low Level RF (LLRF) system is the source of all of the rf signals required for an rf linear accelerator. These signals are amplified to drive accelerator and buncher cavities. It can even provide the synchronizing signal for the rf power for a synchrotron. The use of Direct Digital Synthesis (DDS) techniques results in a versatile system that can provide multiple coherent signals at the same or different frequencies with adjustable amplitudes and phase relations. Pulsing the DDS allows rf switching with an essentially infinite on/off ratio. The LLRF system includes a versatile phase detector that allows phase-locking the rf frequency to a cavity at any phase angle over the full 360 deg. range. With the use of stepper motor driven slug tuners multiple cavity resonant frequencies can be phase locked to the rf source frequency. No external phase shifters are required and there is no feedback loop phase setup required. All that is needed is to turn the frequency feedback on. The use of Digital Signal Processing (DSP) allows amplitude and phase control over the entire rf pulse. This paper describes the basic principles of a LLRF system that has been used for both proton accelerators and electron accelerators, including multiple tank accelerators, sub-harmonic and fundamental bunchers, and synchrotrons.
Computational Aspects of Realization & Design Algorithms in Linear Systems Theory.
NASA Astrophysics Data System (ADS)
Tsui, Chia-Chi
Realization and design problems are two major problems in linear time-invariant systems control theory and have been solved theoretically. However, little is understood about their numerical properties. Due to the large scale of the problem and the finite precision of computer computation, it is very important and is the purpose of this study to investigate the computational reliability and efficiency of the algorithms for these two problems. In this dissertation, a reliable algorithm to achieve canonical form realization via Hankel matrix is developed. A comparative study of three general realization algorithms, for both numerical reliability and efficiency, shows that the proposed algorithm (via Hankel matrix) is the most preferable one among the three. The design problems, such as the state feedback design for pole placement, the state observer design, and the low order single and multi-functional observer design, have been solved by using canonical form systems matrices. In this dissertation, a set of algorithms for solving these three design problems is developed and analysed. These algorithms are based on Hessenberg form systems matrices which are numerically more reliable to compute than the canonical form systems matrices.
Linear System Models for Ultrasonic Imaging: Application to Signal Statistics
Zemp, Roger J.; Abbey, Craig K.; Insana, Michael F.
2009-01-01
Linear equations for modeling echo signals from shift-variant systems forming ultrasonic B-mode, Doppler, and strain images are analyzed and extended. The approach is based on a solution to the homogeneous wave equation for random inhomogeneous media. When the system is shift-variant, the spatial sensitivity function—defined as a spatial weighting function that determines the scattering volume for a fixed point of time—has advantages over the point-spread function traditionally used to analyze ultrasound systems. Spatial sensitivity functions are necessary for determining statistical moments in the context of rigorous image quality assessment, and they are time-reversed copies of point-spread functions for shift variant systems. A criterion is proposed to assess the validity of a local shift-invariance assumption. The analysis reveals realistic situations in which in-phase signals are correlated to the corresponding quadrature signals, which has strong implications for assessing lesion detectability. Also revealed is an opportunity to enhance near- and far-field spatial resolution by matched filtering unfocused beams. The analysis connects several well-known approaches to modeling ultrasonic echo signals. PMID:12839176
Integrability of Quadratic Non-autonomous Quantum Linear Systems
NASA Astrophysics Data System (ADS)
Lopez, Raquel
The Quantum Harmonic Oscillator is one of the most important models in Quantum Mechanics. Analogous to the classical mass vibrating back and forth on a spring, the quantum oscillator system has attracted substantial attention over the years because of its importance in many advanced and difficult quantum problems. This dissertation deals with solving generalized models of the time-dependent Schrodinger equation which are called generalized quantum harmonic oscillators, and these are characterized by an arbitrary quadratic Hamiltonian of linear momentum and position operators. The primary challenge in this work is that most quantum models with timedependence are not solvable explicitly, yet this challenge became the driving motivation for this work. In this dissertation, the methods used to solve the time-dependent Schrodinger equation are the fundamental singularity (or Green's function) and the Fourier (eigenfunction expansion) methods. Certain Riccati- and Ermakov-type systems arise, and these systems are highlighted and investigated. The overall aims of this dissertation are to show that quadratic Hamiltonian systems are completely integrable systems, and to provide explicit approaches to solving the time-dependent Schr¨odinger equation governed by an arbitrary quadratic Hamiltonian operator. The methods and results established in the dissertation are not yet well recognized in the literature, yet hold for high promise for further future research. Finally, the most recent results in the dissertation correspond to the harmonic oscillator group and its symmetries. A simple derivation of the maximum kinematical invariance groups of the free particle and quantum harmonic oscillator is constructed from the view point of the Riccati- and Ermakov-type systems, which shows an alternative to the traditional Lie Algebra approach. To conclude, a missing class of solutions of the time-dependent Schrodinger equation for the simple harmonic oscillator in one dimension is
Linear Temporal Logic (LTL) Based Monitoring of Smart Manufacturing Systems.
Heddy, Gerald; Huzaifa, Umer; Beling, Peter; Haimes, Yacov; Marvel, Jeremy; Weiss, Brian; LaViers, Amy
2015-01-01
The vision of Smart Manufacturing Systems (SMS) includes collaborative robots that can adapt to a range of scenarios. This vision requires a classification of multiple system behaviors, or sequences of movement, that can achieve the same high-level tasks. Likewise, this vision presents unique challenges regarding the management of environmental variables in concert with discrete, logic-based programming. Overcoming these challenges requires targeted performance and health monitoring of both the logical controller and the physical components of the robotic system. Prognostics and health management (PHM) defines a field of techniques and methods that enable condition-monitoring, diagnostics, and prognostics of physical elements, functional processes, overall systems, etc. PHM is warranted in this effort given that the controller is vulnerable to program changes, which propagate in unexpected ways, logical runtime exceptions, sensor failure, and even bit rot. The physical component's health is affected by the wear and tear experienced by machines constantly in motion. The controller's source of faults is inherently discrete, while the latter occurs in a manner that builds up continuously over time. Such a disconnect poses unique challenges for PHM. This paper presents a robotic monitoring system that captures and resolves this disconnect. This effort leverages supervisory robotic control and model checking with linear temporal logic (LTL), presenting them as a novel monitoring system for PHM. This methodology has been demonstrated in a MATLAB-based simulator for an industry inspired use-case in the context of PHM. Future work will use the methodology to develop adaptive, intelligent control strategies to evenly distribute wear on the joints of the robotic arms, maximizing the life of the system.
Linear Temporal Logic (LTL) Based Monitoring of Smart Manufacturing Systems
Heddy, Gerald; Huzaifa, Umer; Beling, Peter; Haimes, Yacov; Marvel, Jeremy; Weiss, Brian; LaViers, Amy
2017-01-01
The vision of Smart Manufacturing Systems (SMS) includes collaborative robots that can adapt to a range of scenarios. This vision requires a classification of multiple system behaviors, or sequences of movement, that can achieve the same high-level tasks. Likewise, this vision presents unique challenges regarding the management of environmental variables in concert with discrete, logic-based programming. Overcoming these challenges requires targeted performance and health monitoring of both the logical controller and the physical components of the robotic system. Prognostics and health management (PHM) defines a field of techniques and methods that enable condition-monitoring, diagnostics, and prognostics of physical elements, functional processes, overall systems, etc. PHM is warranted in this effort given that the controller is vulnerable to program changes, which propagate in unexpected ways, logical runtime exceptions, sensor failure, and even bit rot. The physical component’s health is affected by the wear and tear experienced by machines constantly in motion. The controller’s source of faults is inherently discrete, while the latter occurs in a manner that builds up continuously over time. Such a disconnect poses unique challenges for PHM. This paper presents a robotic monitoring system that captures and resolves this disconnect. This effort leverages supervisory robotic control and model checking with linear temporal logic (LTL), presenting them as a novel monitoring system for PHM. This methodology has been demonstrated in a MATLAB-based simulator for an industry inspired use-case in the context of PHM. Future work will use the methodology to develop adaptive, intelligent control strategies to evenly distribute wear on the joints of the robotic arms, maximizing the life of the system. PMID:28730154
NASA Technical Reports Server (NTRS)
Gunderson, R. W.; George, J. H.
1974-01-01
Two approaches are investigated for obtaining estimates on the error between approximate and exact solutions of dynamic systems. The first method is primarily useful if the system is nonlinear and of low dimension. The second requires construction of a system of v-functions but is useful for higher dimensional systems, either linear or nonlinear.
NASA Technical Reports Server (NTRS)
Gunderson, R. W.; George, J. H.
1974-01-01
Two approaches are investigated for obtaining estimates on the error between approximate and exact solutions of dynamic systems. The first method is primarily useful if the system is nonlinear and of low dimension. The second requires construction of a system of v-functions but is useful for higher dimensional systems, either linear or nonlinear.
Aerodynamic preliminary analysis system. Part 1: Theory. [linearized potential theory
NASA Technical Reports Server (NTRS)
Bonner, E.; Clever, W.; Dunn, K.
1978-01-01
A comprehensive aerodynamic analysis program based on linearized potential theory is described. The solution treats thickness and attitude problems at subsonic and supersonic speeds. Three dimensional configurations with or without jet flaps having multiple non-planar surfaces of arbitrary planform and open or closed slender bodies of non-circular contour may be analyzed. Longitudinal and lateral-directional static and rotary derivative solutions may be generated. The analysis was implemented on a time sharing system in conjunction with an input tablet digitizer and an interactive graphics input/output display and editing terminal to maximize its responsiveness to the preliminary analysis problem. Nominal case computation time of 45 CPU seconds on the CDC 175 for a 200 panel simulation indicates the program provides an efficient analysis for systematically performing various aerodynamic configuration tradeoff and evaluation studies.
Stability and complexity of small random linear systems
NASA Astrophysics Data System (ADS)
Hastings, Harold
2010-03-01
We explore the stability of the small random linear systems, typically involving 10-20 variables, motivated by dynamics of the world trade network and the US and Canadian power grid. This report was prepared as an account of work sponsored by an agency of the US Government. Neither the US Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the US Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the US Government or any agency thereof.
Convergence Results on Iteration Algorithms to Linear Systems
Wang, Zhuande; Yang, Chuansheng; Yuan, Yubo
2014-01-01
In order to solve the large scale linear systems, backward and Jacobi iteration algorithms are employed. The convergence is the most important issue. In this paper, a unified backward iterative matrix is proposed. It shows that some well-known iterative algorithms can be deduced with it. The most important result is that the convergence results have been proved. Firstly, the spectral radius of the Jacobi iterative matrix is positive and the one of backward iterative matrix is strongly positive (lager than a positive constant). Secondly, the mentioned two iterations have the same convergence results (convergence or divergence simultaneously). Finally, some numerical experiments show that the proposed algorithms are correct and have the merit of backward methods. PMID:24991640
Method and system for non-linear motion estimation
NASA Technical Reports Server (NTRS)
Lu, Ligang (Inventor)
2011-01-01
A method and system for extrapolating and interpolating a visual signal including determining a first motion vector between a first pixel position in a first image to a second pixel position in a second image, determining a second motion vector between the second pixel position in the second image and a third pixel position in a third image, determining a third motion vector between one of the first pixel position in the first image and the second pixel position in the second image, and the second pixel position in the second image and the third pixel position in the third image using a non-linear model, determining a position of the fourth pixel in a fourth image based upon the third motion vector.
Using parallel banded linear system solvers in generalized eigenvalue problems
NASA Technical Reports Server (NTRS)
Zhang, Hong; Moss, William F.
1993-01-01
Subspace iteration is a reliable and cost effective method for solving positive definite banded symmetric generalized eigenproblems, especially in the case of large scale problems. This paper discusses an algorithm that makes use of two parallel banded solvers in subspace iteration. A shift is introduced to decompose the banded linear systems into relatively independent subsystems and to accelerate the iterations. With this shift, an eigenproblem is mapped efficiently into the memories of a multiprocessor and a high speed-up is obtained for parallel implementations. An optimal shift is a shift that balances total computation and communication costs. Under certain conditions, we show how to estimate an optimal shift analytically using the decay rate for the inverse of a banded matrix, and how to improve this estimate. Computational results on iPSC/2 and iPSC/860 multiprocessors are presented.
Model of intermodulation distortion in non-linear multicarrier systems
NASA Astrophysics Data System (ADS)
Frigo, Nicholas J.
1994-02-01
A heuristic model is proposed which allows calculation of the individual spectral components of the intermodulation distortion present in a non-linear system with a multicarrier input. Noting that any given intermodulation product (IMP) can only be created by a subset of the input carriers, we partition them into 'signal' carriers (which create the IMP) and 'noise' carriers, modeled as a Gaussian process. The relationship between an input signal and the statistical average of its output (averaged over the Gaussian noise) is considered to be an effective transfer function. By summing all possible combinations of signal carriers which create power at the IMP frequencies, the distortion power can be calculated exactly as a function of frequency. An analysis of clipping in lightwave CATV links for AM-VSB signals is used to introduce the model, and is compared to a series of experiments.
ERIC Educational Resources Information Center
Leuthold, Frank O.
The 1992 Tennessee Education Improvement Act resulted from a successful law suit by smaller and poorer school systems in Tennessee concerning equity of funding. The Act established the Basic Education Program (BEP), which increased the state sales tax rate, shifted state funds from better funded to poorer school systems, and required systematic…
Robust mean field games for coupled Markov jump linear systems
NASA Astrophysics Data System (ADS)
Moon, Jun; Başar, Tamer
2016-07-01
We consider robust stochastic large population games for coupled Markov jump linear systems (MJLSs). The N agents' individual MJLSs are governed by different infinitesimal generators, and are affected not only by the control input but also by an individual disturbance (or adversarial) input. The mean field term, representing the average behaviour of N agents, is included in the individual worst-case cost function to capture coupling effects among agents. To circumvent the computational complexity and analyse the worst-case effect of the disturbance, we use robust mean field game theory to design low-complexity robust decentralised controllers and to characterise the associated worst-case disturbance. We show that with the individual robust decentralised controller and the corresponding worst-case disturbance, which constitute a saddle-point solution to a generic stochastic differential game for MJLSs, the actual mean field behaviour can be approximated by a deterministic function which is a fixed-point solution to the constructed mean field system. We further show that the closed-loop system is uniformly stable independent of N, and an approximate optimality can be obtained in the sense of ε-Nash equilibrium, where ε can be taken to be arbitrarily close to zero as N becomes sufficiently large. A numerical example is included to illustrate the results.
A Structured Model Reduction Method for Linear Interconnected Systems
NASA Astrophysics Data System (ADS)
Sato, Ryo; Inoue, Masaki; Adachi, Shuichi
2016-09-01
This paper develops a model reduction method for a large-scale interconnected system that consists oflinear dynamic components. In the model reduction, we aim to preserve physical characteristics of each component. To this end, we formulate a structured model reduction problem that reduces the model order of components while preserving the feedback structure. Although there are a few conventional methods for such structured model reduction to preserve stability, they do not explicitly consider performance of the reduced-order feedback system. One of the difficulties in the problem with performance guarantee comes from nonlinearity of a feedback system to each component. The problem is essentially in a class of nonlinear optimization problems, and therefore it cannot be efficiently solved even in numerical computation. In this paper, application of an equivalent transformation and a proper approximation reduces this nonlinear problem to a problem of the weighted linear model reduction. Then, by using the weighted balanced truncation technique, we construct a reduced-order model with preserving the feedback structure to ensure small modeling error. Finally, we verify the effectiveness of the proposed method through numerical experiments.
A linear geospatial streamflow modeling system for data sparse environments
Asante, Kwabena O.; Arlan, Guleid A.; Pervez, Md Shahriar; Rowland, James
2008-01-01
In many river basins around the world, inaccessibility of flow data is a major obstacle to water resource studies and operational monitoring. This paper describes a geospatial streamflow modeling system which is parameterized with global terrain, soils and land cover data and run operationally with satellite‐derived precipitation and evapotranspiration datasets. Simple linear methods transfer water through the subsurface, overland and river flow phases, and the resulting flows are expressed in terms of standard deviations from mean annual flow. In sample applications, the modeling system was used to simulate flow variations in the Congo, Niger, Nile, Zambezi, Orange and Lake Chad basins between 1998 and 2005, and the resulting flows were compared with mean monthly values from the open‐access Global River Discharge Database. While the uncalibrated model cannot predict the absolute magnitude of flow, it can quantify flow anomalies in terms of relative departures from mean flow. Most of the severe flood events identified in the flow anomalies were independently verified by the Dartmouth Flood Observatory (DFO) and the Emergency Disaster Database (EM‐DAT). Despite its limitations, the modeling system is valuable for rapid characterization of the relative magnitude of flood hazards and seasonal flow changes in data sparse settings.
A method to stabilize linear systems using eigenvalue gradient information
NASA Technical Reports Server (NTRS)
Wieseman, C. D.
1985-01-01
Formal optimization methods and eigenvalue gradient information are used to develop a stabilizing control law for a closed loop linear system that is initially unstable. The method was originally formulated by using direct, constrained optimization methods with the constraints being the real parts of the eigenvalues. However, because of problems in trying to achieve stabilizing control laws, the problem was reformulated to be solved differently. The method described uses the Davidon-Fletcher-Powell minimization technique to solve an indirect, constrained minimization problem in which the performance index is the Kreisselmeier-Steinhauser function of the real parts of all the eigenvalues. The method is applied successfully to solve two different problems: the determination of a fourth-order control law stabilizes a single-input single-output active flutter suppression system and the determination of a second-order control law for a multi-input multi-output lateral-directional flight control system. Various sets of design variables and initial starting points were chosen to show the robustness of the method.
Policy Guidelines for Restricted Grant Expenditures and Reporting, Fiscal Year 2001.
ERIC Educational Resources Information Center
Illinois Community Coll. Board, Springfield.
This document presents policy guidelines for restricted grant expenditures and reporting for fiscal year 2001 within the Illinois Community College system. It describes the purpose, allowable expenditures, expenditure limitations, and grant administrative standards for various types of restricted grant expenditures, including: (1) Special…
42 CFR 495.366 - Financial oversight and monitoring of expenditures.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 5 2010-10-01 2010-10-01 false Financial oversight and monitoring of expenditures... monitoring of expenditures. (a) General rule. (1) The State must have a process in place to estimate expenditures for the Medicaid EHR payment incentive program using the Medicaid Budget Expenditure System....
NASA Astrophysics Data System (ADS)
Zehe, Erwin; Loritz, Ralf; Ehret, Uwe; Westhoff, Martijn; Kleidon, Axel; Savenije, Hubert
2017-04-01
It is flabbergasting to note that catchment systems often behave almost linearly, despite of the strong non-linearity of point scale soil water characteristics. In the present study we provide evidence that a thermodynamic treatment of environmental system dynamics is the key to understand how particularly a stronger spatial organization of catchments leads to a more linear rainfall runoff behavior. Our starting point is that water fluxes in a catchment are associated with fluxes of kinetic and potential energy while changes in subsurface water stocks go along with changes in potential energy and chemical energy of subsurface water. Steady state/local equilibrium of the entire system can be defined as a state of minimum free energy, reflecting an equilibrium subsurface water storage, which is determined catchment topography, soil water characteristics and water levels in the stream. Dynamics of the entire system, i.e. deviations from equilibrium storage, are 'pseudo' oscillations in a thermodynamic state space. Either to an excess potential energy in case of wetting while subsequent relaxation back to equilibrium requires drainage/water export. Or to an excess in capillary binding energy in case of driving, while relaxation back to equilibrium requires recharge of the subsurface water stock. While system dynamics is highly non-linear on the 'too dry branch' it is essentially linear on the 'too wet branch' in case of potential energy excess. A steepened topography, which reflects a stronger spatial organization, reduces the equilibrium storage of the catchment system to smaller values, thereby it increases the range of states where the systems behaves linearly due to an excess in potential energy. Contrarily to this a shift to finer textured soils increases the equilibrium storage, which implies that the range of states where the systems behaves linearly is reduced. In this context it is important to note that an increased internal organization of the system due to
National Health Expenditures, 1993
Levit, Katharine R.; Sensenig, Arthur L.; Cowan, Cathy A.; Lazenby, Helen C.; McDonnell, Patricia A.; Won, Darleen K.; Sivarajan, Lekha; Stiller, Jean M.; Donham, Carolyn S.; Stewart, Madie S.
1994-01-01
This article presents data on health care spending for the United States, covering expenditures for various types of medical services and products and their sources of funding from 1960 to 1993. Although these statistics show a slowing in the growth of health care expenditures over the past few years, spending continues to increase faster than the overall economy. The share of the Nation's health care bill funded by the Federal Government through the Medicaid and Medicare programs steadily increased from 1991 to 1993. This significant change in the share of health expenditures funded by the public sector has caused Federal health expenditures as a share of all Federal spending to increase dramatically. PMID:10140156
Spitzmueller, David; Hodler, Juerg; Seifert, Burkhardt; Zanetti, Marco
2010-09-01
OBJECTIVE: The purpose of this study was to evaluate the relationship of the radiological research activity from 1998 to 2007 to the gross domestic product (GDP), health expenditure and public expenditure on education. METHODS: The population-adjusted research activity determined by the number of articles published, the cumulative impact factor (IF) and the cumulative IF per capita were correlated with per capita values of the GDP, health expenditure and public education expenditure. Linear regression analysis and multiple regression analysis were used for statistical analysis. RESULTS: The cumulative IF per capita correlated with the GDP per capita (R = 0.94, P < 0.0001), health expenditure per capita (R = 0.93, P < 0.0001) and public expenditure on education per capita (R = 0.93, P < 0.0001). Multiple regression analysis demonstrated that public expenditure on education was an independent predictor of radiological research activity (P < 0.001), whereas the year, GDP and health expenditure did not reach statistical significance (P > 0.05). CONCLUSION: Radiological research activity demonstrates a close relationship to the GDP, health expenditure and public expenditure on education. The last factor independently predicts research activity.
2-D linear motion system. Innovative technology summary report
1998-11-01
The US Department of Energy's (DOE's) nuclear facility decontamination and decommissioning (D and D) program requires buildings to be decontaminated, decommissioned, and surveyed for radiological contamination in an expeditious and cost-effective manner. Simultaneously, the health and safety of personnel involved in the D and D activities is of primary concern. D and D workers must perform duties high off the ground, requiring the use of manlifts or scaffolding, often, in radiologically or chemically contaminated areas or in areas with limited access. Survey and decontamination instruments that are used are sometimes heavy or awkward to use, particularly when the worker is operating from a manlift or scaffolding. Finding alternative methods of performing such work on manlifts or scaffolding is important. The 2-D Linear Motion System (2-D LMS), also known as the Wall Walker{trademark}, is designed to remotely position tools and instruments on walls for use in such activities as radiation surveys, decontamination, and painting. Traditional (baseline) methods for operating equipment for these tasks require workers to perform duties on elevated platforms, sometimes several meters above the ground surface and near potential sources of contamination. The Wall Walker 2-D LMS significantly improves health and safety conditions by facilitating remote operation of equipment. The Wall Walker 2-D LMS performed well in a demonstration of its precision, accuracy, maneuverability, payload capacity, and ease of use. Thus, this innovative technology is demonstrated to be a viable alternative to standard methods of performing work on large, high walls, especially those that have potential contamination concerns. The Wall Walker was used to perform a final release radiological survey on over 167 m{sup 2} of walls. In this application, surveying using a traditional (baseline) method that employs an aerial lift for manual access was 64% of the total cost of the improved technology
Factorial switching linear dynamical systems applied to physiological condition monitoring.
Quinn, John A; Williams, Christopher K I; McIntosh, Neil
2009-09-01
Condition monitoring often involves the analysis of systems with hidden factors that switch between different modes of operation in some way. Given a sequence of observations, the task is to infer the filtering distribution of the switch setting at each time step. In this paper, we present factorial switching linear dynamical systems as a general framework for handling such problems. We show how domain knowledge and learning can be successfully combined in this framework, and introduce a new factor (the "X-factor") for dealing with unmodeled variation. We demonstrate the flexibility of this type of model by applying it to the problem of monitoring the condition of a premature baby receiving intensive care. The state of health of a baby cannot be observed directly, but different underlying factors are associated with particular patterns of physiological measurements and artifacts. We have explicit knowledge of common factors and use the X-factor to model novel patterns which are clinically significant but have unknown cause. Experimental results are given which show the developed methods to be effective on typical intensive care unit monitoring data.
Linear dynamic system approach to groundwater solute transport equation
Cho, W.C.
1984-01-01
Groundwater pollution in the United States has been recognized in the 1980's to be extensive both in degree and geographic distribution. It has been recognized that in many cases groundwater pollution is essentially irreversible from the engineering or economic viewpoint. Under the best circumstance the problem is complicated by insufficient amounts of field data which is costly to obtain. In general, the governing partial differential equation of solute transport is spatially discretized either using finite difference or finite element scheme. The time derivative is also approximated by finite difference. In this study, only the spatial discretization is performed using finite element method and the time derivative is retained in continuous form. The advantage is that special features of finite element are maintained but most important of all is that the equation can be rearranged to be in a standard form of linear dynamic system. Two problems were studied in detail: one is the determination of the locatio of groundwater pollution source(s). The problem is equivalent to identifying an input to the dynamic system and is solved by using the sensitivity theorem. The other one is the prediction of pollutant concentration at a given time at a given location. The eigenvalue technique was employed to solve this problem and the detailed procedures of the computation were delineated.
Low-Rank Linear Dynamical Systems for Motor Imagery EEG
Tan, Chuanqi; Liu, Shaobo
2016-01-01
The common spatial pattern (CSP) and other spatiospectral feature extraction methods have become the most effective and successful approaches to solve the problem of motor imagery electroencephalography (MI-EEG) pattern recognition from multichannel neural activity in recent years. However, these methods need a lot of preprocessing and postprocessing such as filtering, demean, and spatiospectral feature fusion, which influence the classification accuracy easily. In this paper, we utilize linear dynamical systems (LDSs) for EEG signals feature extraction and classification. LDSs model has lots of advantages such as simultaneous spatial and temporal feature matrix generation, free of preprocessing or postprocessing, and low cost. Furthermore, a low-rank matrix decomposition approach is introduced to get rid of noise and resting state component in order to improve the robustness of the system. Then, we propose a low-rank LDSs algorithm to decompose feature subspace of LDSs on finite Grassmannian and obtain a better performance. Extensive experiments are carried out on public dataset from “BCI Competition III Dataset IVa” and “BCI Competition IV Database 2a.” The results show that our proposed three methods yield higher accuracies compared with prevailing approaches such as CSP and CSSP. PMID:28096809
Low-Rank Linear Dynamical Systems for Motor Imagery EEG.
Zhang, Wenchang; Sun, Fuchun; Tan, Chuanqi; Liu, Shaobo
2016-01-01
The common spatial pattern (CSP) and other spatiospectral feature extraction methods have become the most effective and successful approaches to solve the problem of motor imagery electroencephalography (MI-EEG) pattern recognition from multichannel neural activity in recent years. However, these methods need a lot of preprocessing and postprocessing such as filtering, demean, and spatiospectral feature fusion, which influence the classification accuracy easily. In this paper, we utilize linear dynamical systems (LDSs) for EEG signals feature extraction and classification. LDSs model has lots of advantages such as simultaneous spatial and temporal feature matrix generation, free of preprocessing or postprocessing, and low cost. Furthermore, a low-rank matrix decomposition approach is introduced to get rid of noise and resting state component in order to improve the robustness of the system. Then, we propose a low-rank LDSs algorithm to decompose feature subspace of LDSs on finite Grassmannian and obtain a better performance. Extensive experiments are carried out on public dataset from "BCI Competition III Dataset IVa" and "BCI Competition IV Database 2a." The results show that our proposed three methods yield higher accuracies compared with prevailing approaches such as CSP and CSSP.
NASA Astrophysics Data System (ADS)
Zawadzki, Andrzej; Różowicz, Sebastian
2016-05-01
The paper presents a transformation of nonlinear electric circuit into linear one through changing coordinates (local diffeomorphism) with the use of closed feedback loop. The necessary conditions that must be fulfilled by nonlinear system to enable carrying out linearizing procedures are presented. Numerical solutions of state equations for the nonlinear system and equivalent linearized system are included.
Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems
Sharma, S. D.; Kumar, Sudhir; Dagaonkar, S. S.; Bisht, Geetika; Dayanand, S.; Devi, Reena; Deshpande, S. S.; Chaudhary, S.; Bhatt, B. C.; Kannan, S.
2007-01-01
Stereotactic radiosurgery (SRS) is a special radiotherapy technique used to irradiate intracranial lesions by 3-D arrangements of narrow photon beams eliminating the needs of invasive surgery. Three different tertiary collimators, namely BrainLab and Radionics circular cones and BrainLab micro multileaf collimator (mMLC), are used for linear accelerator-based SRS systems (X-Knife). Output factor (St), tissue maximum ratio (TMR) and off axis ratio (OAR) of these three SRS systems were measured using CC01 (Scanditronix/ Welhofer) and Pinpoint (PTW) cylindrical and Markus plane parallel ionization chambers as well as TLD and radiochromic film. Measurement results of CC01 and Pinpoint chambers were very close to each other which indicate that further reduction in volume and physical dimensions of cylindrical ionization chamber is not necessary for SRS/SRT dosimetry. Output factors of BrainLab and Radionics SRS cones were very close to each other while output factors of equivalent diameter mMLC field were different from SRS circular cones. TMR of the three SRS systems compared were very close to one another. OAR of Radionics cone and BrainLab mMLC were very close to each other, within 2%. However, OARs of BrainLab cone were found comparable to OARs of Radionics cone and BrainLab mMLC within maximum variation of 4%. In addition, user-measured similar data of other three mMLC X-Knives were compared with the mMLC X-Knife data measured in this work and found comparable. The concept of switching over to mMLC-based SRS/SRT is thus validated from dosimetric characteristics as well. PMID:21217914
Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems.
Sharma, S D; Kumar, Sudhir; Dagaonkar, S S; Bisht, Geetika; Dayanand, S; Devi, Reena; Deshpande, S S; Chaudhary, S; Bhatt, B C; Kannan, S
2007-01-01
Stereotactic radiosurgery (SRS) is a special radiotherapy technique used to irradiate intracranial lesions by 3-D arrangements of narrow photon beams eliminating the needs of invasive surgery. Three different tertiary collimators, namely BrainLab and Radionics circular cones and BrainLab micro multileaf collimator (mMLC), are used for linear accelerator-based SRS systems (X-Knife). Output factor (S(t)), tissue maximum ratio (TMR) and off axis ratio (OAR) of these three SRS systems were measured using CC01 (Scanditronix/ Welhofer) and Pinpoint (PTW) cylindrical and Markus plane parallel ionization chambers as well as TLD and radiochromic film. Measurement results of CC01 and Pinpoint chambers were very close to each other which indicate that further reduction in volume and physical dimensions of cylindrical ionization chamber is not necessary for SRS/SRT dosimetry. Output factors of BrainLab and Radionics SRS cones were very close to each other while output factors of equivalent diameter mMLC field were different from SRS circular cones. TMR of the three SRS systems compared were very close to one another. OAR of Radionics cone and BrainLab mMLC were very close to each other, within 2%. However, OARs of BrainLab cone were found comparable to OARs of Radionics cone and BrainLab mMLC within maximum variation of 4%. In addition, user-measured similar data of other three mMLC X-Knives were compared with the mMLC X-Knife data measured in this work and found comparable. The concept of switching over to mMLC-based SRS/SRT is thus validated from dosimetric characteristics as well.
A Linear Systems Approach to Segmented Watershed Contaminant Transport
NASA Astrophysics Data System (ADS)
Carleton, J. N.
2013-12-01
The U.S. Environmental Protection Agency (USEPA) employs simulation models to estimate concentrations of pesticide residues in surface waters for risk assessment. These models have historically been used to simulate runoff loadings from homogeneous landscapes to isolated, well-mixed lentic systems that generically represent vulnerable waters. Recent efforts to refine this approach in terms of realism and geographic specificity have focused on enhancing the level of detail of the landscape representation, rather than that of receiving water hydrology. Linear systems theory and transfer function based approaches have been applied by various investigators to the representation of contaminant leaching through soils, and to surface water hydrology (e.g., unit hydrographs), but rarely to contaminant transport either within surface waters, or through multi-compartment systems such as stream networks. This poster describes a straightforward approach to simulating watersheds as segmented into collections of linked water bodies. The approach employs convolution integrals, impulse response functions, and the Discrete Fourier Transform to propagate concentration time series from upstream to downstream locations. Given knowledge only of estimated mean stream residence times, with appropriately-scaled segmentations of catchments, realistic representations of concentration dynamics are shown to be achievable. These representations are based upon high-frequency atrazine monitoring data sets collected over common time periods from upstream and downstream locations within the same small watersheds. Simulated concentrations are shown to match measured concentrations well in both the temporal and spectral domains without the need for calibration, and despite inherent simplifying assumptions such as steady flow. The approach may have utility for enhancing surface water hydrologic representation in contaminant modeling used for regulatory purposes.
EU pharmaceutical expenditure forecast
Urbinati, Duccio; Rémuzat, Cécile; Kornfeld, Åsa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aballéa, Samuel; Mzoughi, Olfa; Toumi, Mondher
2014-01-01
(−€5,589 million), and, far behind them, Germany (−€831 million), Greece (−€808 million), Portugal (−€243 million), and Hungary (−€84 million). The main source of savings came from the cardiovascular, central nervous system, and respiratory areas and from biosimilar entries. Oncology, immunology, and inflammation, in contrast, lead to additional expenditure. The model was particularly sensitive to the time to market of branded products, generic prices, generic penetration, and the distribution of biosimilars. Conclusions The results of this forecast suggested a decrease in pharmaceutical expenditure in the studied period. The model was sensitive to pharmaceutical policy decisions. PMID:27226837
On differential operators generating iterative systems of linear ODEs of maximal symmetry algebra
NASA Astrophysics Data System (ADS)
Ndogmo, J. C.
2017-06-01
Although every iterative scalar linear ordinary differential equation is of maximal symmetry algebra, the situation is different and far more complex for systems of linear ordinary differential equations, and an iterative system of linear equations need not be of maximal symmetry algebra. We illustrate these facts by examples and derive families of vector differential operators whose iterations are all linear systems of equations of maximal symmetry algebra. Some consequences of these results are also discussed.
Symmetry breaking in linearly coupled Korteweg-de Vries systems.
Espinosa-Cerón, A; Malomed, B A; Fujioka, J; Rodríguez, R F
2012-09-01
We consider solitons in a system of linearly coupled Korteweg-de Vries (KdV) equations, which model two-layer settings in various physical media. We demonstrate that traveling symmetric solitons with identical components are stable at velocities lower than a certain threshold value. Above the threshold, which is found exactly, the symmetric modes are unstable against spontaneous symmetry breaking, which gives rise to stable asymmetric solitons. The shape of the asymmetric solitons is found by means of a variational approximation and in the numerical form. Simulations of the evolution of an unstable symmetric soliton sometimes produce its breakup into two different asymmetric modes. Collisions between moving stable solitons, symmetric and asymmetric ones, are studied numerically, featuring noteworthy features. In particular, collisions between asymmetric solitons with identical polarities are always elastic, while in the case of opposite polarities the collision leads to a switch of the polarities of both solitons. Three-soliton collisions are studied too, featuring quite complex interaction scenarios.
Characterising the stabilisability for second-order linear switched systems
NASA Astrophysics Data System (ADS)
Cong, Shen
2013-03-01
The stabilisability of second-order linear switched systems is the topic focused on in a number of papers, however, some of its fundamental characteristics are still unrevealed. In this article, regarding a pair of subsystems, we are interested in characterising this problem from both the state-triggering and time-domain viewpoints and in revealing the inherent connection between them. To this end, we first use polar coordinates to represent the geometric property of switching and the dynamical behaviours caused by it, and then put the geometrised switching control into correspondence with the implicit stabilisation mechanism behind it. Doing this in a strong way relies on classifying switching control into two types intuitively, namely, chattering switching and spinning switching, and then clarifying their distinction and properties rigorously. Furthermore, the uniform convergence of the forced trajectory is shown by presenting estimation on its decay rate; and the limit cycles and sliding motions generated by switching are also accounted for. The results are illustrated by elaborate examples.
Electron linear accelerator system for natural rubber vulcanization
NASA Astrophysics Data System (ADS)
Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.
2017-09-01
Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.
NASA Astrophysics Data System (ADS)
Dobrokhotov, S. Yu.; Shafarevich, A. I.; Tirozzi, B.
2008-06-01
The result of this paper is that any fast-decaying function can be represented as an integral over the canonical Maslov operator, on a special Lagrangian manifold, acting on a specific function. This representation enables one to construct effective explicit formulas for asymptotic solutions of a vast class of linear hyperbolic systems with variable coefficients.
Linear matrix inequalities for analysis and control of linear vector second-order systems
Adegas, Fabiano D.; Stoustrup, Jakob
2014-10-06
Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems. The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form.
Hagenaars, Luc L; Klazinga, Niek S; Mueller, Michael; Morgan, David J; Jeurissen, Patrick P T
2017-10-12
Administration is vital for health care. Its importance may increase as health care systems become more complex, but academic attention has remained minimal. We investigated trends in administrative expenditure across OECD countries, cross-country spending differences, spending differences between health care system typologies, and differences in the scale and scope of administrative functions across typologies. We used OECD data, which include health system governance and financing-related administrative activities by regulators, governance bodies, and insurers (macrolevel), but exclude administrative expenditure by health care providers (mesolevel and microlevel). We find that governance and financing-related administrative spending at the macrolevel has remained stable over the last decade at slightly over 3% of total health spending. Cross-country differences range from 1.3% of health spending in Iceland to 8.3% in the United States. Voluntary private health insurance bears much higher administrative costs than compulsory schemes in all countries. Among compulsory schemes, multiple payers exhibit significantly higher administrative spending than single payers. Among single-payer schemes, those where entitlements are based on residency have significantly lower administrative spending than those with single social health insurance, albeit with a small difference. These differences can partially be explained because multi-payer and voluntary private health insurance schemes require additional administrative functions and enjoy less economies of scale. Studies in hospitals and primary care indicate similar differences in administrative costs across health system typologies at the mesolevel and microlevel of health care delivery, which warrants more research on total administrative costs at all the levels of health systems. Copyright © 2017 John Wiley & Sons, Ltd.
Curtis, Lesley H; Law, Amy W; Anstrom, Kevin J; Schulman, Kevin A
2004-05-01
Despite continuing debate over a prescription drug benefit for the Medicare program, there has been relatively little research estimating the potential cost of providing such a benefit. The objective of this study was to estimate the effect of prescription drug insurance on outpatient prescription drug expenditures among the elderly. We studied respondents aged > or =65 years to the 1997 Medical Expenditure Panel Survey, a representative survey of the U.S. noninstitutionalized population. Survey-weighted linear regression models were used to estimate the probability of any expenditures and total expenditures while controlling for sociodemographic characteristics, chronic conditions, and health status. We used prescription drug insurance status and outpatient prescription drug expenditures. An estimated 34 million elderly people filled 630 million prescriptions in 1997. Thirty-seven percent did not have prescription drug insurance. Total prescription drug expenditures exceeded $23 billion. Persons without prescription drug insurance spent slightly less than $7 billion; those with insurance spent more than $16 billion. After controlling for health status, comorbidity, and demographic characteristics, prescription drug insurance increased expenditures by $183 per person. The marginal increase in total expenditures of extending the average observed benefit to those currently uninsured is $2.3 billion (95% confidence interval, $1.2-3.5 billion). Proposals for a Medicare drug benefit provide high copayments to protect against insurance effects and to address uncertainty in cost estimates of the proposed benefit. By quantifying the insurance effect on expenditures among the elderly, the data reported here could reduce uncertainty in the budget estimation process.
Composite-step product methods for solving nonsymmetric linear systems
Chan, T.F.; Szeto, T.
1994-12-31
The Biconjugate Gradient (BCG) algorithm is the {open_quotes}natural{close_quotes} generalization of the classical Conjugate Gradient method to nonsymmetric linear systems. It is an attractive method because of its simplicity and its good convergence properties. Unfortunately, BCG suffers from two kinds of breakdowns (divisions by 0): one due to the non-existence of the residual polynomial, and the other due to a breakdown in the recurrence relationship used. There are many look-ahead techniques in existence which are designed to handle these breakdowns. Although the step size needed to overcome an exact breakdown can be computed in principle, these methods can unfortunately be quite complicated for handling near breakdowns since the sizes of the look-ahead steps are variable (indeed, the breakdowns can be incurable). Recently, Bank and Chan introduced the Composite Step Biconjugate Gradient (CSBCG) algorithm, an alternative which cures only the first of the two breakdowns mentioned by skipping over steps for which the BCG iterate is not defined. This is done with a simple modification of BCG which needs only a maximum look-ahead step size of 2 to eliminate the (near) breakdown and to smooth the sometimes erratic convergence of BCG. Thus, instead of a more complicated (but less prone to breakdown) version, CSBCG cures only one kind of breakdown, but does so with a minimal modification to the usual implementation of BCG in the hope that its empirically observed stability will be inherited. The authors note, then, that the Composite Step idea can be incorporated anywhere the BCG polynomial is used; in particular, in product methods such as CGS, Bi-CGSTAB, and TFQMR. Doing this not only cures the breakdown mentioned above, but also takes on the advantages of these product methods, namely, no multiplications by the transpose matrix and a faster convergence rate than BCG.
National health expenditures, 1988
1990-01-01
Every year, analysts in the Health Care Financing Administration present figures on what our Nation spends for health. As the result of a comprehensive re-examination of the definitions, concepts, methods, and data sources used to prepare those figures, this year's report contains new estimates of national health expenditures for calendar years 1960 through 1988. Significant changes have been made to estimates of spending for professional services and to estimates of what consumers pay out of pocket for health care. In the first article, trends in use of and expenditure for various types of goods and services are discussed, as well as trends in the sources of funds used to finance health care. In a companion article, the benchmark process is described in more detail, as are the data sources and methods used to prepare annual estimates of health expenditures. PMID:10113395
National health expenditures, 1990
Levit, Katharine R.; Lazenby, Helen C.; Cowan, Cathy A.; Letsch, Suzanne W.
1991-01-01
During 1990, health expenditures as a share of gross national product rose to 12.2 percent, up from 11.6 percent in 1989. This dramatic increase is the second largest increase in the past three decades. The national health expenditure estimates presented in this article document rapidly rising health care costs and provide a context for understanding the health care financing crisis facing the Nation today. The 1990 national health expenditures incorporate the most recently available data. They differ from historical estimates presented in the preceding article. The length of time and complicated process of producing projections required use of 1989 national health expenditures—data available prior to the completion of the 1990 estimates presented here. PMID:10114934
BenAbdallah, Abdallah; Hammami, Mohamed Ali; Kallel, Jalel
2009-03-05
In this paper we present some sufficient conditions for the robust stability and stabilization of time invariant uncertain piecewise linear system using homogenous piecewise polynomial Lyapunov function. The proposed conditions are given in terms of linear matrix inequalities which can be numerically solved. An application of the obtained result is given. It consists in resolving the stabilization of piecewise uncertain linear control systems by using a state piecewise linear feedback.
Dynamic MLC leaf sequencing for integrated linear accelerator control systems
Popple, Richard A.; Brezovich, Ivan A.
2011-11-15
Purpose: Leaf positions for dynamic multileaf collimator (DMLC) intensity modulated radiation therapy must be closely synchronized with MU delivery. For the Varian C3 series MLC controller, if the planned trajectory (leaf position vs. MU) requires velocities exceeding the capability of the MLC, the leaves fall behind the planned positions, causing the controller to momentarily hold the beam and thereby introduce dosimetric errors. We investigated the merits of a new commercial linear accelerator, TrueBeam, that integrates MLC control with prospective dose rate modulation. If treatment is delivered at dose rates so high that leaves would fall behind, the controller reduces the dose rate such that harmony between MU and leaf position is preserved. Methods: For three sets of DMLC leaf trajectories, point doses and two-dimensional dose distributions were measured in phantom using an ionization chamber and film, respectively. The first set, delivered using both a TrueBeam and a conventional C3 controller, comprised a single leaf bank closing at planned velocities of 2.4, 7.1, and 14 cm/s. The maximum achievable leaf velocity for both systems was 3 cm/s. The remaining two sets were derived from clinical fluence maps using a commercial treatment planning system for a range of planned dose rates and were delivered using TrueBeam set to the maximum dose rate, 600 MU/min. Generating trajectories using a planned dose rate that is lower than the delivery dose rate effectively increased the leaf velocity constraint used by the planning system for trajectory calculation. The second set of leaf trajectories was derived from two fluence maps containing regions of zero fluence obtained from representative beams of two different patient treatment plans. The third set was obtained from all nine fields of a head and neck treatment plan. For the head and neck plan, dose-volume histograms of the spinal cord and target for each planned dose rate were obtained. Results: For the single
National health expenditures, 1984
Levit, Katharine R.; Lazenby, Helen; Waldo, Daniel R.; Davidoff, Lawrence M.
1985-01-01
Growth in health care expenditures slowed to 9.1 percent in 1984, the smallest increase in expenditures in 19 years. Economic forces and emerging structural changes within the health sector played a role in slowing growth. Of the $1,580 per person spent for health care in 1984, 41 percent was financed by public programs; 31 percent by private health insurance; and the remainder by other private sources. Together, Medicare and Medicaid accounted for 27 percent of all health spending. PMID:10311395
Linear, Parameter-Varying Control of Aeroservoelastic Systems
NASA Astrophysics Data System (ADS)
Moreno Chicunque, Claudia Patricia
Modern aircraft designers are adopting light-weight, high-aspect ratio flexible wings to improve performance and reduce operation costs. A technical challenge associated with these designs is that the large deformations in flight of the wings lead to adverse interactions between the aircraft aerodynamic forces and structural forces. These adverse interactions produce excessive vibrations that can degrade flying qualities and may result in severe structural damages or catastrophic failure. This dissertation is focused on the application of multivariable robust control techniques for suppression of these adverse interactions in flexible aircraft. Here, the aircraft coupled nonlinear equations of motion are represented in the linear, parameter-varying framework. These equations account for the coupled aerodynamics, rigid body dynamics, and deformable body dynamics of the aircraft. Unfortunately, the inclusion of this coupled dynamics results in high-order models that increase the computational complexity of linear, parameter-varying control techniques. This dissertation addresses three key technologies for linear, parameter-varying control of flexible aircraft: (i) linear, parameter-varying model reduction; (ii) selection of actuators and sensors for vibration suppression; and (iii) design of linear, parameter-varying controllers for vibration suppression. All of these three technologies are applied to an experimental research platform located at the University of Minnesota. The objective of this dissertation is to provide to the flight control community with a set of design methodologies to safely exploit the benefits of light-weight flexible aircraft.
42 CFR 495.366 - Financial oversight and monitoring of expenditures.
Code of Federal Regulations, 2014 CFR
2014-10-01
... incentive program using the Medicaid Budget Expenditure System. (3) The State must have an automated payment and information retrieval mechanized system, (Medicaid Management Information System) to make EHR... expenditures for the Medicaid EHR payment incentive program using the Medicaid Budget Expenditure System. (2...
Gao, Fan; Latash, Mark L; Zatsiorsky, Vladimir M
2006-03-01
We address issues of simultaneous control of the grasping force and the total moment of forces applied to a handheld object during its manipulation. Six young healthy male subjects grasped an instrumented handle and performed its cyclic motion in the vertical direction. The handle allowed for setting different clockwise (negative) or counterclockwise torques. Three movement frequencies: 1, 1.5 and 2 Hz, and five different torques: -1/3, -1/6, 0, 1/6 and 1/3 Nm, were used. The rotational equilibrium was maintained by two means: (1) Concerted changes of the moments produced by the normal and tangential forces, specifically anti-phase changes of the moments during the tasks with zero external torque and in-phase changes during the non-zero-torque tasks, and (2) Redistribution of the normal forces among individual fingers such that the agonist fingers--the fingers that resist external torque--increased the force in phase with the acceleration, while the forces of the antagonist fingers--those that assist the external torque--especially, the fingers with the large moment arms, the index and little fingers, stayed unchanged. The observed effects agree with the principle of superposition--according to which some complex actions, for example, prehension, can be decomposed into elemental actions controlled independently--and the mechanical advantage hypothesis according to which in moment production the fingers are activated in proportion to their moment arms with respect to the axis of rotation. We would like to emphasize the linearity of the observed relations, which was not prescribed by the task mechanics and seems to be produced by specific neural control mechanisms.
[Quantitative analysis of drug expenditures variability in dermatology units].
Moreno-Ramírez, David; Ferrándiz, Lara; Ramírez-Soto, Gabriel; Muñoyerro, M Dolores
2013-01-01
Variability in adjusted drug expenditures among clinical departments raises the possibility of difficult access to certain therapies at the time that avoidable expenditures may also exist. Nevertheless, drug expenditures are not usually applied to clinical practice variability analysis. To identify and quantify variability in drug expenditures in comparable dermatology department of the Servicio Andaluz de Salud. Comparative economic analysis regarding the drug expenditures adjusted to population and health care production in 18 dermatology departments of the Servicio Andaluz de Salud. The 2012 cost and production data (homogeneous production units -HPU-)were provided by Inforcoan, the cost accounting information system of the Servicio Andaluz de Salud. The observed drug expenditure ratio ranged from 0.97?/inh to 8.90?/inh and from 208.45?/HPU to 1,471.95?/ HPU. The Pearson correlation between drug expenditure and population was 0.25 and 0.35 for the correlation between expenditure and homogeneous production (p=0.32 and p=0,15, respectively), both Pearson coefficients confirming the lack of correlation and arelevant degree of variability in drug expenditures. The quantitative analysis of variability performed through Pearson correlation has confirmed the existence of drug expenditure variability among comparable dermatology departments. Copyright © 2013 SEFH. Published by AULA MEDICA. All rights reserved.
NASA Technical Reports Server (NTRS)
Jamison, J. W.
1994-01-01
CFORM was developed by the Kennedy Space Center Robotics Lab to assist in linear control system design and analysis using closed form and transient response mechanisms. The program computes the closed form solution and transient response of a linear (constant coefficient) differential equation. CFORM allows a choice of three input functions: the Unit Step (a unit change in displacement); the Ramp function (step velocity); and the Parabolic function (step acceleration). It is only accurate in cases where the differential equation has distinct roots, and does not handle the case for roots at the origin (s=0). Initial conditions must be zero. Differential equations may be input to CFORM in two forms - polynomial and product of factors. In some linear control analyses, it may be more appropriate to use a related program, Linear Control System Design and Analysis (KSC-11376), which uses root locus and frequency response methods. CFORM was written in VAX FORTRAN for a VAX 11/780 under VAX VMS 4.7. It has a central memory requirement of 30K. CFORM was developed in 1987.
NASA Technical Reports Server (NTRS)
Jamison, J. W.
1994-01-01
CFORM was developed by the Kennedy Space Center Robotics Lab to assist in linear control system design and analysis using closed form and transient response mechanisms. The program computes the closed form solution and transient response of a linear (constant coefficient) differential equation. CFORM allows a choice of three input functions: the Unit Step (a unit change in displacement); the Ramp function (step velocity); and the Parabolic function (step acceleration). It is only accurate in cases where the differential equation has distinct roots, and does not handle the case for roots at the origin (s=0). Initial conditions must be zero. Differential equations may be input to CFORM in two forms - polynomial and product of factors. In some linear control analyses, it may be more appropriate to use a related program, Linear Control System Design and Analysis (KSC-11376), which uses root locus and frequency response methods. CFORM was written in VAX FORTRAN for a VAX 11/780 under VAX VMS 4.7. It has a central memory requirement of 30K. CFORM was developed in 1987.
Iranian Household Financial Protection against Catastrophic Health Care Expenditures
Moghadam, M Nekoei; Banshi, M; Javar, M Akbari; Amiresmaili, M; Ganjavi, S
2012-01-01
Background: Protecting households against financial risks is one of objectives of any health system. In this regard, Iran’s fourth five year developmental plan act in its 90th article, articulated decreasing household’s exposure to catastrophic health expenditure to one percent. Hence, this study aimed to measure percentage of Iranian households exposed to catastrophic health expenditures and to explore its determinants. Methods: The present descriptive-analytical study was carried out retrospectively. Households whose financial contributions to the health system exceeded 40% of disposable income were considered as exposed to catastrophic healthcare expenditures. Influential factors on catastrophic healthcare expenditures were examined by logistic regression and chi-square test. Results: Of 39,088 households, 80 were excluded due to absence of food expenditures. 2.8% of households were exposed to catastrophic health expenditures. Influential factors on catastrophic healthcare were utilizing ambulatory, hospital, and drug addiction cessation services as well as consuming pharmaceuticals. Socioeconomics characteristics such as health insurance coverage, household size, and economic status were other determinants of exposure to catastrophic healthcare expenditures. Conclusion: Iranian health system has not achieved the objective of reducing catastrophic healthcare expenditure to one percent. Inefficient health insurance coverage, different fee schedules practiced by private and public providers, failure of referral system are considered as probable barriers toward decreasing households’ exposure to catastrophic healthcare expenditures. PMID:23193508
Some estimation formulae for continuous time-invariant linear systems
NASA Technical Reports Server (NTRS)
Bierman, G. J.; Sidhu, G. S.
1975-01-01
In this brief paper we examine a Riccati equation decomposition due to Reid and Lainiotis and apply the result to the continuous time-invariant linear filtering problem. Exploitation of the time-invariant structure leads to integration-free covariance recursions which are of use in covariance analyses and in filter implementations. A super-linearly convergent iterative solution to the algebraic Riccati equation (ARE) is developed. The resulting algorithm, arranged in a square-root form, is thought to be numerically stable and competitive with other ARE solution methods. Certain covariance relations that are relevant to the fixed-point and fixed-lag smoothing problems are also discussed.
Barros, Aluísio JD; Santos, Iná S; Bertoldi, Andréa D
2008-01-01
Background In a country where comprehensive free health care is provided via a public health system (SUS), an unexpected high frequency of catastrophic out-of-pocket expenditure has been described. We studied how deliveries were financed among mothers of a birth cohort and whether they were an important source of household out-of-pocket expenditure. Methods All deliveries occurring in the city of Pelotas, Brazil, during 2004, were recruited for a birth cohort study. All mothers were interviewed just after birth and three months later. Comprehensive data on the pregnancy, delivery, birth conditions and newborn health were collected, along with detailed information on expenses related to the delivery. Results The majority of the deliveries (81%) were financed by the public health system, a proportion that increased to more than 95% among the 40% poorest mothers. Less than 1% of these mothers reported some out-of-pocket expenditure. Even among those mothers covered by a private health plan, nearly 50% of births were financed by the SUS. Among the 20% richest, a third of the deliveries were paid by the SUS, 50% by private health plans and 17% by direct payment. Conclusion The public health system offered services in quantity and quality enough to attract even beneficiaries of private health plans and spared mothers from the poorest strata of the population of practically any expense. PMID:18366672
Barros, Aluísio J D; Santos, Iná S; Bertoldi, Andréa D
2008-03-18
In a country where comprehensive free health care is provided via a public health system (SUS), an unexpected high frequency of catastrophic out-of-pocket expenditure has been described. We studied how deliveries were financed among mothers of a birth cohort and whether they were an important source of household out-of-pocket expenditure. All deliveries occurring in the city of Pelotas, Brazil, during 2004, were recruited for a birth cohort study. All mothers were interviewed just after birth and three months later. Comprehensive data on the pregnancy, delivery, birth conditions and newborn health were collected, along with detailed information on expenses related to the delivery. The majority of the deliveries (81%) were financed by the public health system, a proportion that increased to more than 95% among the 40% poorest mothers. Less than 1% of these mothers reported some out-of-pocket expenditure. Even among those mothers covered by a private health plan, nearly 50% of births were financed by the SUS. Among the 20% richest, a third of the deliveries were paid by the SUS, 50% by private health plans and 17% by direct payment. The public health system offered services in quantity and quality enough to attract even beneficiaries of private health plans and spared mothers from the poorest strata of the population of practically any expense.
Performance Models for the Spike Banded Linear System Solver
Manguoglu, Murat; Saied, Faisal; Sameh, Ahmed; ...
2011-01-01
With availability of large-scale parallel platforms comprised of tens-of-thousands of processors and beyond, there is significant impetus for the development of scalable parallel sparse linear system solvers and preconditioners. An integral part of this design process is the development of performance models capable of predicting performance and providing accurate cost models for the solvers and preconditioners. There has been some work in the past on characterizing performance of the iterative solvers themselves. In this paper, we investigate the problem of characterizing performance and scalability of banded preconditioners. Recent work has demonstrated the superior convergence properties and robustness of banded preconditioners,more » compared to state-of-the-art ILU family of preconditioners as well as algebraic multigrid preconditioners. Furthermore, when used in conjunction with efficient banded solvers, banded preconditioners are capable of significantly faster time-to-solution. Our banded solver, the Truncated Spike algorithm is specifically designed for parallel performance and tolerance to deep memory hierarchies. Its regular structure is also highly amenable to accurate performance characterization. Using these characteristics, we derive the following results in this paper: (i) we develop parallel formulations of the Truncated Spike solver, (ii) we develop a highly accurate pseudo-analytical parallel performance model for our solver, (iii) we show excellent predication capabilities of our model – based on which we argue the high scalability of our solver. Our pseudo-analytical performance model is based on analytical performance characterization of each phase of our solver. These analytical models are then parameterized using actual runtime information on target platforms. An important consequence of our performance models is that they reveal underlying performance bottlenecks in both serial and parallel formulations. All of our results are validated
Chen, Chun; Cheng, Zhihong; Jiang, Ping; Sun, Mei; Zhang, Qi; Lv, Jun
2016-12-01
Aiming to control rising medical expenditures and help improve China's healthcare systems, this study examined whether a cap-based medical insurance scheme with shared financial interest between the insurance and healthcare providers is effective in containing hospitals' C-section medical expenditures. We used 6547 caesarean delivery case records from a teaching tertiary-level general public hospital located in Wuxi, China (2004-2013), and used the Chow test to investigate the possibility of significant variation in mean medical expenditures for caesarean deliveries pre- and post-reform. We also used paired sample t-tests and linear regression models to compare the mean medical expenditures between insured and uninsured women undergoing caesarean delivery during the post-reform period. After the scheme's implementation, medical expenditures for caesarean deliveries declined and the medical expenditures of women covered by the scheme were significantly lower than those of uninsured patients. These findings indicated the scheme's effectiveness in minimizing caesarean delivery expenditures. The cap-based medical insurance scheme with shared financial interest between insurance and healthcare providers would likely steer healthcare providers' behaviors in a more cost-effective direction.
Towards Stability Analysis of Jump Linear Systems with State-Dependent and Stochastic Switching
NASA Technical Reports Server (NTRS)
Tejada, Arturo; Gonzalez, Oscar R.; Gray, W. Steven
2004-01-01
This paper analyzes the stability of hierarchical jump linear systems where the supervisor is driven by a Markovian stochastic process and by the values of the supervised jump linear system s states. The stability framework for this class of systems is developed over infinite and finite time horizons. The framework is then used to derive sufficient stability conditions for a specific class of hybrid jump linear systems with performance supervision. New sufficient stochastic stability conditions for discrete-time jump linear systems are also presented.
Iannelli, A; Anty, R; Schneck, A S; Tran, A; Hébuterne, X; Gugenheim, J
2013-09-01
Laparoscopic sleeve gastrectomy (LSG) for morbid obesity is gaining in popularity as it offers several advantages over laparoscopic Roux-en-Y gastric bypass (LRYGBP), but comparative data between these two procedures have rarely been reported. This case control study compared the incidence of low-grade systemic inflammation, insulin resistance, anthropometrics, resting energy expenditure and metabolic syndrome in 30 patients undergoing LRYGBP and 30 patients undergoing LSG, matched for age, sex, body mass index (BMI), and glycosylated hemoglobin (HbA1c). At 1-year after surgery, the percent of excess weight loss was 67.8 ± 20.9 for LRYGBP and 61.6 ± 19.4 for LSG. Patients undergoing LRYGBP showed significantly lower plasma levels of C-reactive protein (3.3 ± 2.7 mg/dL vs. 5.3 ± 3.9 mg/dL; P < 0.05), waist circumference (97.4 ± 16.0 vs. 105.5 ± 14.7 cm; P < 0.05), total cholesterol (4.6 ± 1.0 vs. 5.7 ± 0.9 mmol/L; P < 0.01) and LDL cholesterol (2.6 ± 0.8 vs. 3.6 ± 0.8 mmol/L; P < 0.01). Insulin resistance (HOMA index 1.6 ± 1.0 after LRYGBP vs. 2.3 ± 2.4 after LSG), resting energy expenditure (1666.7 ± 320.5 after LRYGBP vs. 1600.4 ± 427.3 Kcal after LSG) and remission of metabolic syndrome (92.9% after LRYGBP vs. 80% after LSG) were not different between the two groups. In this study, patients undergoing LRYGBP demonstrated significantly improved lipid profiles, decreased systemic low-grade inflammation compared with those undergoing LSG at 1-year follow-up. Copyright © 2013. Published by Elsevier Masson SAS.
Understanding Expenditure Data.
ERIC Educational Resources Information Center
Dyke, Frances L.
2000-01-01
Stresses the importance of common understandings of cost definitions and data collection in order to create reliable databases with optimal utility for inter-institutional analysis. Examines definitions of common expenditure categories, discusses cost-accumulation rules governing financial reporting, and explains differences between direct costs…
Student Service Expenditures Matter
ERIC Educational Resources Information Center
Ehrenberg, Ronald G.; Webber, Douglas A.
2010-01-01
The "Great Recession" has caused a fiscal crisis in both public and private higher education that is unmatched in recent memory. Institutions' attention is focused on what they can cut out of their budgets. Student-service expenditures are often seen as discretionary in institutional budgets; they are viewed by some critics as…
Variational Iterative Methods for Nonsymmetric Systems of Linear Equations.
1981-08-01
approximations to the convection diffusion equation. In Society of Petroleum Engineers of AIME, Proceedinus of the Fifth Svmnosium on Reservoir Simulation , 1979...simultaneous linear equations. In Society of Petroleum Engineers of ADIE, Proceedings 2f the Fourth SyvMosium on Reservoir Simulation , 1976, pp. 149
Conjugate gradient type methods for linear systems with complex symmetric coefficient matrices
NASA Technical Reports Server (NTRS)
Freund, Roland
1989-01-01
We consider conjugate gradient type methods for the solution of large sparse linear system Ax equals b with complex symmetric coefficient matrices A equals A(T). Such linear systems arise in important applications, such as the numerical solution of the complex Helmholtz equation. Furthermore, most complex non-Hermitian linear systems which occur in practice are actually complex symmetric. We investigate conjugate gradient type iterations which are based on a variant of the nonsymmetric Lanczos algorithm for complex symmetric matrices. We propose a new approach with iterates defined by a quasi-minimal residual property. The resulting algorithm presents several advantages over the standard biconjugate gradient method. We also include some remarks on the obvious approach to general complex linear systems by solving equivalent real linear systems for the real and imaginary parts of x. Finally, numerical experiments for linear systems arising from the complex Helmholtz equation are reported.
The convergence of the modified Gauss-Seidel methods for consistent linear systems
NASA Astrophysics Data System (ADS)
Li, Wen
2003-05-01
In this paper we present a convergence analysis for the modified Gauss-Seidel methods given in Gunawardena et al. (Linear Algebra Appl. 154-156 (1991) 125) and Kohno et al. (Linear Algebra Appl. 267 (1997) 113) for consistent linear systems. We prove that the modified Gauss-Seidel method converges for some values of the parameters in the preconditioned matrix.
Amplitude Linearizers for PEP-II 1.2 MW Klystrons and LLRF Systems
Van Winkle, D.; Browne, J.; Fox, J.D.; Mastorides, T.; Rivetta, C.; Teytelman, D.; /SLAC
2006-07-18
The PEP-II B-factory has aggressive current increases planned for luminosity through 2008. At 2.2A (HER) on 4A (LER) currents, we estimate that longitudinal growth rates will be comparable to the damping rates currently achieved in the existing low level RF and longitudinal feedback systems. Prior to having a good non-linear time domain model [1] it was postulated that klystron small signal gain non-linearity may be contributing to measured longitudinal growth rates being higher than linearly predicted growth rates. Five prototype klystron amplitude modulation linearizers have been developed to explore improved linearity in the LLRF system. The linearizers operate at 476 MHz with 15 dB dynamic range and 1 MHz linear control bandwidth. Results from lab measurements and high current beam tests are presented. Future development plans, conclusions from beam testing and ideas for future use of this linearization technique are presented.
Influenza Antiviral Expenditures and Outpatient Prescriptions in the United States, 2003-2012.
Suda, Katie J; Hunkler, Robert J; Matusiak, Linda M; Schumock, Glen T
2015-11-01
The clinical efficacy and cost-effectiveness of influenza antiviral use are controversial, with recent analyses suggesting potentially limited value. Thus, the objectives of this study were to describe influenza antiviral expenditures overall and by health care setting over a 10-year period (2003-2012) and to assess the correlation between outpatient influenza antiviral prescription use and influenza-like illness (ILI) outpatient visits. Retrospective, cross-sectional study. IMS Health National Sales Perspectives and Xponent databases and Centers for Disease Control and Prevention ILINet national influenza surveillance system database. All prescriptions for oseltamivir, rimantadine, or zanamivir from community pharmacies, mail order pharmacies, clinics, nonfederal hospitals, and other health care settings (federal hospitals, military facilities, jails and prisons, universities, staff-model health maintenance organizations, veterinary hospitals and clinics, and long-term care facilities) between January 1, 2003, and December 31, 2012. Prescribing rates were calculated (prescriptions/1000 persons) for each year from 2003 to 2012 by using U.S. Census Bureau data. Influenza season was defined as July 1-June 30 of each calendar year. Linear regression assessed the correlation between influenza antiviral expenditures, prescription use, and ILI diagnoses. From 2003 to 2012, influenza antiviral drug expenditures accounted for $3.74 billion, with the majority from community pharmacies. After adjusting for inflation, no growth was observed for expenditures. A total of 32.8 million influenza antiviral prescriptions were dispensed from community pharmacies during the study period, and these prescriptions experienced 133.2% growth from 2003 to 2012. One third of expenditures and one quarter of dispensed prescriptions were in 2009. Influenza seasons were correlated with ILI and antiviral prescriptions. Annual community pharmacy expenditures were also associated with influenza
42 CFR 495.366 - Financial oversight and monitoring of expenditures.
Code of Federal Regulations, 2012 CFR
2012-10-01
... expenditures for the Medicaid EHR payment incentive program using the Medicaid Budget Expenditure System. (2) The State must have a process in place to report actual expenditures for the Medicaid EHR payment... and information retrieval mechanized system, (Medicaid Management Information System) to make EHR...
DoD Officials Need to Improve Reporting of Obligations and Expenditures for the Guam Realignment
2011-06-17
Application and their travel requirements and expenses into the Defense Travel System. These systems electronically transfer expenditures back to FIS...System for disbursement by the Defense Finance and Accounting Service (DFAS). DON Obligation and Expenditure of MILCON Funds DON activities generate...and the Defense Finance and Accounting Service to: 1. Review all 2009 obligations and expenditures for the Guam realignment and provide
ATOPS B-737 inner-loop control system linear model construction and verification
NASA Technical Reports Server (NTRS)
Broussard, J. R.
1983-01-01
Nonlinear models and block diagrams of an inner-loop control system for the ATOPS B-737 Research Aircraft are presented. Continuous time linear model representations of the nonlinear inner-loop control systems are derived. Closed-loop aircraft simulations comparing nonlinear and linear dynamic responses to step inputs are used to verify the inner-loop control system models.
Solution of homogeneous systems of linear equations arising from compartmental models
Funderlic, R.E.; Mankin, J.B.
1981-12-01
Systems of linear differential equations with constant coefficients, Ax = x, with the matrix A having nonnegative off-diagnonal elements and zero column sums, occur in compartmental analysis. The steady-state solution leads to the homogeneous system of linear equations Ax(infinity)=x(infinity)=0. LU-factorization, the Crout algorithm, error analysis and solution of a modified system are treated.
Model reference adaptive control for linear time varying and nonlinear systems
NASA Technical Reports Server (NTRS)
Abida, L.; Kaufman, H.
1982-01-01
Model reference adaptive control is applied to linear time varying systems and to nonlinear systems amenable to virtual linearization. Asymptotic stability is guaranteed even if the perfect model following conditions do not hold, provided that some sufficient conditions are satisfied. Simulations show the scheme to be capable of effectively controlling certain nonlinear systems.
AN INTRODUCTION TO THE APPLICATION OF DYNAMIC PROGRAMMING TO LINEAR CONTROL SYSTEMS
DYNAMIC PROGRAMMING APPLIED TO OPTIMIZE LINEAR CONTROL SYSTEMS WITH QUADRATIC PERFORMANCE MEASURES. MATHEMATICAL METHODS WHICH MAY BE APPLIED TO SPACE VEHICLE AND RELATED GUIDANCE AND CONTROL PROBLEMS.
Linear stochastic system with delay: Energy balance and entropy production
NASA Astrophysics Data System (ADS)
Munakata, Toyonori; Iwama, Shinpei; Kimizuka, Makoto
2009-03-01
We study the energy balance in a linear stochastic dynamics with delay under the impact of an external periodic force. The linearity of the model, in combination with a response function method, enables us to perform detailed analytic calculations of each term in the energy balance equation. From this, we discuss thermodynamics and entropy production rate σ . With use of the delay time τ and strength of the external force A0 , σ is simply expressed as σ=σD,1(τ)+A02η(τ) , with both σD,1(τ) and η(τ) positive definite. We thus conclude that even when there is no external force (A0=0) , the entropy production rate σ=σD,1(τ) is positive, meaning that the delay force produces work, which is dissipated into a reservoir. Numerical experiments are performed to confirm theoretical results.
Greene, Robert; Dasso, Edwin; Ho, Sam; Frank, Jerry; Scandrett, Graeme; Genaidy, Ash
2013-12-01
The U.S. health care system is currently heading toward unsustainable health care expenditures and increased dissatisfaction with health outcomes. The objective of this population-based study is to uncover practical insights regarding patients with 1 or more chronic illnesses. A cross-sectional investigation was designed to gather data from health records drawn from diverse US geographic markets. A database of 9.74 million fully-insured, working individuals was used, together with members in the same households. Among nearly 3.43 million patients with claims, 2.22 million had chronic conditions. About 24.3% had 1 chronic condition and 40.4% had multi-morbidity. Health care expenditures for chronic conditions accounted for 92% of all costs (52% for chronic costs and 40% for nonchronic costs). Psychiatry, orthopedics-rheumatology, endocrinology, and cardiology areas accounted for two thirds of these chronic condition costs; nonchronic condition costs were dominated by otolaryngology, gastroenterology, dermatology, orthopedics-rheumatology conditions, and preventive services. About 50.1% of all households had 2 or more members with chronic conditions. In summary, multi-morbidity is prevalent not only among those older than age 65 years but also in younger and working individuals, and commonly occurs among several members of a household. The authors suggest that the disease-focused model of medicine should change to a more holistic illness-wellness model, emphasizing not only the physical but also the mental and social elements that can influence individual health. In that way the chronic care model could be broadened in context and content to improve the health of patients and households.
Modelling and Resource Allocation of Linearly Restricted Operating Systems.
1979-12-01
services thus rendered are the products . Clearly, in a limited resource situation, how best to dispense the available resources to achieve some...Preliminary Although a linear programming model for an economic problem had been developed as early as 1939 by the Russian mathematician L. Kantorovich...individual user programs) to achieve productions (computations). The purpose is then to devise a way (A plan) to allocate those available memory spaces
Analysis and Regulation of Nonlinear and Generalized Linear Systems.
1985-09-06
But this intuition is based on a linearized analysis, and may well be too conservative -or even totally inappropiate - for a particular (global...in the field of stochastic estimation. Given a time series, it is often possible to compute sufficient statistics of the associated process...and dynamically updating sufficient statistics with finite resources had received almost no attention in the literature, and turns out to be
A final focus system for the Next Linear Collider
Zimmermann, F.; Brown, K.; Emma, P.; Helm, R.; Irwin, J.; Tenenbaum, P.; Wilson, P.
1995-06-01
The final focus of the Next Linear Collider (NLC) demagnifies electron and positron beams of 250--750 GeV energy down to a transverse size of about 2.5 {times} 350 nm{sup 2} at the interaction point (IP). The basic layout, momentum bandwidth, vibration tolerances, wakefield effects, and the tunability of the proposed final focus design are discussed. Also a perspective is given on the crab cavity and on effects of the solenoid field in the interaction region.
On stochastic control system design methods for weakly coupled large scale linear systems.
NASA Technical Reports Server (NTRS)
Kwong, R.; Chong, C.-Y.; Athans, M.
1972-01-01
This paper considers the problem of decentralized control of two weakly coupled linear stochastic systems, using quadratic performance indices. The basic idea is to have each controller control independently his own system, based upon noisy measurements of his own output. To compensate for the effects of weak coupling upon the resultant performance, fake white plant noise is introduced to each system. The appropriate intensity of the fake plant noise is obtained through the solution of an off-line deterministic matrix optimal control problem. The effects of this design method upon the overall coupled system performance are analyzed as a function of the degree of intersystem coupling.
Algebraic coarsening methods for linear and nonlinear PDE and systems
McWilliams, J C
2000-11-06
In [l] Brandt describes a general approach for algebraic coarsening. Given fine-grid equations and a prescribed relaxation method, an approach is presented for defining both the coarse-grid variables and the coarse-grid equations corresponding to these variables. Although, these two tasks are not necessarily related (and, indeed, are often performed independently and with distinct techniques) in the approaches of [1] both revolve around the same underlying observation. To determine whether a given set of coarse-grid variables is appropriate it is suggested that one should employ compatible relaxation. This is a generalization of so-called F-relaxation (e.g., [2]). Suppose that the coarse-grid variables are defined as a subset of the fine-grid variables. Then, F-relaxation simply means relaxing only the F-variables (i.e., fine-grid variables that do not correspond to coarse-grid variables), while leaving the remaining fine-grid variables (C-variables) unchanged. The generalization of compatible relaxation is in allowing the coarse-grid variables to be defined differently, say as linear combinations of fine-grid variables, or even nondeterministically (see examples in [1]). For the present summary it suffices to consider the simple case. The central observation regarding the set of coarse-grid variables is the following [1]: Observation 1--A general measure for the quality of the set of coarse-grid variables is the convergence rate of compatible relaxation. The conclusion is that a necessary condition for efficient multigrid solution (e.g., with convergence rates independent of problem size) is that the compatible-relaxation convergence be bounded away from 1, independently of the number of variables. This is often a sufficient condition, provided that the coarse-grid equations are sufficiently accurate. Therefore, it is suggested in [1] that the convergence rate of compatible relaxation should be used as a criterion for choosing and evaluating the set of coarse
Wu, Suo-Wei; Pan, Qi; Wei, Liang-Yu; Li, Chao; Wang, Qin; Song, Jing-Chen; Chen, Tong
2016-01-01
Background: The study was to explore the causes of high inpatient expenditure through analyzing the distribution characteristics as well as the influence factors of high inpatient expenditure cases during 3 years within a Grade-A tertiary hospital through various aspects and multiple angles, thus identifying the major influence factors for high medical expenditure to develop further research. Methods: We retrospectively studied 2041 inpatient cases which cost more than RMB 100,000 Yuan per case in a Grade-A tertiary hospital from 2013 to 2015. We analyzed the compositions of the medical cost to evaluate the major factors that cause the high inpatient expenditure. All the data and materials were collected from medical record system, and the statistical methods included t-test, variance of analysis, and multivariate linear regression. Results: The average cost of the 2,041 cases was RMB 152,173 Yuan for medicines and materials of medical costs, which respectively accounted for 33.03% and 32.32% of the total cost; and the average length of hospital stay was 28.39 days/person. Diseases of skeletal and muscular system, circulatory system, and tumor were the top three disease categories of high inpatient expenditure, which accounted for 39.00%, 33.46%, and 18.03%, respectively. Complications, criticality of the disease, gender of the patients, the occurrence of death, and the excessive length of hospital stay all had great impacts on average medical expenditure, while age, hospital infection, and surgery showed no significant impact on average medical cost. Conclusions: The main factors for high inpatient expenditure included the inadequate use of high-value medicines and materials, lacking cost control measures within the hospital, the excessive length of hospital stay for inpatients, and the unnecessary treatment for the patients. PMID:27647192
Dissipative open systems theory as a foundation for the thermodynamics of linear systems.
Delvenne, Jean-Charles; Sandberg, Henrik
2017-03-06
In this paper, we advocate the use of open dynamical systems, i.e. systems sharing input and output variables with their environment, and the dissipativity theory initiated by Jan Willems as models of thermodynamical systems, at the microscopic and macroscopic level alike. We take linear systems as a study case, where we show how to derive a global Lyapunov function to analyse networks of interconnected systems. We define a suitable notion of dynamic non-equilibrium temperature that allows us to derive a discrete Fourier law ruling the exchange of heat between lumped, discrete-space systems, enriched with the Maxwell-Cattaneo correction. We complete these results by a brief recall of the steps that allow complete derivation of the dissipation and fluctuation in macroscopic systems (i.e. at the level of probability distributions) from lossless and deterministic systems.This article is part of the themed issue 'Horizons of cybernetical physics'. © 2017 The Author(s).
Dissipative open systems theory as a foundation for the thermodynamics of linear systems
NASA Astrophysics Data System (ADS)
Delvenne, Jean-Charles; Sandberg, Henrik
2017-03-01
In this paper, we advocate the use of open dynamical systems, i.e. systems sharing input and output variables with their environment, and the dissipativity theory initiated by Jan Willems as models of thermodynamical systems, at the microscopic and macroscopic level alike. We take linear systems as a study case, where we show how to derive a global Lyapunov function to analyse networks of interconnected systems. We define a suitable notion of dynamic non-equilibrium temperature that allows us to derive a discrete Fourier law ruling the exchange of heat between lumped, discrete-space systems, enriched with the Maxwell-Cattaneo correction. We complete these results by a brief recall of the steps that allow complete derivation of the dissipation and fluctuation in macroscopic systems (i.e. at the level of probability distributions) from lossless and deterministic systems. This article is part of the themed issue 'Horizons of cybernetical physics'.
Kash, Bita A; Boyer, Gregory J
2008-01-01
Marketing and advertising activities in the nursing home sector have increased in recent years, following the example of hospitals and health systems. The reasons for this trend may be related to the growth in competition but are not clearly identified yet. Theoretically, advertising becomes necessary to gain an advantage over the competition. The purpose of this study was to identify the reasons for the variation in advertising expenditures among nursing homes in Texas. For this study, we merged 2003 data from the Texas Medicaid Nursing Facility Cost Report, the Texas Nursing Home Quality Reporting System, and the Area Resource File for Texas. Using the Herfindahl-Hirschman Index, we then examined the correlations between advertising expenses and the level of market concentration. We evaluated the association between advertising expenditures and market competition using two logistic and four linear regression models. Total advertising expenses in Texas nursing homes ranged from $0 to $165,000 per year. Higher advertising expenditures were associated with larger facilities, higher occupancy, and high Medicare census. Market competition, however, was not a significant predictor of such expenses. Advertising seems to be more resource-driven than market-driven. Therefore, some advertising expenditures may be unnecessary, may lack impact, and may even be wasteful. Reducing unnecessary advertising costs could free up resources, which may be allocated to necessary resident care activities.
Analysis and application of minimum variance discrete linear system identification
NASA Technical Reports Server (NTRS)
Kotob, S.; Kaufman, H.
1977-01-01
An on-line minimum variance (MV) parameter identifier is developed which embodies both accuracy and computational efficiency. The formulation results in a linear estimation problem with both additive and multiplicative noise (AMN). The resulting filter which utilizes both the covariance of the parameter vector itself and the covariance of the error in identification is proven to be mean-square convergent and mean-square consistent. The MV parameter identification scheme is then used to construct a stable state and parameter estimation algorithm.
On Decay Estimates of Solutions to One-dimensional Linear Parabolic Feedback Control Systems
NASA Astrophysics Data System (ADS)
Nambu, Takao
In feedback stabilization for linear parabolic systems,a control scheme is designed so that the “state” of the system decays with a designated decay rate as t → ∞. An arbitrary linear functional of the state, which is subordinate to the state, also decays at least with the same decay rate. We study in the paper a class of linear parabolic systems of one dimension, and construct a specific control scheme such that a nontrivial linear functional decays exactly faster than the state.
National health expenditures, 1991
Letsch, Suzanne W.; Lazenby, Helen C.; Levit, Katharine R.; Cowan, Cathy A.
1992-01-01
Spending for health care rose to $751.8 billion in 1991, an increase of 11.4 percent from the 1990 level. National health expenditures as a share of gross domestic product increased to 13.2 percent, up from 12.2 percent in 1990. The health care sector exhibited strong growth, despite slow growth in the overall economy. This combination resulted in the largest increase in the share of the Nation's output consumed by health care in the past three decades. In this article, the authors present estimates of health spending in the United States for 1991. The authors also examine reasons for the unusually large growth in Medicaid expenditures and highlight recent trends in the hospital sector. PMID:10127445
Spatiotemporal drivers of energy expenditure in a coastal marine fish.
Brownscombe, Jacob W; Cooke, Steven J; Danylchuk, Andy J
2017-03-01
Animal behavior and energy expenditure often vary significantly across the landscape, and quantifying energy expenditure over space and time provides mechanistic insight into ecological dynamics. Yet, spatiotemporal variability in energy expenditure has rarely been explored in fully aquatic species such as fish. Our objective was to quantify spatially explicit energy expenditure for a tropical marine teleost fish, bonefish (Albula vulpes), to examine how bonefish energetics vary across landscape features and temporal factors. Using a swim tunnel respirometer, we calibrated acoustic accelerometer transmitters implanted in bonefish to estimate their metabolic rates and energy expenditure, and applied this technology in situ using a fine-scale telemetry system on a heterogeneous reef flat in Puerto Rico. Bonefish energy expenditure varied most among habitats, with significant interactions between habitat and temporal factors (i.e., diel period, tide state, season). The energy expenditure was generally highest in shallow water habitats (i.e., seagrass and reef crest). Variation in activity levels was the main driver of these differences in energy expenditure, which in shallow, nearshore habitats is likely related to foraging. Bonefish moderate energy expenditure across seasonal fluctuations in temperature, by selectively using shallow nearshore habitats at moderate water temperatures that correspond with their scope for activity. Quantifying how animals expend energy in association with environmental and ecological factors can provide important insight into behavioral ecology, with implications for bioenergetics models.
Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio
2017-01-01
The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225–287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000–1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue. PMID:28158208
Using crosscorrelation techniques to determine the impulse response of linear systems
NASA Technical Reports Server (NTRS)
Dallabetta, Michael J.; Li, Harry W.; Demuth, Howard B.
1993-01-01
A crosscorrelation method of measuring the impulse response of linear systems is presented. The technique, implementation, and limitations of this method are discussed. A simple system is designed and built using discrete components and the impulse response of a linear circuit is measured. Theoretical and software simulation results are presented.
Characterization of the system functions of ultrasonic linear phased array inspection systems.
Huang, Ruiju; Schmerr, Lester W
2009-02-01
This work characterizes the electrical and electromechanical aspects of an ultrasonic linear phased array inspection system, using a matrix of system functions that are obtained from the measured response of individual array elements in a simple reference experiment. It is shown that for the arrays tested all these system functions are essentially identical, allowing one to use a single system function to characterize the entire array, as done for an ordinary single element transducer. The variation of this single system function with the number of elements firing in the array or with changes of the delay law used is examined. It is also demonstrated that once such a single system function is obtained for an array, it can be used in a complete ultrasonic measurement model to accurately predict the array response measured from a reference reflector in an immersion setup.
Wang, Xin; Sun, Yuanling; Mu, Xin; Guan, Li; Li, Jingjie
2015-08-27
We simulate and analyze Total Health Expenditure (THE) in financial sources and other economic indicators (such as THE per capita, GDP, etc.) in a province of China from 2002 to 2012 on System Dynamics. Based on actual data and certain mathematical methods, we use system dynamic software to construct a logic model for THE and changing proportions, and thus simulate the actual conditions of development and changes in THE. According to the simulation results, the government possess the largest investment in the average annual growth rate of THE, which was 25.16% in 2012. Social investment comprises the majority of the possession ratio, which was up to 41.20%. The personal investment growth rate decreased by almost 21%, but the total amount of personal investment increased by 28075 million yuan, which is far higher than the increase in government investment. Individuals are still the main carriers of health care expenses. The equity of health financial sources is still poor. The System Dynamics method used in this paper identifies a dynamic measurement process, provides a scientific basis for simulation and analysis of the changes in THE and its key constraining factors, as well as put forward suggestions for the improvement of equity of health financial sources.
A Design Method for Pole Placement and Observer of Linear Time-Varying Discrete MIMO Systems
NASA Astrophysics Data System (ADS)
Mutoh, Yasuhiko; Hara, Tomohiro
It is well known that, the pole placement controller can be designing for linear time-varying systems using the Frobenius canonical form, as for the time invariant case. This paper presents the new approach to the design of the pole placement controller for linear time-varying discrete multivariable systems. The concept of the relative degrees of multivariable system plays an important role, and the time-varying feedback gain can be simply calculated without transforming the system into any canonical form, which is regarded as a discrete Ackerman's method. This method is applied in order to calculate the observer gain for linear time-varying systems.
Dynamics and thermodynamics of linear quantum open systems.
Martinez, Esteban A; Paz, Juan Pablo
2013-03-29
We analyze the evolution of the quantum state of networks of quantum oscillators coupled with arbitrary external environments. We show that the reduced density matrix of the network always obeys a local master equation with a simple analytical solution. We use this to study the emergence of thermodynamical laws in the long time regime demonstrating two main results: First, we show that it is impossible to build a quantum absorption refrigerator using linear networks (thus, nonlinearity is an essential resource for such refrigerators recently studied by Levy and Kosloff [Phys. Rev. Lett. 108, 070604 (2012)] and Levy et al. [Phys. Rev. B 85, 061126 (2012)]). Then, we show that the third law imposes constraints on the low frequency behavior of the environmental spectral densities.
Attractor reconstruction for non-linear systems: a methodological note
Nichols, J.M.; Nichols, J.D.
2001-01-01
Attractor reconstruction is an important step in the process of making predictions for non-linear time-series and in the computation of certain invariant quantities used to characterize the dynamics of such series. The utility of computed predictions and invariant quantities is dependent on the accuracy of attractor reconstruction, which in turn is determined by the methods used in the reconstruction process. This paper suggests methods by which the delay and embedding dimension may be selected for a typical delay coordinate reconstruction. A comparison is drawn between the use of the autocorrelation function and mutual information in quantifying the delay. In addition, a false nearest neighbor (FNN) approach is used in minimizing the number of delay vectors needed. Results highlight the need for an accurate reconstruction in the computation of the Lyapunov spectrum and in prediction algorithms.
Dynamics and Thermodynamics of Linear Quantum Open Systems
NASA Astrophysics Data System (ADS)
Martinez, Esteban A.; Paz, Juan Pablo
2013-03-01
We analyze the evolution of the quantum state of networks of quantum oscillators coupled with arbitrary external environments. We show that the reduced density matrix of the network always obeys a local master equation with a simple analytical solution. We use this to study the emergence of thermodynamical laws in the long time regime demonstrating two main results: First, we show that it is impossible to build a quantum absorption refrigerator using linear networks (thus, nonlinearity is an essential resource for such refrigerators recently studied by Levy and Kosloff [Phys. Rev. Lett. 108, 070604 (2012)] and Levy et al. [Phys. Rev. B 85, 061126 (2012)]). Then, we show that the third law imposes constraints on the low frequency behavior of the environmental spectral densities.
Linear and/or curvilinear rail mount system
NASA Technical Reports Server (NTRS)
Thomas, Jackie D. (Inventor); Harris, Lawanna L. (Inventor)
2012-01-01
One or more linear and/or curvilinear mounting rails are coupled to a structure. Each mounting rail defines a channel and at least one cartridge assembly is engaged in the channel. Each cartridge assembly includes a housing that slides within the channel. The housing defines a curvilinearly-shaped recess longitudinally aligned with the channel when the housing is in engagement therewith. The cartridge assembly also includes a cleat fitted in the recess for sliding engagement therealong. The cleat can be coupled to a fastener that passes through the mounting rail and the housing when the housing is so-engaged in the channel. The cleat is positioned in the recess by a position of the fastener.
Dynamic Performance of Subway Vehicle with Linear Induction Motor System
NASA Astrophysics Data System (ADS)
Wu, Pingbo; Luo, Ren; Hu, Yan; Zeng, Jing
The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.
Linear polarization of a group of symbiotic systems
NASA Astrophysics Data System (ADS)
Brandi, E.; García, L. G.; Piirola, V.; Scaltriti, F.; Quiroga, C.
2000-08-01
We report linear polarization measurements of a set of symbiotic stars, made at several epochs during the period 1994-1998. Evidence of intrinsic polarization is looked for from the wavelength dependence of the polarization degree and position angle in UBVRI bands. The results have also been analysed to search for temporal variability of polarization. Several objects have shown a polarization spectrum different from that produced by interstellar dust grains and/or polarimetric variations on time scales as short as several days or months, indicating the presence of polarization component of circumstellar origin. Based on observations taken at Complejo Astronómico El Leoncito (CASLEO), operated under an agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, the Secretaría de Ciencia y Tecnología de la Nación and the National Universities of La Plata, Córdoba and San Juan.
Robust stabilization, robust performance, and disturbance attenuation for uncertain linear systems
NASA Technical Reports Server (NTRS)
Wang, Yeih J.; Shieh, Leang S.; Sunkel, John W.
1992-01-01
This paper presents a linear quadratic regulator approach to the robust stabilization, robust performance, and disturbance attenuation of uncertain linear systems. The state-feedback designed systems provide both the robust stability with optimal performance and the disturbance attenuation with H-infinity-norm bounds. The proposed approach can be applied to matched and/or mismatched uncertain linear systems. For a matched uncertain linear system, it is shown that the disturbance attenuation robust-stabilizing controllers with or without optimal performance always exist and can be easily determined without searching; whereas, for a mismatched uncertain linear system, the introduced tuning parameters greatly enhance the flexibility of finding the disturbance-attenuation robust-stabilizing controllers.
National health expenditure projections, 1994-2005.
Burner, S T; Waldo, D R
1995-01-01
Using 1993 as a baseline and assuming that current laws and practices continue, the authors project U.S. health expenditures through the year 2005. Annual spending growth has declined since 1990, and, in the scenario reported here, that trend continues in 1994. Growth of health spending increases thereafter, but remains below the average experience of the past decade. Even so, health expenditures grow faster than the gross domestic product (GDP), and by 2005, account for 17.9 percent of the GDP. Unless the system changes, Medicare and Medicaid are projected to pay for an increasing share of total spending during the next decade.
Noise robust linear dynamic system for phase unwrapping and smoothing.
Estrada, Julio C; Servin, Manuel; Quiroga, Juan A
2011-03-14
Phase unwrapping techniques remove the modulus ambiguities of wrapped phase maps. The present work shows a first-order feedback system for phase unwrapping and smoothing. This system is a fast sequential unwrapping system which also allows filtering some noise because in deed it is an Infinite Impulse Response (IIR) low-pass filter. In other words, our system is capable of low-pass filtering the wrapped phase as the unwrapping process proceeds. We demonstrate the temporal stability of this unwrapping feedback system, as well as its low-pass filtering capabilities. Our system even outperforms the most common and used unwrapping methods that we tested, such as the Flynn's method, the Goldstain's method, and the Ghiglia least-squares method (weighted or unweighted). The comparisons with these methods shows that our system filters-out some noise while preserving the dynamic range of the phase-data. Its application areas may cover: optical metrology, synthetic aperture radar systems, magnetic resonance, and those imaging systems where information is obtained as a demodulated wrapped phase map.
Experiment-based identification of time delays in linear systems
NASA Astrophysics Data System (ADS)
Jin, Meng-Shi; Sun, Yi-Qiang; Song, Han-Wen; Xu, Jian
2017-03-01
This paper presents an identification approach to time delays in single-degree-of-freedom (SDOF) and multiple-degree-of-freedom (MDOF) systems. In an SDOF system, the impedance function of the delayed system is expressed by the system parameters, the feedback gain, and the time delay. The time delay can be treated as the "frequency" of the difference between the impedance function of the delayed system and that of the corresponding uncontrolled system. Thus, it can be identified from the Fourier transform of the difference between the two impedance functions. In an MDOF system, the pseudo-impedance functions are defined. The relationships between the time delay and the pseudo-impedance functions of the delayed system and uncontrolled system are deduced. Similarly, the time delay can be identified from the Fourier transform of the difference between the two pseudo-impedance functions. The results of numerical examples and experimental tests show that the identification approach to keeps a relatively high accuracy.
Spline collocation method for linear singular hyperbolic systems
NASA Astrophysics Data System (ADS)
Gaidomak, S. V.
2008-07-01
Some classes of singular systems of partial differential equations with variable matrix coefficients and internal hyperbolic structure are considered. The spline collocation method is used to numerically solve such systems. Sufficient conditions for the convergence of the numerical procedure are obtained. Numerical results are presented.
Response of linear dynamic systems with random coefficients
NASA Technical Reports Server (NTRS)
Dickerson, J.
1976-01-01
Numerous models of physical systems contain parameters whose values are not known exactly. The physical and mathematical complexities arising in the prediction of the statistical behavior of such systems are discussed. Although the discussions are far from providing a satisfactory solution to such problems, they perhaps, by utilization of simple examples, will create a greater awareness of the statistical effect of random parameters.
A Granular System of Ellipses under Linear Shear
NASA Astrophysics Data System (ADS)
Wang, Dong; Zheng, Hu; Behringer, Robert P.
2017-06-01
Shear of granular systems of disks (in 2D) and spheres (3D) has been studied extensively. However, less is known about systems of non-spherical particles, i.e., ellipses and polygons, etc. Here we studied a quasi 2D granular system composed of ellipses in a novel apparatus, which provided homogeneous simple shear by utilizing the weak friction between ellipses and the deformable base of the apparatus. Shear jamming, which was first reported for a disk system [1], was also observed for our ellipse system. We contrast shear jamming for systems of disks and systems of ellipses. By tracking the positions and orientations of the ellipses, we observed that the ellipses gradually rotated to align along a preferred direction as the shear strain increased. We also applied Voronoï tessellation to the packing of ellipses, showing that the distribution of the local density changed during shear. By contrast, such a change in the distribution was not observed in a disk system [2].
Simons, J P; Schols, A M; Buurman, W A; Wouters, E F
1999-08-01
The aim of the present study was to investigate, in human lung cancer, the relationship between weight loss and the existence of a low body cell mass (BCM) on the one hand, and the putative presence of systemic inflammation, an increased acute-phase response, anorexia, hypermetabolism and changes in circulating levels of several anabolic and catabolic hormones on the other. In 20 male lung cancer patients, pre-stratified by weight loss of >/=10% (n=10) or of <10% (n=10), the following measurements were performed: BCM (by dual-energy X-ray absorptiometry/bromide dilution), circulating levels of sTNF-R55 and sTNF-R75 (soluble tumour necrosis factor receptors of molecular masses 55 and 75 kDa respectively), interleukin-6, lipopolysaccharide-binding protein, albumin, appetite (scale of 0-10), resting energy expenditure (by indirect calorimetry) and circulating levels of catabolic (cortisol) and anabolic [testosterone, insulin-like growth factor-I (IGF-I)] hormones. Compared with the patients with a weight loss of <10%, those with a weight loss of >/=10% were characterized by higher levels of sTNF-R55 (trend towards significance; P=0.06), and lower levels of albumin (27.4 compared with 34.4 mmol/l; P=0.02), testosterone (13.2 compared with 21.5 nmol/l; P=0.01) and IGF-I (119 compared with 184 ng/ml; P=0.004). In the patient group as a whole, the percentage weight loss was significantly correlated with sTNF-R55 (r=0.59, P=0.02), albumin (r=-0.63, P=0.006) and IGF-I (r=-0.50, P=0.02) levels. Height-adjusted BCM was significantly correlated with sTNF-R55 (r=-0.57, P=0.03), sTNF-R75 (r=-0.50, P=0. 04), lipopolysaccharide-binding protein (r=-0.50, P=0.04), albumin (r=0.56, P=0.02) and resting energy expenditure/BCM (r=-0.54, P=0. 03), and there was a trend towards a correlation with IGF-I concentration (r=0.44, P=0.06). We conclude that, in human lung cancer, weight loss and the presence of a low BCM are associated with systemic inflammation, an increased acute
Vibration analysis of harmonically excited non-linear system using the method of multiple scales
NASA Astrophysics Data System (ADS)
Moon, Byung-Young; Kang, Beom-Soo
2003-05-01
An analytical method is presented for evaluation of the steady state periodic behavior of non-linear systems. This method is based on the substructure synthesis formulation and a multiple scales procedure, which is applied to the analysis of non-linear responses. A complex non-linear system is divided into substructures, of which equations are approximately transformed to modal co-ordinates including non-linear term under the reasonable procedure. Then, the equations are synthesized into the overall system and the solution of the non-linear system can be obtained. Based on the method of multiple scales, the proposed procedure reduces the size of large-degree-of-freedom problem in solving the non-linear equations. Feasibility and advantages of the proposed method are illustrated by the application of the analytic procedure to the non-linear rotating machine system as a large mechanical structure system. Results obtained are reported to be an efficient approach with respect to non-linear response prediction when compared with other conventional methods.
NASA Astrophysics Data System (ADS)
Royston, T. J.; Singh, R.
1996-07-01
While significant non-linear behavior has been observed in many vibration mounting applications, most design studies are typically based on the concept of linear system theory in terms of force or motion transmissibility. In this paper, an improved analytical strategy is presented for the design optimization of complex, active of passive, non-linear mounting systems. This strategy is built upon the computational Galerkin method of weighted residuals, and incorporates order reduction and numerical continuation in an iterative optimization scheme. The overall dynamic characteristics of the mounting system are considered and vibratory power transmission is minimized via adjustment of mount parameters by using both passive and active means. The method is first applied through a computational example case to the optimization of basic passive and active, non-linear isolation configurations. It is found that either active control or intentionally introduced non-linearity can improve the mount's performance; but a combination of both produces the greatest benefit. Next, a novel experimental, active, non-linear isolation system is studied. The effect of non-linearity on vibratory power transmission and active control are assessed via experimental measurements and the enhanced Galerkin method. Results show how harmonic excitation can result in multiharmonic vibratory power transmission. The proposed optimization strategy offers designers some flexibility in utilizing both passive and active means in combination with linear and non-linear components for improved vibration mounts.
Model Checking Linear-Time Properties of Probabilistic Systems
NASA Astrophysics Data System (ADS)
Baier, Christel; Größer, Marcus; Ciesinski, Frank
This chapter is about the verification of Markov decision processes (MDPs) which incorporate one of the fundamental models for reasoning about probabilistic and nondeterministic phenomena in reactive systems. MDPs have their roots in the field of operations research and are nowadays used in a wide variety of areas including verification, robotics, planning, controlling, reinforcement learning, economics and semantics of randomized systems. Furthermore, MDPs served as the basis for the introduction of probabilistic automata which are related to weighted automata. We describe the use of MDPs as an operational model for randomized systems, e.g., systems that employ randomized algorithms, multi-agent systems or systems with unreliable components or surroundings. In this context we outline the theory of verifying ω-regular properties of such operational models. As an integral part of this theory we use ω-automata, i.e., finite-state automata over finite alphabets that accept languages of infinite words. Additionally, basic concepts of important reduction techniques are sketched, namely partial order reduction of MDPs and quotient system reduction of the numerical problem that arises in the verification of MDPs. Furthermore we present several undecidability and decidability results for the controller synthesis problem for partially observable MDPs.
Channel Capacity of Non-Linear Transmission Systems
NASA Astrophysics Data System (ADS)
Ellis, Andrew D.; Zhao, Jian
Since their introduction in the late 1970s, the capacity of optical communication links has grown exponentially, fuelled by a series of key innovations including movement between the three telecommunication windows of 850 nm, 1,310 nm and 1,550 nm, distributed feedback laser, erbium-doped fibre amplifiers (EDFAs), dispersion-shifted and dispersion-managed fibre links, external modulation, wavelength division multiplexing, optical switching, forward error correction (FEC), Raman amplification, and most recently, coherent detection, electronic signal processing and optical orthogonal frequency division multiplexing (OFDM). Throughout this evolution, one constant factor has been the use of single-mode optical fibre, whose fundamental principles dated back to the 1800s, when Irish scientist, John Tyndall demonstrated in a lecture to the Royal Society in London that light could be guided through a curved stream of water [1]. Following many developments, including the proposal for waveguides by J.J. Thompson [2], the presentation of detailed calculations for dielectric waveguides by Snitzer [3], the proposal [4] and fabrication [5] of ultra low loss fibres, single-mode fibres were first adopted for non-experimental use in Dorset, UK in 1975, and are still in use today, despite the evolving designs to control chromatic dispersion and non-linearity.
School Financing: Movement Toward Equality of Expenditures?
ERIC Educational Resources Information Center
Amato, Josephine
In this paper, the political and economic forces influencing attempts to reduce the inequalities in education expenditures are examined. Current programs for financing public education (local, State, and Federal) are compared. In general, State-local tax systems are found to be regressive and improvements are suggested. Inequitability of State aid…
H ∞ output feedback stabilisation of linear discrete-time systems with impulses
NASA Astrophysics Data System (ADS)
Zhao, Shouwei; Sun, Jitao; Pan, Shengtao
2010-10-01
This article addresses the issue of designing an H ∞ output feedback controller for linear discrete-time systems with impulses. First, a new concept of H ∞ output feedback stabilisation for general linear discrete-time systems with impulses is introduced. Then sufficient linear matrix inequality conditions for the stabilisation and H ∞ performance of general discrete systems with impulses are proposed. In addition, the result is applied to resolve typical output feedback control problems for systems with impulses, such as the decentralised H ∞ output feedback control and the simultaneous H ∞ output feedback control. Finally, a numerical simulation is also presented to illustrate the effectiveness of the proposed results.
Fault Detection and Model Identification in Linear Dynamical Systems
2001-02-01
fault detection and isolation (FDI). One avenue of FDI is via the multi-model approach, in which the parameters of the nominal, unfailed model of the system are known, as well as the parameters of one or more fault models. The design goal is to obtain an indicator for when a fault has occurred, and, when more than one type is possible, which type of fault it is. A choice that must be made in tile system design is how to model noise. One way is as a bounded energy signal. This approach places very few restrictions on the types of noisy systems which
Gain scheduled control of linear systems with unsymmetrical saturation actuators
NASA Astrophysics Data System (ADS)
Wu, Wen-Juan; Duan, Guang-Ren
2016-11-01
The problem of stabilisation of a class of nonlinear continuous-time systems with asymmetric saturations on the control is studied in this paper. By combining the parametric Lyapunov equation approach and gain scheduling technique, a state feedback gain scheduling controller is proposed to solve the stabilisation problem of systems with unsymmetrical saturated control. The proposed gain scheduled approach is to increase the value of the design parameter so that the convergence rate of the closed-loop system can be increased. Numerical simulations show the effectiveness of the proposed approach.
Phase and amplitude control system for Stanford Linear Accelerator
Yoo, S.J.
1983-09-26
The computer controlled phase and amplitude detection system measures the instantaneous phase and amplitude of a 1 micro-second 2856 MHz rf pulse at a 180 Hz rate. This will be used for phase feedback control, and also for phase and amplitude jitter measurement. The program, which was originally written by John Fox and Keith Jobe, has been modified to improve the function of the system. The software algorithms used in the measurement are described, as is the performance of the prototype phase and amplitude detector system.
Discontinuous Galerkin Methods for NonLinear Differential Systems
NASA Technical Reports Server (NTRS)
Barth, Timothy; Mansour, Nagi (Technical Monitor)
2001-01-01
This talk considers simplified finite element discretization techniques for first-order systems of conservation laws equipped with a convex (entropy) extension. Using newly developed techniques in entropy symmetrization theory, simplified forms of the discontinuous Galerkin (DG) finite element method have been developed and analyzed. The use of symmetrization variables yields numerical schemes which inherit global entropy stability properties of the PDE (partial differential equation) system. Central to the development of the simplified DG methods is the Eigenvalue Scaling Theorem which characterizes right symmetrizers of an arbitrary first-order hyperbolic system in terms of scaled eigenvectors of the corresponding flux Jacobian matrices. A constructive proof is provided for the Eigenvalue Scaling Theorem with detailed consideration given to the Euler equations of gas dynamics and extended conservation law systems derivable as moments of the Boltzmann equation. Using results from kinetic Boltzmann moment closure theory, we then derive and prove energy stability for several approximate DG fluxes which have practical and theoretical merit.
Conditions of asymptotic stability for linear homogeneous switched systems
NASA Astrophysics Data System (ADS)
Ivanov, Gennady; Alferov, Gennady; Sharlay, Artem; Efimova, Polina
2017-07-01
In this article the authors prove the theorems giving the necessary and sufficient conditions for stability of robotic and mechatronic systems motion in terms of Lyapunov functions theory with the use of set-theoretic approach.
Using Parallel Banded Linear System Solvers in Generalized Eigenvalue Problems
1993-09-01
systems. The PPT algorithm is similar to an algorithm introduced by Lawrie and Sameh in [18]. The PDD algorithm is a variant of PPT which uses the fa-t...AND L. JOHNSSON, Solving banded systems on a parallel processor, Parallel Comput., 5 (1987), pp. 219-246. [10] J. J. DONGARRA AND A. SAMEH , On some...symmetric generalized matrix eigenvalur problem, SIAM J. Matrix Anal. Appl., 14 (1993). [18] D. H. LAWRIE AND A. H. SAMEH , The computation and
Improving the energy efficiency of sparse linear system solvers on multicore and manycore systems.
Anzt, H; Quintana-Ortí, E S
2014-06-28
While most recent breakthroughs in scientific research rely on complex simulations carried out in large-scale supercomputers, the power draft and energy spent for this purpose is increasingly becoming a limiting factor to this trend. In this paper, we provide an overview of the current status in energy-efficient scientific computing by reviewing different technologies used to monitor power draft as well as power- and energy-saving mechanisms available in commodity hardware. For the particular domain of sparse linear algebra, we analyse the energy efficiency of a broad collection of hardware architectures and investigate how algorithmic and implementation modifications can improve the energy performance of sparse linear system solvers, without negatively impacting their performance.
Non-Linear System Identification for Aeroelastic Systems with Application to Experimental Data
NASA Technical Reports Server (NTRS)
Kukreja, Sunil L.
2008-01-01
Representation and identification of a non-linear aeroelastic pitch-plunge system as a model of the NARMAX class is considered. A non-linear difference equation describing this aircraft model is derived theoretically and shown to be of the NARMAX form. Identification methods for NARMAX models are applied to aeroelastic dynamics and its properties demonstrated via continuous-time simulations of experimental conditions. Simulation results show that (i) the outputs of the NARMAX model match closely those generated using continuous-time methods and (ii) NARMAX identification methods applied to aeroelastic dynamics provide accurate discrete-time parameter estimates. Application of NARMAX identification to experimental pitch-plunge dynamics data gives a high percent fit for cross-validated data.
Benzi, Michele; Evans, Thomas M.; Hamilton, Steven P.; ...
2017-03-05
Here, we consider hybrid deterministic-stochastic iterative algorithms for the solution of large, sparse linear systems. Starting from a convergent splitting of the coefficient matrix, we analyze various types of Monte Carlo acceleration schemes applied to the original preconditioned Richardson (stationary) iteration. We expect that these methods will have considerable potential for resiliency to faults when implemented on massively parallel machines. We also establish sufficient conditions for the convergence of the hybrid schemes, and we investigate different types of preconditioners including sparse approximate inverses. Numerical experiments on linear systems arising from the discretization of partial differential equations are presented.
Optimized stiffness for linear time-invariant dynamic system according to a new system design
NASA Astrophysics Data System (ADS)
Veeraklaew, Tawiwat
2012-11-01
This paper deals with a linear time-invariant dynamic system such as spring-mass-damper system. General dynamic systems are quite commonly to be redesigned for another purpose of using. For example, if one automobile must be redesigned to have more weights, the existing suspension must be replaced due to that gained weight. Therefore the stiffness and damping coefficient must be recomputed in order to make the automobile become suitable for using as previous. Here the spring-mass-damper system is used as an example to demonstrate the technique through dynamic optimization where the problem is solved in two categories as minimum energy and maximum jerk. Once the state and control variables are provided from the problem of minimum energy and maximum jerk, respectively, these parameter will be substituted in dynamic equations and leave the stiffness and damping coefficient as the unknown parameters to be solved.
Linear system identification via backward-time observer models
NASA Technical Reports Server (NTRS)
Juang, Jer-Nan; Phan, Minh Q.
1992-01-01
Presented here is an algorithm to compute the Markov parameters of a backward-time observer for a backward-time model from experimental input and output data. The backward-time observer Markov parameters are decomposed to obtain the backward-time system Markov parameters (backward-time pulse response samples) for the backward-time system identification. The identified backward-time system Markov parameters are used in the Eigensystem Realization Algorithm to identify a backward-time state-space model, which can be easily converted to the usual forward-time representation. If one reverses time in the model to be identified, what were damped true system modes become modes with negative damping, growing as the reversed time increases. On the other hand, the noise modes in the identification still maintain the property that they are stable. The shift from positive damping to negative damping of the true system modes allows one to distinguish these modes from noise modes. Experimental results are given to illustrate when and to what extent this concept works.
Stochastic Stability of Sampled Data Systems with a Jump Linear Controller
NASA Technical Reports Server (NTRS)
Gonzalez, Oscar R.; Herencia-Zapana, Heber; Gray, W. Steven
2004-01-01
In this paper an equivalence between the stochastic stability of a sampled-data system and its associated discrete-time representation is established. The sampled-data system consists of a deterministic, linear, time-invariant, continuous-time plant and a stochastic, linear, time-invariant, discrete-time, jump linear controller. The jump linear controller models computer systems and communication networks that are subject to stochastic upsets or disruptions. This sampled-data model has been used in the analysis and design of fault-tolerant systems and computer-control systems with random communication delays without taking into account the inter-sample response. This paper shows that the known equivalence between the stability of a deterministic sampled-data system and the associated discrete-time representation holds even in a stochastic framework.
Krylov Subspace Methods for Complex Non-Hermitian Linear Systems. Thesis
NASA Technical Reports Server (NTRS)
Freund, Roland W.
1991-01-01
We consider Krylov subspace methods for the solution of large sparse linear systems Ax = b with complex non-Hermitian coefficient matrices. Such linear systems arise in important applications, such as inverse scattering, numerical solution of time-dependent Schrodinger equations, underwater acoustics, eddy current computations, numerical computations in quantum chromodynamics, and numerical conformal mapping. Typically, the resulting coefficient matrices A exhibit special structures, such as complex symmetry, or they are shifted Hermitian matrices. In this paper, we first describe a Krylov subspace approach with iterates defined by a quasi-minimal residual property, the QMR method, for solving general complex non-Hermitian linear systems. Then, we study special Krylov subspace methods designed for the two families of complex symmetric respectively shifted Hermitian linear systems. We also include some results concerning the obvious approach to general complex linear systems by solving equivalent real linear systems for the real and imaginary parts of x. Finally, numerical experiments for linear systems arising from the complex Helmholtz equation are reported.
System Combination with Log Linear Models (Author’s Manuscript)
2016-05-19
HMM) topology, and the frame level acoustic log-likelihoods from different systems are combined. As- sume there are K different systems to be...problem is to segment the continuous speech into segments, and then classify each (independent) segment in an acoustic code breaking fashion [9...ρi) ...∑|ρ| i=1 φK(O(i), ρi) φlm(W,ρ) ; η = η1 ... ηK ηlm (4) where φk(·) denotes the acoustic features for one segment from the kth
Cost decomposition of linear systems with application to model reduction
NASA Technical Reports Server (NTRS)
Skelton, R. E.
1980-01-01
A means is provided to assess the value or 'cst' of each component of a large scale system, when the total cost is a quadratic function. Such a 'cost decomposition' of the system has several important uses. When the components represent physical subsystems which can fail, the 'component cost' is useful in failure mode analysis. When the components represent mathematical equations which may be truncated, the 'component cost' becomes a criterion for model truncation. In this latter event component costs provide a mechanism by which the specific control objectives dictate which components should be retained in the model reduction process. This information can be valuable in model reduction and decentralized control problems.
Linear CCD attitude measurement system based on the identification of the auxiliary array CCD
NASA Astrophysics Data System (ADS)
Hu, Yinghui; Yuan, Feng; Li, Kai; Wang, Yan
2015-10-01
Object to the high precision flying target attitude measurement issues of a large space and large field of view, comparing existing measurement methods, the idea is proposed of using two array CCD to assist in identifying the three linear CCD with multi-cooperative target attitude measurement system, and to address the existing nonlinear system errors and calibration parameters and more problems with nine linear CCD spectroscopic test system of too complicated constraints among camera position caused by excessive. The mathematical model of binocular vision and three linear CCD test system are established, co-spot composition triangle utilize three red LED position light, three points' coordinates are given in advance by Cooperate Measuring Machine, the red LED in the composition of the three sides of a triangle adds three blue LED light points as an auxiliary, so that array CCD is easier to identify three red LED light points, and linear CCD camera is installed of a red filter to filter out the blue LED light points while reducing stray light. Using array CCD to measure the spot, identifying and calculating the spatial coordinates solutions of red LED light points, while utilizing linear CCD to measure three red LED spot for solving linear CCD test system, which can be drawn from 27 solution. Measured with array CCD coordinates auxiliary linear CCD has achieved spot identification, and has solved the difficult problems of multi-objective linear CCD identification. Unique combination of linear CCD imaging features, linear CCD special cylindrical lens system is developed using telecentric optical design, the energy center of the spot position in the depth range of convergence in the direction is perpendicular to the optical axis of the small changes ensuring highprecision image quality, and the entire test system improves spatial object attitude measurement speed and precision.
National Health Expenditures, 1978
Gibson, Robert M.
1979-01-01
Outlays for health care in the Nation reached $192.4 billion in calendar year 1978--13 percent higher than in 1977, according to preliminary figures compiled by the Health Care Financing Administration. This estimate represented $863 per person in the United States and was equal to 9.1 percent of the GNP. This latest report in the annual series representing national health expenditures provides detailed estimates of health care spending by type of service and method of financing. Revised estimates are presented extending back to 1965. PMID:10309049
National Health Expenditures, 1996
Levit, Katharine R.; Lazenby, Helen C.; Braden, Bradley R.; Cowan, Cathy A.; Sensenig, Arthur L.; McDonnell, Patricia A.; Stiller, Jean M.; Won, Darleen K.; Martin, Anne B.; Sivarajan, Lekha; Donham, Carolyn S.; Long, Anna M.; Stewart, Madie W.
1997-01-01
The national health expenditures (NHE) series presented in this report for 1960-96 provides a view of the economic history of health care in the United States through spending for health care services and the sources financing that care. In 1996 NHE topped $1 trillion. At the same time, spending grew at the slowest rate, 4.4 percent, ever recorded in the current series. For the first time, this article presents estimates of Medicare managed care payments by type of service, as well as nursing home and home health spending in hospital-based facilities. PMID:10179997
National health expenditures, 1989
Lazenby, Helen C.; Letsch, Suzanne W.
1990-01-01
Spending for health care in the United States grew to $604.1 billion in 1989, an increase of 11.1 percent from the 1988 level. Growth in national health expenditures has been edging upward since 1986, when the annual growth in the health care bill was 7.7 percent. Health care spending continues to command a larger and larger proportion of the resources of the Nation: In 1989, 11.6 percent of the Nation's output, as measured by the gross national product, was consumed by health care, up from 11.2 percent in 1988. PMID:10113559
National Health Expenditures, 1979
Gibson, Robert M
1980-01-01
Outlays for health care in the nation reached $212.2 billion in calendar year 1979—12.5 percent higher than in 1978, according to preliminary figures compiled by the Health Care Financing Administration. This estimate represented $943 per person in the United States and was equal to 9.0 percent of the Gross National Product. This latest report in the annual series representing national health expenditures provides detailed estimates of health care spending by type of service and method of financing. PMID:10309255
National health expenditures, 1989.
Lazenby, H C; Letsch, S W
1990-01-01
Spending for health care in the United States grew to $604.1 billion in 1989, an increase of 11.1 percent from the 1988 level. Growth in national health expenditures has been edging upward since 1986, when the annual growth in the health care bill was 7.7 percent. Health care spending continues to command a larger and larger proportion of the resources of the Nation: In 1989, 11.6 percent of the Nation's output, as measured by the gross national product, was consumed by health care, up from 11.2 percent in 1988.
Solution of homogeneous systems of linear equations arising from compartmental models
Funderlic, R.E.; Mankin, J.B.
1980-12-01
Systems of linear differential equations with constant coefficients, Ax = x-dot, with the matrix A having nonnegative off-diagonal elements and zero column sums occur in compartmental analysis. The steady-state solution leads to the homogeneous system of linear equations Ax(infinity) = x-dot(infinity) = 0. LU factorization, the Crout algorithm, error analysis, and solution of a modified system are treated. 3 figures.
Consensus of Heterogeneous Linear Multiagent Systems With Communication Time-Delays.
Xu, Xiang; Liu, Lu; Feng, Gang
2017-05-23
This paper studies the consensus problem of heterogeneous linear multiagent systems with arbitrarily large constant, time-varying, or distributed communication delays. Novel distributed dynamic controllers are proposed for such multiagent systems with fixed and switching directed communication topologies, respectively. It is shown that the controlled heterogeneous linear multiagent system can reach consensus for arbitrarily large constant, time-varying, and distributed communication delays under some sufficient conditions. Simulation examples are provided to demonstrate the effectiveness of the proposed controllers.
Generation of multi-scroll attractors without equilibria via piecewise linear systems.
Escalante-González, R J; Campos-Cantón, E; Nicol, Matthew
2017-05-01
In this paper, we present a new class of dynamical system without equilibria which possesses a multiscroll attractor. It is a piecewise-linear system which is simple, stable, displays chaotic behavior and serves as a model for analogous non-linear systems. We test for chaos using the 0-1 Test for Chaos from Gottwald and Melbourne [SIAM J. Appl. Dyn. Syst. 8(1), 129-145 (2009)].
Parallel Direct Methods for Solving Banded Linear Systems.
1985-08-01
Dongarra and A. Sameh , On some parallel banded system solvers, Technical Report MCSD, No. 27, Argonne National Lab., 1984. [2] D. Gannon, J. van...Report , Computer Science Dept., Yale University, 1985. In preparation. [10] A.H. Sameh , Numerical Parallel Algorithms - A Survey., D. Lawrie, A. Sameh
Passive dynamic controllers for non-linear mechanical systems
NASA Technical Reports Server (NTRS)
Juang, Jer-Nan; Wu, Shih-Chin; Phan, Minh; Longman, Richard W.
1992-01-01
The objective is to develop active model-independent controllers for slewing and vibration control of nonlinear multibody flexible systems, including flexible robots. The topics are presented in viewgraph form and include: passive stabilization; work-energy rate principle; Liapunov theory; displacement feedback; dynamic controller; displacement and acceleration feedback; velocity feedback; displacement feedback; physical interaction; a 6-DOF robot; and simulation results.
Brunton, Steven L; Brunton, Bingni W; Proctor, Joshua L; Kutz, J Nathan
2016-01-01
In this wIn this work, we explore finite-dimensional linear representations of nonlinear dynamical systems by restricting the Koopman operator to an invariant subspace spanned by specially chosen observable functions. The Koopman operator is an infinite-dimensional linear operator that evolves functions of the state of a dynamical system. Dominant terms in the Koopman expansion are typically computed using dynamic mode decomposition (DMD). DMD uses linear measurements of the state variables, and it has recently been shown that this may be too restrictive for nonlinear systems. Choosing the right nonlinear observable functions to form an invariant subspace where it is possible to obtain linear reduced-order models, especially those that are useful for control, is an open challenge. Here, we investigate the choice of observable functions for Koopman analysis that enable the use of optimal linear control techniques on nonlinear problems. First, to include a cost on the state of the system, as in linear quadratic regulator (LQR) control, it is helpful to include these states in the observable subspace, as in DMD. However, we find that this is only possible when there is a single isolated fixed point, as systems with multiple fixed points or more complicated attractors are not globally topologically conjugate to a finite-dimensional linear system, and cannot be represented by a finite-dimensional linear Koopman subspace that includes the state. We then present a data-driven strategy to identify relevant observable functions for Koopman analysis by leveraging a new algorithm to determine relevant terms in a dynamical system by ℓ1-regularized regression of the data in a nonlinear function space; we also show how this algorithm is related to DMD. Finally, we demonstrate the usefulness of nonlinear observable subspaces in the design of Koopman operator optimal control laws for fully nonlinear systems using techniques from linear optimal control.ork, we explore finite
Poyer, D.A.
1992-08-01
Analysis and evaluation of the impact that programs and policies have on energy consumption and expenditures are confounded by many intervening variables. A clear understanding of how these variables influence energy consumption patterns should be grounded in a rigorously developed framework. In this regard much is documented in the literature. However, an analysis of the comparative relationship between energy demand and variables which influence it among different socioeconomic groups has not been thoroughly explored with any theoretical rigor. It is proposed that differences in patterns of energy use between black, Hispanic, and majority households (where the household head is neither black nor Hispanic) are due to both structural and distribution differences. It is felt that the structural dissimilarities are primarily due to the dynamic nature in which energy consumption patterns evolve, with differences in changing housing patterns playing a significant role. For minorities, this implies a potential difference in the effect of policy and programs on economic welfare when compared to majority households.To test this hypothesis, separate conditional demand systems are estimated for majority, black, and Hispanic households. With the use of separate variance/covariance matrices, various parameter groups are tested for statistically significant differences.
Poyer, D.A.
1992-01-01
Analysis and evaluation of the impact that programs and policies have on energy consumption and expenditures are confounded by many intervening variables. A clear understanding of how these variables influence energy consumption patterns should be grounded in a rigorously developed framework. In this regard much is documented in the literature. However, an analysis of the comparative relationship between energy demand and variables which influence it among different socioeconomic groups has not been thoroughly explored with any theoretical rigor. It is proposed that differences in patterns of energy use between black, Hispanic, and majority households (where the household head is neither black nor Hispanic) are due to both structural and distribution differences. It is felt that the structural dissimilarities are primarily due to the dynamic nature in which energy consumption patterns evolve, with differences in changing housing patterns playing a significant role. For minorities, this implies a potential difference in the effect of policy and programs on economic welfare when compared to majority households.To test this hypothesis, separate conditional demand systems are estimated for majority, black, and Hispanic households. With the use of separate variance/covariance matrices, various parameter groups are tested for statistically significant differences.
48 CFR 252.225-7005 - Identification of expenditures in the United States.
Code of Federal Regulations, 2011 CFR
2011-10-01
... expenditures in the United States. 252.225-7005 Section 252.225-7005 Federal Acquisition Regulations System... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7005 Identification of expenditures in the United States. As prescribed in 225.1103(1), use the following clause: Identification of Expenditures in...
48 CFR 252.225-7005 - Identification of expenditures in the United States.
Code of Federal Regulations, 2014 CFR
2014-10-01
... expenditures in the United States. 252.225-7005 Section 252.225-7005 Federal Acquisition Regulations System... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7005 Identification of expenditures in the United States. As prescribed in 225.1103(1), use the following clause: Identification of Expenditures in...
48 CFR 252.225-7005 - Identification of expenditures in the United States.
Code of Federal Regulations, 2013 CFR
2013-10-01
... expenditures in the United States. 252.225-7005 Section 252.225-7005 Federal Acquisition Regulations System... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7005 Identification of expenditures in the United States. As prescribed in 225.1103(1), use the following clause: Identification of Expenditures in...
HOLMES, WILLIAM R.
2014-01-01
Reaction diffusion systems are often used to study pattern formation in biological systems. However, most methods for understanding their behavior are challenging and can rarely be applied to complex systems common in biological applications. I present a relatively simple and efficient, non-linear stability technique that greatly aids such analysis when rates of diffusion are substantially different. This technique reduces a system of reaction diffusion equations to a system of ordinary differential equations tracking the evolution of a large amplitude, spatially localized perturbation of a homogeneous steady state. Stability properties of this system, determined using standard bifurcation techniques and software, describe both linear and non-linear patterning regimes of the reaction diffusion system. I describe the class of systems this method can be applied to and demonstrate its application. Analysis of Schnakenberg and substrate inhibition models is performed to demonstrate the methods capabilities in simplified settings and show that even these simple models have non-linear patterning regimes not previously detected. The real power of this technique however is its simplicity and applicability to larger complex systems where other non-linear methods become intractable. This is demonstrated through analysis of a chemotaxis regulatory network comprised of interacting proteins and phospholipids. In each case, predictions of this method are verified against results of numerical simulation, linear stability, asymptotic, and / or full PDE bifurcation analyses. PMID:24158538
Closed-loop structural stability for linear-quadratic optimal system
NASA Technical Reports Server (NTRS)
Wong, P. K.; Athans, M.
1976-01-01
This paper contains an explicit parameterization of a subclass of linear constant gain feedback maps that will not destabilize an originally open-loop stable system. These results can then be used to obtain several new structural stability results for multi-input linear-quadratic feedback optimal designs.
System and method for linearly amplifying optical analog signals by backward Raman scattering
Lin, Cheng-Heui
1988-07-05
A system for linearly amplifying an optical analog signal by backward stimulated Raman scattering comprises a laser source for generating a pump pulse; and an optic fiber having two opposed apertures, a first aperture for receiving the pump pulse and a second aperture for receiving the optical analog signal, wherein the optical analog signal is linearly amplified to an amplified optical analog signal.
Compensating inherent linear move water application errors using a variable rate irrigation system
USDA-ARS?s Scientific Manuscript database
Continuous move irrigation systems such as linear move and center pivot irrigate unevenly when applying conventional uniform water rates due to the towers/motors stop/advance pattern. The effect of the cart movement pattern on linear move water application is larger on the first two spans which intr...
System and method for linearly amplifying optical analog signals by backward Raman scattering
Lin, Cheng-Heui
1988-01-01
A system for linearly amplifying an optical analog signal by backward stimulated Raman scattering comprises a laser source for generating a pump pulse; and an optic fiber having two opposed apertures, a first aperture for receiving the pump pulse and a second aperture for receiving the optical analog signal, wherein the optical analog signal is linearly amplified to an amplified optical analog signal.
ERIC Educational Resources Information Center
Ramirez, Rene; Flores, Homero
This paper takes G.K. Chesterton's short story, "The Three Horsemen of Apocalypse," as a motivating introduction to the study of linear equations systems, as well as a review of the concept of linear function. The guide has three objectives: (1) to illustrate how to use non-mathematical sources to create math problems; (2) to use the graphing…
On the Resonance Concept in Systems of Linear and Nonlinear Ordinary Differential Equations
1965-11-01
Determinanten und Matrizen mit Anwen- dungen in Physik und Technik). Berlin: Akademie-Verlag 1949. The author wishes to express his thanks to Prof.Dr.R.Iglisch...Case in the System of Ordinary Linear Differential Equations, Part III ( Studium des Resonanzfalles bei Systemen linearer gew6hnlicher
FAST modularization framework for wind turbine simulation: full-system linearization
NASA Astrophysics Data System (ADS)
Jonkman, J. M.; Jonkman, B. J.
2016-09-01
The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations e.g. for design-standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system response and exploit well- established methods and tools for analyzing linear systems. This paper presents the development and verification of the new linearization functionality of the open-source engineering tool FAST v8 for land-based wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly.
FAST Modularization Framework for Wind Turbine Simulation: Full-System Linearization
Jonkman, Jason M.; Jonkman, Bonnie J.
2016-10-03
The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations e.g. for design-standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system response and exploit well-established methods and tools for analyzing linear systems. Here, this paper presents the development and verification of the new linearization functionality of the open-source engineering tool FAST v8 for land-based wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly.
FAST Modularization Framework for Wind Turbine Simulation: Full-System Linearization: Preprint
Jonkman, Jason; Jonkman, Bonnie
2016-11-01
The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations e.g. for design-standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system response and exploit well-established methods and tools for analyzing linear systems. This paper presents the development and verification of the new linearization functionality of the open-source engineering tool FAST v8 for land-based wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly.
FAST Modularization Framework for Wind Turbine Simulation: Full-System Linearization
Jonkman, Jason M.; Jonkman, Bonnie J.
2016-10-03
The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations e.g. for design-standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system response and exploit well-established methods and tools for analyzing linear systems. Here, this paper presents the development and verification of the new linearization functionality of the open-source engineering tool FAST v8 for land-based wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly.
Fault detection and isolation for linear time-invariant systems
Liu, B.; Si, J.
1994-12-31
This paper is concerned with the problem of detecting and isolating faults by an observer. If the initial error of state estimation is zero, we show that faults can be isolated if and only if the system has a left-invertible detectability matrix which is defined in the present paper. For the more realistic case of nonzero initial error of state estimation, we develop fault isolation filters such that failures to be detected can be asymptotically isolated. We give necessary and sufficient conditions for the existence of such filters. We provide a method to design a fault isolation filter. This design procedure guarantees to isolate up to n faults, where n is the dimension of the system.
Portable linear-focused solar thermal energy collecting system
NASA Technical Reports Server (NTRS)
Miller, C. G.; Pohl, J. G. (Inventor)
1977-01-01
A solar heat collection system is provided by utilizing a line-focusing device that is effectively a cylindrically curved concentrator within a protected environment formed by a transparent inflatable casing. A target, such as a fluid or gas carrying conduit is positioned within or near the casing containing the concentrator, at the line focus of the concentrator. The casing can be inflated at the site of use by a low pressure air supply to form a unitary light weight structure. The collector, including casing, concentrator and target, is readily transportable and can be used either at ground level or on rooftops. The inflatable concentrator can be replaced with a rigid metal or other concentrator while maintaining the novel advantages of the whole solar heat collection system.
DEVELOPMENT OF INTEGRATED RAILWAY LINEAR PLAN SUPPORT SYSTEM
NASA Astrophysics Data System (ADS)
Kobayashi, Mitsuaki; Horii, Hironobu
A rail alignment has a great effect on travelling performance, speed, and time. We have developed a total system of rail alignment planning powered by a coordinate calculation program of line shapes, CAD, 3D simulation technology, which makes it possible to plan rail tracks by a graphical user interface for the people who posess a certain level of knowledge about a rail alignment. This system has functions of 2D design (plane line shape calculation, layout of turnouts), longitudinal section profile design (vertical line shape calculation), and cross section profile design of rail tracks. It also enables to check the rail track construction gauge and plan a rail track structure in a 3D view. These functions facilitated a simulation with accurate coordinate calculation results and made high-quality rail alignment planning effective.
Controller Design for Linear Stochastic Systems with Uncertain Parameters.
1985-03-01
example may be designed on a numerical basis. Also, the equivalence of this solution to the minimax solution may be analyzed numerically . Finally, in...must be such that Equation (3a) has a unique solution that is sample-path continuous, c) w must be such that the cost function, (5), is well-defined...problem can be reformulated as an optimization problem with equality constraints. 3.3. Problem Redefinition and Solution The system equations , (3
Advanced Design Linear Noise-Attenuating Earphone-Earcup System.
1981-08-01
actual earcup. Provision is made to include values fnr stiffness, mass, compliance of the earcushions, compliance of the skin and other measurable...Ce = Compliance of earcup Rc = Damping of earcushion ( Ignores damping of skin as earcushion value is much larger Cc = Compliance of earcushion Cs...Compliance of skin Cca = Compliance of earcup cavity ELECTRICAL CIRCUIT SIMULATION OF SINGLE EARCUP SYSTEM Figure 3 -6- In addition, the designers kept
PHELIX: design of transformer-driven linear implosion system
Turchi, Peter J; Atchison, Walter L; Rousculp, Chris L; Reinovsky, Robert E
2008-01-01
Experiments involving electromagnetically-imploded, solid-density liners can be achieved at reduced cost and energy if we start with a scale-size based on diagnostic resolution, rather than on the largest capacitor bank or generator we could bring to bear. For minimum resolution of 100 microns or less, many useful experiments could be performed with initial liner diameters that are factors of two to three smaller than used on high-energy systems, such as Atlas, thereby reducing energy requirements to sub-megajoule levels. Reduction in scale-size, however, also decreases the inductance change associated with liner motion relative to other inductances in the circuit. To improve coupling efficiency to liner kinetic energy, we invoke a current step-up transformer. Scaling relations have been developed for reducing the size and energy of such systems and compared with detailed numerical simulations. We discuss these calculations and describe the engineering embodiment of the resulting design for a system called PHELIX (Precision High Energy-density Liner Implosion eXperiment).
Brunton, Steven L.; Brunton, Bingni W.; Proctor, Joshua L.; Kutz, J. Nathan
2016-01-01
In this work, we explore finite-dimensional linear representations of nonlinear dynamical systems by restricting the Koopman operator to an invariant subspace spanned by specially chosen observable functions. The Koopman operator is an infinite-dimensional linear operator that evolves functions of the state of a dynamical system. Dominant terms in the Koopman expansion are typically computed using dynamic mode decomposition (DMD). DMD uses linear measurements of the state variables, and it has recently been shown that this may be too restrictive for nonlinear systems. Choosing the right nonlinear observable functions to form an invariant subspace where it is possible to obtain linear reduced-order models, especially those that are useful for control, is an open challenge. Here, we investigate the choice of observable functions for Koopman analysis that enable the use of optimal linear control techniques on nonlinear problems. First, to include a cost on the state of the system, as in linear quadratic regulator (LQR) control, it is helpful to include these states in the observable subspace, as in DMD. However, we find that this is only possible when there is a single isolated fixed point, as systems with multiple fixed points or more complicated attractors are not globally topologically conjugate to a finite-dimensional linear system, and cannot be represented by a finite-dimensional linear Koopman subspace that includes the state. We then present a data-driven strategy to identify relevant observable functions for Koopman analysis by leveraging a new algorithm to determine relevant terms in a dynamical system by ℓ1-regularized regression of the data in a nonlinear function space; we also show how this algorithm is related to DMD. Finally, we demonstrate the usefulness of nonlinear observable subspaces in the design of Koopman operator optimal control laws for fully nonlinear systems using techniques from linear optimal control. PMID:26919740
Static Linear Fresnel Lenses as LCPV System in a Greenhouse
NASA Astrophysics Data System (ADS)
Sonneveld, P. J.; Swinkels, G. L. A. M.; van Tuijl, B. A. J.; Janssen, H. J. J.; de Zwart, H. F.
2011-12-01
A low concentrating PV system with water cooling (LCPVT system) will result in electrical and thermal energy output from the solar energy excess entering a building or greenhouse. All the direct radiation could be converted, which corresponds to 75% of the incoming solar energy. This will significantly reduce the demand of cooling of the building. For an optimal performance it is beneficial to construct asymmetric roof elements with a steep inclination at the north side (the exact angle of course depends on the latitude of the building site). The Fresnel lens structure is oriented in upwards direction. In the current design, two of them are placed between an AR-coated double glass structure to prevent pollution and condensation on the lenses. Compared with a previous system, the number of lenses is reduced from 3 to 2 lenses, which reduces the costs of the system by limiting the number of receivers. By the upward facing of the lens structure, the focus quality is preserved over a much broader range of angles of incidence compared to a lens with downward facing structures. Each PMMA lens with a size of 1.20 m×1.60 m is composed of 12 `tiles' for easy production. The focal distance of the lens is 1,875 m and the concentration factor 50x. In most cases the focus line is thinner than 3 cm and the transmission is above 80%. The performance of these lenses with respect of the shape of the focal area and the position of the focal line has been analyzed with ray tracing techniques. From this analyses it was concluded that tracking of the receiver module is possible with two motors. One motor controls the distance between lens and receiver and one motor controls the translocation of the receivers parallel to the lens. The second conclusion was that the positions of the focal line are within the bounds of the greenhouse construction for almost the whole year. Only in winter, the focal line will be unreachable from time to time. A 480 m2 greenhouse with the LCPVT system
Robust stability analysis of uncertain switched linear systems with unstable subsystems
NASA Astrophysics Data System (ADS)
Yu, Qiang; Wu, Baowei
2015-05-01
The problem of robust stability for switched linear systems with all the subsystems being unstable is investigated. Unlike the most existing results in which each switching mode in the system is asymptotically stable, the subsystems may be unstable in this paper. A necessary condition of stability for switched linear systems is first obtained with certain hypothesis. Then, under two assumptions, sufficient conditions of exponential stability for both deterministic and uncertain switched linear systems are presented by using the invariant subspace theory and average dwell time method. Moreover, we further develop multiple Lyapunov functions and propose a method for constructing multiple Lyapunov functions for the considered switched linear systems with certain switching law. Several examples are included to show the effectiveness of the theoretical findings.
11 CFR 100.113 - Independent expenditures.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 11 Federal Elections 1 2013-01-01 2012-01-01 true Independent expenditures. 100.113 Section 100...) Definition of Expenditure (2 U.S.C. 431(9)) § 100.113 Independent expenditures. An independent expenditure that meets the requirements of 11 CFR 104.4 or part 109 is an expenditure, and such independent...
11 CFR 100.113 - Independent expenditures.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 11 Federal Elections 1 2014-01-01 2014-01-01 false Independent expenditures. 100.113 Section 100...) Definition of Expenditure (2 U.S.C. 431(9)) § 100.113 Independent expenditures. An independent expenditure that meets the requirements of 11 CFR 104.4 or part 109 is an expenditure, and such independent...
11 CFR 100.113 - Independent expenditures.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 11 Federal Elections 1 2011-01-01 2011-01-01 false Independent expenditures. 100.113 Section 100...) Definition of Expenditure (2 U.S.C. 431(9)) § 100.113 Independent expenditures. An independent expenditure that meets the requirements of 11 CFR 104.4 or part 109 is an expenditure, and such independent...
11 CFR 100.113 - Independent expenditures.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 11 Federal Elections 1 2012-01-01 2012-01-01 false Independent expenditures. 100.113 Section 100...) Definition of Expenditure (2 U.S.C. 431(9)) § 100.113 Independent expenditures. An independent expenditure that meets the requirements of 11 CFR 104.4 or part 109 is an expenditure, and such independent...
2 CFR 200.13 - Capital expenditures.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Capital expenditures. 200.13 Section 200.13... REQUIREMENTS FOR FEDERAL AWARDS Acronyms and Definitions Acronyms § 200.13 Capital expenditures. Capital expenditures means expenditures to acquire capital assets or expenditures to make additions, improvements...
11 CFR 100.113 - Independent expenditures.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 11 Federal Elections 1 2010-01-01 2010-01-01 false Independent expenditures. 100.113 Section 100...) Definition of Expenditure (2 U.S.C. 431(9)) § 100.113 Independent expenditures. An independent expenditure that meets the requirements of 11 CFR 104.4 or part 109 is an expenditure, and such...
Luu, Quoc T; DuChateau, Paul
2009-07-01
Experiments have established that different radiation types have different magnitudes of biological response. When biological response is defined in terms of the Relative Biologic Effectiveness (RBE) and different radiation type is characterized by Linear Energy Transfer (LET), the plot of the RBE versus LET (RBE-LET) curve shows RBE to increase with increasing LET, to reach a maximum, and to decrease with further increasing LET. Perhaps due to the descriptive nature of biology, most quantitative models for the RBE-LET curve ignore the reality of the underlying molecular biology. On the other hand, the molecular basis for the RBE-LET curve is not completely known despite recent efforts. Here we introduce a differential equation formulation for a signal-and-system model that sees cells as systems, different radiation types as input, and cellular responses as output. Because of scant knowledge of the underlying biochemical network, the current version is necessarily a work in progress. It explains the RBE-LET curve using not just input parameters but also systems internal state parameters. These systems internal state parameters represent parts of a biochemical network within a cell. Although multiple biochemical parts may well be involved, the shape of the RBE-LET curve is reproduced when only three system parameters are related to three biochemical parts: the molecular machinery for DNA double strand break repair; the molecular pathways for handling oxidative stress; and the radiolytic products of the cellular water. Despite being a simplified ''toy model,'' changes in the systems state parameters lead to model curves that are refutable in a modern molecular biology laboratory. As the parts in the biochemical network of the radiation response are being further elucidated, this model can incorporate new systems state parameters to allow a more accurate fit.
NASA Astrophysics Data System (ADS)
Zattoni, Elena
2017-01-01
This paper investigates the problem of structural model matching by output feedback in linear impulsive systems with control feedthrough. Namely, given a linear impulsive plant, possibly featuring an algebraic link from the control input to the output, and given a linear impulsive model, the problem consists in finding a linear impulsive regulator that achieves exact matching between the respective forced responses of the linear impulsive plant and of the linear impulsive model, for all the admissible input functions and all the admissible sequences of jump times, by means of a dynamic feedback of the plant output. The problem solvability is characterized by a necessary and sufficient condition. The regulator synthesis is outlined through the proof of sufficiency, which is constructive.
Households encountering with catastrophic health expenditures in Ferdows, Iran.
Ghoddoosinejad, Javad; Jannati, Ali; Gholipour, Kamal; Baghban Baghestan, Elham
2014-08-01
Out-of-pocket payments are the main sources of healthcare financing in most developing countries. Healthcare services can impose a massive cost burden on households, especially in developing countries. The purpose of this study was to calculate households encountered with catastrophic healthcare expenditures in Ferdows, Iran. The sample included 100 households representing 20% of all households in Ferdows, Iran. The data were collected using self-administered questionnaire. The ability to pay of households was calculated, and then if costs of household health were at least 40% of their ability to pay, it was considered as catastrophic expenditures. Rate of households encountered to catastrophic health expenditures was estimated to be 24%, of which dentistry services had the highest part in catastrophic health expenditures. Low ability to pay of households should be supported against these expenditures. More equitable health system would solve the problem, although more financial aid should be provided for households encountered to catastrophic costs.
Linear hydraulic drive system for a Stirling engine
Walsh, Michael M.
1984-02-21
A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.
Computer Aided Design for Linear Control State Variable System (SVS).
1987-12-01
if last rank = size then Writeln(list,’The system is obseryable with index ’,Value2, .’) If (valuT2 >= size ) and ( lat rank < size), hen Writeln...gamma:aryls ) var A2,A3,A4,A5 :arls 1,j :in eger; tesi value,step :real; es value:=1.0e-08; stepT-1 for:=1 o size do %or i:= o size do be in FI-ii -1 0. A2f
Evaluating Sparse Linear System Solvers on Scalable Parallel Architectures
2008-10-01
iterations will be necessary to assure sufficient accuracy whenever we do not use a direct method to solve (1.3) or (1.5). The overall SPIKE algorithm...boosting is activated, SPIKE is not used as a direct solver but rather as a preconditioner. In this case outer iterations via a Krylov subspace method ...robustness. Preconditioning aims to improve the robustness of iterative methods by transforming the system into M−1Ax = M−1f, or AM−1(Mx) = f. (3.2
Fault-tolerant control for a class of non-linear systems with dead-zone
NASA Astrophysics Data System (ADS)
Chen, Mou; Jiang, Bin; Guo, William W.
2016-05-01
In this paper, a fault-tolerant control scheme is proposed for a class of single-input and single-output non-linear systems with the unknown time-varying system fault and the dead-zone. The non-linear state observer is designed for the non-linear system using differential mean value theorem, and the non-linear fault estimator that estimates the unknown time-varying system fault is developed. On the basis of the designed fault estimator, the observer-based fault-tolerant tracking control is then developed using the backstepping technique for non-linear systems with the dead-zone. The stability of the whole closed-loop system is rigorously proved via Lyapunov analysis and the satisfactory tracking control performance is guaranteed in the presence of the unknown time-varying system fault and the dead-zone. Numerical simulation results are presented to illustrate the effectiveness of the proposed backstepping fault-tolerant control scheme for non-linear systems.
Impoverishing effects of catastrophic health expenditures in Malawi.
Mchenga, Martina; Chirwa, Gowokani Chijere; Chiwaula, Levison S
2017-01-21
Out of pocket (OOP) health spending can potentially expose households to risk of incurring large medical bills, and this may impact on their welfare. This work investigates the effect of catastrophic OOP on the incidence and depth of poverty in Malawi. The paper is based on data that was collected from 12,271 households that were interviewed during the third Malawi integrated household survey (IHS-3). The paper considered a household to have incurred a catastrophic health expenditure if the share of health expenditure in the household's non-food expenditure was greater than a given threshold ranging between 10 and 40%. As we increase the threshold from 10 to 40%, we found that OOP drives between 9.37 and 0.73% of households into catastrophic health expenditure. The extent by which households exceed a given threshold (mean overshoot) drops from 1.01% of expenditure to 0.08%, as the threshold increased. When OOP is accounted for in poverty estimation, additional 0.93% of the population is considered poor and the poverty gap rises by almost 2.54%. Our analysis suggests that people in rural areas and middle income households are at higher risk of facing catastrophic health expenditure. We conclude that catastrophic health expenditure increases the incidence and depth of poverty in Malawi. This calls for the introduction of social insurance system to minimize the incidence of catastrophic health expenditure especially to the rural and middle income population.