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Sample records for cost-effective digital control

  1. A Cost-Effective Model for Digital Forensic Investigations

    NASA Astrophysics Data System (ADS)

    Overill, Richard; Kwan, Michael; Chow, Kam-Pui; Lai, Pierre; Law, Frank

    Because of the way computers operate, every discrete event potentially leaves a digital trace. These digital traces must be retrieved during a digital forensic investigation to prove or refute an alleged crime. Given resource constraints, it is not always feasible (or necessary) for law enforcement to retrieve all the related digital traces and to conduct comprehensive investigations. This paper attempts to address the issue by proposing a model for conducting swift, practical and cost-effective digital forensic investigations.

  2. Costs and Cost-Effectiveness of Plasmodium vivax Control

    PubMed Central

    White, Michael T.; Yeung, Shunmay; Patouillard, Edith; Cibulskis, Richard

    2016-01-01

    The continued success of efforts to reduce the global malaria burden will require sustained funding for interventions specifically targeting Plasmodium vivax. The optimal use of limited financial resources necessitates cost and cost-effectiveness analyses of strategies for diagnosing and treating P. vivax and vector control tools. Herein, we review the existing published evidence on the costs and cost-effectiveness of interventions for controlling P. vivax, identifying nine studies focused on diagnosis and treatment and seven studies focused on vector control. Although many of the results from the much more extensive P. falciparum literature can be applied to P. vivax, it is not always possible to extrapolate results from P. falciparum–specific cost-effectiveness analyses. Notably, there is a need for additional studies to evaluate the potential cost-effectiveness of radical cure with primaquine for the prevention of P. vivax relapses with glucose-6-phosphate dehydrogenase testing. PMID:28025283

  3. Cost-effective bidirectional digitized radio-over-fiber systems employing sigma delta modulation

    NASA Astrophysics Data System (ADS)

    Lee, Kyung Woon; Jung, HyunDo; Park, Jung Ho

    2016-11-01

    We propose a cost effective digitized radio-over-fiber (D-RoF) system employing a sigma delta modulation (SDM) and a bidirectional transmission technique using phase modulated downlink and intensity modulated uplink. SDM is transparent to different radio access technologies and modulation formats, and more suitable for a downlink of wireless system because a digital to analog converter (DAC) can be avoided at the base station (BS). Also, Central station and BS share the same light source by using a phase modulation for the downlink and an intensity modulation for the uplink transmission. Avoiding DACs and light sources have advantages in terms of cost reduction, power consumption, and compatibility with conventional wireless network structure. We have designed a cost effective bidirectional D-RoF system using a low pass SDM and measured the downlink and uplink transmission performance in terms of error vector magnitude, signal spectra, and constellations, which are based on the 10MHz LTE 64-QAM standard.

  4. Cost effectiveness of Aedes aegypti control programmes: participatory versus vertical.

    PubMed

    Baly, A; Toledo, M E; Boelaert, M; Reyes, A; Vanlerberghe, V; Ceballos, E; Carvajal, M; Maso, R; La Rosa, M; Denis, O; Van der Stuyft, P

    2007-06-01

    We conducted an economic appraisal of two strategies for Aedes aegypti control: a vertical versus a community-based approach. Costs were calculated for the period 2000-2002 in three pilot areas of Santiago de Cuba where a community intervention was implemented and compared with three control areas with routine vertical programme activities. Reduction in A. aegypti foci was chosen as the measure of effectiveness. The pre-intervention number of foci (614 vs. 632) and economical costs for vector control (US$243746 vs. US$263486) were comparable in the intervention and control areas. During the intervention period (2001-2002), a 13% decrease in recurrent costs for the health system was observed. Within the control areas, these recurrent relative costs remained stable. The number of A. aegypti foci in the pilot areas and the control areas fell by 459 and 467, respectively. The community-based approach was more cost effective from a health system perspective (US$964 vs. US$1406 per focus) as well as from society perspective (US$1508 vs. US$1767 per focus).

  5. Rotavirus vaccine: a cost effective control measure for India.

    PubMed

    Kumar, Arun; Goel, Manish K; Jain, Ram Bilas; Khanna, Pardeep; Vibha, Vibha

    2012-04-01

    Globally, rotavirus diarrhea results in 453,000 deaths in children younger than 5 y—37% of deaths attributable to diarrhea and 5% of all deaths in children younger than 5 y. India alone accounts for 22% (~100,000 deaths) of all deaths attributable to rotavirus infection. Two oral rotavirus vaccines are available: Rotarix, a monovalent P1A[8] G1 vaccine (GlaxoSmithKline), and RotaTeq, a pentavalent bovine-human reassortant vaccine (Merck). Rotarix is administered in a 2-dose schedule with the first and second doses of DTP (DTP1, DTP2). RotaTeq requires a 3-dose schedule with DTP1, DTP2 and DTP3 with an interval of 4–10 weeks between doses. The first dose of either vaccine should be administered to infants aged 6–15 weeks irrespective of the history of previous rotavirus infection, and the maximum age for administering the last dose of either vaccine should be 32 weeks. Although India would require funding from international health organizations/GAVI until new indigenous rotavirus vaccine candidates are developed at a cheaper price, introduction of vaccination into the national immunization program would be a cost-effective step toward control of the rotavirus diarrhea-related morbidity and mortality in India.

  6. Cost-effectiveness of digital mammography screening before the age of 50 in The Netherlands.

    PubMed

    Sankatsing, Valérie D V; Heijnsdijk, Eveline A M; van Luijt, Paula A; van Ravesteyn, Nicolien T; Fracheboud, Jacques; de Koning, Harry J

    2015-10-15

    In the Netherlands, routine mammography screening starts at age 50. This starting age may have to be reconsidered because of the increasing breast cancer incidence among women aged 40 to 49 and the recent implementation of digital mammography. We assessed the cost-effectiveness of digital mammography screening that starts between age 40 and 49, using a microsimulation model. Women were screened before age 50, in addition to the current programme (biennial 50-74). Screening strategies varied in starting age (between 40 and 50) and frequency (annual or biennial). The numbers of breast cancers diagnosed, life-years gained (LYG) and breast cancer deaths averted were predicted and incremental cost-effectiveness ratios (ICERs) were calculated to compare screening scenarios. Biennial screening from age 50 to 74 (current strategy) was estimated to gain 157 life years per 1,000 women with lifelong follow-up, compared to a situation without screening, and cost €3,376/LYG (3.5% discounted). Additional screening increased the number of LYG, compared to no screening, ranging from 168 to 242. The costs to generate one additional LYG (i.e., ICER), comparing a screening strategy to the less intensive alternative, were estimated at €5,329 (biennial 48-74 vs. current strategy), €7,628 (biennial 45-74 vs. biennial 48-74), €10,826 (biennial 40-74 vs. biennial 45-74) and €18,759 (annual 40-49 + biennial 50-74 vs. biennial 40-74). Other strategies (49 + biennial 50-74 and annual 45-49 + biennial 50-74) resulted in less favourable ICERs. These findings show that extending the Dutch screening programme by screening between age 40 and 49 is cost-effective, particularly for biennial strategies.

  7. Mobile source emission control cost-effectiveness: Issues, uncertainties, and results

    SciTech Connect

    Wang, M.Q.

    1994-12-01

    Emissions from mobile sources undoubtedly contribute to US urban air pollution problems. Consequently, mobile source control measures, ranging from vehicle emission standards to reducing vehicle travel, have been adopted or proposed to help attain air quality standards. To rank various mobile source control measures, various government agencies and private organizations calculate cost-effectiveness in dollars per ton of emissions reduced. Arguments for or against certain control measures are often made on the basis of the calculated cost-effectiveness. Yet, different studies may yield significantly different cost-effectiveness results, because of the various methodologies used and assumptions regarding the values of costs and emission reductions. Because of the methodological differences, the cost-effectiveness results may not be comparable between studies. Use of incomparable cost-effectiveness results may result in adoption of ineffective control measures. This paper first discusses some important methodological issues involved in cost-effectiveness calculation for mobile sources and proposes appropriate, systematic methods for dealing with these issues. Various studies have been completed recently to evaluate the cost-effectiveness of mobile source emission control measures. These studies resulted in wide variations in the cost-effectiveness for same control measures. Methodological assumptions used in each study are presented and, based on the proposed methods for cost-effectiveness calculation, adjustments are applied to the original estimates in each study to correct inappropriate methodological assumptions and to make the studies comparable. Finally, mobile source control measures are ranked on the basis of the adjusted cost-effectiveness estimates.

  8. Optimal control and cost-effective analysis of malaria/visceral leishmaniasis co-infection

    PubMed Central

    Agusto, Folashade B.; ELmojtaba, Ibrahim M.

    2017-01-01

    In this paper, a deterministic model involving the transmission dynamics of malaria/visceral leishmaniasis co-infection is presented and studied. Optimal control theory is then applied to investigate the optimal strategies for curtailing the spread of the diseases using the use of personal protection, indoor residual spraying and culling of infected reservoirs as the system control variables. Various combination strategies were examined so as to investigate the impact of the controls on the spread of the disease. And we investigated the most cost-effective strategy of all the control strategies using three approaches, the infection averted ratio (IAR), the average cost-effectiveness ratio (ACER) and incremental cost-effectiveness ratio (ICER). Our results show that the implementation of the strategy combining all the time dependent control variables is the most cost-effective control strategy. This result is further emphasized by using the results obtained from the cost objective functional, the ACER, and the ICER. PMID:28166308

  9. A high performance cost-effective digital complex correlator for an X-band polarimetry survey.

    PubMed

    Bergano, Miguel; Rocha, Armando; Cupido, Luís; Barbosa, Domingos; Villela, Thyrso; Boas, José Vilas; Rocha, Graça; Smoot, George F

    2016-01-01

    The detailed knowledge of the Milky Way radio emission is important to characterize galactic foregrounds masking extragalactic and cosmological signals. The update of the global sky models describing radio emissions over a very large spectral band requires high sensitivity experiments capable of observing large sky areas with long integration times. Here, we present the design of a new 10 GHz (X-band) polarimeter digital back-end to map the polarization components of the galactic synchrotron radiation field of the Northern Hemisphere sky. The design follows the digital processing trends in radio astronomy and implements a large bandwidth (1 GHz) digital complex cross-correlator to extract the Stokes parameters of the incoming synchrotron radiation field. The hardware constraints cover the implemented VLSI hardware description language code and the preliminary results. The implementation is based on the simultaneous digitized acquisition of the Cartesian components of the two linear receiver polarization channels. The design strategy involves a double data rate acquisition of the ADC interleaved parallel bus, and field programmable gate array device programming at the register transfer mode. The digital core of the back-end is capable of processing 32 Gbps and is built around an Altera field programmable gate array clocked at 250 MHz, 1 GSps analog to digital converters and a clock generator. The control of the field programmable gate array internal signal delays and a convenient use of its phase locked loops provide the timing requirements to achieve the target bandwidths and sensitivity. This solution is convenient for radio astronomy experiments requiring large bandwidth, high functionality, high volume availability and low cost. Of particular interest, this correlator was developed for the Galactic Emission Mapping project and is suitable for large sky area polarization continuum surveys. The solutions may also be adapted to be used at signal processing

  10. Burner modifications for cost effective NO{sub x} control

    SciTech Connect

    Melick, T.A.; Hensley, M.E.; Gustafson, D.A.

    1998-12-31

    The development of commercial Low NO{sub x} Burners has provided Energy and Environmental Research Corporation (EER) with the expertise to modify existing burner equipment to provide the controlled fuel/air mixing conditions required for low NO{sub x} contribution. This approach represents a viable alternative to a full burner retrofit for many applications. EER has modified burners to lower NO{sub x} emissions at Louisville Gas and Electric`s (LG and E) Cane Run Station and at Jamestown Board of Public Utilities (JBPU). This paper discusses the method and results of these burner modifications.

  11. Identifying cost-effective dynamic policies to control epidemics.

    PubMed

    Yaesoubi, Reza; Cohen, Ted

    2016-12-10

    We describe a mathematical decision model for identifying dynamic health policies for controlling epidemics. These dynamic policies aim to select the best current intervention based on accumulating epidemic data and the availability of resources at each decision point. We propose an algorithm to approximate dynamic policies that optimize the population's net health benefit, a performance measure which accounts for both health and monetary outcomes. We further illustrate how dynamic policies can be defined and optimized for the control of a novel viral pathogen, where a policy maker must decide (i) when to employ or lift a transmission-reducing intervention (e.g. school closure) and (ii) how to prioritize population members for vaccination when a limited quantity of vaccines first become available. Within the context of this application, we demonstrate that dynamic policies can produce higher net health benefit than more commonly described static policies that specify a pre-determined sequence of interventions to employ throughout epidemics. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Burner modifications for cost effective NO{sub x} control

    SciTech Connect

    Melick, T.A.; Hensley, M.E.; Gustafson, D.A.

    1998-07-01

    The development of commercial low NO{sub x} burners has provided Energy and Environmental Research Corporation (EER) with the expertise to modify existing burner equipment to provide the controlled fuel/air mixing conditions required for low NO{sub x} combustion. This approach represents a viable lower cost alternative to a full burner retrofit for many applications. EER has modified burners to lower NO{sub x} emissions at Louisville Gas and Electric's (LG and E) Cane Run Station and at Jamestown Board of Public Utilities (JBPU). This paper will discuss the method and results of these burner modifications on a 180 and 170 Mwe boiler for LG and E and four boilers at JBPU. NO{sub x} reductions of greater than 50% have been demonstrated with burner modifications only that have achieved NO{sub x} compliance on these six boilers. EER will also be modifying cell burners for Dayton Power and Light at their JM Stuart Station. Unit {number_sign}3 is a 605 Mwe B and W universal pressure opposed wall fired boiler. EER will retrofit the burners this October through November and results will be available by the first of December. With deregulation of the utility industry approaching, many utilities are looking for lower cost alternatives to satisfy NO{sub x} regulations. Justifying new low NO{sub x} burners on a boiler that is 30 to 40 years old and has limited remaining life is also difficult. Performing modifications to the existing burners provides the utility an option. Modifications are usually 2 to 4 times less expensive than new low NO{sub x} burners.

  13. Digital flight control research

    NASA Technical Reports Server (NTRS)

    Potter, J. E.; Stern, R. G.; Smith, T. B.; Sinha, P.

    1974-01-01

    The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator.

  14. One Health approach to cost-effective rabies control in India

    PubMed Central

    Shah, Hiral A.; Pandey, Abhishek; Bilinski, Alyssa M.; Kakkar, Manish; Clark, Andrew D.; Galvani, Alison P.

    2016-01-01

    Over 20,000 rabies deaths occur annually in India, representing one-third of global human rabies. The Indian state of Tamil Nadu has pioneered a “One Health” committee to address the challenge of rabies in dogs and humans. Currently, rabies control in Tamil Nadu involves postexposure vaccination of humans after dog bites, whereas potential supplemental approaches include canine vaccination and sterilization. We developed a data-driven rabies transmission model fit to human rabies autopsy data and human rabies surveillance data from Tamil Nadu. Integrating local estimates for canine demography and costs, we predicted the impact of canine vaccination and sterilization on human health outcomes and evaluated cost-effectiveness according to the WHO criteria for India, which correspond to thresholds of $1,582 and $4,746 per disability-adjusted life-years (DALYs) for very cost-effective and cost-effective strategies, respectively. We found that highly feasible strategies focused on stray dogs, vaccinating as few as 7% of dogs annually, could very cost-effectively reduce human rabies deaths by 70% within 5 y, and a modest expansion to vaccinating 13% of stray dogs could cost-effectively reduce human rabies by almost 90%. Through integration over parameter uncertainty, we find that, for a cost-effectiveness threshold above $1,400 per DALY, canine interventions are at least 95% likely to be optimal. If owners are willing to bring dogs to central point campaigns at double the rate that campaign teams can capture strays, expanded annual targets become cost-effective. This case study of cost-effective canine interventions in Tamil Nadu may have applicability to other settings in India and beyond. PMID:27994161

  15. [Analysis of Cost-effectiveness of screening for breast cancer with conventional mammography, digital and magnetic resonance imaging].

    PubMed

    Peregrino, Antonio Augusto de Freitas; Vianna, Cid Manso de Mello; de Almeida, Carlos Eduardo Veloso; Gonzáles, Gabriela Bittencourt; Machado, Samara Cristina Ferreira; Costa e Silva, Frances Valéria; Rodrigues, Marcus Paulo da Silva

    2012-01-01

    A cost-effectiveness analysis was conducted in screening for breast cancer. The use of conventional mammography, digital and magnetic resonance imaging were compared with natural disease history as a baseline. A Markov model projected breast cancer in a group of 100,000 women for a 30 year period, with screening every two years. Four distinct scenarios were modeled: (1) the natural history of breast cancer, as a baseline, (2) conventional film mammography, (3) digital mammography and (4) magnetic resonance imaging. The costs of the scenarios modeled ranged from R$ 194.216,68 for natural history, to R$ 48.614.338,31, for screening with magnetic resonance imaging. The difference in effectiveness between the interventions ranged from 300 to 78.000 years of life gained in the cohort. The ratio of incremental cost-effectiveness in terms of cost per life-year gains, conventional mammographic screening has produced an extra year for R$ 13.573,07. The ICER of magnetic resonance imaging was R$ 2.904.328,88, compared to no screening. In conclusion, it is more cost-effective to perform the screening with conventional mammography than other technological interventions.

  16. Cost-effectiveness of interventions to control Campylobacter in the New Zealand poultry meat food supply.

    PubMed

    Lake, Robin J; Horn, Beverley J; Dunn, Alex H; Parris, Ruth; Green, F Terri; McNickle, Don C

    2013-07-01

    An analysis of the cost-effectiveness of interventions to control Campylobacter in the New Zealand poultry supply examined a series of interventions. Effectiveness was evaluated in terms of reduced health burden measured by disability-adjusted life years (DALYs). Costs of implementation were estimated from the value of cost elements, determined by discussions with industry. Benefits were estimated by changing the inputs to a poultry food chain quantitative risk model. Proportional reductions in the number of predicted Campylobacter infections were converted into reductions in the burden of disease measured in DALYs. Cost-effectiveness ratios were calculated for each intervention, as cost per DALY reduction and the ratios compared. The results suggest that the most cost-effective interventions (lowest ratios) are at the primary processing stage. Potential phage-based controls in broiler houses were also highly cost-effective. This study is limited by the ability to quantify costs of implementation and assumptions required to estimate health benefits, but it supports the implementation of interventions at the primary processing stage as providing the greatest quantum of benefit and lowest cost-effectiveness ratios.

  17. A Cost-Effective Atomic Force Microscope for Undergraduate Control Laboratories

    ERIC Educational Resources Information Center

    Jones, C. N.; Goncalves, J.

    2010-01-01

    This paper presents a simple, cost-effective and robust atomic force microscope (AFM), which has been purposely designed and built for use as a teaching aid in undergraduate controls labs. The guiding design principle is to have all components be open and visible to the students, so the inner functioning of the microscope has been made clear to…

  18. Cost-Effective Control of Infectious Disease Outbreaks Accounting for Societal Reaction

    PubMed Central

    Fast, Shannon M.; González, Marta C.; Markuzon, Natasha

    2015-01-01

    Background Studies of cost-effective disease prevention have typically focused on the tradeoff between the cost of disease transmission and the cost of applying control measures. We present a novel approach that also accounts for the cost of social disruptions resulting from the spread of disease. These disruptions, which we call social response, can include heightened anxiety, strain on healthcare infrastructure, economic losses, or violence. Methodology The spread of disease and social response are simulated under several different intervention strategies. The modeled social response depends upon the perceived risk of the disease, the extent of disease spread, and the media involvement. Using Monte Carlo simulation, we estimate the total number of infections and total social response for each strategy. We then identify the strategy that minimizes the expected total cost of the disease, which includes the cost of the disease itself, the cost of control measures, and the cost of social response. Conclusions The model-based simulations suggest that the least-cost disease control strategy depends upon the perceived risk of the disease, as well as media intervention. The most cost-effective solution for diseases with low perceived risk was to implement moderate control measures. For diseases with higher perceived severity, such as SARS or Ebola, the most cost-effective strategy shifted toward intervening earlier in the outbreak, with greater resources. When intervention elicited increased media involvement, it remained important to control high severity diseases quickly. For moderate severity diseases, however, it became most cost-effective to implement no intervention and allow the disease to run its course. Our simulation results imply that, when diseases are perceived as severe, the costs of social response have a significant influence on selecting the most cost-effective strategy. PMID:26288274

  19. Optimal control and cost effectiveness analysis for Newcastle disease eco-epidemiological model in Tanzania.

    PubMed

    Hugo, Alfred; Makinde, Oluwole Daniel; Kumar, Santosh; Chibwana, Fred F

    2017-12-01

    In this paper, a deterministic compartmental eco- epidemiological model with optimal control of Newcastle disease (ND) in Tanzania is proposed and analysed. Necessary conditions of optimal control problem were rigorously analysed using Pontryagin's maximum principle and the numerical values of model parameters were estimated using maximum likelihood estimator. Three control strategies were incorporated such as chicken vaccination (preventive), human education campaign and treatment of infected human (curative) and its' impact were graphically observed. The incremental cost effectiveness analysis technique used to determine the most cost effectiveness strategy and we observe that combination of chicken vaccination and human education campaign strategy is the best strategy to implement in limited resources. Therefore, ND can be controlled if the farmers will apply chicken vaccination properly and well in time.

  20. Digital automatic gain control

    NASA Technical Reports Server (NTRS)

    Uzdy, Z.

    1980-01-01

    Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.

  1. Cost-effectiveness of Occupational Therapy in Older People: Systematic Review of Randomized Controlled Trials.

    PubMed

    Nagayama, Hirofumi; Tomori, Kounosuke; Ohno, Kanta; Takahashi, Kayoko; Yamauchi, Keita

    2016-06-01

    A systematic review of the cost-effectiveness of occupational therapy for older people was conducted. MEDLINE, CINAHL, Web of Science, PsycINFO, Cochrane Library, OT seeker and unpublished trials registers were searched. Reference lists of all potentially eligible studies were searched with no language restrictions. We included trial-based full economic evaluations that considered both costs and outcomes in occupational therapy for older people compared with standard care (i.e. other therapy) or no intervention. We reviewed each trial for methodological quality using the Cochrane risk of bias tool and assessed the quality of economic evaluations using a Drummond checklist. In the results of this review, we included five eligible studies (1-5) that were randomized controlled trials with high-quality economic evaluation. Two studies were full economic evaluations of interventions for fall prevention (1 and 2); two studies were full economic evaluations of preventive occupational therapy interventions (3 and 4; one was a comparison of an occupational therapy group with a social work group); one study was a full economic evaluation of occupational therapy for individuals with dementia (5). Two of the studies (one was preventive occupational therapy [3] and the other was occupational therapy for dementia [5]) found a significant effect and confirmed the cost-effectiveness of occupational therapy for older people compared with the control group. These studies found that occupational therapy for older people was clinically effective and cost-effective in comparison with standard care or other therapies. With reference to their clinical implication, these intervention studies (using a client-centred approach) suggested potentially cost-effective means to motivate clients to maintain their own health. However, this review has limitations because of the high heterogeneity of the reviewed studies on full economic evaluations of occupational therapy for older people. Future

  2. A professional and cost effective digital video editing and image storage system for the operating room.

    PubMed

    Scollato, A; Perrini, P; Benedetto, N; Di Lorenzo, N

    2007-06-01

    We propose an easy-to-construct digital video editing system ideal to produce video documentation and still images. A digital video editing system applicable to many video sources in the operating room is described in detail. The proposed system has proved easy to use and permits one to obtain videography quickly and easily. Mixing different streams of video input from all the devices in use in the operating room, the application of filters and effects produces a final, professional end-product. Recording on a DVD provides an inexpensive, portable and easy-to-use medium to store or re-edit or tape at a later time. From stored videography it is easy to extract high-quality, still images useful for teaching, presentations and publications. In conclusion digital videography and still photography can easily be recorded by the proposed system, producing high-quality video recording. The use of firewire ports provides good compatibility with next-generation hardware and software. The high standard of quality makes the proposed system one of the lowest priced products available today.

  3. Cost-Effectiveness Analysis of Breast Cancer Control Interventions in Peru

    PubMed Central

    Zelle, Sten G.; Vidaurre, Tatiana; Abugattas, Julio E.; Manrique, Javier E.; Sarria, Gustavo; Jeronimo, José; Seinfeld, Janice N.; Lauer, Jeremy A.; Sepulveda, Cecilia R.; Venegas, Diego; Baltussen, Rob

    2013-01-01

    Objectives In Peru, a country with constrained health resources, breast cancer control is characterized by late stage treatment and poor survival. To support breast cancer control in Peru, this study aims to determine the cost-effectiveness of different breast cancer control interventions relevant for the Peruvian context. Methods We performed a cost-effectiveness analysis (CEA) according to WHO-CHOICE guidelines, from a healthcare perspective. Different screening, early detection, palliative, and treatment interventions were evaluated using mathematical modeling. Effectiveness estimates were based on observational studies, modeling, and on information from Instituto Nacional de Enfermedades Neoplásicas (INEN). Resource utilizations and unit costs were based on estimates from INEN and observational studies. Cost-effectiveness estimates are in 2012 United States dollars (US$) per disability adjusted life year (DALY) averted. Results The current breast cancer program in Peru ($8,426 per DALY averted) could be improved through implementing triennial or biennial screening strategies. These strategies seem the most cost-effective in Peru, particularly when mobile mammography is applied (from $4,125 per DALY averted), or when both CBE screening and mammography screening are combined (from $4,239 per DALY averted). Triennially, these interventions costs between $63 million and $72 million per year. Late stage treatment, trastuzumab therapy and annual screening strategies are the least cost-effective. Conclusions Our analysis suggests that breast cancer control in Peru should be oriented towards early detection through combining fixed and mobile mammography screening (age 45-69) triennially. However, a phased introduction of triennial CBE screening (age 40-69) with upfront FNA in non-urban settings, and both CBE (age 40-49) and fixed mammography screening (age 50-69) in urban settings, seems a more feasible option and is also cost-effective. The implementation of this

  4. A cost-effective transparency-based digital imaging for efficient and accurate wound area measurement.

    PubMed

    Li, Pei-Nan; Li, Hong; Wu, Mo-Li; Wang, Shou-Yu; Kong, Qing-You; Zhang, Zhen; Sun, Yuan; Liu, Jia; Lv, De-Cheng

    2012-01-01

    Wound measurement is an objective and direct way to trace the course of wound healing and to evaluate therapeutic efficacy. Nevertheless, the accuracy and efficiency of the current measurement methods need to be improved. Taking the advantages of reliability of transparency tracing and the accuracy of computer-aided digital imaging, a transparency-based digital imaging approach is established, by which data from 340 wound tracing were collected from 6 experimental groups (8 rats/group) at 8 experimental time points (Day 1, 3, 5, 7, 10, 12, 14 and 16) and orderly archived onto a transparency model sheet. This sheet was scanned and its image was saved in JPG form. Since a set of standard area units from 1 mm(2) to 1 cm(2) was integrated into the sheet, the tracing areas in JPG image were measured directly, using the "Magnetic lasso tool" in Adobe Photoshop program. The pixel values/PVs of individual outlined regions were obtained and recorded in an average speed of 27 second/region. All PV data were saved in an excel form and their corresponding areas were calculated simultaneously by the formula of Y (PV of the outlined region)/X (PV of standard area unit) × Z (area of standard unit). It took a researcher less than 3 hours to finish area calculation of 340 regions. In contrast, over 3 hours were expended by three skillful researchers to accomplish the above work with traditional transparency-based method. Moreover, unlike the results obtained traditionally, little variation was found among the data calculated by different persons and the standard area units in different sizes and shapes. Given its accurate, reproductive and efficient properties, this transparency-based digital imaging approach would be of significant values in basic wound healing research and clinical practice.

  5. Cost-effective control strategies for animal and zoonotic diseases in pastoralist populations.

    PubMed

    Zinsstag, J; Abakar, M F; Ibrahim, M; Tschopp, R; Crump, L; Bonfoh, B; Schelling, E

    2016-11-01

    Animal diseases and zoonoses abound among pastoralist livestock, which is composed of cattle, sheep, goats, yak, camels, llamas, reindeer, horses and donkeys. There is endemic and, periodically, epidemic transmission of highly contagious viral and bacterial diseases in Africa, Asia and Latin America. Pastoralist livestock is often multiparasitised with endo- and ectoparasites, as well as being affected by vectorborne viral and protozoal diseases. Pastoral livestock can be a reservoir of such diseases and can also, conversely, be at risk from exposure to wildlife reservoirs. Public and private animal health services currently underperform in almost all pastoral areas due to structural reforms and lack of income, as indicated in assessments of national Veterinary Services by the World Organisation for Animal Health. Control of infectious disease in industrialised countries has been achieved through large-scale public funding of control measures and compensation for culled stock. Such means are not available in pastoralist areas of most low- and middle-income countries (LMICs). While the cost-effectiveness and profitability of the control of animal diseases and zoonoses is less of a consideration for industrialised countries, in the experience of the authors, understanding the economic implications of a control programme is a prerequisite for successful attempts to improve animal health in LMICs. The incremental costs of animal disease control can potentially be shared using crosssector assessments, integrated control, and regional coordination efforts to mitigate transboundary disease risks. In this paper, the authors discuss cost-effective animal disease and zoonoses control in LMICs. It illustrates frameworks and examples of integrated control and cross-sector economics, showing conditions under which these diseases could be controlled in a cost-effective way.

  6. Cost and cost-effectiveness of PPM-DOTS for tuberculosis control: evidence from India.

    PubMed Central

    Floyd, Katherine; Arora, V. K.; Murthy, K. J. R.; Lonnroth, Knut; Singla, Neeta; Akbar, Y.; Zignol, Matteo; Uplekar, Mukund

    2006-01-01

    OBJECTIVE: To assess the cost and cost-effectiveness of the Public-Private Mix DOTS (PPM-DOTS) strategy for tuberculosis (TB) control in India. METHODS: We collected data on the costs and effects of pilot PPM-DOTS projects in Delhi and Hyderabad using documentary data and interviews. The cost of PPM-DOTS was compared with public sector DOTS (i.e. DOTS delivered through public sector facilities only) and non-DOTS treatment in the private sector. Costs for 2002 in US$ were assessed for the public sector, private practitioners, and patients/attendants. Effectiveness was measured as the number of cases successfully treated. FINDINGS: The average cost per patient treated was US$ 111-123 for PPM-DOTS and public sector DOTS, and US$ 111-172 for non-DOTS treatment in the private sector. From the public sector's perspective, the cost per patient treated was lower in PPM-DOTS projects than in public sector DOTS programmes (US$ 24-33 versus US$ 63). DOTS implementation in either the public or private sectors improved treatment outcomes and substantially lowered costs incurred by patients and their attendants, compared to non-DOTS treatment in the private sector (US$ 50-60 for DOTS compared to over US$ 100 for non-DOTS). The average cost-effectiveness of PPM-DOTS and public sector DOTS was similar, at US$ 120-140 per patient successfully treated, compared to US$ 218-338 for non-DOTS private sector treatment. Incremental cost-effectiveness analysis showed that PPM-DOTS can improve effectiveness while also lowering costs. CONCLUSION: PPM-DOTS can be an affordable and cost-effective approach to improving TB control in India, and can substantially lower the economic burden of TB for patients. PMID:16799727

  7. A Cost-Effectiveness Tool for Informing Policies on Zika Virus Control

    PubMed Central

    Tamagnan, Jules A.; Medlock, Jan; Ndeffo-Mbah, Martial L.; Fish, Durland; Ávila-Agüero, María L.; Marín, Rodrigo; Ko, Albert I.; Galvani, Alison P.

    2016-01-01

    Background As Zika virus continues to spread, decisions regarding resource allocations to control the outbreak underscore the need for a tool to weigh policies according to their cost and the health burden they could avert. For example, to combat the current Zika outbreak the US President requested the allocation of $1.8 billion from Congress in February 2016. Methodology/Principal Findings Illustrated through an interactive tool, we evaluated how the number of Zika cases averted, the period during pregnancy in which Zika infection poses a risk of microcephaly, and probabilities of microcephaly and Guillain-Barré Syndrome (GBS) impact the cost at which an intervention is cost-effective. From Northeast Brazilian microcephaly incidence data, we estimated the probability of microcephaly in infants born to Zika-infected women (0.49% to 2.10%). We also estimated the probability of GBS arising from Zika infections in Brazil (0.02% to 0.06%) and Colombia (0.08%). We calculated that each microcephaly and GBS case incurs the loss of 29.95 DALYs and 1.25 DALYs per case, as well as direct medical costs for Latin America and the Caribbean of $91,102 and $28,818, respectively. We demonstrated the utility of our cost-effectiveness tool with examples evaluating funding commitments by Costa Rica and Brazil, the US presidential proposal, and the novel approach of genetically modified mosquitoes. Our analyses indicate that the commitments and the proposal are likely to be cost-effective, whereas the cost-effectiveness of genetically modified mosquitoes depends on the country of implementation. Conclusions/Significance Current estimates from our tool suggest that the health burden from microcephaly and GBS warrants substantial expenditures focused on Zika virus control. Our results justify the funding committed in Costa Rica and Brazil and many aspects of the budget outlined in the US president’s proposal. As data continue to be collected, new parameter estimates can be customized

  8. Cost-Effectiveness of Chagas Disease Vector Control Strategies in Northwestern Argentina

    PubMed Central

    Vazquez-Prokopec, Gonzalo M.; Spillmann, Cynthia; Zaidenberg, Mario; Kitron, Uriel; Gürtler, Ricardo E.

    2009-01-01

    Background Control and prevention of Chagas disease rely mostly on residual spraying of insecticides. In Argentina, vector control shifted from a vertical to a fully horizontal strategy based on community participation between 1992 and 2004. The effects of such strategy on Triatoma infestans, the main domestic vector, and on disease transmission have not been assessed. Methods and Findings Based on retrospective (1993–2004) records from the Argentinean Ministry of Health for the Moreno Department, Northwestern Argentina, we performed a cost-effectiveness (CE) analysis and compared the observed CE of the fully horizontal vector control strategy with the expected CE for a vertical or a mixed (i.e., vertical attack phase followed by horizontal surveillance) strategy. Total direct costs (in 2004 US$) of the horizontal and mixed strategies were, respectively, 3.3 and 1.7 times lower than the costs of the vertical strategy, due to reductions in personnel costs. The estimated CE ratios for the vertical, mixed and horizontal strategies were US$132, US$82 and US$45 per averted human case, respectively. When per diems were excluded from the costs (i.e., simulating the decentralization of control activities), the CE of vertical, mixed and horizontal strategies was reduced to US$60, US$42 and US$32 per averted case, respectively. Conclusions and Significance The mixed strategy would have averted between 1.6 and 4.0 times more human cases than the fully horizontal strategy, and would have been the most cost-effective option to interrupt parasite transmission in the Department. In rural and dispersed areas where waning vertical vector programs cannot accomplish full insecticide coverage, alternative strategies need to be developed. If properly implemented, community participation represents not only the most appealing but also the most cost-effective alternative to accomplish such objectives. PMID:19156190

  9. Programmable Digital Controller

    NASA Technical Reports Server (NTRS)

    Wassick, Gregory J.

    2012-01-01

    An existing three-channel analog servo loop controller has been redesigned for piezoelectric-transducer-based (PZT-based) etalon control applications to a digital servo loop controller. This change offers several improvements over the previous analog controller, including software control over proportional-integral-derivative (PID) parameters, inclusion of other data of interest such as temperature and pressure in the control laws, improved ability to compensate for PZT hysteresis and mechanical mount fluctuations, ability to provide pre-programmed scanning and stepping routines, improved user interface, expanded data acquisition, and reduced size, weight, and power.

  10. Analysis of U.S. produced water controls -- Are they cost-effective?

    SciTech Connect

    Veil, J.A.

    1995-12-31

    The US Environmental Protection Agency (EPA) establishes controls on produced water discharges into US waters through effluent limitations guidelines (ELGs), and general and individual discharge permits. Over the past 20 years, produced water controls have become much stricter, and in some areas, no discharge of produced water is allowed. In setting discharge standards, EPA considers vast amounts of data, makes assumptions regarding which data and what approaches are representative, selects the most appropriate analytical methods, and interprets the analytical results. Despite EPA`s considerable efforts to accurately understand and characterize the economic and environmental impacts of produced water discharges before proposing and adopting ELGs and issuing permits, current US produced water controls may be overly restrictive and not cost-effective. This paper summarizes several studies that have reviewed in detail EPA`s data, assumptions, and analytical methods for earlier proposed regulations and general permits. These include the offshore oil and gas ELGs, EPA`s Region 6 general permit for coastal waters, and most recently, the proposed ELGs for the coastal oil and gas industry. By substituting different data, using revised assumptions, and reanalyzing data that are equally or more valid, the studies reach alternate conclusions on the cost-effectiveness of current produced water controls.

  11. Digital flight control systems

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1977-01-01

    The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

  12. Cost-effectiveness of telehealth for patients with depression: evidence from the Healthlines randomised controlled trial

    PubMed Central

    Hollinghurst, Sandra; Edwards, Louisa; Thomas, Clare; Foster, Alexis; Davies, Ben; Gaunt, Daisy; Montgomery, Alan A.; Salisbury, Chris

    2016-01-01

    Background Depression is a prevalent long-term condition that is associated with substantial resource use. Telehealth may offer a cost-effective means of supporting the management of people with depression. Aims To investigate the cost-effectiveness of a telehealth intervention (‘Healthlines') for patients with depression. Method A prospective patient-level economic evaluation conducted alongside a randomised controlled trial. Patients were recruited through primary care, and the intervention was delivered via a telehealth service. Participants with a confirmed diagnosis of depression and PHQ-9 score ≥10 were recruited from 43 English general practices. A series of up to 10 scripted, theory-led, telephone encounters with health information advisers supported participants to effect a behaviour change, use online resources, optimise medication and improve adherence. The intervention was delivered alongside usual care and was designed to support rather than duplicate primary care. Cost-effectiveness from a combined health and social care perspective was measured by net monetary benefit at the end of 12 months of follow-up, calculated from incremental cost and incremental quality-adjusted life years (QALYs). Cost–consequence analysis included cost of lost productivity, participant out-of-pocket expenditure and the clinical outcome. Results A total of 609 participants were randomised – 307 to receive the Healthlines intervention plus usual care and 302 to receive usual care alone. Forty-five per cent of participants had missing quality of life data, 41% had missing cost data and 51% of participants had missing data on either cost or utility, or both. Multiple imputation was used for the base-case analysis. The intervention was associated with incremental mean per-patient National Health Service/personal social services cost of £168 (95% CI £43 to £294) and an incremental QALY gain of 0.001 (95% CI −0.023 to 0.026). The incremental cost-effectiveness ratio

  13. Digital numerically controlled oscillator

    NASA Technical Reports Server (NTRS)

    Cellier, A.; Huey, D. C.; Ma, L. N. (Inventor)

    1980-01-01

    The frequency and phase of an output signal from an oscillator circuit are controlled with accuracy by a digital input word. Positive and negative alterations in output frequency are both provided for by translating all values of input words so that they are positive. The oscillator reference frequency is corrected only in one direction, by adding phase to the output frequency of the oscillator. The input control word is translated to a single algebraic sign and the digital 1 is added thereto. The translated input control word is then accumulated. A reference clock signal having a frequency at an integer multiple of the desired frequency of the output signal is generated. The accumulated control word is then compared with a threshold level. The output signal is adjusted in a single direction by dividing the frequency of the reference clock signal by a first integer or by an integer different from the first integer.

  14. Cost-effectiveness of community health workers in tuberculosis control in Bangladesh.

    PubMed Central

    Islam, Md Akramul; Wakai, Susumu; Ishikawa, Nobukatsu; Chowdhury, A. M. R.; Vaughan, J. Patrick

    2002-01-01

    OBJECTIVE: To compare the cost-effectiveness of the tuberculosis (TB) programme run by the Bangladesh Rural Advancement Committee (BRAC), which uses community health workers (CHWs), with that of the government TB programme which does not use CHWs. METHODS: TB control statistics and cost data for July 1996 - June 1997 were collected from both government and BRAC thanas (subdistricts) in rural Bangladesh. To measure the cost per patient cured, total costs were divided by the total number of patients cured. FINDINGS: In the BRAC and government areas, respectively, a total of 186 and 185 TB patients were identified over one year, with cure rates among sputum-positive patients of 84% and 82%. However, the cost per patient cured was US$ 64 in the BRAC area compared to US$ 96 in the government area. CONCLUSION: The government programme was 50% more expensive for similar outcomes. Although both the BRAC and government TB control programmes appeared to achieve satisfactory cure rates using DOTS (a five-point strategy), the involvement of CHWs was found to be more cost-effective in rural Bangladesh. With the same budget, the BRAC programme could cure three TB patients for every two in the government programme. PMID:12132000

  15. Digital Optical Control System

    NASA Astrophysics Data System (ADS)

    Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.

    1988-09-01

    We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.

  16. Optimal combinations of control strategies and cost-effective analysis for visceral leishmaniasis disease transmission

    PubMed Central

    Biswas, Santanu; Subramanian, Abhishek; ELMojtaba, Ibrahim M.; Chattopadhyay, Joydev; Sarkar, Ram Rup

    2017-01-01

    Visceral leishmaniasis (VL) is a deadly neglected tropical disease that poses a serious problem in various countries all over the world. Implementation of various intervention strategies fail in controlling the spread of this disease due to issues of parasite drug resistance and resistance of sandfly vectors to insecticide sprays. Due to this, policy makers need to develop novel strategies or resort to a combination of multiple intervention strategies to control the spread of the disease. To address this issue, we propose an extensive SIR-type model for anthroponotic visceral leishmaniasis transmission with seasonal fluctuations modeled in the form of periodic sandfly biting rate. Fitting the model for real data reported in South Sudan, we estimate the model parameters and compare the model predictions with known VL cases. Using optimal control theory, we study the effects of popular control strategies namely, drug-based treatment of symptomatic and PKDL-infected individuals, insecticide treated bednets and spray of insecticides on the dynamics of infected human and vector populations. We propose that the strategies remain ineffective in curbing the disease individually, as opposed to the use of optimal combinations of the mentioned strategies. Testing the model for different optimal combinations while considering periodic seasonal fluctuations, we find that the optimal combination of treatment of individuals and insecticide sprays perform well in controlling the disease for the time period of intervention introduced. Performing a cost-effective analysis we identify that the same strategy also proves to be efficacious and cost-effective. Finally, we suggest that our model would be helpful for policy makers to predict the best intervention strategies for specific time periods and their appropriate implementation for elimination of visceral leishmaniasis. PMID:28222162

  17. Optimal combinations of control strategies and cost-effective analysis for visceral leishmaniasis disease transmission.

    PubMed

    Biswas, Santanu; Subramanian, Abhishek; ELMojtaba, Ibrahim M; Chattopadhyay, Joydev; Sarkar, Ram Rup

    2017-01-01

    Visceral leishmaniasis (VL) is a deadly neglected tropical disease that poses a serious problem in various countries all over the world. Implementation of various intervention strategies fail in controlling the spread of this disease due to issues of parasite drug resistance and resistance of sandfly vectors to insecticide sprays. Due to this, policy makers need to develop novel strategies or resort to a combination of multiple intervention strategies to control the spread of the disease. To address this issue, we propose an extensive SIR-type model for anthroponotic visceral leishmaniasis transmission with seasonal fluctuations modeled in the form of periodic sandfly biting rate. Fitting the model for real data reported in South Sudan, we estimate the model parameters and compare the model predictions with known VL cases. Using optimal control theory, we study the effects of popular control strategies namely, drug-based treatment of symptomatic and PKDL-infected individuals, insecticide treated bednets and spray of insecticides on the dynamics of infected human and vector populations. We propose that the strategies remain ineffective in curbing the disease individually, as opposed to the use of optimal combinations of the mentioned strategies. Testing the model for different optimal combinations while considering periodic seasonal fluctuations, we find that the optimal combination of treatment of individuals and insecticide sprays perform well in controlling the disease for the time period of intervention introduced. Performing a cost-effective analysis we identify that the same strategy also proves to be efficacious and cost-effective. Finally, we suggest that our model would be helpful for policy makers to predict the best intervention strategies for specific time periods and their appropriate implementation for elimination of visceral leishmaniasis.

  18. Cost effectiveness of regulation-compliant filtration to control sediment and metal pollution in urban runoff.

    PubMed

    Smith, C Scott; Lejano, Raul P; Ogunseitan, Oladele A; Hipi, J Aaron

    2007-11-01

    The implementation of Total Maximum Daily Load (TMDL) to control urban runoff presents major structural and managerial challenges for cities. We developed a decision support system (DSS) for TMDL compliance at the city level to solve for a phased, least-cost strategy toward meeting four TMDLs using stormwater filtration. Based on a case-study city, we modeled wet weather flows and associated discharge of Total Suspended Sediment (TSS), cadmium, copper, and zinc to receiving waters by coupling U.S. EPA's Storm Water Management Model (SWMM v. 5.0) with the geographic dataset of the urban drainage network. We linked a mixed integer linear programming algorithm to the watershed model for deriving cost-effective selection and placement of curb inlet filters to meet mass- and concentration-based TMDL requirements. The least cost solution for meeting the city's TMDL waste load allocations for TSS (73.9% reduction), Cd (50.6% reduction), Cu (30.0% reduction), and Zn (55.7% reduction) would require 1071 filter inserts at a cost of $1.7 million. In contrast, random placement of 1071 filters or uniform placement of 1266 filters is effective only for TSS and would cost $4.0 million and $4.8 million, respectively. Our results demonstrate the increases in cost-effectiveness of using an optimization-based DSS for urban watershed management.

  19. Using counterfactuals to evaluate the cost-effectiveness of controlling biological invasions.

    PubMed

    McConnachie, Matthew M; van Wilgen, Brian W; Ferraro, Paul J; Forsyth, Aurelia T; Richardson, David M; Gaertner, Mirijam; Cowling, Richard M

    2016-03-01

    Prioritizing limited conservation funds for controlling biological invasions requires accurate estimates of the effectiveness of interventions to remove invasive species and their cost-effectiveness (cost per unit area or individual). Despite billions of dollars spent controlling biological invasions worldwide, it is unclear whether those efforts are effective, and cost-effective. The paucity of evidence results from the difficulty in measuring the effect of invasive species removal: a researcher must estimate the difference in outcomes (e.g. invasive species cover) between where the removal program intervened and what might have been observed if the program had not intervened. In the program evaluation literature, this is called a counterfactual analysis, which formally compares what actually happened and what would have happened in the absence of an intervention. When program implementation is not randomized, estimating counterfactual outcomes is especially difficult. We show how a thorough understanding of program implementation, combined with a matching empirical design can improve the way counterfactual outcomes are estimated in nonexperimental contexts. As a practical demonstration, we estimated the cost-effectiveness of South Africa's Working for Water program, arguably the world's most ambitious invasive species control program, in removing invasive alien trees from different land use types, across a large area in the Cape Floristic Region. We estimated that the proportion of the treatment area covered by invasive trees would have been 49% higher (5.5% instead of 2.7% of the grid cells occupied) had the program not intervened. Our estimates of cost per hectare to remove invasive species, however, are three to five times higher than the predictions made when the program was initiated. Had there been no control (counter-factual), invasive trees would have spread on untransformed land, but not on land parcels containing plantations or land transformed by

  20. [Cost effective planning of controlled trials with diagnostic instruments of limited reproducibility].

    PubMed

    Krummenauer, F; Förster, G

    1999-06-01

    This paper proposes a simple approach for sample size prediction in controlled diagnostic or clinical trials for group comparison when the diagnostic (imaging) instrument under consideration shows limited reliability and thus calls for taking replicate measurements on each study subject. Using a specified cost function for the overall trial, a cost optimum replication number per subject is predicted, resulting in a cost-optimum predicted group size. This approach results in remarkable cost-effectiveness, as single assessment costs based on the imaging method under consideration only present a small fraction of the overall costs of preparing study subjects for a series of measurement replications by, for example, injection of nuclear or contrast agents.

  1. Cost-effectiveness of interventions to prevent HIV and STDs among women: a randomized controlled trial.

    PubMed

    Ruger, Jennifer Prah; Abdallah, Arbi Ben; Ng, Nora Y; Luekens, Craig; Cottler, Linda

    2014-10-01

    Injection drug use is a leading transmission route of HIV and STDs, and disease prevention among drug users is an important public health concern. This study assesses cost-effectiveness of behavioral interventions for reducing HIV and STDs infections among injection drug-using women. Cost-effectiveness analysis was conducted from societal and provider perspectives for randomized trial data and Bernoullian model estimates of infections averted for three increasingly intensive interventions: (1) NIDA's standard intervention (SI); (2) SI plus a well woman exam (WWE); and (3) SI, WWE, plus four educational sessions (4ES). Trial results indicate that 4ES was cost-effective relative to WWE, which was dominated by SI, for most diseases. Model estimates, however, suggest that WWE was cost-effective relative to SI and dominated 4ES for all diseases. Trial and model results agree that WWE is cost-effective relative to SI per hepatitis C infection averted ($109 308 for in trial, $6 016 in model) and per gonorrhea infection averted ($9 461 in trial, $14 044 in model). In sensitivity analysis, trial results are sensitive to 5 % change in WWE effectiveness relative to SI for hepatitis C and HIV. In the model, WWE remained cost-effective or cost-saving relative to SI for HIV prevention across a range of assumptions. WWE is cost-effective relative to SI for preventing hepatitis C and gonorrhea. WWE may have similar effects as the costlier 4ES.

  2. Modelling geographic variation in the cost-effectiveness of control policies for infectious vector diseases: the example of Chagas disease.

    PubMed

    Castillo-Riquelme, Marianela; Chalabi, Zaid; Lord, Joanne; Guhl, Felipe; Campbell-Lendrum, Diarmid; Davies, Clive; Fox-Rushby, Julia

    2008-03-01

    Few cost-effectiveness analysis (CEA) models have accounted for geographic variation in input parameters. This paper describes a deterministic discrete-time multi-state model to estimate the cost-effectiveness of vector control policies for Chagas disease, where implementation varies according to village characteristics. The model outputs include the total number of new infections, disability adjusted life years (DALYs) incurred, costs of associated healthcare, and total costs of the Ministry of Health's control policy for house surveillance and spraying. Incremental net benefits were estimated to determine Colombian villages in which it is cost-effective to implement the control policy. The robustness of these conclusions was evaluated by deterministic sensitivity analyses. The model should help provide a decision-support system to compare control policies and to allocate resources geographically.

  3. Psycho-educational CBT-Insomnia workshops in the community. A cost-effectiveness analysis alongside a randomised controlled trial.

    PubMed

    Bonin, Eva-Maria; Beecham, Jennifer; Swift, Naomi; Raikundalia, Shriti; Brown, June S L

    2014-04-01

    Around one in three of the UK population suffer from sleep problems, resulting in high costs to society. Cognitive behaviour therapy for insomnia (CBT-I) has been shown to be effective. Community-based workshops may be a cost-effective way to provide CBT-I to groups that are usually hard to reach or reluctant to seek treatment. A sample of 151 participants aged 18 or over from five London boroughs who self-referred were randomised into a group receiving workshops and a waiting list control group. 111 provided complete data on service use and outcome measures. Results from the cost-effectiveness and cost-utility analyses are presented using cost-effectiveness acceptability curves. At a maximum willingness to pay per quality-adjusted life-year (QALY) of £30,000, the probability of the intervention being cost-effective is 80%. If commissioners are willing to pay £150 per point improvement on the Insomnia Severity Index, which is approximately the cost of the intervention, there is a 97% probability of cost-effectiveness. Community-based CBT-I workshops are likely to be a cost-effective intervention to improve insomnia symptoms and are a promising low-level option to include within the panoply of interventions that are encouraged within the UK policy of increasing access to psychological therapies.

  4. Modeling of Control Costs, Emissions, and Control Retrofits for Cost Effectiveness and Feasibility Analyses

    EPA Pesticide Factsheets

    Learn about EPA’s use of the Integrated Planning Model (IPM) to develop estimates of SO2 and NOx emission control costs, projections of futureemissions, and projections of capacity of future control retrofits, assuming controls on EGUs.

  5. Cost and cost-effectiveness of nationwide school-based helminth control in Uganda

    PubMed Central

    BROOKER, SIMON; KABATEREINE, NARCIS B; FLEMING, FIONA; DEVLIN, NANCY

    2009-01-01

    Estimates of cost and cost-effectiveness are typically based on a limited number of small-scale studies with no investigation of the existence of economies to scale or intra-country variation in cost and cost-effectiveness. This information gap hinders the efficient allocation of health care resources and the ability to generalize estimates to other settings. The current study investigates the intra-country variation in the cost and cost-effectiveness of nationwide school-based treatment of helminth (worm) infection in Uganda. Programme cost data were collected through semi-structured interviews with districts officials and from accounting records in six of the 23 intervention districts. Both financial and economic costs were assessed. Costs were estimated on the basis of cost in US$ per schoolchild treated and an incremental cost effectiveness ratio (cost in US$ per case of anaemia averted) was used to evaluate programme cost-effectiveness. Sensitivity analysis was performed to assess the effect of discount rate and drug price. The overall economic cost per child treated in the six districts was US$ 0.54 and the cost-effectiveness was US$ 3.19 per case of anaemia averted. Analysis indicated that estimates of both cost and cost-effectiveness differ markedly with the total number of children which received treatment, indicating economies of scale. There was also substantial variation between districts in the cost per individual treated (US$ 0.41-0.91) and cost per anaemia case averted (US$ 1.70-9.51). Independent variables were shown to be statistically associated with both sets of estimates. This study highlights the potential bias in transferring data across settings without understanding the nature of observed variations. PMID:18024966

  6. Cognitive-Behavioral Treatment for Panic Disorder with Agoraphobia: A Randomized, Controlled Trial and Cost-Effectiveness Analysis

    ERIC Educational Resources Information Center

    Roberge, Pasquale; Marchand, Andre; Reinharz, Daniel; Savard, Pierre

    2008-01-01

    A randomized, controlled trial was conducted to examine the cost-effectiveness of cognitive-behavioral treatment (CBT) for panic disorder with agoraphobia. A total of 100 participants were randomly assigned to standard (n = 33), group (n = 35), and brief (n = 32) treatment conditions. Results show significant clinical and statistical improvement…

  7. Cost-Effectiveness of Breast Cancer Control Strategies in Central America: The Cases of Costa Rica and Mexico

    PubMed Central

    Niëns, Laurens M.; Zelle, Sten G.; Gutiérrez-Delgado, Cristina; Rivera Peña, Gustavo; Hidalgo Balarezo, Blanca Rosa; Rodriguez Steller, Erick; Rutten, Frans F. H.

    2014-01-01

    This paper reports the most cost-effective policy options to support and improve breast cancer control in Costa Rica and Mexico. Total costs and effects of breast cancer interventions were estimated using the health care perspective and WHO-CHOICE methodology. Effects were measured in disability-adjusted life years (DALYs) averted. Costs were assessed in 2009 United States Dollars (US$). To the extent available, analyses were based on locally obtained data. In Costa Rica, the current strategy of treating breast cancer in stages I to IV at a 80% coverage level seems to be the most cost-effective with an incremental cost-effectiveness ratio (ICER) of US$4,739 per DALY averted. At a coverage level of 95%, biennial clinical breast examination (CBE) screening could improve Costa Rica's population health twofold, and can still be considered very cost-effective (ICER US$5,964/DALY). For Mexico, our results indicate that at 95% coverage a mass-media awareness raising program (MAR) could be the most cost-effective (ICER US$5,021/DALY). If more resources are available in Mexico, biennial mammography screening for women 50–70 yrs (ICER US$12,718/DALY), adding trastuzumab (ICER US$13,994/DALY) or screening women 40–70 yrs biennially plus trastuzumab (ICER US$17,115/DALY) are less cost-effective options. We recommend both Costa Rica and Mexico to engage in MAR, CBE or mammography screening programs, depending on their budget. The results of this study should be interpreted with caution however, as the evidence on the intervention effectiveness is uncertain. Also, these programs require several organizational, budgetary and human resources, and the accessibility of breast cancer diagnostic, referral, treatment and palliative care facilities should be improved simultaneously. A gradual implementation of early detection programs should give the respective Ministries of Health the time to negotiate the required budget, train the required human resources and understand possible

  8. Cost-effectiveness of breast cancer control strategies in Central America: the cases of Costa Rica and Mexico.

    PubMed

    Niëns, Laurens M; Zelle, Sten G; Gutiérrez-Delgado, Cristina; Rivera Peña, Gustavo; Hidalgo Balarezo, Blanca Rosa; Rodriguez Steller, Erick; Rutten, Frans F H

    2014-01-01

    This paper reports the most cost-effective policy options to support and improve breast cancer control in Costa Rica and Mexico. Total costs and effects of breast cancer interventions were estimated using the health care perspective and WHO-CHOICE methodology. Effects were measured in disability-adjusted life years (DALYs) averted. Costs were assessed in 2009 United States Dollars (US$). To the extent available, analyses were based on locally obtained data. In Costa Rica, the current strategy of treating breast cancer in stages I to IV at a 80% coverage level seems to be the most cost-effective with an incremental cost-effectiveness ratio (ICER) of US$4,739 per DALY averted. At a coverage level of 95%, biennial clinical breast examination (CBE) screening could improve Costa Rica's population health twofold, and can still be considered very cost-effective (ICER US$5,964/DALY). For Mexico, our results indicate that at 95% coverage a mass-media awareness raising program (MAR) could be the most cost-effective (ICER US$5,021/DALY). If more resources are available in Mexico, biennial mammography screening for women 50-70 yrs (ICER US$12,718/DALY), adding trastuzumab (ICER US$13,994/DALY) or screening women 40-70 yrs biennially plus trastuzumab (ICER US$17,115/DALY) are less cost-effective options. We recommend both Costa Rica and Mexico to engage in MAR, CBE or mammography screening programs, depending on their budget. The results of this study should be interpreted with caution however, as the evidence on the intervention effectiveness is uncertain. Also, these programs require several organizational, budgetary and human resources, and the accessibility of breast cancer diagnostic, referral, treatment and palliative care facilities should be improved simultaneously. A gradual implementation of early detection programs should give the respective Ministries of Health the time to negotiate the required budget, train the required human resources and understand possible

  9. Digital Fire Control Systems Support

    DTIC Science & Technology

    2012-09-27

    Systems ( DFCS ) for the M119A2 and M777A2. The DFCS is a fully integrated digital fire control system that has weapon platform application to the...Lightweight 155 mm (LW155) Towed Howitzer and the M119A2 Lightweight 105mm Towed Howitzer. 15. SUBJECT TERMS Digital Fire Control Systems ( DFCS ) 16...Joint Lightweight 155, has been tasked to develop and maintain the Digital Fire Control Systems ( DFCS ) for the M119A2 and M777A2. The DFCS is a fully

  10. A cost-effective, case-control study on the association between breast cancer and pregnancy through web mining.

    PubMed

    Yoon, Hong-Jun; Xu, Songhua; Tourassi, Georgia

    2013-05-01

    We report a case-control, breast cancer epidemiological study through mining people stories from the Internet. The aim of the study is to test whether mining openly available, personal stories from the Internet can be a cost-effective way for reliable epidemiological discoveries. As a case study, we focus on the association between breast cancer risk and pregnancy, which is clearly established through controlled clinical survey studies. Specifically, we mined 30,000 online obituary articles. Replicating a case-control study design, our web mining based approach confirmed the general trends reported by traditional epidemiological studies. Our web mining study demonstrates promising preliminary evidence that online content mining can be a cost-effective way for epidemiological knowledge discovery.

  11. Cost effectiveness of group follow-up after structured education for type 1 diabetes: a cluster randomised controlled trial

    PubMed Central

    2014-01-01

    Background This study examines the cost effectiveness of group follow-up after participation in the Dose Adjustment for Normal Eating (DAFNE) structured education programme for type 1 diabetes. Methods Economic evaluation conducted alongside a cluster randomised controlled trial involving 437 adults with type 1 diabetes in Ireland. Group follow-up involved two group education ‘booster’ sessions post-DAFNE. Individual follow-up involved two standard one-to-one hospital clinic visits. Incremental costs, quality-adjusted life years (QALYs) gained and cost effectiveness were estimated at 18 months. Uncertainty was explored using sensitivity analysis and by estimating cost effectiveness acceptability curves. Results Group follow-up was associated with a mean reduction in QALYs gained of 0.04 per patient (P value, 0.052; 95% CI, −0.08 to 0.01, intra-class correlation (ICC), 0.033) and a mean reduction in total healthcare costs of €772 (P value, 0.020; 95% CI, −1,415 to −128: ICC, 0.016) per patient. At alternative threshold values of €5,000, €15,000, €25,000, €35,000, and €45,000, the probability of group follow-up being cost effective was estimated to be 1.000, 0.762, 0.204, 0.078, and 0.033 respectively. Conclusions The results do not support implementation of group follow-up as the sole means of follow-up post-DAFNE. Given the reported cost savings, future studies should explore the cost effectiveness of alternative models of group care for diabetes. Trial registration Current Controlled Trials ISRCTN79759174 (assigned: 9 February 2007). PMID:24927851

  12. Optimal isolation control strategies and cost-effectiveness analysis of a two-strain avian influenza model.

    PubMed

    Agusto, F B

    2013-09-01

    The most important and effective measures against disease outbreaks in the absence of valid medicines or vaccine are quarantine and isolation strategies. In this paper optimal control theory is applied to a system of ordinary differential equation describing a two-strain avian influenza transmission via the Pontryagin's Maximum Principle. To this end, a pair of control variables representing the isolation strategies for individuals with avian and mutant strains were incorporated into the transmission model. The infection averted ratio (IAR) and the incremental cost-effectiveness ratio (ICER) were calculated to investigate the cost-effectiveness of all possible combinations of the control strategies. The simulation results show that the implementation of the combination strategy during the epidemic is the most cost-effective strategy for avian influenza transmission. This is followed by the control strategy involving isolation of individuals with the mutant strain. Also observed was the fact that low mutating and more virulent virus results in an increased control effort of isolating individuals with the avian strain; and high mutating with more virulent virus results in increased efforts in isolating individuals with the mutant strain.

  13. Is Surgery for Displaced, Midshaft Clavicle Fractures in Adults Cost-Effective? Results Based on a Multicenter Randomized Controlled Trial

    PubMed Central

    2010-01-01

    Objectives To determine the cost-effectiveness of open reduction internal fixation (ORIF) of displaced, midshaft clavicle fractures in adults. Design Formal cost-effectiveness analysis based on a prospective, randomized controlled trial. Setting Eight hospitals in Canada (seven university affiliated and one community hospital) Patients/Participants 132 adults with acute, completely displaced, midshaft clavicle fractures Intervention Clavicle ORIF versus nonoperative treatment Main Outcome Measurements Utilities derived from SF-6D Results The base-case cost per quality adjusted life year (QALY) gained for ORIF was $65,000. Cost-effectiveness improved to $28,150/QALY gained when the functional benefit from ORIF was assumed to be permanent, with cost per QALY gained falling below $50,000 when the functional advantage persisted for 9.3 years or more. In other sensitivity analyses, the cost per QALY gained for ORIF fell below $50,000 when ORIF cost less than $10,465 (base case cost $13,668) or the long-term utility difference between nonoperative treatment and ORIF was greater than 0.034 (base-case difference 0.014). Short-term disutility associated with fracture healing also affected cost-effectiveness, with the cost per QALY gained for ORIF falling below $50,000 when the utility of a fracture treated nonoperatively prior to union was less than 0.617 (base-case utility 0.706) or when nonoperative treatment increased the time to union by 20 weeks (base-case difference 12 weeks). Conclusions The cost-effectiveness of ORIF after acute clavicle fracture depended on the durability of functional advantage for ORIF compared to nonoperative treatment. When functional benefits persisted for more than 9 years, ORIF had favorable value compared with many accepted health interventions. PMID:20577073

  14. Digital control of HVDC converters

    SciTech Connect

    Pilotto, L.A.S.; Roitman, M.; Alves, J.E.R.

    1989-05-01

    This paper presents the project of a completely digital HVDC converter controller based on a 16-bit microcomputer. It was decided to achieve as much as possible by software in order to minimize functions performed by external hardware. The presented design comprises software programmed functions such as a PID current control amplifier, voltage dependent current order limiters and an alpha-minimum symmetrization unit, among others. HVDC control principles are briefly reviewed and a detailed description of both the hardware and software structure of the controller is presented. The digital controller was implemented in an HVDC simulator and several dynamic performance tests demonstrated the efficiency of the proposed methodology.

  15. Cost-Effectiveness of Group and Internet Cognitive Behavioral Therapy for Insomnia in Adolescents: Results from a Randomized Controlled Trial

    PubMed Central

    De Bruin, Eduard J.; van Steensel, Francisca J.A.; Meijer, Anne Marie

    2016-01-01

    Study Objectives: To investigate cost-effectiveness of adolescent cognitive behavioral therapy for insomnia (CBTI) in group- and Internet-delivered formats, from a societal perspective with a time horizon of 1 y Methods: Costs and effects data up to 1-y follow-up were obtained from a randomized controlled trial (RCT) comparing Internet CBTI to face-to-face group CBTI. The study was conducted at the laboratory of the Research Institute of Child Development and Education at the University of Amsterdam, and the academic youth mental health care center UvAMinds in Amsterdam. Sixty-two participants meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for insomnia were randomized to face-to-face group CBTI (GT; n = 31, age = 15.6 y ± 1.8, 71.0% girls) or individual Internet CBTI (IT; n = 31, age = 15.4 y ± 1.5, 83.9% girls). The intervention consisted of six weekly sessions and a 2-mo follow up booster-session of CBTI, consisting of psychoeducation, sleep hygiene, restriction of time in bed, stimulus control, cognitive therapy, and relaxation techniques. GT sessions were held in groups of six to eight adolescents guided by two trained sleep therapists. IT consisted of individual Internet therapy with preprogrammed content similar to GT, and guided by trained sleep therapists. Results: Outcome measures were subjective sleep efficiency (SE) ≥ 85%, and quality-adjusted life-years (QALY). Analyses were conducted from a societal perspective. Incremental cost-effectiveness ratios (ICERs) were calculated using bootstrap sampling, and presented in cost-effectiveness planes. Primary analysis showed costs over 1 y were higher for GT but effects were similar for IT and GT. Bootstrapped ICERs demonstrated there is a high probability of IT being cost-effective compared to GT. Secondary analyses confirmed robustness of results. Conclusions: Internet CBTI is a cost-effective treatment compared to group CBTI for adolescents, although

  16. A cost-effective high-throughput digital system for observation and acquisition of animal behavioral data.

    PubMed

    Farrimond, Jonathan A; Hill, Andrew J; Jones, Nicholas A; Stephens, Gary J; Whalley, Benjamin J; Williams, Claire M

    2009-05-01

    We have designed and implemented a low-cost digital system using closed-circuit television cameras coupled to a digital acquisition system for the recording of in vivo behavioral data in rodents and for allowing observation and recording of more than 10 animals simultaneously at a reduced cost, as compared with commercially available solutions. This system has been validated using two experimental rodent models: one involving chemically induced seizures and one assessing appetite and feeding. We present observational results showing comparable or improved levels of accuracy and observer consistency between this new system and traditional methods in these experimental models, discuss advantages of the presented system over conventional analog systems and commercially available digital systems, and propose possible extensions to the system and applications to nonrodent studies.

  17. Cost-effectiveness of trachoma control measures: comparing targeted household treatment and mass treatment of children.

    PubMed Central

    Frick, K. D.; Lietman, T. M.; Holm, S. O.; Jha, H. C.; Chaudhary, J. S.; Bhatta, R. C.

    2001-01-01

    OBJECTIVE: The present study compares the cost-effectiveness of targeted household treatment and mass treatment of children in the most westerly part of Nepal. METHODS: Effectiveness was measured as the percentage point change in the prevalence of trachoma. Resource measures included personnel time required for treatment, transportation, the time that study subjects had to wait to receive treatment, and the quantity of azithromycin used. The costs of the programme were calculated from the perspectives of the public health programme sponsor, the study subjects, and the society as a whole. FINDINGS: Previous studies have indicated no statistically significant differences in effectiveness, and the present work showed no significant differences in total personnel and transportation costs per child aged 1-10 years, the total time that adults spent waiting, or the quantity of azithromycin per child. However, the mass treatment of children was slightly more effective and used less of each resource per child aged 1-10 years than the targeted treatment of households. CONCLUSION: From all perspectives, the mass treatment of children is at least as effective and no more expensive than targeted household treatment, notwithstanding the absence of statistically significant differences. Less expensive targeting methods are required in order to make targeted household treatment more cost-effective. PMID:11285663

  18. Cost-effectiveness Analysis of Hospital Infection Control Response to an Epidemic Respiratory Virus Threat

    PubMed Central

    Dan, Yock Young; Sim, Joe; Lim, Jeremy; Hsu, Li Yang; Chow, Wai Leng; Fisher, Dale A.; Wong, Yue Sie; Ho, Khek Yu

    2009-01-01

    The outbreak of influenza A pandemic (H1N1) 2009 prompted many countries in Asia, previously strongly affected by severe acute respiratory syndrome (SARS), to respond with stringent measures, particularly in preventing outbreaks in hospitals. We studied actual direct costs and cost-effectiveness of different response measures from a hospital perspective in tertiary hospitals in Singapore by simulating outbreaks of SARS, pandemic (H1N1) 2009, and 1918 Spanish influenza. Protection measures targeting only infected patients yielded lowest incremental cost/death averted of $23,000 (US$) for pandemic (H1N1) 2009. Enforced protection in high-risk areas (Yellow Alert) and full protection throughout the hospital (Orange Alert) averted deaths but came at an incremental cost of up to $2.5 million/death averted. SARS and Spanish influenza favored more stringent measures. High case-fatality rates, virulence, and high proportion of atypical manifestations impacted cost-effectiveness the most. A calibrated approach in accordance with viral characteristics and community risks may help refine responses to future epidemics. PMID:19961669

  19. Digitally controlled distributed phase shifter

    SciTech Connect

    Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

    1992-12-31

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one of two discrete bias voltages. The application of the discrete bias voltages change the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  20. Digitally controlled distributed phase shifter

    DOEpatents

    Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

    1993-01-01

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  1. Digitally controlled distributed phase shifter

    DOEpatents

    Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

    1993-08-17

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  2. Space Digital Controller for Improved Motor Control

    NASA Astrophysics Data System (ADS)

    Alves-Nunes, Samuel; Daras, Gaetan; Dehez, Bruno; Maillard, Christophe; Bekemans, Marc; Michel, Raymond

    2014-08-01

    Performing digital motor control into space equipment is a new challenge. The new DPC (Digital Programmable Controller) is the first chip that we can use as a micro-controller, allowing us to drive motors with digital control schemes. In this paper, the digital control of hybrid stepper motors is considered. This kind of motor is used for solar array rotation and antenna actuation. New digital control technology brings a lot of advantages, allowing an important reduction of thermal losses inside the motor, and a reduction of thermal constraints on power drive electronic components. The opportunity to drive motors with a digital controller also brings many new functionalities like post-failure torque analysis, micro- vibrations and cogging torque reduction, or electro- mechanical damping of solar array oscillations. To evaluate the performance of the system, Field-Oriented Control (FOC) is implemented on a hybrid stepper motor. A test-bench, made of an active load, has been made to emulate the mechanical behaviour of the solar array, by the use of a torsionally-compliant model. The experimental results show that we can drastically reduce electrical power consumption, compared with the currently used open-loop control scheme.

  3. Development and Design of Cost-Effective, Real-Time Implementable Sediment and Contaminant Release Controls

    SciTech Connect

    Hampson, Steve

    2007-08-01

    Alternative design options for integrated storm water and sediment control systems were developed and evaluated for Outfalls 008, 011 and 015 of the Paducah Gaseous Diffusion Plant. The remedial options were required to be cost effective and implementable in a relatively short timeframe. Additionally, construction activities were to minimize earth disturbance, especially with respect to excavation. The current database for storm water and effluent sediment oncentration was assessed for the three outfalls. It was concluded that there was a significant lack of data and recommendations for monitoring equipment were provided to initiate a comprehensive surface water and sediment data acquisition system. Modeling was completed for current conditions. Peak flow, runoff volume, peak sediment concentration and storm sediment load were modeled for storm events, ranging from 0.5 inches (12.7mm) to 3.0 inches (6.2mm). Predicted peak flows ranged from 2.5 cfs (0.071 m3/s) for Outfall 011 and a 0.5 inches (12.7mm) storm to 210 cfs (5.95 m3/s) for Outfall 008 and a 3.0 inches (76.2mm) storm. Additionally, the 100-yr 24-hr NRCS Type II storm was modeled. Storm sediment loads, for the corresponding outfalls and storm events, ranged from 0.1 to 9.0 tons (8.18 tonnes). Retention ponds were designed and evaluated for each of the three outfalls. The ponds had a dual function; 1) contain the storm runoff volume for smaller storm events and 2) passively treat and discharge runoff that was in excess of the pond’s storage capacity. Stored runoff was transferred to alternative secondary treatment systems. The expected performance of these treatment systems was evaluated. The performance of the outfall ponds was evaluated for storm events ranging from 0.5 inches (12.7mm) to 4.0 inches (101.6mm). Outfall 011 has a watershed of 33.3 acres. Pond 011 (Outfall 011) has the largest storage capacity of the three outfalls, and therefore the highest potential for effective treatment. The predicted

  4. All digital pulsewidth control loop

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Yi; Jan, Shiun-Dian; Pu, Ruei-Iun

    2013-03-01

    This work presents an all-digital pulsewidth control loop (ADPWCL). The proposed system accepts a wide range of input duty cycles and performs a fast correction to the target output pulsewidth. An all-digital delay-locked loop (DLL) with fast locking time using a simplified time to digital converter and a new differential two-step delay element is proposed. The area of the delay element is much smaller than that in conventional designs, while having the same delay range. A test chip is verified in a 0.18-µm CMOS process. The measured duty cycle ranges from 4% to 98% with 7-bit resolution.

  5. A telerobotic digital controller system

    NASA Technical Reports Server (NTRS)

    Brown, Richard J.

    1992-01-01

    This system is a network of joint mounted dual axes digital servo-controllers (DDSC), providing control of various joints and end effectors of different robotic systems. This report provides description of and user required information for the Digital Controller System Network (DSCN) and, in particular, the DDSC, Model DDSC-2, developed to perform the controller functions. The DDSC can control 3 phase brushless or brush type DC motors, requiring up to 8 amps. Only four wires, two for power and 2 for serial communication, are required, except for local sensor and motor connections. This highly capable, very flexible, programmable servo-controller, contained on a single, compact printed circuit board measuring only 4.5 x 5.1 inches, is applicable to control systems of all types from sub-arc second precision pointing to control of robotic joints and end effectors. This document concentrates on the robotic applications for the DDSC.

  6. Self management, joint protection and exercises in hand osteoarthritis: a randomised controlled trial with cost effectiveness analyses

    PubMed Central

    2011-01-01

    Background There is limited evidence for the clinical and cost effectiveness of occupational therapy (OT) approaches in the management of hand osteoarthritis (OA). Joint protection and hand exercises have been proposed by European guidelines, however the clinical and cost effectiveness of each intervention is unknown. This multicentre two-by-two factorial randomised controlled trial aims to address the following questions: • Is joint protection delivered by an OT more effective in reducing hand pain and disability than no joint protection in people with hand OA in primary care? • Are hand exercises delivered by an OT more effective in reducing hand pain and disability than no hand exercises in people with hand OA in primary care? • Which of the four management approaches explored within the study (leaflet and advice, joint protection, hand exercise, or joint protection and hand exercise combined) provides the most cost-effective use of health care resources Methods/Design Participants aged 50 years and over registered at three general practices in North Staffordshire and Cheshire will be mailed a health survey questionnaire (estimated mailing sample n = 9,500). Those fulfilling the eligibility criteria on the health survey questionnaire will be invited to attend a clinical assessment to assess for the presence of hand or thumb base OA using the ACR criteria. Eligible participants will be randomised to one of four groups: leaflet and advice; joint protection (looking after your joints); hand exercises; or joint protection and hand exercises combined (estimated n = 252). The primary outcome measure will be the OARSI/OMERACT responder criteria combining hand pain and disability (measured using the AUSCAN) and global improvement, 6 months post-randomisation. Secondary outcomes will also be collected for example pain, functional limitation and quality of life. Outcomes will be collected at baseline and 3, 6 and 12 months post-randomisation. The main analysis will

  7. A novel cost-effective medium for the production of Bacillus thuringiensis subsp. israelensis for mosquito control.

    PubMed

    Poopathi, Subbiah; Archana, B

    2012-03-01

    Bacillus thuringiensis subsp. israelensis (Bti) has been used for mosquito-control programmes the world-wide. Indeed, the large-scale production of Bti for mosquito control is very expensive due to the high cost of its culture. In the present study, we attempted to widen the scope in developing cost-effective culture medium for Bti production, based on the raw materials available on the biosphere, including coconut cake powder, CCP (Cocos nucifera), neem cake powder, NCP (Azadirachta indica) and groundnut cake powder, GCP (Arachis hypogea). Among these raw materials, the biomass production of Bti, sporulation and toxin synthesizing from 'CCP' in combination with mineral salt (MnCl(2)) was comfortably satisfactory. Bioassays with mosquito species (Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti) and field trials were also satisfactory. The present investigation suggests that coconut cake-based culture medium can be used as an alternative for industrial production of Bti in mosquito-control programme. Therefore, the study is very important from the point of effective production of Bti from cost-effective culture medium for the control of mosquito vectors.

  8. Cost Effective Prototyping

    NASA Technical Reports Server (NTRS)

    Wickman, Jerry L.; Kundu, Nikhil K.

    1996-01-01

    This laboratory exercise seeks to develop a cost effective prototype development. The exercise has the potential of linking part design, CAD, mold development, quality control, metrology, mold flow, materials testing, fixture design, automation, limited parts production and other issues as related to plastics manufacturing.

  9. Digital Control For Remote Manipulators

    NASA Technical Reports Server (NTRS)

    Bejczy, Antal K.; Dotson, Ronald S.

    1987-01-01

    Multiple microprocessors enable large separations between controllers and manipulators. Controller for remote manipulator requires no direct mechanical connection between slave arm and master arm moved by human operator. Employs two-way digital data transmission rather than mechanical linkage between master and slave. Manipulator a considerable distance from operator. Software for controller distributed between master and slave locations. Organized into modules. Hardware and software for system demonstrated in laboratory model.

  10. Digital Breast Tomosynthesis in Addition to Conventional 2DMammography Reduces Recall Rates and is CostEffective.

    PubMed

    Pozz, Agostino; Corte, Angelo Della; Lakis, Mustapha A El; Jeong, HeonJae

    2016-01-01

    Digital breast tomosynthesis (DBT) as a breast cancer screening modality, through generation of three dimensional images during standard mammographic compression, can reduce interference from breast tissue overlap, increasing conspicuity of invasive cancers while concomitantly reducing falsepositive results. We here conducted a systematic review on previous studies to synthesize the evidence of DBT efficacy, eventually 18 articles being included in the analysis. The most commonly emerging topics were advantages of DBT screening tool in terms of recall rates, cancer detection rates and costeffectiveness, preventing unnecessary burdens on women and the healthcare system. Further research is needed to evaluate the potential impact of DBT on longerterm outcomes, such as interval cancer rates and mortality, to better understand the broader clinical and economic implications of its adoption.

  11. Cost-effectiveness of routine immunization to control Japanese encephalitis in Shanghai, China.

    PubMed Central

    Ding, Ding; Kilgore, Paul E.; Clemens, John D.; Wei, Liu; Zhi-Yi, Xu

    2003-01-01

    OBJECTIVE: To assess the cost-effectiveness of inactivated and live attenuated Japanese encephalitis (JE) vaccines given to infants and children in Shanghai. METHODS: A decision-analytical model was constructed in order to compare costs and outcomes for three hypothetical cohorts of 100,000 children followed from birth in 1997 to the age of 30 years who received either no JE vaccine, inactivated JE vaccine (P3), or live attenuated JE vaccine (SA 14-14-2). Cumulative incidences of JE from birth to 30 years of age in the pre-immunization era, i.e. before 1968, were used to estimate expected rates of JE in the absence of vaccination. The economic consequences were measured as cost per case, per death, and per disability-adjusted life year (DALY) averted for the two JE immunization programmes. FINDINGS: In comparison with no JE immunization, a programme using the P3 vaccine would prevent 420 JE cases and 105 JE deaths and would save 6456 DALYs per 100,000 persons; the use of the SA 14-14-2 vaccine would prevent 427 cases and 107 deaths and would save 6556 DALYs per 100,000 persons. Both kinds of immunization were cost saving but the SA 14-14-2 vaccine strategy resulted in a saving that was 47% greater (512,456 US dollars) than that obtained with the P3 vaccine strategy (348,246 US dollars). CONCLUSION: Both JE immunization strategies resulted in cost savings in comparison with no JE immunization. This provides a strong economic rationale for vaccinating against JE in Shanghai and suggests that vaccination against JE might be economically justifiable in other parts of China and in certain other developing countries of Asia where the disease is endemic. PMID:12856051

  12. Cost effectiveness analysis of elementary school-located vaccination against influenza – Results from a randomized controlled trial

    PubMed Central

    Yoo, Byung-Kwang; Humiston, Sharon G.; Szilagyi, Peter G.; Schaffer, Stanley J.; Long, Christine; Kolasa, Maureen

    2015-01-01

    School-located vaccination against influenza (SLV-I) has been suggested to help meet the need for annual vaccination of large numbers of school-aged children with seasonal influenza vaccine. However, little is known about the cost and cost-effectiveness of SLV-I. We conducted a cost-analysis and a cost-effectiveness analysis based on a randomized controlled trial (RCT) of an SLV-I program implemented in Monroe County, New York during the 2009–2010 vaccination season. We hypothesized that SLV-I is more cost effective, or less-costly, compared to a conventional, office-located influenza vaccination delivery. First and second SLV-I clinics were offered in 21 intervention elementary schools (n=9,027 children) with standard of care (no SLV-I) in 11 control schools (n=4,534 children). The direct costs, to purchase and administer vaccines, were estimated from our RCT. The effectiveness measure, receipt of ≥1 dose of influenza vaccine, was 13.2 percentage points higher in SLV-I schools than control schools. The school costs ($9.16/dose in 2009 dollars) plus project costs ($23.00/dose) plus vendor costs excluding vaccine purchase ($19.89/dose) was higher in direct costs ($52.05/dose) than the previously reported mean/median cost [$38.23/$21.44 per dose] for providing influenza vaccination in pediatric practices. However SLV-I averted parent costs to visit medical practices ($35.08 per vaccine). Combining direct and averted costs through Monte Carlo Simulation, SLV-I costs were $19.26/dose in net costs, which is below practice-based influenza vaccination costs. The incremental cost-effectiveness ratio (ICER) was estimated to be $92.50 or $38.59 (also including averted parent costs). When additionally accounting for the costs averted by disease prevention (i.e., both reduced disease transmission to household members and reduced loss of productivity from caring for a sick child), the SLV-I model appears to be cost-saving to society, compared to “no vaccination”. Our

  13. Cost effectiveness analysis of elementary school-located vaccination against influenza--results from a randomized controlled trial.

    PubMed

    Yoo, Byung-Kwang; Humiston, Sharon G; Szilagyi, Peter G; Schaffer, Stanley J; Long, Christine; Kolasa, Maureen

    2013-04-19

    School-located vaccination against influenza (SLV-I) has been suggested to help meet the need for annual vaccination of large numbers of school-aged children with seasonal influenza vaccine. However, little is known about the cost and cost-effectiveness of SLV-I. We conducted a cost-analysis and a cost-effectiveness analysis based on a randomized controlled trial (RCT) of an SLV-I program implemented in Monroe County, New York during the 2009-2010 vaccination season. We hypothesized that SLV-I is more cost effective, or less-costly, compared to a conventional, office-located influenza vaccination delivery. First and second SLV-I clinics were offered in 21 intervention elementary schools (n=9027 children) with standard of care (no SLV-I) in 11 control schools (n=4534 children). The direct costs, to purchase and administer vaccines, were estimated from our RCT. The effectiveness measure, receipt of ≥1 dose of influenza vaccine, was 13.2 percentage points higher in SLV-I schools than control schools. The school costs ($9.16/dose in 2009 dollars) plus project costs ($23.00/dose) plus vendor costs excluding vaccine purchase ($19.89/dose) was higher in direct costs ($52.05/dose) than the previously reported mean/median cost [$38.23/$21.44 per dose] for providing influenza vaccination in pediatric practices. However SLV-I averted parent costs to visit medical practices ($35.08 per vaccine). Combining direct and averted costs through Monte Carlo Simulation, SLV-I costs were $19.26/dose in net costs, which is below practice-based influenza vaccination costs. The incremental cost-effectiveness ratio (ICER) was estimated to be $92.50 or $38.59 (also including averted parent costs). When additionally accounting for the costs averted by disease prevention (i.e., both reduced disease transmission to household members and reduced loss of productivity from caring for a sick child), the SLV-I model appears to be cost-saving to society, compared to "no vaccination". Our findings

  14. Digitally controlled sonars

    NASA Technical Reports Server (NTRS)

    Hansen, G. R.

    1983-01-01

    Sonars are usually designed and constructed as stand alone instruments. That is, all elements or subsystems of the sonar are provided: power conditioning, displays, intercommunications, control, receiver, transmitter, and transducer. The sonars which are a part of the Advanced Ocean Test Development Platform (AOTDP) represent a departure from this manner of implementation and are configured more like an instrumentation system. Only the transducer, transmitter, and receiver which are unique to a particular sonar function; Up, Down, Side Scan, exist as separable subsystems. The remaining functions are reserved to the AOTDP and serve all sonars and other instrumentation in a shared manner. The organization and functions of the common AOTDP elements were described and then the interface with the sonars discussed. The techniques for software control of the sonar parameters were explained followed by the details of the realization of the sonar functions and some discussion of the performance of the side scan sonars.

  15. Direct Digital Control Study.

    DTIC Science & Technology

    1985-02-01

    please attach additional pages to answer this question. 6. What is the "rule of thumb" used to calculate the number of DDC control loops and 1/0 points...I ’ : ’ ~ 2’, . Vkt ; .nw]i.<[[I’ S, ,ten,m Service Company would like to receive a copy of i I ication. Should additional information be required

  16. The B-747 flight control system maintenance and reliability data base for cost effectiveness tradeoff studies

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Primary and automatic flight controls are combined for a total flight control reliability and maintenance cost data base using information from two previous reports and additional cost data gathered from a major airline. A comparison of the current B-747 flight control system effects on reliability and operating cost with that of a B-747 designed for an active control wing load alleviation system is provided.

  17. The Cost-Effectiveness of Low-Cost Essential Antihypertensive Medicines for Hypertension Control in China: A Modelling Study

    PubMed Central

    Gu, Dongfeng; He, Jiang; Coxson, Pamela G.; Rasmussen, Petra W.; Huang, Chen; Thanataveerat, Anusorn; Tzong, Keane Y.; Xiong, Juyang; Wang, Miao; Zhao, Dong; Goldman, Lee; Moran, Andrew E.

    2015-01-01

    Background Hypertension is China’s leading cardiovascular disease risk factor. Improved hypertension control in China would result in result in enormous health gains in the world’s largest population. A computer simulation model projected the cost-effectiveness of hypertension treatment in Chinese adults, assuming a range of essential medicines list drug costs. Methods and Findings The Cardiovascular Disease Policy Model-China, a Markov-style computer simulation model, simulated hypertension screening, essential medicines program implementation, hypertension control program administration, drug treatment and monitoring costs, disease-related costs, and quality-adjusted life years (QALYs) gained by preventing cardiovascular disease or lost because of drug side effects in untreated hypertensive adults aged 35–84 y over 2015–2025. Cost-effectiveness was assessed in cardiovascular disease patients (secondary prevention) and for two blood pressure ranges in primary prevention (stage one, 140–159/90–99 mm Hg; stage two, ≥160/≥100 mm Hg). Treatment of isolated systolic hypertension and combined systolic and diastolic hypertension were modeled as a reduction in systolic blood pressure; treatment of isolated diastolic hypertension was modeled as a reduction in diastolic blood pressure. One-way and probabilistic sensitivity analyses explored ranges of antihypertensive drug effectiveness and costs, monitoring frequency, medication adherence, side effect severity, background hypertension prevalence, antihypertensive medication treatment, case fatality, incidence and prevalence, and cardiovascular disease treatment costs. Median antihypertensive costs from Shanghai and Yunnan province were entered into the model in order to estimate the effects of very low and high drug prices. Incremental cost-effectiveness ratios less than the per capita gross domestic product of China (11,900 international dollars [Int$] in 2015) were considered cost-effective. Treating

  18. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman; Sarah R. Nuss-Warren

    2007-02-01

    The objective of this project is to identify, develop, test, and commercialize emissions control and monitoring technologies that can be implemented by exploration and production (E&P) operators to significantly lower the cost of environmental compliance and expedite project permitting. The project team takes considerable advantage of the emissions control research and development efforts and practices that have been underway in the gas pipeline industry for the last 12 years. These efforts and practices are expected to closely interface with the E&P industry to develop cost-effective options that apply to widely-used field and gathering engines, and which can be readily commercialized. The project is separated into two phases. Phase 1 work establishes an E&P industry liaison group, develops a frequency distribution of installed E&P field engines, and identifies and assesses commercially available and emerging engine emissions control and monitoring technologies. Current and expected E&P engine emissions and monitoring requirements are reviewed, and priority technologies are identified for further development. The identified promising technologies are tested on a laboratory engine to confirm their generic viability. In addition, a full-scale field test of prototype emissions controls will be conducted on at least ten representative field engine models with challenging emissions profiles. Emissions monitoring systems that are integrated with existing controls packages will be developed. Technology transfer/commercialization is expected to be implemented through compressor fleet leasing operators, engine component suppliers, the industry liaison group, and the Petroleum Technology Transfer Council. This topical report discusses work completed during Phase 1 of the project Cost Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines. In this report information, data, and results are compiled and summarized from quarterly

  19. Cost effectiveness of physiotherapy, manual therapy, and general practitioner care for neck pain: economic evaluation alongside a randomised controlled trial

    PubMed Central

    Bos, Ingeborg B C Korthals-de; Hoving, Jan L; van Tulder, Maurits W; Mölken, Maureen P M H Rutten-van; Adèr, Herman J; de Vet, Henrica C W; Koes, Bart W; Vondeling, Hindrik; Bouter, Lex M

    2003-01-01

    Objective To evaluate the cost effectiveness of physiotherapy, manual therapy, and care by a general practitioner for patients with neck pain. Design Economic evaluation alongside a randomised controlled trial. Setting Primary care. Participants 183 patients with neck pain for at least two weeks recruited by 42 general practitioners and randomly allocated to manual therapy (n=60, spinal mobilisation), physiotherapy (n=59, mainly exercise), or general practitioner care (n=64, counselling, education, and drugs). Main outcome measures Clinical outcomes were perceived recovery, intensity of pain, functional disability, and quality of life. Direct and indirect costs were measured by means of cost diaries that were kept by patients for one year. Differences in mean costs between groups, cost effectiveness, and cost utility ratios were evaluated by applying non-parametric bootstrapping techniques. Results The manual therapy group showed a faster improvement than the physiotherapy group and the general practitioner care group up to 26 weeks, but differences were negligible by follow up at 52 weeks. The total costs of manual therapy (€447; £273; $402) were around one third of the costs of physiotherapy (€1297) and general practitioner care (€1379). These differences were significant: P<0.01 for manual therapy versus physiotherapy and manual therapy versus general practitioner care and P=0.55 for general practitioner care versus physiotherapy. The cost effectiveness ratios and the cost utility ratios showed that manual therapy was less costly and more effective than physiotherapy or general practitioner care. Conclusions Manual therapy (spinal mobilisation) is more effective and less costly for treating neck pain than physiotherapy or care by a general practitioner. What is already known on this topicThe cost of treating neck pain is considerableMany conservative interventions are available, such as prescription drugs, yet their cost effectiveness has not been

  20. Cost effective analysis of recall methods for cervical cancer screening in Selangor--results from a prospective randomized controlled trial.

    PubMed

    Rashid, Rima Marhayu Abdul; Ramli, Sophia; John, Jennifer; Dahlui, Maznah

    2014-01-01

    Cervical cancer screening in Malaysia is by opportunistic Pap smear which contributes to the low uptake rate. To overcome this, a pilot project called the SIPPS program (translated as information system of Pap smear program) had been introduced whereby women aged 20-65 years old are invited for Pap smear and receive recall to repeat the test. This study aimed at determining which recall method is most cost-effective in getting women to repeat Pap smear. A randomised control trial was conducted where one thousand women were recalled for repeat smear either by registered letter, phone messages, phone call or the usual postal letter. The total cost applied for cost-effectiveness analysis includes the cost of sending letter for first invitation, cost of the recall method and cost of two Pap smears. Cost-effective analysis (CEA) of Pap smear uptake by each recall method was then performed. The uptake of Pap smear by postal letter, registered letters, SMS and phone calls were 18.8%, 20.0%, 21.6% and 34.4%, respectively (p<0.05). The CER for the recall method was lowest by phone call compared to other interventions; RM 69.18 (SD RM 0.14) compared to RM 106.53 (SD RM 0.13), RM 134.02 (SD RM 0.15) and RM 136.38 (SD RM 0.11) for SMS, registered letter and letter, respectively. ICER showed that it is most cost saving if the usual method of recall by postal letter be changed to recall by phone call. The possibility of letter as a recall for repeat Pap smear to reach the women is higher compared to sending SMS or making phone call. However, getting women to do repeat Pap smear is better with phone call which allows direct communication. Despite the high cost of the phone call as a recall method for repeat Pap smear, it is the most cost-effective method compared to others.

  1. The OPTIMIST study: optimisation of cost effectiveness through individualised FSH stimulation dosages for IVF treatment. A randomised controlled trial

    PubMed Central

    2012-01-01

    Background Costs of in vitro fertilisation (IVF) are high, which is partly due to the use of follicle stimulating hormone (FSH). FSH is usually administered in a standard dose. However, due to differences in ovarian reserve between women, ovarian response also differs with potential negative consequences on pregnancy rates. A Markov decision-analytic model showed that FSH dose individualisation according to ovarian reserve is likely to be cost-effective in women who are eligible for IVF. However, this has never been confirmed in a large randomised controlled trial (RCT). The aim of the present study is to assess whether an individualised FSH dose regime based on an ovarian reserve test (ORT) is more cost-effective than a standard dose regime. Methods/Design Multicentre RCT in subfertile women indicated for a first IVF or intracytoplasmic sperm injection cycle, who are aged < 44 years, have a regular menstrual cycle and no major abnormalities at transvaginal sonography. Women with polycystic ovary syndrome, endocrine or metabolic abnormalities and women undergoing IVF with oocyte donation, will not be included. Ovarian reserve will be assessed by measuring the antral follicle count. Women with a predicted poor response or hyperresponse will be randomised for a standard versus an individualised FSH regime (150 IU/day, 225-450 IU/day and 100 IU/day, respectively). Participants will undergo a maximum of three stimulation cycles during maximally 18 months. The primary study outcome is the cumulative ongoing pregnancy rate resulting in live birth achieved within 18 months after randomisation. Secondary outcomes are parameters for ovarian response, multiple pregnancies, number of cycles needed per live birth, total IU of FSH per stimulation cycle, and costs. All data will be analysed according to the intention-to-treat principle. Cost-effectiveness analysis will be performed to assess whether the health and associated economic benefits of individualised treatment of

  2. Cost effective malaria risk control using remote sensing and environmental data

    NASA Astrophysics Data System (ADS)

    Rahman, Md. Z.; Roytman, Leonid; Kadik, Abdel Hamid

    2012-06-01

    Malaria transmission in many part of the world specifically in Bangladesh and southern African countries is unstable and epidemic. An estimate of over a million cases is reported annually. Malaria is heterogeneous, potentially due to variations in ecological settings, socio-economic status, land cover, and agricultural practices. Malaria control only relies on treatment and supply of bed networks. Drug resistance to these diseases is widespread. Vector control is minimal. Malaria control in those countries faces many formidable challenges such as inadequate accessibility to effective treatment, lack of trained manpower, inaccessibility of endemic areas, poverty, lack of education, poor health infrastructure and low health budgets. Health facilities for malaria management are limited, surveillance is inadequate, and vector control is insufficient. Control can only be successful if the right methods are used at the right time in the right place. This paper aims to improve malaria control by developing malaria risk maps and risk models using satellite remote sensing data by identifying, assessing, and mapping determinants of malaria associated with environmental, socio-economic, malaria control, and agricultural factors.

  3. A Decision Support System for Cost-Effectiveness Analysis for Control and Security of Computer Systems.

    DTIC Science & Technology

    1985-09-01

    Support System for Cost- Master’s Thesis Effectiveness Analysis for Control and September 1985 Security of Computer Systems 6. PERFORMING ORG . REPORT...F )3010 >~T .0 0 Find directory U Figulre 8. i reaFlw iara fies.obe ->~Ne8 DrbelExoue Controls Inc z W &Z ,~L. UJ. LiL La CA CC 449 -*LA- D. P Erase

  4. COST EFFECTIVE CONTROL OF HEXAVALENT CHROMIUM AIR EMISSIONS FROM FUNCTIONAL CHROMIUM ELECTROPLATING

    EPA Science Inventory

    This paper will summrize thie pollution prevention (p2) method to control stack emissions from hard chromium plating operations performed by the USEPA's National Risk Management Research Laboratory (NRMRL) over the last four years. During literature research and user surveys, it...

  5. Digital electronic engine control history

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.

    1984-01-01

    Full authority digital electronic engine controls (DEECs) were studied, developed, and ground tested because of projected benefits in operability, improved performance, reduced maintenance, improved reliability, and lower life cycle costs. The issues of operability and improved performance, however, are assessed in a flight test program. The DEEC on a F100 engine in an F-15 aircraft was demonstrated and evaluated. The events leading to the flight test program are chronicled and important management and technical results are identified.

  6. Cost effective development of a Shuttle-based astronomical instrument control system

    NASA Astrophysics Data System (ADS)

    Parise, R. A.; Blum, A.; Budney, T. J.; Stone, R. W.

    1982-10-01

    The high level language FORTH is used for the electronic control of the Space Shuttle-based Ultraviolet Imaging Telescope, in a flight computer system which minimizes costs. The greater part of the breadboard version of the flight computer is assembled from commercially available components, reducing novel circuit design features and permitting simultaneous development of both hardware and software. The commercial boards are then refabricated on aluminum core heat conducting stock, using high reliability parts to produce the flight versions of the system. The system's ground support equipment employs a MINC-25 minicomputer which performs such functions as flight computer software development, PROM programming, test and integration support, and flight operations support. The implementation of these concepts in flight computer telescope controls is described.

  7. Cost effective development of a Shuttle-based astronomical instrument control system

    NASA Technical Reports Server (NTRS)

    Parise, R. A.; Blum, A.; Budney, T. J.; Stone, R. W.

    1982-01-01

    The high level language FORTH is used for the electronic control of the Space Shuttle-based Ultraviolet Imaging Telescope, in a flight computer system which minimizes costs. The greater part of the breadboard version of the flight computer is assembled from commercially available components, reducing novel circuit design features and permitting simultaneous development of both hardware and software. The commercial boards are then refabricated on aluminum core heat conducting stock, using high reliability parts to produce the flight versions of the system. The system's ground support equipment employs a MINC-25 minicomputer which performs such functions as flight computer software development, PROM programming, test and integration support, and flight operations support. The implementation of these concepts in flight computer telescope controls is described.

  8. Adaptive Control, Learning, and Cost-Effective Sensor Systems for Robotics or Advanced Automation Systems.

    DTIC Science & Technology

    1985-12-31

    31 DEC 05 p NCLASSIFIED CSDL-R-1829GNSMB4- 3 --B7 F/G 6/4 NL 22 40 2= 1111Q2 El- MICROCOPY RESOLUTION TEST CHART Nvon i m , nr DA~)S 163- irI CSDL-R...and detection, pattern recognition , hypothesis testing, control theory, as well as the conventional expert system’s rules and heuristics. The general...done in the automatic interpretation of electrocardiograms using statistical pattern recognition methods( 29 ). However, these systems are generally not

  9. Burner modifications for very cost effective NO{sub x} control

    SciTech Connect

    Melick, T.A.; Hensley, M.E.; Gustafson, D.A.

    1996-12-31

    The development of commercial Low NO{sub x} Burners has provided Energy and Environmental Research Corporation (EER) with the expertise to modify existing burner equipment to provide the controlled fuel/air mixing conditions required for low NO{sub x} combustion. This approach represents a viable alternative to a full burner retrofit for many applications. EER has modified burners to lower NO{sub x} emissions at Louisville Gas & Electric`s (LG&E) Cane Run Station and at Jamestown Board of Public Utilities (JBPU). This paper will discuss the method and results of these burner modifications.

  10. Burner modifications for very cost effective NO{sub x} control

    SciTech Connect

    Melick, T.A.; Hensley, M.E.; Gustafson, D.A.

    1996-12-31

    The development of commercial Low NO{sub x} Burners has provided Energy and Environmental Research Corporation (EER) with the expertise to modify existing burner equipment to provide the controlled fuel/air mixing conditions required for low NO{sub x} combustion. This approach represents a viable alternative to a full burner retrofit for many applications. EER has modified burners to lower NO{sub x} emissions at Louisville Gas and Electric`s (LG and E) Cane Run Station and at Jamestown Board of Public Utilities (JBPU). This paper will discuss the method and results of these burner modifications.

  11. Is control through utilization a cost effective Prosopis juliflora management strategy?

    PubMed

    Wakie, Tewodros T; Hoag, Dana; Evangelista, Paul H; Luizza, Matthew; Laituri, Melinda

    2016-03-01

    The invasive tree Prosopis juliflora is known to cause negative impacts on invaded ranges. High P. juliflora eradication costs have swayed developing countries to follow a new and less expensive approach known as control through utilization. However, the net benefits of this new approach have not been thoroughly evaluated. Our objective was to assess the economic feasibility of selected P. juliflora eradication and utilization approaches that are currently practiced in one of the severely affected developing countries, Ethiopia. The selected approaches include converting P. juliflora infested lands into irrigated farms (conversion), charcoal production, and seed flour production. We estimate the costs and revenues of the selected P. juliflora eradication and utilization approaches by interviewing 19 enterprise owners. We assess the economic feasibility of the enterprises by performing enterprise, break-even, investment, sensitivity, and risk analyses. Our results show that conversion to irrigated cotton is economically profitable, with Net Present Value (NPV) of 5234 US$/ha over 10 years and an interest rate of 10% per year. Conversion greatly reduces the spread of P. juliflora on farmlands. Managing P. juliflora infested lands for charcoal production with a four-year harvest cycle is profitable, with NPV of 805 US$/ha. However, the production process needs vigilant regulation to protect native plants from exploitation and caution should be taken to prevent charcoal production sites from becoming potential seed sources. Though flour from P. juliflora pods can reduce invasions by destroying viable seeds, flour enterprises in Ethiopia are unprofitable. Conversion and charcoal production can be undertaken with small investment costs, while flour production requires high investment costs. Introducing new changes in the production and management steps of P. juliflora flour might be considered to make the enterprise profitable. Our study shows that control

  12. Digital Controller For Emergency Beacon

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1990-01-01

    Prototype digital controller intended for use in 406-MHz emergency beacon. Undergoing development according to international specifications, 406-MHz emergency beacon system includes satellites providing worldwide monitoring of beacons, with Doppler tracking to locate each beacon within 5 km. Controller turns beacon on and off and generates binary codes identifying source (e.g., ship, aircraft, person, or vehicle on land). Codes transmitted by phase modulation. Knowing code, monitor attempts to communicate with user, monitor uses code information to dispatch rescue team appropriate to type and locations of carrier.

  13. Digital adaptive flight controller development

    NASA Technical Reports Server (NTRS)

    Kaufman, H.; Alag, G.; Berry, P.; Kotob, S.

    1974-01-01

    A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Two designs are described for an example aircraft. Each of these designs uses a weighted least squares procedure to identify parameters defining the dynamics of the aircraft. The two designs differ in the way in which control law parameters are determined. One uses the solution of an optimal linear regulator problem to determine these parameters while the other uses a procedure called single stage optimization. Extensive simulation results and analysis leading to the designs are presented.

  14. Centralized digital control of accelerators

    SciTech Connect

    Melen, R.E.

    1983-09-01

    In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

  15. Digital electrospray for controlled deposition.

    PubMed

    Deng, Weiwei; Waits, C Mike; Gomez, Alessandro

    2010-03-01

    Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. "Digital" refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 mum and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 mum and a O(kHz) response frequency. The latter is controlled by the viscous damping time.

  16. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E & P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman; Sarah R. Nuss-Warren

    2006-09-30

    Continuing work in controlled testing uses a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout the gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NO{sub X} emissions. Technologies including one pre-combustion chamber, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing have been evaluated in previous reports. Current work tests non-production, prototype, mid-pressure fuel valves and begins analysis of these tests. This analysis reveals questions which must be answered before coming to any firm conclusions about the use of the180 psig fuel valve. The research team plans to continue with the remaining pre-combustion chamber tests in the coming quarter. By using the Ajax DP-115 these tests are completed in a low-cost and efficient manner. The various technologies can be quickly exchanged with different hardware, and it is inexpensive to run the engine. Progress in moving toward field testing is discussed, and a change in strategy is suggested. Although field engines are available to test, it is suggested that the final field testing be put on hold due to information from outside publications during this last quarter. Instead, KSU would focus on related field-testing and characterization in an outside project that will close an apparent technology gap. The results of this characterization will give a more solid footing to the field testing that will complete this project.

  17. Cost effectiveness of day and inpatient psychiatric treatment: results of a randomised controlled trial.

    PubMed Central

    Creed, F.; Mbaya, P.; Lancashire, S.; Tomenson, B.; Williams, B.; Holme, S.

    1997-01-01

    OBJECTIVE: To compare direct and indirect costs of day and inpatient treatment of acute psychiatric illness. DESIGN: Randomised controlled trial with outcome and costs assessed over 12 months after the date of admission. SETTING: Teaching hospital in an inner city area. SUBJECTS: 179 patients with acute psychiatric illness referred for admission who were suitable for random allocation to day hospital or inpatient treatment. 77 (43%) patients had schizophrenia. INTERVENTIONS: Routine inpatient or day hospital treatment. MAIN OUTCOME MEASURES: Direct and indirect costs over 12 months, clinical symptoms, social functioning, and burden on relatives over the follow up period. RESULTS: Clinical and social outcomes were similar at 12 months, except that inpatients improved significantly faster than day patients and burden on relatives was significantly less in the day hospital group at one year. Median direct costs to the hospital were 1923 pounds (95% confidence interval 750 pounds to 3174 pounds) per patient less for day hospital treatment than inpatient treatment. Indirect costs were greater for day patients; when these were included, overall day hospital treatment was 2165 pounds cheaper than inpatient treatment (95% confidence interval of median difference 737 pounds to 3593 pounds). Including costs to informants when appropriate meant that day hospital treatment was 1994 pounds per patient cheaper (95% confidence interval 600 pounds to 3543 pounds). CONCLUSIONS: Day patient treatment is cheaper for the 30-40% of potential admissions that can be treated in this way. Carers of day hospital patients may bear additional costs. Carers of all patients with acute psychiatric illness are often themselves severely distressed at the time of admission, but day hospital treatment leads to less burden on carers in the long term. PMID:9161310

  18. Optimal digital redesign of cascaded analogue controllers

    NASA Technical Reports Server (NTRS)

    Shieh, L. S.; Decrocq, B. B.; Zhang, J. L.

    1991-01-01

    This paper presents a new, optimal digital redesign technique for finding an optimal cascaded digital controller from the given continuous-time counterpart by minimizing a quadratic performance index. The control gains can be obtained by solving a set of Liapunov equations. The developed optimal cascaded digital controller enables the state and/or outputs of the digitally controlled closed-loop sampled-data system to optimally match those of the original continuous-time closed-loop system at any instant between sampling periods. The developed control law can be implemented using inexpensive and reliable digital electronics with a relatively long sampling period.

  19. COST-EFFECTIVE CONTROL OF NOx WITH INTEGRATED ULTRA LOW-NOx BURNERS AND SNCR

    SciTech Connect

    Hamid Farzan; Jennifer Sivy; Alan Sayre; John Boyle

    2003-07-01

    Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), McDermott Technology, Inc. (MTI), the Babcock & Wilcox Company (B&W), and Fuel Tech teamed together to investigate an integrated solution for NOx control. The system was comprised of B&W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NO{sub x}OUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. The technology's emission target is achieving 0.15 lb NO{sub x}/10{sup 6} Btu for full-scale boilers. Development of the low-NOx burner technology has been a focus in B&W's combustion program. The DRB-4Z{trademark} burner (see Figure 1.1) is B&W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner is designed to reduce NO{sub x} by diverting air away from the core of the flame, which reduces local stoichiometry during coal devolatilization and, thereby, reduces initial NO{sub x} formation. Figure 1.2 shows the historical NO{sub x} emission levels from different B&W burners. Figure 1.2 shows that based on three large-scale commercial installations of the DRB-4Z{trademark} burners in combination with OFA ports, using Western subbituminous coal, the NO{sub x} emissions ranged from 0.16 to 0.18 lb/10{sup 6} Btu. It appears that with continuing research and development the Ozone Transport Rule (OTR) emission level of 0.15 lb NO{sub x}/10{sup 6} Btu is within the reach of combustion modification techniques for boilers using western U.S. subbituminous coals. Although NO{sub x} emissions from the DRB-4Z{trademark} burner are nearing OTR emission level with subbituminous coals, the utility boiler owners that use bituminous coals can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them.

  20. Cost effectiveness analysis of intravenous ketorolac and morphine for treating pain after limb injury: double blind randomised controlled trial

    PubMed Central

    Rainer, Timothy H; Jacobs, Philip; Ng, Y C; Cheung, N K; Tam, Michael; Lam, Peggo K W; Wong, Robert; Cocks, Robert A

    2000-01-01

    Objectives To investigate the cost effectiveness of intravenous ketorolac compared with intravenous morphine in relieving pain after blunt limb injury in an accident and emergency department. Design Double blind, randomised, controlled study and cost consequences analysis. Setting Emergency department of a university hospital in the New Territories of Hong Kong. Participants 148 adult patients with painful isolated limb injuries (limb injuries without other injuries). Main outcome measures Primary outcome measure was a cost consequences analysis comparing the use of ketorolac with morphine; secondary outcome measures were pain relief at rest and with limb movement, adverse events, patients' satisfaction, and time spent in the emergency department. Results No difference was found in the median time taken to achieve pain relief at rest between the group receiving ketorolac and the group receiving morphine, but with movement the median reduction in pain score in the ketorolac group was 1.09 per hour (95% confidence interval 1.05 to 2.02) compared with 0.87 (0.84 to 1.06) in the morphine group (P=0.003). The odds of experiencing adverse events was 144.2 (41.5 to 501.6) times more likely with morphine than with ketorolac. The median time from the initial delivery of analgesia to the participant leaving the department was 20 (4.0 to 39.0) minutes shorter in the ketorolac group than in the morphine group (P=0.02). The mean cost per person was $HK44 (£4; $5.6) in the ketorolac group and $HK229 in the morphine group (P<0.0001). The median score for patients' satisfaction was 6.0 for ketorolac and 5.0 for morphine (P<0.0001). Conclusion Intravenous ketorolac is a more cost effective analgesic than intravenous morphine in the management of isolated limb injury in an emergency department in Hong Kong, and its use may be considered as the dominant strategy. PMID:11082083

  1. Searching for the most cost-effective strategy for controlling epidemics spreading on regular and small-world networks

    PubMed Central

    Kleczkowski, Adam; Oleś, Katarzyna; Gudowska-Nowak, Ewa; Gilligan, Christopher A.

    2012-01-01

    We present a combined epidemiological and economic model for control of diseases spreading on local and small-world networks. The disease is characterized by a pre-symptomatic infectious stage that makes detection and control of cases more difficult. The effectiveness of local (ring-vaccination or culling) and global control strategies is analysed by comparing the net present values of the combined cost of preventive treatment and illness. The optimal strategy is then selected by minimizing the total cost of the epidemic. We show that three main strategies emerge, with treating a large number of individuals (global strategy, GS), treating a small number of individuals in a well-defined neighbourhood of a detected case (local strategy) and allowing the disease to spread unchecked (null strategy, NS). The choice of the optimal strategy is governed mainly by a relative cost of palliative and preventive treatments. If the disease spreads within the well-defined neighbourhood, the local strategy is optimal unless the cost of a single vaccine is much higher than the cost associated with hospitalization. In the latter case, it is most cost-effective to refrain from prevention. Destruction of local correlations, either by long-range (small-world) links or by inclusion of many initial foci, expands the range of costs for which the NS is most cost-effective. The GS emerges for the case when the cost of prevention is much lower than the cost of treatment and there is a substantial non-local component in the disease spread. We also show that local treatment is only desirable if the disease spreads on a small-world network with sufficiently few long-range links; otherwise it is optimal to treat globally. In the mean-field case, there are only two optimal solutions, to treat all if the cost of the vaccine is low and to treat nobody if it is high. The basic reproduction ratio, R0, does not depend on the rate of responsive treatment in this case and the disease always invades (but

  2. Searching for the most cost-effective strategy for controlling epidemics spreading on regular and small-world networks.

    PubMed

    Kleczkowski, Adam; Oleś, Katarzyna; Gudowska-Nowak, Ewa; Gilligan, Christopher A

    2012-01-07

    We present a combined epidemiological and economic model for control of diseases spreading on local and small-world networks. The disease is characterized by a pre-symptomatic infectious stage that makes detection and control of cases more difficult. The effectiveness of local (ring-vaccination or culling) and global control strategies is analysed by comparing the net present values of the combined cost of preventive treatment and illness. The optimal strategy is then selected by minimizing the total cost of the epidemic. We show that three main strategies emerge, with treating a large number of individuals (global strategy, GS), treating a small number of individuals in a well-defined neighbourhood of a detected case (local strategy) and allowing the disease to spread unchecked (null strategy, NS). The choice of the optimal strategy is governed mainly by a relative cost of palliative and preventive treatments. If the disease spreads within the well-defined neighbourhood, the local strategy is optimal unless the cost of a single vaccine is much higher than the cost associated with hospitalization. In the latter case, it is most cost-effective to refrain from prevention. Destruction of local correlations, either by long-range (small-world) links or by inclusion of many initial foci, expands the range of costs for which the NS is most cost-effective. The GS emerges for the case when the cost of prevention is much lower than the cost of treatment and there is a substantial non-local component in the disease spread. We also show that local treatment is only desirable if the disease spreads on a small-world network with sufficiently few long-range links; otherwise it is optimal to treat globally. In the mean-field case, there are only two optimal solutions, to treat all if the cost of the vaccine is low and to treat nobody if it is high. The basic reproduction ratio, R(0), does not depend on the rate of responsive treatment in this case and the disease always invades

  3. Aircraft digital control design methods

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E.; Tashker, M. G.

    1976-01-01

    Variations in design methods for aircraft digital flight control are evaluated and compared. The methods fall into two categories; those where the design is done in the continuous domain (or s plane) and those where the design is done in the discrete domain (or z plane). Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the uncompensated s plane design method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

  4. Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control

    NASA Technical Reports Server (NTRS)

    Baer-Riedhart, Jennifer L.; Landy, Robert J.

    1987-01-01

    The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

  5. Cost-Effective Control of Plant Disease When Epidemiological Knowledge Is Incomplete: Modelling Bahia Bark Scaling of Citrus

    PubMed Central

    Neri, Franco M.; DeSimone, R. Erik; Gilligan, Christopher A.

    2014-01-01

    A spatially-explicit, stochastic model is developed for Bahia bark scaling, a threat to citrus production in north-eastern Brazil, and is used to assess epidemiological principles underlying the cost-effectiveness of disease control strategies. The model is fitted via Markov chain Monte Carlo with data augmentation to snapshots of disease spread derived from a previously-reported multi-year experiment. Goodness-of-fit tests strongly supported the fit of the model, even though the detailed etiology of the disease is unknown and was not explicitly included in the model. Key epidemiological parameters including the infection rate, incubation period and scale of dispersal are estimated from the spread data. This allows us to scale-up the experimental results to predict the effect of the level of initial inoculum on disease progression in a typically-sized citrus grove. The efficacies of two cultural control measures are assessed: altering the spacing of host plants, and roguing symptomatic trees. Reducing planting density can slow disease spread significantly if the distance between hosts is sufficiently large. However, low density groves have fewer plants per hectare. The optimum density of productive plants is therefore recovered at an intermediate host spacing. Roguing, even when detection of symptomatic plants is imperfect, can lead to very effective control. However, scouting for disease symptoms incurs a cost. We use the model to balance the cost of scouting against the number of plants lost to disease, and show how to determine a roguing schedule that optimises profit. The trade-offs underlying the two optima we identify—the optimal host spacing and the optimal roguing schedule—are applicable to many pathosystems. Our work demonstrates how a carefully parameterised mathematical model can be used to find these optima. It also illustrates how mathematical models can be used in even this most challenging of situations in which the underlying epidemiology is ill

  6. Cost effectiveness of an intensive blood glucose control policy in patients with type 2 diabetes: economic analysis alongside randomised controlled trial (UKPDS 41)

    PubMed Central

    Gray, Alastair; Raikou, Maria; McGuire, Alistair; Fenn, Paul; Stevens, Richard; Cull, Carole; Stratton, Irene; Adler, Amanda; Holman, Rury; Turner, Robert

    2000-01-01

    Objective To estimate the cost effectiveness of conventional versus intensive blood glucose control in patients with type 2 diabetes. Design Incremental cost effectiveness analysis alongside randomised controlled trial. Setting 23 UK hospital clinic based study centres. Participants 3867 patients with newly diagnosed type 2 diabetes (mean age 53 years). Interventions Conventional (primarily diet) glucose control policy versus intensive control policy with a sulphonylurea or insulin. Main outcome measures Incremental cost per event-free year gained within the trial period. Results Intensive glucose control increased trial treatment costs by £695 (95% confidence interval £555 to £836) per patient but reduced the cost of complications by £957 (£233 to £1681) compared with conventional management. If standard practice visit patterns were assumed rather than trial conditions, the incremental cost of intensive management was £478 (−£275 to £1232) per patient. The within trial event-free time gained in the intensive group was 0.60 (0.12 to 1.10) years and the lifetime gain 1.14 (0.69 to 1.61) years. The incremental cost per event-free year gained was £1166 (costs and effects discounted at 6% a year) and £563 (costs discounted at 6% a year and effects not discounted). Conclusions Intensive blood glucose control in patients with type 2 diabetes significantly increased treatment costs but substantially reduced the cost of complications and increased the time free of complications. PMID:10818026

  7. Research in digital adaptive flight controllers

    NASA Technical Reports Server (NTRS)

    Kaufman, H.

    1976-01-01

    A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Both explicit controllers which directly utilize parameter identification and implicit controllers which do not require identification were considered. Extensive analytical and simulation efforts resulted in the recommendation of two explicit digital adaptive flight controllers. Interface weighted least squares estimation procedures with control logic were developed using either optimal regulator theory or with control logic based upon single stage performance indices.

  8. Cost-effective instrumentation and control upgrades for commercial nuclear power plants using surety principles developed at Sandia National Laboratories

    SciTech Connect

    Rochau, G.E.; Dalton, L.J.

    1997-11-01

    Many nuclear power plants use instrument and control systems based on analog electronics. The state of the art in process control and instrumentation has advanced to use digital electronics and incorporate advanced technology. This technology includes distributed microprocessors, fiber optics, intelligent systems (neural networks), and advanced displays. The technology is used to optimize processes and enhance the man-machine interface while maintaining control and safety of the processes. Nuclear power plant operators have been hesitant to install this technology because of the cost and uncertainty in the regulatory process. This technology can be directly applied in an operating nuclear power plant provided a surety principle-based {open_quotes}administrator{close_quotes} hardware system is included in parallel with the upgrade Sandia National Laboratories has developed a rigorous approach to High Consequence System Surety (HCSS). This approach addresses the key issues of safety, security, and control while satisfying requirements for reliability and quality. HCSS principles can be applied to nuclear power plants in a manner that allows the off-the-shelf use of process control instrumentation while maintaining a high level of safety and enhancing the plant performance. We propose that an HCSS administrator be constructed as a standardized approach to address regulatory issues. Such an administrator would allow a plant control system to be constructed with commercially available, state-of-the-art equipment and be customized to the needs of the individual plant operator.

  9. Cost-effectiveness of smoking cessation treatment initiated during psychiatric hospitalization: analysis from a randomized, controlled trial

    PubMed Central

    Barnett, Paul G.; Wong, Wynnie; Jeffers, Abra; Hall, Sharon M.; Prochaska, Judith J.

    2016-01-01

    Objective We examined the cost-effectiveness of smoking cessation treatment for psychiatric inpatients. Method Smokers, regardless of intention to quit, were recruited during psychiatric hospitalization and randomized to receive stage-based smoking cessation services or usual aftercare. Smoking cessation services, quality of life, and biochemically-verified abstinence from cigarettes were assessed during 18-months of follow-up. Trial findings were combined with literature on changes in smoking status and the age and gender adjusted effect of smoking on health care cost, mortality, and quality of life in a Markov model of cost-effectiveness during a lifetime horizon. Results Among 223 smokers randomized between 2006 and 2008, the mean cost of smoking cessation services was $189 in the experimental treatment group and $37 in the usual care condition (p < 0.001). At the end of follow-up, 18.75% of the experimental group was abstinent from cigarettes, compared to 6.80% abstinence in the usual care group (p <0.05). The model projected that the intervention added $43 in lifetime cost and generated 0.101 additional Quality Adjusted Life Years (QALYs), an incremental cost-effectiveness ratio of $428 per QALY. Probabilistic sensitivity analysis found the experimental intervention was cost-effective against the acceptance criteria of $50,000/QALY in 99.0% of the replicates. Conclusions A cessation intervention for smokers identified in psychiatric hospitalization did not result in higher mental health care costs in the short-run and was highly cost-effective over the long-term. The stage-based intervention was a feasible and cost-effective way of addressing the high smoking prevalence in persons with serious mental illness. PMID:26528651

  10. Individual cognitive stimulation therapy for dementia: a clinical effectiveness and cost-effectiveness pragmatic, multicentre, randomised controlled trial.

    PubMed Central

    Orgeta, Vasiliki; Leung, Phuong; Yates, Lauren; Kang, Sujin; Hoare, Zoe; Henderson, Catherine; Whitaker, Chris; Burns, Alistair; Knapp, Martin; Leroi, Iracema; Moniz-Cook, Esme D; Pearson, Stephen; Simpson, Stephen; Spector, Aimee; Roberts, Steven; Russell, Ian T; de Waal, Hugo; Woods, Robert T; Orrell, Martin

    2015-01-01

    BACKGROUND Group cognitive stimulation therapy programmes can benefit cognition and quality of life for people with dementia. Evidence for home-based, carer-led cognitive stimulation interventions is limited. OBJECTIVES To evaluate the clinical effectiveness and cost-effectiveness of carer-delivered individual cognitive stimulation therapy (iCST) for people with dementia and their family carers, compared with treatment as usual (TAU). DESIGN A multicentre, single-blind, randomised controlled trial assessing clinical effectiveness and cost-effectiveness. Assessments were at baseline, 13 weeks and 26 weeks (primary end point). SETTING Participants were recruited through Memory Clinics and Community Mental Health Teams for older people. PARTICIPANTS A total of 356 caregiving dyads were recruited and 273 completed the trial. INTERVENTION iCST consisted of structured cognitive stimulation sessions for people with dementia, completed up to three times weekly over 25 weeks. Family carers were supported to deliver the sessions at home. MAIN OUTCOME MEASURES Primary outcomes for the person with dementia were cognition and quality of life. Secondary outcomes included behavioural and psychological symptoms, activities of daily living, depressive symptoms and relationship quality. The primary outcome for the family carers was mental/physical health (Short Form questionnaire-12 items). Health-related quality of life (European Quality of Life-5 Dimensions), mood symptoms, resilience and relationship quality comprised the secondary outcomes. Costs were estimated from health and social care and societal perspectives. RESULTS There were no differences in any of the primary outcomes for people with dementia between intervention and TAU [cognition: mean difference -0.55, 95% confidence interval (CI) -2.00 to 0.90; p-value = 0.45; self-reported quality of life: mean difference -0.02, 95% CI -1.22 to 0.82; p-value = 0.97 at the 6-month follow-up]. iCST did not improve mental

  11. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman; Sarah R. Nuss-Warren

    2006-12-31

    This report highlights work done on a project intended to lower the cost of environmental compliance and expedite project permitting for Exploration and Production (E&P) operators by identifying, developing, testing, and commercializing emissions control and monitoring technologies. Promising technologies have already been identified and developed. Current work focuses on testing these promising technologies. Specifically, several technologies are being tested in the laboratory for application to lean-burn engines or fully characterized on-site for use with rich-burn engines. Upon completion of these tests, the most cost-effective and robust technologies will be tested in the field and commercialization will ensue. During this quarter, progress in laboratory testing for lean-burn engines was limited by maintenance issues on the KSU Ajax DP-115. The difficulties that required maintenance to be performed will likely require that the 180 psig prototype valve be tested in the future, if possible. The maintenance was performed, and it is expected that the Ajax will be available for testing in the coming quarter. Although laboratory testing was slowed as a result of maintenance issues, progress in experimental characterization of technologies has been significant. NSCR systems will be characterized as applied to rich-burn engines on-site. This characterization will ensure high-quality data in final field testing on rich-burn engines and is considered to be essential, despite that the work requires the delay of official field testing until 2008. Many preliminary and administrative tasks have been completed, including initial site selection, official proposal submittal, and beginning a process to approve necessary changes to installed field engines.

  12. Cost-Effectiveness of a Long-Term Internet-Delivered Worksite Health Promotion Programme on Physical Activity and Nutrition: A Cluster Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Robroek, Suzan J. W.; Polinder, Suzanne; Bredt, Folef J.; Burdorf, Alex

    2012-01-01

    This study aims to evaluate the cost-effectiveness of a long-term workplace health promotion programme on physical activity (PA) and nutrition. In total, 924 participants enrolled in a 2-year cluster randomized controlled trial, with departments (n = 74) within companies (n = 6) as the unit of randomization. The intervention was compared with a…

  13. A Cost-Effectiveness Tool to Guide the Prioritization of Interventions for Rheumatic Fever and Rheumatic Heart Disease Control in African Nations

    PubMed Central

    Lubinga, Solomon J.; Mayosi, Bongani; Babigumira, Joseph B.

    2016-01-01

    Background Rheumatic heart disease (RHD) prevalence and mortality rates remain especially high in many parts of Africa. While effective prevention and treatment exist, coverage rates of the various interventions are low. Little is known about the comparative cost-effectiveness of different RHD interventions in limited resource settings. We developed an economic evaluation tool to assist ministries of health in allocating resources and planning RHD control programs. Methodology/Principal Findings We constructed a Markov model of the natural history of acute rheumatic fever (ARF) and RHD, taking transition probabilities and intervention effectiveness data from previously published studies and expert opinion. Our model estimates the incremental cost-effectiveness of scaling up coverage of primary prevention (PP), secondary prevention (SP) and heart valve surgery (VS) interventions for RHD. We take a healthcare system perspective on costs and measure outcomes as disability-adjusted life-years (DALYs), discounting both at 3%. Univariate and probabilistic sensitivity analyses are also built into the modeling tool. We illustrate the use of this model in a hypothetical low-income African country, drawing on available disease burden and cost data. We found that, in our hypothetical country, PP would be cost saving and SP would be very cost-effective. International referral for VS (e.g., to a country like India that has existing surgical capacity) would be cost-effective, but building in-country VS services would not be cost-effective at typical low-income country thresholds. Conclusions/Significance Our cost-effectiveness analysis tool is designed to inform priorities for ARF/RHD control programs in Africa at the national or subnational level. In contrast to previous literature, our preliminary findings suggest PP could be the most efficient and cheapest approach in poor countries. We provide our model for public use in the form of a Supplementary File. Our research has

  14. Evaluation of the cost effectiveness of exenatide versus insulin glargine in patients with sub-optimally controlled Type 2 diabetes in the United Kingdom

    PubMed Central

    Woehl, Anette; Evans, Mark; Tetlow, Anthony P; McEwan, Philip

    2008-01-01

    Objective Exenatide belongs to a new therapeutic class in the treatment of diabetes (incretin mimetics), allowing glucose-dependent glycaemic control in Type 2 diabetes. Randomised controlled trial data suggest that exenatide is as effective as insulin glargine at reducing HbA1c in combination therapy with metformin and sulphonylureas; with reduced weight but higher incidence of adverse gastrointestinal events. The objective of this study is to evaluate the cost effectiveness of exenatide versus insulin glargine using RCT data and a previously published model of Type 2 diabetes disease progression that is based on the United Kingdom Prospective Diabetes Study; the perspective of the health-payer of the United Kingdom National Health Service. Methods The study used a discrete event simulation model designed to forecast the costs and health outcome of a cohort of 1,000 subjects aged over 40 years with sub-optimally-controlled Type 2 diabetes, following initiation of either exenatide, or insulin glargine, in addition to oral hypoglycaemic agents. Sensitivity analysis for a higher treatment discontinuation rate in exenatide patients was applied to the cohort in three different scenarios; (1) either ignored or (2) exenatide-failures excluded or (3) exenatide-failures switched to insulin glargine. Analyses were undertaken to evaluate the price sensitivity of exenatide in terms of relative cost effectiveness. Baseline cohort profiles and effectiveness data were taken from a published randomised controlled trial. Results The relative cost-effectiveness of exenatide and insulin glargine was tested under a variety of conditions, in which insulin glargine was dominant in all cases. Using the most conservative of assumptions, the cost-effectiveness ratio of exenatide vs. insulin glargine at the current UK NHS price was -£29,149/QALY (insulin glargine dominant) and thus exenatide is not cost-effective when compared with insulin glargine, at the current UK NHS price. Conclusion

  15. A cost effectiveness analysis within a randomised controlled trial of post-acute care of older people in a community hospital

    PubMed Central

    O'Reilly, Jacqueline; Lowson, Karin; Young, John; Forster, Anne; Green, John; Small, Neil

    2006-01-01

    Objective To assess the cost effectiveness of post-acute care for older people in a locality based community hospital compared with a department for care of elderly people in a district general hospital, which admits patients aged over 76 years with acute medical conditions. Design Cost effectiveness analysis within a randomised controlled trial. Setting Community hospital and district general hospital in Yorkshire, England. Participants 220 patients needing rehabilitation after an acute illness for which they required admission to hospital. Interventions Multidisciplinary care in the district general hospital or prompt transfer to the community hospital. Main outcome measures EuroQol EQ-5D scores transformed into quality adjusted life years (QALYs), and health and social service costs over six months from randomisation. Results The mean QALY score for the community hospital group was marginally non-significantly higher than that for the district general hospital group (0.38 v 0.35) at six months after recruitment. The mean (standard deviation) costs per patient of the health and social services resources used were similar for both groups: community hospital group £7233 (euros 10 567; $13 341) (£5031), district general hospital group £7351 (£6229), and these findings were robust to several sensitivity analyses. The incremental cost effectiveness ratio for community hospital care dominated. A cost effectiveness acceptability curve, based on bootstrapped simulations, suggests that at a willingness to pay threshold of £10 000 per QALY, 51% of community hospital cases will be cost effective, which rises to 53% of cases when the threshold is £30 000 per QALY. Conclusion Post-acute care for older people in a locality based community hospital is of similar cost effectiveness to that of an elderly care department in a district general hospital. PMID:16861254

  16. Digital flight control actuation system study

    NASA Technical Reports Server (NTRS)

    Rossing, R.; Hupp, R.

    1974-01-01

    Flight control actuators and feedback sensors suitable for use in a redundant digital flight control system were examined. The most appropriate design approach for an advanced digital flight control actuation system for development and use in a fly-by-wire system was selected. The concept which was selected consisted of a PM torque motor direct drive. The selected system is compatible with concurrent and independent development efforts on the computer system and the control law mechanizations.

  17. A cost-effective approach to the development of printed materials: a randomized controlled trial of three strategies.

    PubMed

    Paul, C L; Redman, S; Sanson-Fisher, R W

    2004-12-01

    Printed materials have been a primary mode of communication in public health education. Three major approaches to the development of these materials--the application of characteristics identified in the literature, behavioral strategies and marketing strategies--have major implications for both the effectiveness and cost of materials. However, little attention has been directed towards the cost-effectiveness of such approaches. In the present study, three pamphlets were developed using successive addition of each approach: first literature characteristics only ('C' pamphlet), then behavioral strategies ('C + B' pamphlet) and then marketing strategies ('C + B + M' pamphlet). Each pamphlet encouraged women to join a Pap Test Reminder Service (PTRS). Each pamphlet was mailed to a randomly selected sample of 2700 women aged 50-69 years. Registrations with the PTRS were monitored and 420 women in each pamphlet group were surveyed by telephone. It was reported that the 'C + B' and 'C + B + M' pamphlets were significantly more effective than the 'C' pamphlet. The 'C + B' pamphlet was the most cost-effective of the three pamphlets. There were no significant differences between any of the pamphlet groups on acceptability, knowledge or attitudes. It was suggested that the inclusion of behavioral strategies is likely to be a cost-effective approach to the development of printed health education materials.

  18. Assessment of the impact of fibrates and diet on survival and their cost-effectiveness: evidence from randomized, controlled trials in coronary heart disease and health economic evaluations.

    PubMed

    Montagne, O; Vedel, I; Durand-Zaleski, I

    1999-11-01

    The fibrates are one of several classes of lipid-reducing agents commonly prescribed to reduce hypercholesterolemia and prevent coronary heart disease. In today's evidence-based, cost-conscious health care environment, interventions promoted by policymakers must provide clear clinical benefits and economic value. We assessed the evidence regarding the impact of fibrates and diet on survival and the cost-effectiveness of these interventions. A literature search was conducted for randomized, controlled trials of diet, fibrates, and heart disease that were published after 1971; both primary and secondary prevention clinical trials were reviewed, and recent literature reviews and meta-analyses were searched. The evidence that diet alone improves survival is poor, although specifically increasing intake of polyunsaturated fatty acid (including n-3 fatty acids) relative to saturated fatty acid intake may provide some clinical benefit in the secondary prevention of coronary heart disease. The cost-effectiveness of dietary intervention is also questionable because compliance is extremely poor. There is no consistent evidence from primary or secondary prevention trials that fibrates improve survival; in fact, fibrates may increase the risk of death from noncoronary causes. No consistent data suggest that fibrates are a cost-effective therapy. Because diet and fibrates do not appear to improve survival or provide value, policymakers should promote the use of alternative drug interventions that have consistently been proved to reduce mortality and are cost-effective.

  19. Are lower levels of red blood cell transfusion more cost-effective than liberal levels after cardiac surgery? Findings from the TITRe2 randomised controlled trial

    PubMed Central

    Stokes, E A; Wordsworth, S; Bargo, D; Pike, K; Rogers, C A; Brierley, R C M; Angelini, G D; Murphy, G J; Reeves, B C

    2016-01-01

    Objective To assess the incremental cost and cost-effectiveness of a restrictive versus a liberal red blood cell transfusion threshold after cardiac surgery. Design A within-trial cost-effectiveness analysis with a 3-month time horizon, based on a multicentre superiority randomised controlled trial from the perspective of the National Health Service (NHS) and personal social services in the UK. Setting 17 specialist cardiac surgery centres in UK NHS hospitals. Participants 2003 patients aged >16 years undergoing non-emergency cardiac surgery with a postoperative haemoglobin of <9 g/dL. Interventions Restrictive (transfuse if haemoglobin <7.5 g/dL) or liberal (transfuse if haemoglobin <9 g/dL) threshold during hospitalisation after surgery. Main outcome measures Health-related quality of life measured using the EQ-5D-3L to calculate quality-adjusted life years (QALYs). Results The total costs from surgery up to 3 months were £17 945 and £18 127 in the restrictive and liberal groups (mean difference is −£182, 95% CI −£1108 to £744). The cost difference was largely attributable to the difference in the cost of red blood cells. Mean QALYs to 3 months were 0.18 in both groups (restrictive minus liberal difference is 0.0004, 95% CI −0.0037 to 0.0045). The point estimate for the base-case cost-effectiveness analysis suggested that the restrictive group was slightly more effective and slightly less costly than the liberal group and, therefore, cost-effective. However, there is great uncertainty around these results partly due to the negligible differences in QALYs gained. Conclusions We conclude that there is no clear difference in the cost-effectiveness of restrictive and liberal thresholds for red blood cell transfusion after cardiac surgery. Trial registration number ISRCTN70923932; Results. PMID:27481621

  20. Cost-effectiveness of screening for anal cancer using regular digital ano-rectal examinations in men who have sex with men living with HIV

    PubMed Central

    Ong, Jason J; Fairley, Christopher K; Carroll, Susan; Walker, Sandra; Chen, Marcus; Read, Tim; Grulich, Andrew; Bradshaw, Catriona; Kaldor, John; Clarke, Philip

    2016-01-01

    Introduction Anal cancer in men who have sex with men (MSM) living with HIV is an important issue but there are no consistent guidelines for how to screen for this cancer. In settings where screening with anal cytology is unavailable, regular anal examinations have been proposed in some guidelines but their cost-effectiveness is unknown. Methods Our objective was to estimate the cost-effectiveness of regular anal examinations to screen for anal cancer in HIV-positive MSM living in Australia using a probabilistic Markov model. Data sources were based on the medical literature and a clinical trial of HIV-positive MSM receiving an annual anal examination in Australia. The main outcome measures for calculating effectiveness were undiscounted and discounted (at 3%) lifetime costs, life years gained, quality-adjusted life years (QALY) gained and incremental cost-effectiveness ratio (ICER). Results Base-case analysis estimated the average cost of screening for and management of anal cancer ranged from $195 for no screening to $1,915 for lifetime annual screening of men aged ≥ 50. Screening of men aged ≥ 50 generated ICERs of $29,760 per QALY gained (for screening every four years), $32,222 (every three years) and $45,484 (every two years). Uncertainty for ICERs was mostly influenced by the cost (financially and decrease in quality of life) from a false-positive result, progression rate of anal cancer, specificity of the anal examination, the probability of detection outside a screening program and the discount rate. Conclusions Screening for anal cancer by incorporating regular anal examinations into routine HIV care for MSM aged ≥ 50 is most likely to be cost-effective by conventional standards. Given that anal pap smears are not widely available yet in many clinical settings, regular anal exams for MSM living with HIV to detect anal cancer earlier should be implemented. PMID:26942721

  1. Digital control system for space structural dampers

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.

    1984-01-01

    Digital control systems for space structural dampers, also referred to as inertia or proof-mass dampers are investigated. A damper concept is improved by adding a small taper to the proof-mass, and using a proximeter to determine position. Another damper using a three inch stroke rather than the standard one inch stroke is described. Provisions are made for a relative velocity feedback. In one approach, the digital controller is modified to accept the signal from a linear velocity transducer. In the other, the velocity feedback is included in the digital program. An overall system concept for the use of the dampers is presented.

  2. Inherent Error in Asynchronous Digital Flight Controls.

    DTIC Science & Technology

    1980-02-01

    the algorithm for estimating T, * will wait until the state observers (x*) equal the state variables (xp) and this system is in steady state. From...Appendix A (this system is in steady state at the time 200T) and Appendix C (the state observers equal the state variables at time approximate equals 40T...system, the DIGITAL CONTROLLER #1 in the monitor will wait until the state observers (x*) equal the state variables (xp). Then p the DIGITAL CONTROLLER

  3. Cost-effectiveness of an experimental caries-control regimen in a 3.4-yr randomized clinical trial among 11-12-yr-old Finnish schoolchildren.

    PubMed

    Hietasalo, Pauliina; Seppä, Liisa; Lahti, Satu; Niinimaa, Ahti; Kallio, Jouko; Aronen, Pasi; Sintonen, Harri; Hausen, Hannu

    2009-12-01

    The aim of this study was to assess the cost-effectiveness of an experimental caries-control regimen in a randomized clinical trial (RCT) conducted in Pori, Finland, in 2001-2005. Children (n = 497) who were 11-12 yr of age and had at least one active initial caries lesion at baseline were studied. The children in the experimental group (n = 250) were offered an individually designed patient-centered regimen for caries control. The children in the control group (n = 247) received standard dental care. Furthermore, the whole population was exposed to continuous community-level oral health promotion. Individual costs of treatment procedures and outcomes (DMFS increment score) for the follow-up period of 3.4 yr were calculated for each child in both groups. The incremental cost-effectiveness ratio was euro 34.07 per averted DMF surface. The experimental regimen was more effective, and also more costly. However, the total costs decreased year after year, and for the last 2 yr the experimental regimen was less expensive than the standard dental care. The experimental regimen would probably have been more cost-effective than standard dental care if the follow-up period had been longer, the regimen less comprehensive, and/or if dental nurses had conducted the preventive procedures.

  4. Evaluating Multi-Input/Multi-Output Digital Control Systems

    NASA Technical Reports Server (NTRS)

    Pototzky, Anthony S.; Wieseman, Carol D.; Hoadley, Sherwood T.; Mukhopadhyay, Vivek

    1994-01-01

    Controller-performance-evaluation (CPE) methodology for multi-input/multi-output (MIMO) digital control systems developed. Procedures identify potentially destabilizing controllers and confirm satisfactory performance of stabilizing ones. Methodology generic and used in many types of multi-loop digital-controller applications, including digital flight-control systems, digitally controlled spacecraft structures, and actively controlled wind-tunnel models. Also applicable to other complex, highly dynamic digital controllers, such as those in high-performance robot systems.

  5. Clinical Impact and Cost-Effectiveness of an Education Program for PD Patients: A Randomized Controlled Trial

    PubMed Central

    Ory-Magne, Fabienne; Arcari, Céline; Mohara, Christine; Pourcel, Laure; Derumeaux, Hélène; Bérard, Emilie; Bourrel, Robert; Molinier, Laurent; Brefel-Courbon, Christine

    2016-01-01

    Background Parkinson’s disease (PD) is characterized by its impact on quality of life, constituting a substantial economic burden on society. Education programs implicating patients more in the management of their illness and complementing medical treatment may be a beneficial adjunct in PD. This study assessed the impact of an education program on quality of life and its cost-effectiveness in PD patients. Methods This single-center, prospective, randomized study assessed an education program consisting of individual and group sessions over a 12-month period. A total of 120 PD patients were assigned to either the Treated by Behavioral Intervention group (TTBI) or the no TTBI group. The primary outcome criterion was quality of life assessed using PDQ39. The Unified Parkinson’s Disease Rating Scale (UPDRS) and psychological status were collected. An economic evaluation was performed, including calculations of incremental cost-effectiveness ratios (ICERs). Results After 12 months of follow-up, changes recorded in the PDQ39 between the groups were not significantly different but better changes were observed in each dimension in the TTBI group compared to the no TTBI group. UPDRS I, II and total score were significantly improved in TTBI group compared to the no TTBI group. Mean annual costs did not differ significantly between the two groups. Conclusion This study suggested that the education program positively impacts the perceived health of PD patients without increasing medical costs. PMID:27685455

  6. The Cost-Effectiveness of Two Forms of Case Management Compared to a Control Group for Persons with Dementia and Their Informal Caregivers from a Societal Perspective

    PubMed Central

    Eekhout, Iris; Joling, Karlijn J.; van Mierlo, Lisa D.; Meiland, Franka J. M.; van Hout, Hein P. J.; de Rooij, Sophia E.

    2016-01-01

    Objectives The objective of this article was to compare the costs and cost-effectiveness of the two most prominent types of case management in the Netherlands (intensive case management and linkage models) against no access to case management (control group) for people with already diagnosed dementia and their informal caregivers. Methods The economic evaluation was conducted from a societal perspective embedded within a two year prospective, observational, controlled, cohort study with 521 informal caregivers and community-dwelling persons with dementia. Case management provided within one care organization (intensive case management model, ICMM), case management where care was provided by different care organizations within one region (Linkage model, LM), and a group with no access to case management (control) were compared. The economic evaluation related incremental costs to incremental effects regarding neuropsychiatric symptoms (NPI), psychological health of the informal caregiver (GHQ-12), and quality adjusted life years (QALY) of the person with dementia and informal caregiver. Results Inverse-propensity-score-weighted models showed no significant differences in clinical or total cost outcomes between the three groups. Informal care costs were significantly lower in the ICMM group compared to both other groups. Day center costs were significantly lower in the ICMM group compared to the control group. For all outcomes, the probability that the ICMM was cost-effective in comparison with LM and the control group was larger than 0.97 at a threshold ratio of 0 €/incremental unit of effect. Conclusion This study provides preliminary evidence that the ICMM is cost-effective compared to the control group and the LM. However, the findings should be interpreted with caution since this study was not a randomized controlled trial. PMID:27655234

  7. Digital Control Of A Telescope In An Airplane

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann C.; Snyder, Philip K.

    1991-01-01

    Options for design of aim-stabilizing system analyzed. Report discusses feasibility of digital control system stabilizing aim of 30-in. telescope aboard NASA C141 airplane known as Kuiper Atmospheric Observatory. Proposed digital compensator consists of input analog-to-digital converter, digital controller processor, and output digital-to-analog converter.

  8. Digital control system for space structure dampers

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.

    1985-01-01

    A digital controller was developed using an SKD-51 System Design Kit, which incorporates an 8031 microcontroller. The necessary interfaces were installed in the wire wrap area of the SKD-51 and a pulse width modulator was developed to drive the coil of the actuator. Also, control equations were developed, using floating-point arithmetic. The design of the digital control system is emphasized, and it is shown that, provided certain rules are followed, an adequate design can be achieved. It is recommended that the so-called w-plane design method be used, and that the time elapsed before output of the up-dated coil-force signal be kept as small as possible. However, the cycle time for the controller should be watched carefully, because very small values for this time can lead to digital noise.

  9. Designing Digital Control Systems With Averaged Measurements

    NASA Technical Reports Server (NTRS)

    Polites, Michael E.; Beale, Guy O.

    1990-01-01

    Rational criteria represent improvement over "cut-and-try" approach. Recent development in theory of control systems yields improvements in mathematical modeling and design of digital feedback controllers using time-averaged measurements. By using one of new formulations for systems with time-averaged measurements, designer takes averaging effect into account when modeling plant, eliminating need to iterate design and simulation phases.

  10. GMA200 ATEGG Digital Controls Demonstration.

    DTIC Science & Technology

    1979-10-01

    Technologyi Demonstrator Variable Cycle Engines Digital Controls Control Modes Turbine Engine Controls Signal Synthesis 20 A 8STRACI ’CantInue -n r.ct...Turbine Outlet Temperature TX Temperature at Station Location X UTC Universal Test Console VCE Variable Cycle Engine VG Variable Geometry W Flow WA...Definition of engine control variables - ATEGG is a variaole cycle engine with a multi-input, multi-output structure. The multi-input part of tna

  11. Cost-Effectiveness of Financial Incentives to Promote Adherence to Depot Antipsychotic Medication: Economic Evaluation of a Cluster-Randomised Controlled Trial

    PubMed Central

    Henderson, Catherine; Knapp, Martin; Yeeles, Ksenija; Bremner, Stephen; Eldridge, Sandra; David, Anthony S.; O’Connell, Nicola; Burns, Tom; Priebe, Stefan

    2015-01-01

    Background Offering a modest financial incentive to people with psychosis can promote adherence to depot antipsychotic medication, but the cost-effectiveness of this approach has not been examined. Methods Economic evaluation within a pragmatic cluster-randomised controlled trial. 141 patients under the care of 73 teams (clusters) were randomised to intervention or control; 138 patients with diagnoses of schizophrenia, schizo-affective disorder or bipolar disorder participated. Intervention participants received £15 per depot injection over 12 months, additional to usual acute, mental and community primary health services. The control group received usual health services. Main outcome measures: incremental cost per 20% increase in adherence to depot antipsychotic medication; incremental cost of ‘good’ adherence (defined as taking at least 95% of the prescribed number of depot medications over the intervention period). Findings Economic and outcome data for baseline and 12-month follow-up were available for 117 participants. The adjusted difference in adherence between groups was 12.2% (73.4% control vs. 85.6% intervention); the adjusted costs difference was £598 (95% CI -£4 533, £5 730). The extra cost per patient to increase adherence to depot medications by 20% was £982 (95% CI -£8 020, £14 000). The extra cost per patient of achieving 'good' adherence was £2 950 (CI -£19 400, £27 800). Probability of cost-effectiveness exceeded 97.5% at willingness-to-pay values of £14 000 for a 20% increase in adherence and £27 800 for good adherence. Interpretation Offering a modest financial incentive to people with psychosis is cost-effective in promoting adherence to depot antipsychotic medication. Direct healthcare costs (including costs of the financial incentive) are unlikely to be increased by this intervention. Trial Registration ISRCTN.com 77769281 PMID:26448540

  12. Cost-effectiveness of aftercare services for people with severe mental disorders: an analysis parallel to a randomised controlled clinical trial in Iran.

    PubMed

    Moradi-Lakeh, Maziar; Yaghoubi, Mohsen; Hajebi, Ahmad; Malakouti, Seyed Kazem; Vasfi, Mohamad Ghadiri

    2017-02-01

    Aftercare services are not part of the usual care for people with severe mental disorders in Iran. This study was performed to assess the cost-effectiveness of aftercare services, including telephone follow-up or home visit, in addition to caregivers' education and training of social skills, for all subjects during the 20 months after hospital discharge. An economic evaluation was performed along with a registered randomised controlled trial (IRCT201009052557N2) on two groups of 60 persons recruited between 2010 and 2012. Intervention's effectiveness was measured by psychopathology and quality of life indicators. Cost-effectiveness and cost-utility were analysed from the societal and Ministry of Health (MoH) perspectives. All indicators of psychopathology, quality of life and satisfaction with services in the intervention group were significantly different from the control group. Mean intervention costs was US$674 (95% confidence interval [CI]: 572-776) per subject in the intervention group. Average total direct costs were US$1445 (95% CI: 1086-1804) and US$1640 (95% CI: 1087-2093) per subject in the intervention and control groups respectively. From the societal perspective, intervention had more effects with lower costs. The ratios for incremental cost-effectiveness was US$8399.1 (95% CI: 8178.2-8620.0) per quality-adjusted life year (QALY) gained from the MoH perspective for 20 months of follow-up. This study showed that aftercare services can create opportunities to use hospital beds more efficiently for unmet needs of people with psychiatric disorders. Indirect and intangible costs were not considered in this study, if taken into account, they are likely to further increase the efficiency of intervention.

  13. Guidelines for selection and application of the most cost-effective NO sub x control technologies for gas, oil and coal fired boilers

    SciTech Connect

    Czerniak, D.O.; Booth, R.B.; McDonald, B.L. ); Feenstra, D.R. )

    1991-01-01

    As a result of the new Clean Air Act, lower NO{sub x} emissions from stationary sources will be required of utilities and independent power producers that burn all fuels including gas, oil and coal. This new legislation, as well as new and more stringent NO{sub x} reduction orders imposed by state and local regulatory agencies, will require rapid evaluation, purchase, installation and start-up of a variety of control technologies. There is substantial volume of literature available discussing NO{sub x} control technologies, their control effectiveness, costs, and chemical reaction mechanisms in forming NO{sub x}. This paper, however, presents more practical aspects of developing a NO{sub x} control strategy and implementing the appropriate cost-effective control technology on a utility or industrial boiler.

  14. Digital system identification and its application to digital flight control

    NASA Technical Reports Server (NTRS)

    Kotob, S.; Kaufman, H.

    1974-01-01

    On-line system identification of linear discrete systems for implementation in a digital adaptive flight controller is considered by the conventional extended Kalman filter and a decoupling process in which the linear state estimation problem and the linear parameter identification problem are each treated separately and alternately. Input requirements for parameter identifiability are established using the standard conditions of observability for a time variant system. Experimental results for simulated linearized lateral aircraft motion are included along with the effect of different initialization and updating procedures for the priming trajectory used by the filter.

  15. Effectiveness and cost-effectiveness of meaning-centered group psychotherapy in cancer survivors: protocol of a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Meaning-focused coping may be at the core of adequate adjustment to life after cancer. Cancer survivors who experience their life as meaningful are better adjusted, have better quality of life and psychological functioning. Meaning-Centered Group Psychotherapy for Cancer Survivors (MCGP-CS) was designed to help patients to sustain or enhance a sense of meaning and purpose in their lives. The aim of the proposed study is to evaluate the effectiveness and cost-effectiveness of MCGP-CS. Methods/Design Survivors diagnosed with cancer in the last 5 years and treated with curative intent, are recruited via several hospitals in the Netherlands. After screening, 168 survivors are randomly assigned to one of the three study arms: 1. Meaning-Centered Group Psychotherapy (MCGP-CS) 2. Supportive group psychotherapy (SGP) 3. Care as usual (CAU). Baseline assessment takes place before randomisation, with follow up assessments post-intervention and at 3, 6 and 12 months follow-up. Primary outcome is meaning making (PMP, PTGI, SPWB). Secondary outcome measures address quality of life (EORTC-30), anxiety and depression (HADS), hopelessness (BHS), optimism (LOT-R), adjustment to cancer (MAC), and costs (TIC-P, EQ-5D, PRODISQ). Discussion Meaning-focused coping is key to adjustment to life after cancer, however, there is a lack of evidence based psychological interventions in this area. Many cancer survivors experience feelings of loneliness and alienation, and have a need for peer support, therefore a group method in particular, can be beneficial for sustaining or enhancing a sense of meaning. If this MCGP-CS is effective for cancer survivors, it can be implemented in the practice of psycho-oncology care. Trial registration Netherlands Trial Register, NTR3571 PMID:24467861

  16. Study protocol for a randomised controlled multicentre study: the Foraminotomy ACDF Cost-Effectiveness Trial (FACET) in patients with cervical radiculopathy

    PubMed Central

    Broekema, A E H; Kuijlen, J M A; Lesman-Leegte, G A T; Bartels, R H M A; van Asselt, A D I; Vroomen, P C A J; Reneman, M F; Soer, R; Groen, R J M

    2017-01-01

    Introduction Cervical radiculopathy due to discogenic or spondylotic stenosis of the neuroforamen can be surgically treated by an anterior discectomy with fusion (ACDF) or a posterior foraminotomy (FOR). Most surgeons prefer ACDF, although there are indications that FOR is as effective as ACDF, has a lower complication rate and is less expensive. A head-to-head comparison of the 2 surgical techniques in a randomised controlled trial has not yet been performed. The study objectives of the Foraminotomy ACDF Cost-Effectiveness Trial (FACET) study are to compare clinical outcomes, complication rates and cost-effectiveness of FOR to ACDF. Methods and analysis The FACET study is a prospective randomised controlled trial conducted in 7 medical centres in the Netherlands. The follow-up period is 2 years. The main inclusion criterion is a radiculopathy of the C4, C5, C6 or C7 nerve root, due to a single-level isolated cervical foraminal stenosis caused by a soft disc and/or osteophytic component, requiring operative decompression. A sample size of 308 patients is required to test the hypothesis of clinical non-inferiority of FOR versus ACDF. Primary outcomes are: ‘operative success’, the measured decrease in radiculopathy assessed by the visual analogue scale and ‘patient success’, assessed by the modified Odom's criteria. Secondary outcomes are: Work Ability Index (single-item WAI), quality of life (EuroQol 5 Dimensions 5 level Survey, EQ-5D-5L), Neck Disability Index (NDI) and complications. An economic evaluation will assess cost-effectiveness. In addition, a budget impact analysis will be performed. Ethics and dissemination Ethical approval was obtained from the Institutional Ethics Committee of the University Medical Center Groningen. Results of this study will be disseminated through national and international papers. The participants and relevant patient support groups will be informed about the results of the study. Trial registration number NTR5536, pre

  17. Aircraft digital flight control technical review

    NASA Technical Reports Server (NTRS)

    Davenport, Otha B.; Leggett, David B.

    1993-01-01

    The Aircraft Digital Flight Control Technical Review was initiated by two pilot induced oscillation (PIO) incidents in the spring and summer of 1992. Maj. Gen. Franklin (PEO) wondered why the Air Force development process for digital flight control systems was not preventing PIO problems. Consequently, a technical review team was formed to examine the development process and determine why PIO problems continued to occur. The team was also to identify the 'best practices' used in the various programs. The charter of the team was to focus on the PIO problem, assess the current development process, and document the 'best practices.' The team reviewed all major USAF aircraft programs with digital flight controls, specifically, the F-15E, F-16C/D, F-22, F-111, C-17, and B-2. The team interviewed contractor, System Program Office (SPO), and Combined Test Force (CTF) personnel on these programs. The team also went to NAS Patuxent River to interview USN personnel about the F/A-18 program. The team also reviewed experimental USAF and NASA systems with digital flight control systems: X-29, X-31, F-15 STOL and Maneuver Technology Demonstrator (SMTD), and the Variable In-Flight Stability Test Aircraft (VISTA). The team also discussed the problem with other experts in the field including Ralph Smith and personnel from Calspan. The major conclusions and recommendations from the review are presented.

  18. Digital electronic engine control F-15 overview

    NASA Technical Reports Server (NTRS)

    Kock, B.

    1984-01-01

    A flight test evaluation of the digital elctronic engine control (DEEC) system was conducted. An overview of the flight program is presented. The roles of the participating parties, the system, and the flight program objectives are described. The test program approach is discussed, and the engine performance benefits are summarized. A description of the follow-on programs is included.

  19. Digital control of highly augmented combat rotorcraft

    NASA Technical Reports Server (NTRS)

    Tischler, Mark B.

    1987-01-01

    Proposed concepts for the next generation of combat helicopters are to be embodied in a complex, highly maneuverable, multiroled vehicle with avionics systems. Single pilot and nap-of-the-Earth operations require handling qualities which minimize the involvement of the pilot in basic stabilization tasks. To meet these requirements will demand a full authority, high-gain, multimode, multiply-redundant, digital flight-control system. The gap between these requirements and current low-authority, low-bandwidth operational rotorcraft flight-control technology is considerable. This research aims at smoothing the transition between current technology and advanced concept requirements. The state of the art of high-bandwidth digital flight-control systems are reviewed; areas of specific concern for flight-control systems of modern combat are exposed; and the important concepts are illustrated in design and analysis of high-gain, digital systems with a detailed case study involving a current rotorcraft system. Approximate and exact methods are explained and illustrated for treating the important concerns which are unique to digital systems.

  20. Automatic Exposure Control Device for Digital Mammography

    DTIC Science & Technology

    2004-08-01

    developing innovative approaches for controlling DM exposures. These approaches entail using the digital detector and an artificial neural network to...of interest that determine the exposure parameters for the fully exposed image; and (2) to use an artificial neural network to select exposure

  1. Automatic Exposure Control Device for Digital Mammography

    DTIC Science & Technology

    2001-08-01

    developing innovative approaches for controlling DM exposures. These approaches entail using the digital detector and an artificial neural network to...34 regions of interest that determine the exposure parameters for the fully exposed image; and (2) to use an artificial neural network to select exposure

  2. A cluster randomized controlled trial of the effectiveness and cost-effectiveness of Intermediate Care Clinics for Diabetes (ICCD): study protocol for a randomized controlled trial

    PubMed Central

    2012-01-01

    Background World-wide healthcare systems are faced with an epidemic of type 2 diabetes. In the United Kingdom, clinical care is primarily provided by general practitioners (GPs) rather than hospital specialists. Intermediate care clinics for diabetes (ICCD) potentially provide a model for supporting GPs in their care of people with poorly controlled type 2 diabetes and in their management of cardiovascular risk factors. This study aims to (1) compare patients with type 2 diabetes registered with practices that have access to an ICCD service with those that have access only to usual hospital care; (2) assess the cost-effectiveness of the intervention; and (3) explore the views and experiences of patients, health professionals and other stakeholders. Methods/Design This two-arm cluster randomized controlled trial (with integral economic evaluation and qualitative study) is set in general practices in three UK Primary Care Trusts. Practices are randomized to one of two groups with patients referred to either an ICCD (intervention) or to hospital care (control). Intervention group: GP practices in the intervention arm have the opportunity to refer patients to an ICCD - a multidisciplinary team led by a specialist nurse and a diabetologist. Patients are reviewed and managed in the ICCD for a short period with a goal of improving diabetes and cardiovascular risk factor control and are then referred back to practice. or Control group: Standard GP care, with referral to secondary care as required, but no access to ICCD. Participants are adults aged 18 years or older who have type 2 diabetes that is difficult for their GPs to control. The primary outcome is the proportion of participants reaching three risk factor targets: HbA1c (≤7.0%); blood pressure (<140/80); and cholesterol (<4 mmol/l), at the end of the 18-month intervention period. The main secondary outcomes are the proportion of participants reaching individual risk factor targets and the overall 10-year risks

  3. Quadruplex digital flight control system assessment

    NASA Technical Reports Server (NTRS)

    Mulcare, D. B.; Downing, L. E.; Smith, M. K.

    1988-01-01

    Described are the development and validation of a double fail-operational digital flight control system architecture for critical pitch axis functions. Architectural tradeoffs are assessed, system simulator modifications are described, and demonstration testing results are critiqued. Assessment tools and their application are also illustrated. Ultimately, the vital role of system simulation, tailored to digital mechanization attributes, is shown to be essential to validating the airworthiness of full-time critical functions such as augmented fly-by-wire systems for relaxed static stability airplanes.

  4. Evaluation of the Cost-Effectiveness of Pyramidal, Modified Pyramidal and Monoscreen Traps for the Control of the Tsetse Fly, Glossina fuscipes fuscipes, in Uganda

    PubMed Central

    Abila, P.P.; Okello-Onen, J.; Okoth, J.O.; Matete, G.O.; Wamwiri, F.; Politzar, H.

    2007-01-01

    Several trap designs have been used for sampling and control of the tsetse fly, Glossina fuscipes fuscipes, Newstead (Diptera: Glossinidae) based on preferences of individual researchers and program managers with little understanding of the comparative efficiency and cost-effectiveness of trap designs. This study was carried out to evaluate the cost-effectiveness of four commonly used trap designs: monoscreen, modified pyramidal and pyramidal, relative to the standard biconical trap. The study was performed under high tsetse challenge on Buvuma Island, Lake Victoria, Uganda, using a 4 × 4 Latin square design replicated 3 times, so as to separate the trap positions and day effects from the treatment effect. A total of 12 trap positions were tested over 4 days. The monoscreen trap caught significantly higher numbers of G. f. fuscipes (P<0.05) followed by biconical, modified pyramidal and pyramidal traps. Analysis of variance showed that treatment factor was a highly significant source of variation in the data. The index of increase in trap catches relative biconical were O.60 (pyramidal), 0.68 (modified pyramidal) and 1.25 (monoscreen). The monoscreen trap was cheaper (US$ 2.61) and required less material to construct than pyramidal trap (US$ 3.48), biconical and the modified pyramidal traps (US$ 4.06 each). Based on the number of flies caught per meter of material, the monoscreen trap proved to be the most cost-effective (232 flies/m) followed by the biconical trap (185 flies/m). The modified pyramidal and the pyramidal traps caught 112 and 125 flies/m, respectively. PMID:20345292

  5. Digital gate pulse generator for cycloconverter control

    DOEpatents

    Klein, Frederick F.; Mutone, Gioacchino A.

    1989-01-01

    The present invention provides a digital gate pulse generator which controls the output of a cycloconverter used for electrical power conversion applications by determining the timing and delivery of the firing pulses to the switching devices in the cycloconverter. Previous gate pulse generators have been built with largely analog or discrete digital circuitry which require many precision components and periodic adjustment. The gate pulse generator of the present invention utilizes digital techniques and a predetermined series of values to develop the necessary timing signals for firing the switching device. Each timing signal is compared with a reference signal to determine the exact firing time. The present invention is significantly more compact than previous gate pulse generators, responds quickly to changes in the output demand and requires only one precision component and no adjustments.

  6. The clinical and cost-effectiveness of brief advice for excessive alcohol consumption among people attending sexual health clinics: a randomised controlled trial

    PubMed Central

    Crawford, Mike J; Sanatinia, Rahil; Barrett, Barbara; Byford, Sarah; Dean, Madeleine; Green, John; Jones, Rachael; Leurent, Baptiste; Sweeting, Michael J; Touquet, Robin; Greene, Linda; Tyrer, Peter; Ward, Helen; Lingford-Hughes, Anne

    2015-01-01

    Objectives To examine the clinical and cost-effectiveness of brief advice for excessive alcohol consumption among people who attend sexual health clinics. Methods Two-arm, parallel group, assessor blind, pragmatic, randomised controlled trial. 802 people aged 19 years or over who attended one of three sexual health clinics and were drinking excessively were randomised to either brief advice or control treatment. Brief advice consisted of feedback on alcohol and health, written information and an offer of an appointment with an Alcohol Health Worker. Control participants received a leaflet on health and lifestyle. The primary outcome was mean weekly alcohol consumption during the previous 90 days measured 6 months after randomisation. The main secondary outcome was unprotected sex during this period. Results Among the 402 randomised to brief advice, 397 (99%) received it. The adjusted mean difference in alcohol consumption at 6 months was −2.33 units per week (95% CI −4.69 to 0.03, p=0.053) among those in the active compared to the control arm of the trial. Unprotected sex was reported by 154 (53%) of those who received brief advice, and 178 (59%) controls (adjusted OR=0.89, 95% CI 0.63 to 1.25, p=0.496). There were no significant differences in costs between study groups at 6 months. Conclusions Introduction of universal screening and brief advice for excessive alcohol use among people attending sexual health clinics does not result in clinically important reductions in alcohol consumption or provide a cost-effective use of resources. Trial registration number Current Controlled Trials ISRCTN 99963322. PMID:24936090

  7. Digital control algorithms for microgravity isolation systems

    NASA Technical Reports Server (NTRS)

    Sinha, Alok; Wang, Yung-Peng

    1992-01-01

    New digital control algorithms were developed to achieve the desired acceleration transmissibility function. The attractive electromagnets have been taken as actuators. The relative displacement and the acceleration of the mass were used as feedback signals. Two approaches were developed to find that controller transfer function in Z-domain, which yields the desired transmissibility at each frequency. In the first approach, the controller transfer function is obtained by assuming that the desired transmissibility is known in Z-domain. Since the desired transmissibility H sub d(S) = 1/(tauS+1)(exp 2) is given in S-domain, the first task is to obtain the desired transmissibility in Z-domain. There are three methods to perform this task: bilinear transformation, and backward and forward rectangular rules. The bilinear transformation and backward rectangular rule lead to improper controller transfer functions, which are physically not realizable. The forward rectangular rule does lead to a physically realizable controller. However, this controller is found to be marginally stable because of a pole at Z=1. In order to eliminate this pole, a hybrid control structure is proposed. Here the control input is composed of two parts: analog and digital. The analog input simply represents the velocity (or the integral of acceleration) feedback; and the digital controller which uses only relative displacement signal, is then obtained to achieve the desired closed-loop transfer function. The stability analysis indicates that the controller transfer function is stable for typical values of sampling period. In the second approach, the aforementioned hybrid control structure is again used. First, an analog controller transfer function corresponding to relative displacement feedback is obtained to achieve the transmissibility as 1/(tauS+1)(exp 2). Then the transfer function for the digital control input is obtained by discretizing this analog controller transfer function via bilinear

  8. Obsessive Compulsive Treatment Efficacy Trial (OCTET) comparing the clinical and cost effectiveness of self-managed therapies: study protocol for a randomised controlled trial

    PubMed Central

    2014-01-01

    Background UK National Institute of Health and Clinical Excellence guidelines for obsessive compulsive disorder (OCD) specify recommendations for the treatment and management of OCD using a stepped care approach. Steps three to six of this model recommend treatment options for people with OCD that range from low-intensity guided self-help (GSH) to more intensive psychological and pharmacological interventions. Cognitive behavioural therapy (CBT), including exposure and response prevention, is the recommended psychological treatment. However, whilst there is some preliminary evidence that self-managed therapy packages for OCD can be effective, a more robust evidence base of their clinical and cost effectiveness and acceptability is required. Methods/Design Our proposed study will test two different self-help treatments for OCD: 1) computerised CBT (cCBT) using OCFighter, an internet-delivered OCD treatment package; and 2) GSH using a book. Both treatments will be accompanied by email or telephone support from a mental health professional. We will evaluate the effectiveness, cost and patient and health professional acceptability of the treatments. Discussion This study will provide more robust evidence of efficacy, cost effectiveness and acceptability of self-help treatments for OCD. If cCBT and/or GSH prove effective, it will provide additional, more accessible treatment options for people with OCD. Trial registration Current Controlled Trials: ISRCTN73535163. Date of registration: 5 April 2011 PMID:25011730

  9. Distributed and recoverable digital control system

    NASA Technical Reports Server (NTRS)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2010-01-01

    A real-time multi-tasking digital control system with rapid recovery capability is disclosed. The control system includes a plurality of computing units comprising a plurality of redundant processing units, with each of the processing units configured to generate one or more redundant control commands. One or more internal monitors are employed for detecting data errors in the control commands. One or more recovery triggers are provided for initiating rapid recovery of a processing unit if data errors are detected. The control system also includes a plurality of actuator control units each in operative communication with the computing units. The actuator control units are configured to initiate a rapid recovery if data errors are detected in one or more of the processing units. A plurality of smart actuators communicates with the actuator control units, and a plurality of redundant sensors communicates with the computing units.

  10. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Keith Hohn; Sarah R. Nuss-Warren

    2011-08-31

    This final report describes a project intended to identify, develop, test, and commercialize emissions control and monitoring technologies that can be implemented by E&P operators to significantly lower their cost of environmental compliance and expedite project permitting. Technologies were installed and tested in controlled laboratory situations and then installed and tested on field engines based on the recommendations of an industry-based steering committee, analysis of installed horsepower, analysis of available emissions control and monitoring technologies, and review of technology and market gaps. The industry-recognized solution for lean-burn engines, a low-emissions-retrofit including increased airflow and pre-combustion chambers, was found to successfully control engine emissions of oxides of nitrogen (NO{sub X}) and carbon monoxide (CO). However, the standard non-selective catalytic reduction (NSCR) system recognized by the industry was found to be unable to consistently control both NO{sub X} and CO emissions. The standard NSCR system was observed to produce emissions levels that changed dramatically on a day-to-day or even hour-to-hour basis. Because difficulties with this system seemed to be the result of exhaust gas oxygen (EGO) sensors that produced identical output for very different exhaust gas conditions, models were developed to describe the behavior of the EGO sensor and an alternative, the universal exhaust gas oxygen (UEGO) sensor. Meanwhile, an integrated NSCR system using an advanced, signal-conditioned UEGO sensor was tested and found to control both NO{sub X} and CO emissions. In conjunction with this project, advanced monitoring technologies, such as Ion Sense, and improved sensors for emissions control, such as the AFM1000+ have been developed and commercialized.

  11. Cost-effectiveness of social marketing of insecticide-treated nets for malaria control in the United Republic of Tanzania.

    PubMed Central

    Hanson, Kara; Kikumbih, Nassor; Armstrong Schellenberg, Joanna; Mponda, Haji; Nathan, Rose; Lake, Sally; Mills, Anne; Tanner, Marcel; Lengeler, Christian

    2003-01-01

    OBJECTIVE: To assess the costs and consequences of a social marketing approach to malaria control in children by means of insecticide-treated nets in two rural districts of the United Republic of Tanzania, compared with no net use. METHODS: Project cost data were collected prospectively from accounting records. Community effectiveness was estimated on the basis of a nested case-control study and a cross-sectional cluster sample survey. FINDINGS: The social marketing approach to the distribution of insecticide-treated nets was estimated to cost 1560 US dollars per death averted and 57 US dollars per disability-adjusted life year averted. These figures fell to 1018 US dollars and 37 US dollars, respectively, when the costs and consequences of untreated nets were taken into account. CONCLUSION: The social marketing of insecticide-treated nets is an attractive intervention for preventing childhood deaths from malaria. PMID:12764493

  12. Efficient control of air pollution through plants, a cost-effective alternative: studies on Dalbergia sissoo Roxb.

    PubMed

    Kapoor, C S; Bamniya, B R; Kapoor, K

    2013-09-01

    Plants can be used as both passive biomonitors and biomitigators in urban and industrial environments to indicate the environmental quality and to ameliorate pollution level in a locality. Many studies reveal that plants are negatively affected by the ambient levels of air pollutants. The present study was conducted to evaluate the impact of air pollution on comparative basis with reference to changes in photosynthetic pigments, plant height, leaves, as well as, biochemical parameters of plants of different sites around Udaipur city receiving varying levels of pollution load. The investigated tree species Dalbergia sissoo Roxb. (Family: Fabaceae) exhibited a reduction in various physiological and biochemical growth parameters that correspond with air pollution levels at different sites. The tree species growing in polluted and control areas were compared with respect to foliar dust load, leaf area, and chlorophyll and total carbohydrate and total protein concentration in the leaves. Our studies suggest that D. sissoo Roxb. can successfully be grown in an area for monitoring air pollution, where it is mild and droughts are common. It will prove as an ideal tree species to control pollution effectively beside acting as a shade tree and being a source of food for birds and animals. By plantation of D. sissoo Roxb., mitigative measure at the polluted sites to control generation of particulate matter and the air quality required can be ensured. Our results also confirm that industrial and vehicular air pollution level in Udaipur city is shifting beyond limits.

  13. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Greg Beshouri; Kirby S. Chapman; Jim McCarthy; Sarah R. Nuss-Warren; Mike Whelan

    2006-03-01

    This quarterly report re-evaluates current market objectives in the exploration and production industry, discusses continuing progress in testing that evaluates emission control technologies applied to a two-stroke cycle natural gas-fueled engine, and presents a scheme for enacting remote monitoring and control of engines during upcoming field tests. The examination of current market objectives takes into account technological developments and changing expectations for environmental permitting which may have occurred over the last year. This demonstrates that the continuing work in controlled testing and toward field testing is on track Market pressures currently affecting the gas exploration and production industry are shown to include a push for increased production, as well as an increasing cost for environmental compliance. This cost includes the direct cost of adding control technologies to field engines as well as the indirect cost of difficulty obtaining permits. Environmental regulations continue to require lower emissions targets, and some groups of engines which had not previously been regulated will be required to obtain permits in the future. While the focus remains on NOx and CO, some permits require reporting of additional emissions chemicals. Continuing work in controlled testing uses a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout the gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NOx emissions. Technologies including one pre-combustion chamber, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing have been evaluated in previous reports. Current work focuses on final preparations for testing

  14. Technology research for digital flight control

    NASA Technical Reports Server (NTRS)

    Carestia, R. A.

    1983-01-01

    The use of advanced digital systems for flight control and guidance for a specific mission is investigated. The research areas include advanced electronic system architectures, tests with the global positioning system (GPS) in a helicopter, and advanced integrated systems concept for rotorcraft. Emphasis is on a search and rescue mission, differential global positioning systems to provide a data base of performance information for navigation, and a study to determine the present usage and trends of microcomputers and microcomputer components in the avionics industries.

  15. Digital adaptive control laws for VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Stein, G.

    1979-01-01

    Honeywell has designed a digital self-adaptive flight control system for flight test in the VALT Research Aircraft (a modified CH-47). The final design resulted from a comparison of two different adaptive concepts: one based on explicit parameter estimates from a real-time maximum likelihood estimation algorithm and the other based on an implicit model reference adaptive system. The two designs are compared on the basis of performance and complexity.

  16. Digital LLRF controller for NICA booster

    NASA Astrophysics Data System (ADS)

    Fatkin, G. A.; Batrakov, A. M.; Ilyin, I. V.; Vasilyev, M. Yu.

    2016-10-01

    The digital LLRF controller based on embedded microcontroller for the booster of the Dubna superconducting accelerator complex NICA is presented. It allows setting the frequency in accordance with the magnetic field value in the 0.5-5 MHz range with an inaccuracy ± 110 Hz. A novel method of frequency calculation based on the derivative is proposed. The specialized tester module allows tuning up and checking the RF system during comissioning and operation.

  17. Ion propulsion cost effectivity

    NASA Technical Reports Server (NTRS)

    Zafran, S.; Biess, J. J.

    1978-01-01

    Ion propulsion modules employing 8-cm thrusters and 30-cm thrusters were studied for Multimission Modular Spacecraft (MMS) applications. Recurring and nonrecurring cost elements were generated for these modules. As a result, ion propulsion cost drivers were identified to be Shuttle charges, solar array, power processing, and thruster costs. Cost effective design approaches included short length module configurations, array power sharing, operation at reduced thruster input power, simplified power processing units, and power processor output switching. The MMS mission model employed indicated that nonrecurring costs have to be shared with other programs unless the mission model grows. Extended performance missions exhibited the greatest benefits when compared with monopropellant hydrazine propulsion.

  18. Floating-point system quantization errors in digital control systems

    NASA Technical Reports Server (NTRS)

    Phillips, C. L.; Vallely, D. P.

    1978-01-01

    This paper considers digital controllers (filters) operating in floating-point arithmetic in either open-loop or closed-loop systems. A quantization error analysis technique is developed, and is implemented by a digital computer program that is based on a digital simulation of the system. The program can be integrated into existing digital simulations of a system.

  19. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman

    2004-01-01

    During the fourth reporting period, the project team investigated the Non-Selective Catalytic Reduction technologies that are in use on rich-burn four-stroke cycle engines. Several engines were instrumented and data collected to obtain a rich set of engine emissions and performance data. During the data collection, the performance of the catalyst under a variety of operating conditions was measured. This information will be necessary to specify a set of sensors that can then be used to reliably implement NSCRs as plausible technologies to reduce NOx emissions for four-stroke cycle engines used in the E&P industry. A complete summary all the technologies investigated to data is included in the report. For each technology, the summary includes a description of the process, the emission reduction that is to be expected, information on the cost of the technology, development status, practical considerations, compatibility with other air pollutant control technologies, and any references used to obtain the information.

  20. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Sarah R. Nuss-Warren; Kirby S. Chapman

    2005-12-01

    This quarterly report discusses continuing work in the testing phase of the project that evaluates emission control technologies applied to a two-stroke cycle natural gas-fueled engine. In this phase, a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) is used to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout the gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NO{sub x} emissions. This report describes potential emission reduction technologies, some of which have already been tested, and describes progress toward completing remaining tests to evaluate further synergies between some of the more promising technologies. While the end-goal is a closed-loop control system coupled with a low cost NO{sub x} retrofit package, additional work remains. Technologies including pre-combustion chambers, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing have been evaluated in previous reports. Current work focuses on preparing the test cell for tests using a 180 psig fuel valve. By using the Ajax DP-115 these tests are completed in a low-cost and efficient manner. The various technologies can be quickly exchanged with different hardware, and it is inexpensive to run the engine.

  1. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman

    2005-10-01

    This quarterly report discusses the results from a testing phase of the project that evaluates emission control technologies applied to a two-stroke cycle natural gas-fueled engine. In this phase, a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) is used to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NO{sub x} emissions. This report describes potential emission reduction technologies followed by a battery of tests that demonstrate synergies between some of the more promising technologies. While the end-goal is a closed loop control, low cost NO{sub x} retrofit package, additional work remains. The battery of tests include pre-combustion chambers, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing. During several phases of the tests, the ignition timing also was varied to determine the optimal point for ignition timing. The results from these tests suggest that an optimum exists where fuel consumption is minimized along with NO{sub x} emissions. By using the Ajax DP-115 these tests are completed in a low-cost and efficient manner. The various technologies can be quickly exchanged with different hardware, and the cost to operate the engine is very inexpensive.

  2. Control of hair growth using long-pulsed alexandrite laser is an efficient and cost effective therapy for patients suffering from recurrent pilonidal disease.

    PubMed

    Khan, Muhammad Adil Abbas; Javed, Ammar Asrar; Govindan, Karthikeyan Srinivasan; Rafiq, Sadia; Thomas, Kay; Baker, Lynne; Kenealy, John

    2016-07-01

    Pilonidal sinus (PNS) and its surgical management have a profound impact on hospital resources in terms of finances and productive man-hours. Surgical treatment has been the mainstay of treatment of both acute and chronic pilonidal sinus but recurrence is common. The control of hair growth in the sinus region plays an important role in preventing recurrence. Here, we discuss our experience of treating 19 patients suffering from recurrent pilonidal sinus with laser depilation and its long-term cost effectiveness. This is a retrospective study on patients who had recurrence of pilonidal sinus following multiple surgical treatments. They were treated using long-pulsed alexandrite laser for depilation in the sinus area, an outpatient procedure. Their clinical characteristics and outcomes were then evaluated. There was a significant reduction in hair density after laser treatment (p < 0.001). The disease-free period after laser treatment was significantly longer than that one after surgical treatment (p < 0.001). The average cost of repeated surgical treatment per disease-free month was significantly higher than that of laser treatment (p < 0.001). Evidence suggests the role of natal cleft hair growth in the evolution of the pilonidal disease; therefore, control of hair growth should be considered as an adjunct to the initial treatment via surgery. Compared to surgical treatment of recurrences, laser depilation is an efficient and cost-effective method of preventing recurrence and reducing morbidity and loss of man-hours. We suggest that laser depilation of the pilonidal sinus should be funded by clinical commissioning groups.

  3. Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines

    SciTech Connect

    Kirby S. Chapman; Sarah R. Nuss-Warren

    2006-07-01

    Continuing work in controlled testing uses a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout the gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NOX emissions. Technologies including one pre-combustion chamber, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing have been evaluated in previous reports. Current work focuses on final preparations for testing pre-combustion chambers with different characteristics and using mid-to-high-pressure fuel valves and initial runs of these tests. By using the Ajax DP-115 these tests are completed in a low-cost and efficient manner. The various technologies can be quickly exchanged with different hardware, and it is inexpensive to run the engine. Progress in moving toward field testing is discussed, and changes to the first planned field test are presented. Although changes have been made to the previous plan, it is expected that several new sites will be selected soon. Field tests will begin in the next quarter.

  4. Digital control system for space structural dampers

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.

    1984-01-01

    A recently developed concept for a damper was improved by adding a small taper to the proof-mass, and using a proximeter to determine position. Also, an experimental damper was built using a three-inch stroke in place of the standard one-inch stroke. The analog controller initially used was replaced by an independent digital controller slaved to a TRS-80 Model I computer, which also serves as a highly effective, low-cost development system. An overall system concept for the use of proof-mass dampers is presented.

  5. Digitally controlled twelve-pulse firing generator

    SciTech Connect

    Berde, D.; Ferrara, A.A.

    1981-01-01

    Control System Studies for the Tokamak Fusion Test Reactor (TFTR) indicate that accurate thyristor firing in the AC-to-DC conversion system is required in order to achieve good regulation of the various field currents. Rapid update and exact firing angle control are required to avoid instabilities, large eddy currents, or parasitic oscillations. The Prototype Firing Generator was designed to satisfy these requirements. To achieve the required /plus or minus/0.77/degree/firing accuracy, a three-phase-locked loop reference was designed; otherwise, the Firing Generator employs digital circuitry. The unit, housed in a standard CAMAC crate, operates under microcomputer control. Functions are performed under program control, which resides in nonvolatile read-only memory. Communication with CICADA control system is provided via an 11-bit parallel interface.

  6. Error-control techniques for digital communication

    NASA Astrophysics Data System (ADS)

    Michelson, A. M.; Levesque, A. H.

    The reliable transmission of digital information is discussed, taking into account the communication system design problem, the elements of a digital communication system, important channel models, information theory and channel capacity, modulation performance on the AWGN channel, and combined modulation and coding for efficient signal design. Other topics studied are related to fundamental and simple block codes, the algebra of linear block codes, binary cyclic codes and BCH codes, decoding techniques for binary BCH codes, nonbinary BCH codes and Reed-Solomon codes, the performance of linear block codes with bounded-distance decoding an introduction to convolutional codes, maximum likelihood decoding of convolutional codes, sequential decoding, and applications of error-control coding. Attention is given to groups, fields, vector spaces, binary linear block codes, the parity-check matrix revisited, dual codes, Hamming distance and the weight distribution, code geometry and error-correction capability, and the representations of finite fields.

  7. IDSAC-IUCAA digital sampler array controller

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Sabyasachi; Chordia, Pravin; Ramaprakash, A. N.; Burse, Mahesh P.; Joshi, Bhushan; Chillal, Kalpesh

    2016-07-01

    In order to run the large format detector arrays and mosaics that are required by most astronomical instruments, readout electronic controllers are required which can process multiple CCD outputs simultaneously at high speeds and low noise levels. These CCD controllers need to be modular and configurable, should be able to run multiple detector types to cater to a wide variety of requirements. IUCAA Digital Sampler Array Controller (IDSAC), is a generic CCD Controller based on a fully scalable architecture which is adequately flexible and powerful enough to control a wide variety of detectors used in ground based astronomy. The controller has a modular backplane architecture that consists of Single Board Controller Cards (SBCs) and can control up to 5 CCDs (mosaic or independent). Each Single Board Controller (SBC) has all the resources to a run Single large format CCD having up to four outputs. All SBCs are identical and are easily interchangeable without needing any reconfiguration. A four channel video processor on each SBC can process up to four output CCDs with or without dummy outputs at 0.5 Megapixels/Sec/Channel with 16 bit resolution. Each SBC has a USB 2.0 interface which can be connected to a host computer via optional USB to Fibre converters. The SBC uses a reconfigurable hardware (FPGA) as a Master Controller. IDSAC offers Digital Correlated Double Sampling (DCDS) to eliminate thermal kTC noise. CDS performed in Digital domain (DCDS) has several advantages over its analog counterpart, such as - less electronics, faster readout and easier post processing. It is also flexible with sampling rate and pixel throughput while maintaining the core circuit topology intact. Noise characterization of the IDSAC CDS signal chain has been performed by analytical modelling and practical measurements. Various types of noise such as white, pink, power supply, bias etc. has been considered while creating an analytical noise model tool to predict noise of a controller

  8. Protocol investigating the clinical outcomes and cost-effectiveness of cognitive–behavioural therapy delivered remotely for unscheduled care users with health anxiety: randomised controlled trial

    PubMed Central

    Patel, Shireen; Malins, Sam; Guo, Boliang; James, Marilyn; Kai, Joe; Kaylor-Hughes, Catherine; Rowley, Emma; Simpson, Jayne; Smart, David; Stubley, Michelle; Tyrer, Helen

    2016-01-01

    Background Health anxiety and medically unexplained symptoms cost the National Health Service (NHS) an estimated £3 billion per year in unnecessary costs with little evidence of patient benefit. Effective treatment is rarely taken up due to issues such as stigma or previous negative experiences with mental health services. An approach to overcome this might be to offer remotely delivered psychological therapy, which can be just as effective as face-to-face therapy and may be more accessible and suitable. Aims To investigate the clinical outcomes and cost-effectiveness of remotely delivered cognitive–behavioural therapy (CBT) to people with high health anxiety repeatedly accessing unscheduled care (trial registration: NCT02298036). Method A multicentre randomised controlled trial (RCT) will be undertaken in primary and secondary care providers of unscheduled care across the East Midlands. One hundred and forty-four eligible participants will be equally randomised to receive either remote CBT (6–12 sessions) or treatment as usual (TAU). Two doctoral research studies will investigate the barriers and facilitators to delivering the intervention and the factors contributing to the optimisation of therapeutic outcome. Results This trial will be the first to test the clinical outcomes and cost-effectiveness of remotely delivered CBT for the treatment of high health anxiety. Conclusions The findings will enable an understanding as to how this intervention might fit into a wider care pathway to enhance patient experience of care. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-commercial, No Derivatives (CC BY-NC-ND) licence. PMID:27703758

  9. Prospective randomized controlled study using polyethylene mesh for inguinal hernia meshplasty as a safe and cost-effective alternative to polypropylene mesh.

    PubMed

    Gundre, Nitin P; Iyer, Sandhya P; Subramaniyan, Prabhakar

    2012-03-01

    Most patients who come to a general hospital in a developing country are poor. The most important prohibiting factor for use of polypropylene mesh in hernia repair is its exorbitant cost. Hence, research workers have been on the lookout for an equally effective but economically affordable mesh. Worldwide, surgical repair of inguinal hernia is the most common general surgery procedure performed at the present. Lifetime risk of groin hernia is 15% in males and 5% in females. Most of the patients who visit a general hospital are from either lower middle class or poor socioeconomic strata. The most important prohibiting factor for use of polypropylene mesh in hernia repair for the common man is its exorbitant cost. The aim of this study is to document the feasibility, safety and cost-effectiveness of the use of polyethylene mesh. A single blind, prospective, randomized controlled study, comparing 35 patients of two groups was conducted in a tertiary teaching hospital over a period of 5 years. The patients in both groups underwent inguinal hernioplasty, and were administered similar antibiotics and analgesics. The postoperative course with regard to pain, seroma formation, infection, hospital stay, recurrence and scar quality was evaluated and compared. Statistical analysis was performed with Chi square test. The properties of both meshes were the same with respect to ease of handling, pain score, seroma formation, infection rate, resumption of daily activities, scar quality and mesh rejection. Recurrence rate was zero for both groups. Polyethylene mesh was 2,808 times cheaper than the commercially available polypropylene mesh. This study proved the safety, simplicity, efficacy and cost-effectiveness of polyethylene mesh for inguinal hernia meshplasty, insuring economical, accessible health care for the financially weak section of the population.

  10. Droplet position control in digital microfluidic systems.

    PubMed

    Bhattacharjee, Biddut; Najjaran, Homayoun

    2010-02-01

    Research on so called digital microfluidic systems (DMS) capable of manipulating individual microdroplets on a cell-based structure has enormously increased in the past few years, mainly due to the demand of the technology-dependent biomedical applications. Significant research in this area has been related to the simulation and modeling of droplet motion, demonstration of different drop actuation techniques on laboratory-scale prototypes, and droplet routing and scheduling for more efficient assay procedures. This paper introduces the basics of the control analysis and design of a DMS, which is a relatively unexplored area in digital microfluidics. This paper starts with a discussion on a simplified dynamic model of droplet motion in a planar array of cells, and continues with more complicated dynamic models that are necessary to realize the structure of an appropriate closed-loop control system for the DMS. The control analysis and design includes both the transient and steady-state responses of the DMS under external driving forces. The proposed control analysis and design approach is implemented into SIMULINK models to demonstrate the performance of the DMS through simulation using the system parameters previously reported in the literature.

  11. Efficient control structures for digital programmable retinas

    NASA Astrophysics Data System (ADS)

    Bernard, Thierry M.

    2001-05-01

    A digital programmable artificial retina (PAR) is a functional extension of a CMOS imager, in which every pixel is fitted with a local ADC and a tiny digital programmable processor. From an architectural viewpoint, a PAR is an SIMD array processor with local optical input. A PAR is aimed at processing images on-site until they can be output from the array under concentrated form. The overall goal is to get compact, fast and inexpensive vision systems, in particular for robotics applications. A 256 by 256 PAR with up to a few tens bits of local memory per pixel is now within reach at reasonable cost. However, whereas the local memory size benefits quadratically from the feature size decrease, wiring density improvement can only be linear, at best. So control should become more complex with the danger of a growing proportion of the digital pixel area being devoted to instruction or address decoding. We propose efficient scalable solutions to this problem at the architectural, circuit and topological levels, which attempt to minimize both silicon area and power consumption.

  12. Digital system accurately controls velocity of electromechanical drive

    NASA Technical Reports Server (NTRS)

    Nichols, G. B.

    1965-01-01

    Digital circuit accurately regulates electromechanical drive mechanism velocity. The gain and phase characteristics of digital circuits are relatively unimportant. Control accuracy depends only on the stability of the input signal frequency.

  13. Effects of shared medical appointments on quality of life and cost-effectiveness for patients with a chronic neuromuscular disease. Study protocol of a randomized controlled trial

    PubMed Central

    2011-01-01

    Background Shared medical appointments are a series of one-to-one doctor-patient contacts, in presence of a group of 6-10 fellow patients. This group visits substitute the annual control visits of patients with the neurologist. The same items attended to in a one-to- one appointment are addressed. The possible advantages of a shared medical appointment could be an added value to the present management of neuromuscular patients. The currently problem-focused one-to-one out-patient visits often leave little time for the patient's psychosocial needs, patient education, and patient empowerment. Methods/design A randomized, prospective controlled study (RCT) with a follow up of 6 months will be conducted to evaluate the clinical and cost-effectiveness of shared medical appointments compared to usual care for 300 neuromuscular patients and their partners at the Radboud University Nijmegen Medical Center. Every included patient will be randomly allocated to one of the two study arms. This study has been reviewed and approved by the medical ethics committee of the region Arnhem-Nijmegen, the Netherlands. The primary outcome measure is quality of life as measured by the EQ-5D, SF-36 and the Individualized neuromuscular Quality of Life Questionnaire. The primary analysis will be an intention-to-treat analysis on the area under the curve of the quality of life scores. A linear mixed model will be used with random factor group and fixed factors treatment, baseline score and type of neuromuscular disease. For the economic evaluation an incremental cost-effectiveness analysis will be conducted from a societal perspective, relating differences in costs to difference in health outcome. Results are expected in 2012. Discussion This study will be the first randomized controlled trial which evaluates the effect of shared medical appointments versus usual care for neuromuscular patients. This will enable to determine if there is additional value of shared medical appointments to the

  14. Telemonitoring-based service redesign for the management of uncontrolled hypertension (HITS): cost and cost-effectiveness analysis of a randomised controlled trial

    PubMed Central

    Stoddart, Andrew; Hanley, Janet; Wild, Sarah; Pagliari, Claudia; Paterson, Mary; Lewis, Steff; Sheikh, Aziz; Krishan, Ashma; Padfield, Paul; McKinstry, Brian

    2013-01-01

    Objectives To compare the costs and cost-effectiveness of managing patients with uncontrolled blood pressure (BP) using telemonitoring versus usual care from the perspective of the National Health Service (NHS). Design Within trial post hoc economic evaluation of data from a pragmatic randomised controlled trial using an intention-to-treat approach. Setting 20 socioeconomically diverse general practices in Lothian, Scotland. Participants 401 primary care patients aged 29–95 with uncontrolled daytime ambulatory blood pressure (ABP) (≥135/85, but <210/135 mm Hg). Intervention Participants were centrally randomised to 6 months of a telemonitoring service comprising of self-monitoring of BP transmitted to a secure website for review by the attending nurse/doctor and patient, with optional automated patient decision-support by text/email (n=200) or usual care (n-201). Randomisation was undertaken with minimisation for age, sex, family practice, use of three or more hypertension drugs and self-monitoring history. Main outcome measures Mean difference in total NHS costs between trial arms and blinded assessment of mean cost per 1 mm Hg systolic BP point reduced. Results Home telemonitoring of BP costs significantly more than usual care (mean difference per patient £115.32 (95% CI £83.49 to £146.63; p<0.001)). Increased costs were due to telemonitoring service costs, patient training and additional general practitioner and nurse consultations. The mean cost of systolic BP reduction was £25.56/mm Hg (95% CI £16.06 to £46.89) per patient. Conclusions Over the 6-month trial period, supported telemonitoring was more effective at reducing BP than usual care but also more expensive. If clinical gains are maintained, these additional costs would be very likely to be compensated for by reductions in the cost of future cardiovascular events. Longer-term modelling of costs and outcomes is required to fully examine the cost-effectiveness implications. Trial

  15. [Cost-effectiveness of colorectal cancer screening].

    PubMed

    Heresbach, Denis; Manfrédi, Sylvain; Branger, Bernard; Bretagne, Jean-François

    2006-01-01

    Colorectal cancer (CRC) screening in France is based on a faecal occult blood test every two years in average risk subjects 50-74 years of age while other endoscopic or non-endoscopic screening methods are used in Europe and in the USA. Beside the reduced incidence of and mortality from CRC found in available studies, cost-effectiveness data need to be taken into account. Because of the delay between randomized controlled trials and clinical results, transitional probabilistic models of screening programs are useful for public health policy makers. The aim of the present review was to promote the implementation of cost-effectiveness studies, to provide a guide to analyze cost-effectiveness studies on CRC screening and, to propose a French cost effectiveness study comparing CRC screening strategies. Most of these trials were performed by US or UK authors and demonstrate that the incremental cost-effectiveness ratio varies between 5 000 and 15 000 US dollars/one year life gained, with wide variations: these results were highly dependent on the unit costs of the different devices as well as the predictive values of the screening tests. Although CRC screening programs have been implemented in several administrative districts of France since 2002, and the results of these randomized controlled trials using fecal occult blood have been updated, cost-effectiveness criteria need to be integrated; especially since the results of screening campaigns based on other tools such as flexible sigmoidoscopy should be available in 2007.

  16. Space shuttle digital flight control system

    NASA Technical Reports Server (NTRS)

    Minott, G. M.; Peller, J. B.; Cox, K. J.

    1976-01-01

    The space shuttle digital, fly by wire, flight control system presents an interesting challenge in avionics system design. In residence in each of four redundant general purpose computers at lift off are the guidance, navigation, and control algorithms for the entire flight. The mission is divided into several flight segments: first stage ascent, second stage ascent; abort to launch site, abort once around; on orbit operations, entry, terminal area energy management; and approach and landing. The FCS is complicated in that it must perform the functions to fly the shuttle as a boost vehicle, as a spacecraft, as a reentry vehicle, and as a conventional aircraft. The crew is provided with both manual and automatic modes of operations in all flight phases including touchdown and rollout.

  17. The clinical effectiveness and cost-effectiveness of brief intervention for excessive alcohol consumption among people attending sexual health clinics: a randomised controlled trial (SHEAR).

    PubMed Central

    Crawford, Mike J; Sanatinia, Rahil; Barrett, Barbara; Byford, Sarah; Dean, Madeleine; Green, John; Jones, Rachael; Leurent, Baptiste; Lingford-Hughes, Anne; Sweeting, Michael; Touquet, Robin; Tyrer, Peter; Ward, Helen

    2014-01-01

    BACKGROUND Excessive use of alcohol is associated with poor sexual health, but the clinical effectiveness and cost-effectiveness of brief alcohol intervention in this setting has not been investigated. OBJECTIVE To examine the effects and cost-effectiveness of brief intervention for excessive alcohol consumption among people who attend sexual health clinics. DESIGN A two-arm, parallel-group, single-blind, pragmatic, randomised controlled trial. Participants were randomised via an independent and remote telephone randomisation service using permuted blocks, stratified by clinic. SETTING Study participants were recruited from three sexual health clinics in central and west London. PARTICIPANTS For inclusion, potential participants had to be aged ≥ 19 years, drink excessive alcohol according to the Modified-Single Alcohol Screening Question, and be willing to provide written informed consent. We excluded those who were unable to communicate in English sufficiently well to complete the baseline assessment and those who could not provide contact details for the follow-up assessment. INTERVENTIONS Brief advice was delivered by the treating clinician and comprised feedback on the possible health consequences of excessive drinking, a discussion of whether the participant's clinic attendance was linked to current alcohol use, written information on alcohol and health and an offer of an appointment with an alcohol health worker (AHW). Appointments with AHWs took place either in person or by telephone, lasted up to 30 minutes, and used the 'FRAMES' (Feedback about the adverse effects of alcohol, an emphasis on personal Responsibility for changing drinking behaviour, Advice about alcohol consumption, a Menu of options for further help and advice, an Empathic stance towards the patient and an emphasis on Self-efficacy) approach. Those in the control arm of the trial were offered a copy of a leaflet providing general information on health and lifestyle. MAIN OUTCOME MEASURES

  18. Optimal digital redesign of continuous-time controllers

    NASA Technical Reports Server (NTRS)

    Shieh, Leang S.; Zhang, Jian L.; Coleman, Norman P.

    1991-01-01

    This paper proposes a new optimal digital redesign technique for finding a dynamic digital control law from the available analog counterpart and simultaneously minimizing a quadratic performance index. The proposed technique can be applied to a system with a more general class of reference inputs, and the developed digital regulator can be implemented using low cost microcomputers.

  19. Exploring the comparative cost-effectiveness of economic incentive and command-and-control instruments, and of renewable energy technologies in PM10 emission control: A case study of Lima-Callao, Peru

    NASA Astrophysics Data System (ADS)

    Kroeger, Timm

    Much economic literature expounds the superior cost-effectiveness of economic incentive (EI) policies over command-and-control (CAC) ones, based on appealing theoretical arguments. However, one of the assumptions underlying much of this literature is that monitoring and enforcement (M&E) of policies are not only feasible, but essentially costless. In reality, M&E are never costless and sometimes infeasible, and, crucially, M&E requirements vary across policy types. Furthermore, in technical economic terms, cost-effectiveness is defined with respect to variable costs only; however, in choosing among policies, the objective generally is to identify that with the lowest total (variable plus fixed) cost per unit abatement, which in its own right may be termed cost-effective. The neglect of M&E and of fixed costs throws up the question of the validity of much of the policy advice that draws on the environmental economics literature for developing countries, where the institutional capacity for effective M&E often is strongly limited, and where creating this capacity will require considerable infrastructure investments. The limited institutional capacity also has led to the suggestion that in developing countries, conventional environmental policies, such as input or output taxes, emission charges, or standards, may be less cost-effective than non-conventional environmental policies, such as direct public provision of electricity from renewable sources, because the M&E capacity required for the implementation of non-conventional policies is often less stringent. I test the hypotheses of superior cost-effectiveness of EI over CAC and of non-conventional over conventional environmental policy instruments. The samples of pollution control policies used to test the hypotheses are drawn from a list of frequently recommended urban air pollution abatement measures for developing countries, plus two renewable energy sources. Both sets of environmental policy types are compared

  20. Digitally Controlled Slot Coupled Patch Array

    NASA Technical Reports Server (NTRS)

    D'Arista, Thomas; Pauly, Jerry

    2010-01-01

    A four-element array conformed to a singly curved conducting surface has been demonstrated to provide 2 dB axial ratio of 14 percent, while maintaining VSWR (voltage standing wave ratio) of 2:1 and gain of 13 dBiC. The array is digitally controlled and can be scanned with the LMS Adaptive Algorithm using the power spectrum as the objective, as well as the Direction of Arrival (DoA) of the beam to set the amplitude of the power spectrum. The total height of the array above the conducting surface is 1.5 inches (3.8 cm). A uniquely configured microstrip-coupled aperture over a conducting surface produced supergain characteristics, achieving 12.5 dBiC across the 2-to-2.13- GHz and 2.2-to-2.3-GHz frequency bands. This design is optimized to retain VSWR and axial ratio across the band as well. The four elements are uniquely configured with respect to one another for performance enhancement, and the appropriate phase excitation to each element for scan can be found either by analytical beam synthesis using the genetic algorithm with the measured or simulated far field radiation pattern, or an adaptive algorithm implemented with the digitized signal. The commercially available tuners and field-programmable gate array (FPGA) boards utilized required precise phase coherent configuration control, and with custom code developed by Nokomis, Inc., were shown to be fully functional in a two-channel configuration controlled by FPGA boards. A four-channel tuner configuration and oscilloscope configuration were also demonstrated although algorithm post-processing was required.

  1. Cost and cost-effectiveness of nationwide school-based helminth control in Uganda: intra-country variation and effects of scaling-up.

    PubMed

    Brooker, Simon; Kabatereine, Narcis B; Fleming, Fiona; Devlin, Nancy

    2008-01-01

    Estimates of cost and cost-effectiveness are typically based on a limited number of small-scale studies with no investigation of the existence of economies to scale or intra-country variation in cost and cost-effectiveness. This information gap hinders the efficient allocation of health care resources and the ability to generalize estimates to other settings. The current study investigates the intra-country variation in the cost and cost-effectiveness of nationwide school-based treatment of helminth (worm) infection in Uganda. Programme cost data were collected through semi-structured interviews with district officials and from accounting records in six of the 23 intervention districts. Both financial and economic costs were assessed. Costs were estimated on the basis of cost in US$ per schoolchild treated, and an incremental cost-effectiveness ratio (cost in US$ per case of anaemia averted) was used to evaluate programme cost-effectiveness. Sensitivity analysis was performed to assess the effect of discount rate and drug price. The overall economic cost per child treated in the six districts was US$0.54 and the cost-effectiveness was US$3.19 per case of anaemia averted. Analysis indicated that estimates of both cost and cost-effectiveness differ markedly with the total number of children who received treatment, indicating economies of scale. There was also substantial variation between districts in the cost per individual treated (US$0.41-0.91) and cost per anaemia case averted (US$1.70-9.51). Independent variables were shown to be statistically associated with both sets of estimates. This study highlights the potential bias in transferring data across settings without understanding the nature of observed variations.

  2. Digital Control of Flight Simulator Motion Base Actuator.

    DTIC Science & Technology

    1984-01-01

    SYNTHESIS 3.1 Basic Considerations As a starting point for digital controller design a proportional plus integral ( PI ) control law of the form - V(s...on closed loop stability arising from digital realization of the PI control law, computational time delay and sampling have to be taken into

  3. Rationale and support for a One Health program for canine vaccination as the most cost-effective means of controlling zoonotic rabies in endemic settings.

    PubMed

    Lavan, Robert P; King, Alasdair I MacG; Sutton, David J; Tunceli, Kaan

    2017-03-23

    Although dog vaccination has been demonstrated to reduce and eliminate rabies in humans, during meetings there are often calls for further pilot studies. The assembled data proves that a widespread approach is now required. While zoonotic rabies has a minimal presence in developed nations, it is endemic throughout most of Asia and Africa, where it is considered to be a neglected tropical disease. In these areas, rabies causes an estimated annual mortality of at least 55,000 human deaths. Worldwide rabid dogs are the source of the vast majority of human rabies exposures. The World Health Organization (WHO), the Food and Agriculture Organization (FAO) of the United Nations and the World Organization for Animal Health (OIE) advocate a collaborative One Health approach involving human public health and veterinary agencies, with mass canine vaccination programs in endemic areas being the mainstay of strategies to eliminate dog-mediated human rabies. While post-exposure prophylaxis (PEP) is effective in preventing deaths in people exposed to rabies, it is comparatively expensive and has little impact on the canine reservoir that is the primary source of zoonotic rabies. Indiscriminate culling of the dog population is expensive and there is little evidence that it is effective in controlling rabies in non-island locations. Mass canine vaccination programs using a One Health framework that achieves a minimum 70% vaccination coverage during annual campaigns have proven to be cost-effective in controlling zoonotic rabies in endemic, resource-poor regions. Case studies, such as in Tanzania and Bhutan, illustrate how an approach based on mass canine rabies vaccination has effectively reduced both canine and human rabies to minimal levels. The multiple benefits of mass canine rabies vaccination in these cases included eliminating rabies in the domestic dog reservoirs, eliminating human rabies cases, and decreasing the rabies economic burden by reducing expenditures on PEP.

  4. Digital Camera Control for Faster Inspection

    NASA Technical Reports Server (NTRS)

    Brown, Katharine; Siekierski, James D.; Mangieri, Mark L.; Dekome, Kent; Cobarruvias, John; Piplani, Perry J.; Busa, Joel

    2009-01-01

    Digital Camera Control Software (DCCS) is a computer program for controlling a boom and a boom-mounted camera used to inspect the external surface of a space shuttle in orbit around the Earth. Running in a laptop computer in the space-shuttle crew cabin, DCCS commands integrated displays and controls. By means of a simple one-button command, a crewmember can view low- resolution images to quickly spot problem areas and can then cause a rapid transition to high- resolution images. The crewmember can command that camera settings apply to a specific small area of interest within the field of view of the camera so as to maximize image quality within that area. DCCS also provides critical high-resolution images to a ground screening team, which analyzes the images to assess damage (if any); in so doing, DCCS enables the team to clear initially suspect areas more quickly than would otherwise be possible and further saves time by minimizing the probability of re-imaging of areas already inspected. On the basis of experience with a previous version (2.0) of the software, the present version (3.0) incorporates a number of advanced imaging features that optimize crewmember capability and efficiency.

  5. Digital control of magnetic bearings supporting a multimass flexible rotor

    NASA Technical Reports Server (NTRS)

    Keith, F. J.; Williams, R. D.; Allaire, P. E.; Schafer, R. M.

    1993-01-01

    The characteristics of magnetic bearings used to support a three mass flexible rotor operated at speeds up to 14,000 RPM are discussed. The magnetic components of the bearing are of a type reported in the literature previously, but the earlier analog controls were replaced by digital ones. Analog-to-digital and digital-to-analog converters and digital control software were installed in an AT&T PC. This PC-based digital controller was used to operate one of the magnetic bearings on the test rig. Basic proportional-derivative control was applied to the bearings, and the bearing stiffness and damping characteristics were evaluated. Particular attention is paid to the frequency dependent behavior of the stiffness and damping properties, and comparisons are made between the actual controllers and ideal proportional-derivative control.

  6. Cost-effectiveness of controlling emissions for various alternative-fuel vehicle types, with vehicle and fuel price subsidies estimated on the basis of monetary values of emission reductions

    SciTech Connect

    Wang, M.Q.

    1993-12-31

    Emission-control cost-effectiveness is estimated for ten alternative-fuel vehicle (AFV) types (i.e., vehicles fueled with reformulated gasoline, M85 flexible-fuel vehicles [FFVs], M100 FFVs, dedicated M85 vehicles, dedicated M100 vehicles, E85 FFVS, dual-fuel liquefied petroleum gas vehicles, dual-fuel compressed natural gas vehicles [CNGVs], dedicated CNGVs, and electric vehicles [EVs]). Given the assumptions made, CNGVs are found to be most cost-effective in controlling emissions and E85 FFVs to be least cost-effective, with the other vehicle types falling between these two. AFV cost-effectiveness is further calculated for various cases representing changes in costs of vehicles and fuels, AFV emission reductions, and baseline gasoline vehicle emissions, among other factors. Changes in these parameters can change cost-effectiveness dramatically. However, the rank of the ten AFV types according to their cost-effectiveness remains essentially unchanged. Based on assumed dollars-per-ton emission values and estimated AFV emission reductions, the per-vehicle monetary value of emission reductions is calculated for each AFV type. Calculated emission reduction values ranged from as little as $500 to as much as $40,000 per vehicle, depending on AFV type, dollar-per-ton emission values, and baseline gasoline vehicle emissions. Among the ten vehicle types, vehicles fueled with reformulated gasoline have the lowest per-vehicle value, while EVs have the highest per-vehicle value, reflecting the magnitude of emission reductions by these vehicle types. To translate the calculated per-vehicle emission reduction values to individual AFV users, AFV fuel or vehicle price subsidies are designed to be equal to AFV emission reduction values. The subsidies designed in this way are substantial. In fact, providing the subsidies to AFVs would change most AFV types from net cost increases to net cost decreases, relative to conventional gasoline vehicles.

  7. COSPAS/SARSAT 406-MHz emergency beacon digital controller

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1988-01-01

    The digital control portion of a low-cost 406-MHz COSPAS/SARSAT emergency beacon has been designed and breadboarded at the NASA Lewis Research Center. This report discusses the requirements and design tradeoffs of the digital controller and describes the hardware and software design, which is available only to United States citizens and companies.

  8. Digital Flight Control System for Tactical Fighter. Volume 1. Digital Flight Control System Analysis

    DTIC Science & Technology

    1974-06-01

    30 34 34 37 38 41 45 47 47 53 55 5fi 5 « (il R4 G7 * ..it hv^irWMiM MraiMtMiaiiMiflMaiMifliarii^^MMiyiiJ ■.pi.miwwuiwi.iiii.iii, mm...the Digital Control Software System 5 (DIGIKON) 3 Control and Computational Requirements 7 4 Interactive Analysis, Design, and Performance...Evaluation 7 in the s-Plane 5 Interactive Analysis, Design, and Performance Evaluation 8 in the s-z Plane 6 Interactive Analysis, Design, and Performance

  9. Digital control of the Kuiper Airborne Observatory telescope

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann C.; Snyder, Philip K.

    1989-01-01

    The feasibility of using a digital controller to stabilize a telescope mounted in an airplane is investigated. The telescope is a 30 in. infrared telescope mounted aboard a NASA C-141 aircraft known as the Kuiper Airborne Observatory. Current efforts to refurbish the 14-year-old compensation system have led to considering a digital controller. A typical digital controller is modeled and added into the telescope system model. This model is simulated on a computer to generate the Bode plots and time responses which determine system stability and performance parameters. Important aspects of digital control system hardware are discussed. A summary of the findings shows that a digital control system would result in satisfactory telescope performance.

  10. Cost-effectiveness and quality of life in surgeon versus general practitioner-organised colon cancer surveillance: a randomised controlled trial

    PubMed Central

    Augestad, Knut Magne; Norum, Jan; Dehof, Stefan; Aspevik, Ranveig; Ringberg, Unni; Nestvold, Torunn; Vonen, Barthold; Skrøvseth, Stein Olav; Lindsetmo, Rolv-Ole

    2013-01-01

    Objective To assess whether colon cancer follow-up can be organised by general practitioners (GPs) without a decline in the patient's quality of life (QoL) and increase in cost or time to cancer diagnoses, compared to hospital follow-up. Design Randomised controlled trial. Setting Northern Norway Health Authority Trust, 4 trusts, 11 hospitals and 88 local communities. Participants Patients surgically treated for colon cancer, hospital surgeons and community GPs. Intervention 24-month follow-up according to national guidelines at the community GP office. To ensure a high follow-up guideline adherence, a decision support tool for patients and GPs were used. Main outcome measures Primary outcomes were QoL, measured by the global health scales of the European Organisation for Research and Treatment of Cancer QoL Questionnaire (EORTC QLQ C-30) and EuroQol-5D (EQ-5D). Secondary outcomes were cost-effectiveness and time to cancer diagnoses. Results 110 patients were randomised to intervention (n=55) or control (n=55), and followed by 78 GPs (942 follow-up months) and 70 surgeons (942 follow-up months), respectively. Compared to baseline, there was a significant improvement in postoperative QoL (p=0.003), but no differences between groups were revealed (mean difference at 1, 3, 6, 9, 12, 15, 18, 21 and 24-month follow-up appointments): Global Health; Δ−2.23, p=0.20; EQ-5D index; Δ−0.10, p=0.48, EQ-5D VAS; Δ−1.1, p=0.44. There were no differences in time to recurrent cancer diagnosis (GP 35 days vs surgeon 45 days, p=0.46); 14 recurrences were detected (GP 6 vs surgeon 8) and 7 metastases surgeries performed (GP 3 vs surgeon 4). The follow-up programme initiated 1186 healthcare contacts (GP 678 vs surgeon 508), 1105 diagnostic tests (GP 592 vs surgeon 513) and 778 hospital travels (GP 250 vs surgeon 528). GP organised follow-up was associated with societal cost savings (£8233 vs £9889, p<0.001). Conclusions GP-organised follow-up was associated with no

  11. Effectiveness and cost effectiveness of guided online treatment for patients with major depressive disorder on a waiting list for psychotherapy: study protocol of a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Depressive disorders are highly prevalent and result in negative consequences for both patients and society. It is therefore important that these disorders are treated adequately. However, due to increased demand for mental healthcare and subsequent increased costs, it would be desirable to reduce costs associated with major depressive disorder while maintaining or improving the quality of care within the healthcare system. Introducing evidence-based online self-help interventions in mental healthcare might be the way to maintain clinical effects while minimizing costs by reducing the number of face-to-face sessions. This study aims to evaluate the clinical and economical effects of a guided online self-help intervention when offered to patients with major depressive disorder on a waiting list for psychotherapy in specialized mental health centers (MHCs). Methods Patients at mental health centers identified with a Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) diagnosis of major depression who are awaiting face-to-face treatment are studied in a randomized controlled trial. During this waiting list period, patients are randomized and either (1) receive an internet-based guided self-help treatment or (2) receive a self-help book. The 5-week internet-based guided self-help intervention and the self-help booklet are based on problem solving treatment. After the intervention, patients are allowed to start regular face-to-face treatment at MHCs. Costs and effects are measured at baseline, after the intervention at 6 to 8 weeks, 6 months and 12 months. The primary outcome measure is symptoms of depression. Secondary outcome measures are diagnosis of depression, number of face-to-face sessions, absence of work and healthcare uptake in general. Additional outcome measures are anxiety, insomnia, quality of life and mastery. Discussion This study evaluates the effectiveness and cost effectiveness of internet-based guided self

  12. The development and demonstration of hybrid programmable attitude control electronics. [with adaptable analog/digital design approach

    NASA Technical Reports Server (NTRS)

    Smith, L. S.; Kopf, E. H., Jr.

    1974-01-01

    HYPACE provides an adaptable, analog/digital design approach that permits preflight and in-flight accommodation of mission changes, component performance variations, spacecraft changes, etc., through programing. This enabled broad multimission flexibility of application in a cost-effective manner. The HYPACE design, which was demonstrated in breadboard form on a single-axis gas-bearing spacecraft simulation, uses a single control channel to perform the attitude control functions sequentially, thus significantly reducing the number of component parts over hard-wired designs. The success of this effort resulted in the concept being selected for the Mariner/Jupiter/Saturn 1977 spacecraft application.

  13. REVIEW OF NRC APPROVED DIGITAL CONTROL SYSTEMS ANALYSIS

    SciTech Connect

    D.W. Markman

    1999-09-17

    Preliminary design concepts for the proposed Subsurface Repository at Yucca Mountain indicate extensive reliance on modern, computer-based, digital control technologies. The purpose of this analysis is to investigate the degree to which the U. S. Nuclear Regulatory Commission (NRC) has accepted and approved the use of digital control technology for safety-related applications within the nuclear power industry. This analysis reviews cases of existing digitally-based control systems that have been approved by the NRC. These cases can serve as precedence for using similar types of digitally-based control technologies within the Subsurface Repository. While it is anticipated that the Yucca Mountain Project (YMP) will not contain control systems as complex as those required for a nuclear power plant, the review of these existing NRC approved applications will provide the YMP with valuable insight into the NRCs review process and design expectations for safety-related digital control systems. According to the YMP Compliance Program Guidance, portions of various NUREGS, Regulatory Guidelines, and nuclear IEEE standards the nuclear power plant safety related concept would be applied to some of the designs on a case-by-case basis. This analysis will consider key design methods, capabilities, successes, and important limitations or problems of selected control systems that have been approved for use in the Nuclear Power industry. An additional purpose of this analysis is to provide background information in support of further development of design criteria for the YMP. The scope and primary objectives of this analysis are to: (1) Identify and research the extent and precedence of digital control and remotely operated systems approved by the NRC for the nuclear power industry. Help provide a basis for using and relying on digital technologies for nuclear related safety critical applications. (2) Identify the basic control architecture and methods of key digital control

  14. Research study on IPS digital controller design

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.; Folkerts, C.

    1976-01-01

    The performance is investigated of the simplified continuous-data model of the Instrument Pointing System (IPS). Although the ultimate objective is to study the digital model of the system, knowledge on the performance of the continuous-data model is important in the sense that the characteristics of the digital system should approach those of the continuous-data system as the sampling period approaches zero.

  15. COST EFFECTIVE VOC EMISSION CONTROL STARTEGIES FOR MILITARY, AEROSPACE,AND INDUSTRIAL PAINT SPRAY BOOTH OPERATIONS: COMBINING IMPROVED VENTILATION SYSTEMS WITH INNOVATIVE, LOW COST EMISSION CONTROL TECHNOLOGIES

    EPA Science Inventory

    The paper describes a full-scale demonstration program in which several paint booths were modified for recirculation ventilation; the booth exhaust streams are vented to an innovative volatile organic compound (VOC) emission control system having extremely low operating costs. ...

  16. Direct Digital Control of HVAC (Heating, Ventilating, and Air Conditioning).

    DTIC Science & Technology

    1985-01-01

    many feet downstream from the damper. For most HVAC applications, PI control is an adequate control technique. A more detailed description of PID control...consumption of two HVAC Systems with PI Control . (Ref 2) 26 Conventional Built-up Control D lirect Digital System complexity F igure 14. Relationships between

  17. Research into the (Cost-) effectiveness of the ketogenic diet among children and adolescents with intractable epilepsy: design of a randomized controlled trial

    PubMed Central

    2011-01-01

    Background Epilepsy is a neurological disorder, characterized by recurrent unprovoked seizures which have a high impact on the individual as well as on society as a whole. In addition to the economic burden, epilepsy imposes a substantial burden on the patients and their surroundings. Patients with uncontrolled epilepsy depend heavily on informal care and on health care professionals. About 30% of patients suffer from drug-resistant epilepsy. The ketogenic diet can be a treatment of last resort, especially for children. The beneficial effect of the ketogenic diet has been proven, but information is lacking about its cost-effectiveness. In the current study we will evaluate the (cost-) effectiveness of the ketogenic diet in children and adolescents with intractable epilepsy. Methods/Design In a RCT we will compare the ketogenic diet with usual care. Embedded in this RCT will be a trial-based and model-based economic evaluation, looking from a societal perspective at the cost-effectiveness and cost-utility of the ketogenic diet versus usual care. Fifty children and adolescents (aged 1-18) with intractable epilepsy will be screened for eligibility before randomization into the intervention or the usual care group. The primary outcome measure is the proportion of children with a 50% or more reduction in seizure frequency. Secondary outcomes include seizure severity, side effects/complaints, neurocognitive, socio-emotional functioning, and quality of life. Costs and productivity losses will be assessed continuously by a prospective diary and a retrospective questionnaire. Measurements will take place during consults at baseline, at 6 weeks and at 4 months after the baseline period, and 3, 6, 9 and 12 months follow-up after the 4 months consult. Discussion The proposed research project will be the first study to provide data about the cost-effectiveness of the ketogenic diet for children and adolescents with intractable epilepsy, in comparison with usual care. It is

  18. Digital Controller For Laser-Beam-Steering Subsystem

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon

    1995-01-01

    Report presents additional information about proposed apparatus described in "Beam-Steering Subsystem for Laser Communication" (NPO-19069). Discusses design of digital beam-steering control subsystem and, in particular, that part of design pertaining to digital compensation for frequency response of steering mirror.

  19. Digital Control System For Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Hoadley, Sherwood T.; Mcgraw, Sandra

    1995-01-01

    Multiple functions performed by multiple coordinated processors for real-time control. Multiple input, multiple-output, multiple-function digital control system developed for wind-tunnel model of advanced fighter airplane with actively controlled flexible wings. Digital control system provides flexibility in selection of control laws, sensors, and actuators, plus some redundancy to accommodate failures in some of its subsystems. Implements feedback control scheme providing simultaneously for suppression of flutter, control of roll angle, roll-rate tracking during maximized roll maneuvers, and alleviation of loads during roll maneuvers.

  20. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Monenegro, Justino (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used proportional-integral-derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM-based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a DSP (Digital Signal Processor) or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSP) devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. An alternative is required for compact implementation of such functionality to withstand the harsh environment

  1. Army/NASA small turboshaft engine digital controls research program

    NASA Technical Reports Server (NTRS)

    Sellers, J. F.; Baez, A. N.

    1981-01-01

    The emphasis of a program to conduct digital controls research for small turboshaft engines is on engine test evaluation of advanced control logic using a flexible microprocessor based digital control system designed specifically for research on advanced control logic. Control software is stored in programmable memory. New control algorithms may be stored in a floppy disk and loaded directly into memory. This feature facilitates comparative evaluation of different advanced control modes. The central processor in the digital control is an Intel 8086 16 bit microprocessor. Control software is programmed in assembly language. Software checkout is accomplished prior to engine test by connecting the digital control to a real time hybrid computer simulation of the engine. The engine currently installed in the facility has a hydromechanical control modified to allow electrohydraulic fuel metering and VG actuation by the digital control. Simulation results are presented which show that the modern control reduces the transient rotor speed droop caused by unanticipated load changes such as cyclic pitch or wind gust transients.

  2. Digital control of high-intensity acoustic testing

    NASA Technical Reports Server (NTRS)

    Slusser, R. A.

    1975-01-01

    To eliminate previous system instabilities and control high-intensity acoustic tests, a digital control vibration test system is modified by a software change. Three systems for the control of acoustic testing are compared: a hybrid digital/analog system, a digital vibration system, and the same digital vibration system modified by a software change to allow acoustic testing. It is shown that the hybrid system and the modified vibration system exhibit almost equal performance, although the hybrid system performs testing twice as fast. The development of a specialized acoustic test control system is justified since it costs far less than the general-purpose vibration control system. However, the latter is much easier to set up for a test, which is important in preventing overtesting of valuable spacecraft components.

  3. Cost effectiveness of a manual based coping strategy programme in promoting the mental health of family carers of people with dementia (the START (STrAtegies for RelaTives) study): a pragmatic randomised controlled trial

    PubMed Central

    King, Derek; Romeo, Renee; Schehl, Barbara; Barber, Julie; Griffin, Mark; Rapaport, Penny; Livingston, Debbie; Mummery, Cath; Walker, Zuzana; Hoe, Juanita; Sampson, Elizabeth L; Cooper, Claudia; Livingston, Gill

    2013-01-01

    Objective To assess whether the START (STrAtegies for RelatTives) intervention added to treatment as usual is cost effective compared with usual treatment alone. Design Cost effectiveness analysis nested within a pragmatic randomised controlled trial. Setting Three mental health and one neurological outpatient dementia service in London and Essex, UK. Participants Family carers of people with dementia. Intervention Eight session, manual based, coping intervention delivered by supervised psychology graduates to family carers of people with dementia added to usual treatment, compared with usual treatment alone. Primary outcome measures Costs measured from a health and social care perspective were analysed alongside the Hospital Anxiety and Depression Scale total score (HADS-T) of affective symptoms and quality adjusted life years (QALYs) in cost effectiveness analyses over eight months from baseline. Results Of the 260 participants recruited to the study, 173 were randomised to the START intervention, and 87 to usual treatment alone. Mean HADS-T scores were lower in the intervention group than the usual treatment group over the 8 month evaluation period (mean difference −1.79 (95% CI −3.32 to −0.33)), indicating better outcomes associated with the START intervention. There was a small improvement in health related quality of life as measured by QALYs (0.03 (−0.01 to 0.08)). Costs were no different between the intervention and usual treatment groups (£252 (−28 to 565) higher for START group). The cost effectiveness calculations suggested that START had a greater than 99% chance of being cost effective compared with usual treatment alone at a willingness to pay threshold of £30 000 per QALY gained, and a high probability of cost effectiveness on the HADS-T measure. Conclusions The manual based coping intervention START, when added to treatment as usual, was cost effective compared with treatment as usual alone by reference to both outcome measures

  4. Cost-effectiveness of a pragmatic structured education intervention for the prevention of type 2 diabetes: economic evaluation of data from the Let's Prevent Diabetes cluster-randomised controlled trial

    PubMed Central

    Ahrabian, D; Davies, M J; Khunti, K; Yates, T; Gray, A M

    2017-01-01

    Objectives Prevention of type 2 diabetes mellitus (TD2M) is a priority for healthcare systems. We estimated the cost-effectiveness compared with standard care of a structured education programme (Let's Prevent) targeting lifestyle and behaviour change to prevent progression to T2DM in people with prediabetes. Design Cost-effectiveness analysis alongside randomised controlled trial. Setting 44 general practices in Leicestershire, England. Participants 880 participants with prediabetes randomised to receive either standard care or a 6-hour group structured education programme with follow-up sessions in a primary care setting. Main outcome measure Incremental cost utility from the UK National Health Service (NHS) perspective. Quality of life and resource use measured from baseline and during the 36 months follow-up using the EuroQoL EQ-5D and 15D instruments and an economic questionnaire. Outcomes measured using quality-adjusted life years (QALYs) and healthcare costs calculated in 2012–2013 prices. Results After accounting for clustering and missing data, the intervention group was found to have a net gain of 0.046 (95% CI −0.0171 to 0.109) QALYs over 3 years, adjusted for baseline utility, at an additional cost of £168 (95% CI −395 to 732) per patient compared with the standard care group. The incremental cost-effectiveness ratio is £3643/QALY with an 86% probability of being cost-effective at a willingness to pay threshold of £20 000/QALY. Conclusions The education programme had higher costs and higher quality of life compared with the standard care group. The Let's Prevent programme is very likely to be cost-effective at a willingness to pay threshold of £20 000/QALY gained. Trial registration number ISRCTN80605705. PMID:28069625

  5. Floating-point system quantization errors in digital control systems

    NASA Technical Reports Server (NTRS)

    Phillips, C. L.

    1973-01-01

    The results are reported of research into the effects on system operation of signal quantization in a digital control system. The investigation considered digital controllers (filters) operating in floating-point arithmetic in either open-loop or closed-loop systems. An error analysis technique is developed, and is implemented by a digital computer program that is based on a digital simulation of the system. As an output the program gives the programing form required for minimum system quantization errors (either maximum of rms errors), and the maximum and rms errors that appear in the system output for a given bit configuration. The program can be integrated into existing digital simulations of a system.

  6. Cost-effectiveness of a tailored intervention designed to increase breast cancer screening among a non-adherent population: a randomized controlled trial

    PubMed Central

    2012-01-01

    Background Although the percentage of women who initiate breast cancer screening is rising, the rate of continued adherence is poor. The purpose of this study was to examine the effectiveness and cost-effectiveness of a tailored print intervention compared with a non-tailored print intervention for increasing the breast cancer screening rate among a non-adherent population. Methods In total, 1859 participants aged 51–59 years (except those aged 55 years) were recruited from a Japanese urban community setting. Participants were randomly assigned to receive either a tailored print reminder (tailored intervention group) or non-tailored print reminder (non-tailored intervention group). The primary outcome was improvement in the breast cancer screening rate. The screening rates and cost-effectiveness were examined for each treatment group (tailored vs. non-tailored) and each intervention subgroup during a follow-up period of five months. All analyses followed the intention-to-treat principle. Results The number of women who underwent a screening mammogram following the reminder was 277 (19.9%) in the tailored reminder group and 27 (5.8%) in the non-tailored reminder group. A logistic regression model revealed that the odds of a woman who received a tailored print reminder undergoing mammography was 4.02 times those of a women who had received a non-tailored print reminder (95% confidence interval, 2.67–6.06). The cost of one mammography screening increase was 2,544 JPY or 30 USD in the tailored intervention group and 4,366 JPY or 52 USD in the non-tailored intervention group. Conclusions Providing a tailored print reminder was an effective and cost-effective strategy for improving breast cancer screening rates among non-adherent women. PMID:22962858

  7. A cost-effectiveness analysis of provider and community interventions to improve the treatment of uncomplicated malaria in Nigeria: study protocol for a randomized controlled trial

    PubMed Central

    2012-01-01

    Background There is mounting evidence of poor adherence by health service personnel to clinical guidelines for malaria following a symptomatic diagnosis. In response to this, the World Health Organization (WHO) recommends that in all settings clinical suspicion of malaria should be confirmed by parasitological diagnosis using microscopy or Rapid Diagnostic Test (RDT). The Government of Nigeria plans to introduce RDTs in public health facilities over the coming year. In this context, we will evaluate the effectiveness and cost-effectiveness of two interventions designed to support the roll-out of RDTs and improve the rational use of ACTs. It is feared that without supporting interventions, non-adherence will remain a serious impediment to implementing malaria treatment guidelines. Methods/design A three-arm stratified cluster randomized trial is used to compare the effectiveness and cost-effectiveness of: (1) provider malaria training intervention versus expected standard practice in malaria diagnosis and treatment; (2) provider malaria training intervention plus school-based intervention versus expected standard practice; and (3) the combined provider plus school-based intervention versus provider intervention alone. RDTs will be introduced in all arms of the trial. The primary outcome is the proportion of patients attending facilities that report a fever or suspected malaria and receive treatment according to malaria guidelines. This will be measured by surveying patients (or caregivers) as they exit primary health centers, pharmacies, and patent medicine dealers. Cost-effectiveness will be presented in terms of the primary outcome and a range of secondary outcomes, including changes in provider and community knowledge. Costs will be estimated from both a societal and provider perspective using standard economic evaluation methodologies. Trial registration Clinicaltrials.gov NCT01350752 PMID:22682276

  8. F-15 digital electronic engine control system description

    NASA Technical Reports Server (NTRS)

    Myers, L. P.

    1984-01-01

    A digital electronic engine control (DEEC) was developed for use on the F100-PW-100 turbofan engine. This control system has full authority control, capable of moving all the controlled variables over their full ranges. The digital computational electronics and fault detection and accomodation logic maintains safe engine operation. A hydromechanical backup control (BUC) is an integral part of the fuel metering unit and provides gas generator control at a reduced performance level in the event of an electronics failure. The DEEC's features, hardware, and major logic diagrams are described.

  9. 76 FR 62642 - Digital Broadcast Television Redistribution Control; Corrections

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... From the Federal Register Online via the Government Publishing Office ] FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 Digital Broadcast Television Redistribution Control; Corrections AGENCY: Federal Communications Commission. ACTION: Technical amendment. SUMMARY: The Federal Communications Commission (FCC)...

  10. Trends in software reliability for digital flight control

    NASA Technical Reports Server (NTRS)

    Hecht, H.; Hecht, M.

    1983-01-01

    Software error data of major recent Digital Flight Control Systems Development Programs. The report summarizes the data, compare these data with similar data from previous surveys and identifies trends and disciplines to improve software reliability.

  11. Comparison of flight results with digital simulation for a digital electronic engine control in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Myers, L. P.; Burcham, F. W., Jr.

    1983-01-01

    Substantial benefits of a full authority digital electronic engine control on an air breathing engine were demonstrated repeatedly in simulation studies, ground engine tests, and engine altitude test facilities. A digital engine electronic control system showed improvements in efficiency, performance, and operation. An additional benefit of full authority digital controls is the capability of detecting and correcting failures and providing engine health diagnostics.

  12. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Ormsby, John (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing (DSP) functions. Such capability also makes and FPGA a suitable platform for the digital implementation of closed loop controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM- based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance in a compact form-factor. Other researchers have presented the notion that a second order digital filter with proportional-integral-derivative (PID) control functionality can be implemented in an FPGA. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSF) devices. Our goal is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. Meeting our goals requires alternative compact implementation of such functionality to withstand the harsh environment encountered on spacecraft. Radiation tolerant FPGA's are a feasible option for reaching these goals.

  13. Implementation of Adaptive Digital Controllers on Programmable Logic Devices

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Montenegro, Justino (Technical Monitor)

    2002-01-01

    Much has been made of the capabilities of Field Programmable Gate Arrays (FPGA's) in the hardware implementation of fast digital signal processing functions. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used Proportional-Integral-Derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM- based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a Digital Signal Processor (DSP) device or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using DSP devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, Pulse Width Modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. An alternative is required for compact implementation of such functionality to withstand the harsh environment encountered on spacemap. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive-control algorithm

  14. Cost effectiveness of letrozole and purified urinary FSH in treating women with clomiphene citrate-resistant polycystic ovarian syndrome: a randomized controlled trial.

    PubMed

    Hassan, AbdelGany; Shehata, Nesreen; Wahba, Amr

    2017-04-01

    We aimed to compare the cost effectiveness of letrozole versus purified urinary follicle stimulating hormone (FSH) in treating patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). This was a randomized trial conducted in Cairo University and Beni-Suef University Hospitals, Egypt. A cohort of 140 eligible women was randomized to receive either letrozole 2.5 mg twice daily for five days, or FSH using a graduated regimen starting with a dose of 75 IU. Treatment was repeated for three months if pregnancy did not occur. There were no significant differences between the two treatments in the cumulative clinical pregnancy rate (30% vs. 34%; p = 0.578), cumulative ovulation rate (47% vs. 57%; p = 0.236), miscarriage rate (9% vs. 4%, p > 0.999) or multiple pregnancy rate (0% and 8%, p = 0.491) but the FSH cycles were 4.8 times more expensive. Letrozole and FSH were both effective in treating women with CC-resistant PCOS but letrozole was more cost effective.Study registration number: NCT02304107.

  15. The design of digital-adaptive controllers for VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.; Broussard, J. R.; Berry, P. W.

    1976-01-01

    Design procedures for VTOL automatic control systems have been developed and are presented. Using linear-optimal estimation and control techniques as a starting point, digital-adaptive control laws have been designed for the VALT Research Aircraft, a tandem-rotor helicopter which is equipped for fully automatic flight in terminal area operations. These control laws are designed to interface with velocity-command and attitude-command guidance logic, which could be used in short-haul VTOL operations. Developments reported here include new algorithms for designing non-zero-set-point digital regulators, design procedures for rate-limited systems, and algorithms for dynamic control trim setting.

  16. The cost-effectiveness of harm reduction.

    PubMed

    Wilson, David P; Donald, Braedon; Shattock, Andrew J; Wilson, David; Fraser-Hurt, Nicole

    2015-02-01

    HIV prevalence worldwide among people who inject drugs (PWID) is around 19%. Harm reduction for PWID includes needle-syringe programs (NSPs) and opioid substitution therapy (OST) but often coupled with antiretroviral therapy (ART) for people living with HIV. Numerous studies have examined the effectiveness of each harm reduction strategy. This commentary discusses the evidence of effectiveness of the packages of harm reduction services and their cost-effectiveness with respect to HIV-related outcomes as well as estimate resources required to meet global and regional coverage targets. NSPs have been shown to be safe and very effective in reducing HIV transmission in diverse settings; there are many historical and very recent examples in diverse settings where the absence of, or reduction in, NSPs have resulted in exploding HIV epidemics compared to controlled epidemics with NSP implementation. NSPs are relatively inexpensive to implement and highly cost-effective according to commonly used willingness-to-pay thresholds. There is strong evidence that substitution therapy is effective, reducing the risk of HIV acquisition by 54% on average among PWID. OST is relatively expensive to implement when only HIV outcomes are considered; other societal benefits substantially improve the cost-effectiveness ratios to be highly favourable. Many studies have shown that ART is cost-effective for keeping people alive but there is only weak supportive, but growing evidence, of the additional effectiveness and cost-effectiveness of ART as prevention among PWID. Packages of combined harm reduction approaches are highly likely to be more effective and cost-effective than partial approaches. The coverage of harm reduction programs remains extremely low across the world. The total annual costs of scaling up each of the harm reduction strategies from current coverage levels, by region, to meet WHO guideline coverage targets are high with ART greatest, followed by OST and then NSPs. But

  17. Active flutter suppression using optical output feedback digital controllers

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A method for synthesizing digital active flutter suppression controllers using the concept of optimal output feedback is presented. A convergent algorithm is employed to determine constrained control law parameters that minimize an infinite time discrete quadratic performance index. Low order compensator dynamics are included in the control law and the compensator parameters are computed along with the output feedback gain as part of the optimization process. An input noise adjustment procedure is used to improve the stability margins of the digital active flutter controller. Sample rate variation, prefilter pole variation, control structure variation and gain scheduling are discussed. A digital control law which accommodates computation delay can stabilize the wing with reasonable rms performance and adequate stability margins.

  18. Digital adaptive control laws for the F-8

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Harvey, C. A.

    1976-01-01

    NASA is conducting a flight control research program in digital fly-by-wire technology using a modified F-8C aircraft. The first phase of this program used Apollo hardware to demonstrate the practicality of digital fly-by-wire in an actual test vehicle. For the second phase, conventional aircraft sensors and a large floating point digital computer are being utilized to test advanced control laws and redundancy concepts. As part of NASA's research in digital fly-by-wire technology, Honeywell developed digital adaptive flight control laws for flight test in the F-8C. Adaptation of the control laws was to be based on information sensed from conventional aircraft sensors excluding air data. The control laws were constrained to use only existing elevator, rudder, and ailerons as control effectors, each powered by existing actuators. Three adaptive control laws were successfully designed using maximum likelihood estimation, a Liapunov stable model tracker and a self-excited limit cycle concept. The maximum likelihood estimation design was selected as the most promising because of its capability to identify more than surface effectiveness parameters. The adaptive concepts, the control laws and comparisons of predicted performance are described.

  19. Cost effective management of space venture risks

    NASA Technical Reports Server (NTRS)

    Giuntini, Ronald E.; Storm, Richard E.

    1986-01-01

    The development of a model for the cost-effective management of space venture risks is discussed. The risk assessment and control program of insurance companies is examined. A simplified system development cycle which consists of a conceptual design phase, a preliminary design phase, a final design phase, a construction phase, and a system operations and maintenance phase is described. The model incorporates insurance safety risk methods and reliability engineering, and testing practices used in the development of large aerospace and defense systems.

  20. Prophylactic digitalization fails to control dysrhythmia in thoracic esophageal operations.

    PubMed

    Ritchie, A J; Tolan, M; Whiteside, M; McGuigan, J A; Gibbons, J R

    1993-01-01

    A prospective, controlled, randomized study of 80 patients undergoing esophageal operations was undertaken, in which one group of patients was given digoxin and the other was not. The incidence of cardiac dysrhythmia was compared in each group. Twenty-six patients underwent operation for benign disease. Equal numbers were digitalized or not and no dysrhythmias occurred. Fifty-four patients underwent operation for malignant disease. Of 26 in the group digitalized, 12 suffered dysrhythmia (46%). Of 28 not digitalized, 9 suffered dysrhythmia (32%). Overall, 39% of patients with malignant disease suffered a dysrhythmia compared with none with benign disease (p < 0.002 by chi 2).

  1. Integrated low power digital gyro control electronics

    NASA Technical Reports Server (NTRS)

    M'Closkey, Robert (Inventor); Challoner, A. Dorian (Inventor); Grayver, Eugene (Inventor); Hayworth, Ken J. (Inventor)

    2005-01-01

    Embodiments of the invention generally encompass a digital, application specific integrated circuit (ASIC) has been designed to perform excitation of a selected mode within a vibratory rate gyroscope, damping, or force-rebalance, of other modes within the sensor, and signal demodulation of the in-phase and quadrature components of the signal containing the angular rate information. The ASIC filters dedicated to each channel may be individually programmed to accommodate different rate sensor designs/technology or variations within the same class of sensors. The ASIC architecture employs a low-power design, making the ASIC, particularly suitable for use in power-sensitive applications.

  2. Developments in Digital Addressable Lighting Control

    NASA Astrophysics Data System (ADS)

    Moeck, Martin

    In DALI control, a small built-in chip acts as the de-central controller in the ballast. DALI complies with an open source protocol based on standard IEC60929. One small controller controls up to 64 ballasts. Today, manufacturers are adding more devices, such as sensors, blind motor controllers, and switches. Recently, web browser based remote control was developed for the DALI Lighting Laboratory at Pennsylvania State University. This paper reports on first experiences with advanced DALI features.

  3. Fault tolerant programmable digital attitude control electronics study

    NASA Technical Reports Server (NTRS)

    Sorensen, A. A.

    1974-01-01

    The attitude control electronics mechanization study to develop a fault tolerant autonomous concept for a three axis system is reported. Programmable digital electronics are compared to general purpose digital computers. The requirements, constraints, and tradeoffs are discussed. It is concluded that: (1) general fault tolerance can be achieved relatively economically, (2) recovery times of less than one second can be obtained, (3) the number of faulty behavior patterns must be limited, and (4) adjoined processes are the best indicators of faulty operation.

  4. Digital set point control of nonlinear stochastic systems

    NASA Technical Reports Server (NTRS)

    Moose, R. L.; Vanlandingham, H. F.; Zwicke, P. E.

    1978-01-01

    A technique for digital control of nonlinear stochastic plants is presented. The development achieves a practical digital algorithm with which the closed-loop system behaves in a classical Type I manner even with gross nonlinearities in the plant structure and low signal-to-noise power ratios. The design procedure is explained in detail and illustrated by an example whose simulated responses testify to the practicality of the approach.

  5. Improving Hypertension Control and Patient Engagement Using Digital Tools.

    PubMed

    Milani, Richard V; Lavie, Carl J; Bober, Robert M; Milani, Alexander R; Ventura, Hector O

    2017-01-01

    Hypertension is present in 30% of the adult US population and is a major contributor to cardiovascular disease. The established office-based approach yields only 50% blood pressure control rates and low levels of patient engagement. Available home technology now provides accurate, reliable data that can be transmitted directly to the electronic medical record. We evaluated blood pressure control in 156 patients with uncontrolled hypertension enrolled into a home-based digital-medicine blood pressure program and compared them with 400 patients (matched to age, sex, body mass index, and blood pressure) in a usual-care group after 90 days. Digital-medicine patients completed questionnaires online, were asked to submit at least one blood pressure reading/week, and received medication management and lifestyle recommendations via a clinical pharmacist and a health coach. Blood pressure units were commercially available that transmitted data directly to the electronic medical record. Digital-medicine patients averaged 4.2 blood pressure readings per week. At 90 days, 71% of digital-medicine vs 31% of usual-care patients had achieved target blood pressure control. Mean decrease in systolic/diastolic blood pressure was 14/5 mm Hg in digital medicine, vs 4/2 mm Hg in usual care (P < .001). Excess sodium consumption decreased from 32% to 8% in the digital-medicine group (P = .004). Mean patient activation increased from 41.9 to 44.1 (P = .008), and the percentage of patients with low patient activation decreased from 15% to 6% (P = .03) in the digital-medicine group. A digital hypertension program is feasible and associated with significant improvement in blood pressure control rates and lifestyle change. Utilization of a virtual health intervention using connected devices improves patient activation and is well accepted by patients.

  6. Cost effectiveness of a multi-stage return to work program for workers on sick leave due to low back pain, design of a population based controlled trial [ISRCTN60233560

    PubMed Central

    Steenstra, Ivan A; Anema, Johannes R; Bongers, Paulien M; de Vet, Henrica CW; van Mechelen, Willem

    2003-01-01

    Background To describe the design of a population based randomized controlled trial (RCT), including a cost-effectiveness analysis, comparing participative ergonomics interventions between 2–8 weeks of sick leave and Graded Activity after 8 weeks of sick leave with usual care, in occupational back pain management. Methods Design An RCT and cost-effectiveness evaluation in employees sick-listed for a period of 2 to 6 weeks due to low back pain. Interventions used are 1. Communication between general practitioner and occupational physician plus Participative Ergonomics protocol performed by an ergonomist. 2. Graded Activity based on cognitive behavioural principles by a physiotherapist. 3. Usual care, provided by an occupational physician according to the Dutch guidelines for the occupational health management of workers with low back pain. The primary outcome measure is return to work. Secondary outcome measures are pain intensity, functional status and general improvement. Intermediate variables are kinesiophobia and pain coping. The cost-effectiveness analysis includes the direct and indirect costs due to low back pain. The outcome measures are assessed before randomization (after 2–6 weeks on sick leave) and 12 weeks, 26 weeks and 52 weeks after first day of sick leave. Discussion The combination of these interventions has been subject of earlier research in Canada. The results of the current RCT will: 1. crossvalidate the Canadian findings in an different sociocultural environment; 2. add to the cost-effectiveness on treatment options for workers in the sub acute phase of low back pain. Results might lead to alterations of existing (inter)national guidelines. PMID:14629775

  7. Using a digital signal processor as a data stream controller for digital subtraction angiography

    SciTech Connect

    Meng, J.D.; Katz, J.E.

    1991-10-01

    High speed, flexibility, and good arithmetic abilities make digital signal processors (DSP) a good choice as input/output controllers for real time applications. The DSP can be made to pre-process data in real time to reduce data volume, to open early windows on what is being acquired and to implement local servo loops. We present an example of a DSP as an input/output controller for a digital subtraction angiographic imaging system. The DSP pre-processes the raw data, reducing data volume by a factor of two, and is potentially capable of producing real-time subtracted images for immediate display.

  8. MAS2-8 radar and digital control unit

    NASA Technical Reports Server (NTRS)

    Oberg, J. M.; Ulaby, F. T.

    1974-01-01

    The design of the MAS 2-8 (2 to 8 GHz microwave-active spectrometer), a ground-based sensor system, is presented. A major modification in 1974 to the MAS 2-8, that of a control subsystem to automate the data-taking operation, is the prime focus. The digital control unit automatically changes all system parameters except FM rate and records the return signal on paper tape. The overall system operation and a detailed discussion of the design and operation of the digital control unit are presented.

  9. Digital control in LLRF system for CYCIAE-100 cyclotron

    NASA Astrophysics Data System (ADS)

    Yin, Zhiguo; Fu, Xiaoliang; Ji, Bin; Zhang, Tianjue; Wang, Chuan

    2016-05-01

    As a driven accelerator, the CYCIAE-100 cyclotron is designed by China Institute of Atomic Energy for the Beijing Radio Ion-beam Facility project. The cyclotron RF system is designed to use two RF power sources of 100 kW to drive two half-wavelength cavities respectively. Two Dee accelerating electrodes are kept separately from each other inside the cyclotron, while their accelerating voltages are maintained in phase by the efforts of LLRF control. An analog-digital hybrid LLRF system has been developed to achieve cavity tuning control, dee voltage amplitude and phase stabilization etc. The analog subsystems designs are focused on RF signal up/down conversion, tuning control, and dee voltage regulation. The digital system provides an RF signal source, aligns the cavity phases and maintains a Finite State Machine. The digital parts combine with the analog functions to provide the LLRF control. A brief system hardware introduction will be given in this paper, followed by the review of several major characteristics of the digital control in the 100 MeV cyclotron LLRF system. The commissioning is also introduced, and most of the optimization during the process was done by changing the digital parts.

  10. Cost-effectiveness of nurse-led self-help for recurrent depression in the primary care setting: design of a pragmatic randomised controlled trial

    PubMed Central

    2012-01-01

    Background Major Depressive Disorder is a leading cause of disability, tends to run a recurrent course and is associated with substantial economic costs due to increased healthcare utilization and productivity losses. Interventions aimed at the prevention of recurrences may reduce patients' suffering and costs. Besides antidepressants, several psychological treatments such as preventive cognitive therapy (PCT) are effective in the prevention of recurrences of depression. Yet, many patients find long-term use of antidepressants unattractive, do not want to engage in therapy sessions and in the primary care setting psychologists are often not available. Therefore, it is important to study whether PCT can be used in a nurse-led self-help format in primary care. This study sets out to test the hypothesis that usual care plus nurse-led self-help for recurrent depression in primary care is feasible, acceptable and cost-effective compared to usual care only. Design Patients are randomly assigned to ‘nurse-led self-help treatment plus usual care’ (134 participants) or ‘usual care’ (134 participants). Randomisation is stratified according to the number of previous episodes (2 or 3 previous episodes versus 4 or more). The primary clinical outcome is the cumulative recurrence rate of depression meeting DSM-IV criteria as assessed by the Structured-Clinical-Interview-for-DSM-IV- disorders at one year after completion of the intervention. Secondary clinical outcomes are quality of life, severity of depressive symptoms, co-morbid psychopathology and self-efficacy. As putative effect-moderators, demographic characteristics, number of previous episodes, type of treatment during previous episodes, age of onset, self-efficacy and symptoms of pain and fatigue are assessed. Cumulative recurrence rate ratios are obtained under a Poisson regression model. Number-needed-to-be-treated is calculated as the inverse of the risk-difference. The economic evaluation is conducted from a

  11. Cost-Effectiveness of a Specialist Geriatric Medical Intervention for Frail Older People Discharged from Acute Medical Units: Economic Evaluation in a Two-Centre Randomised Controlled Trial (AMIGOS)

    PubMed Central

    Tanajewski, Lukasz; Franklin, Matthew; Gkountouras, Georgios; Berdunov, Vladislav; Edmans, Judi; Conroy, Simon; Bradshaw, Lucy E.; Gladman, John R. F.; Elliott, Rachel A.

    2015-01-01

    Background Poor outcomes and high resource-use are observed for frail older people discharged from acute medical units. A specialist geriatric medical intervention, to facilitate Comprehensive Geriatric Assessment, was developed to reduce the incidence of adverse outcomes and associated high resource-use in this group in the post-discharge period. Objective To examine the costs and cost-effectiveness of a specialist geriatric medical intervention for frail older people in the 90 days following discharge from an acute medical unit, compared with standard care. Methods Economic evaluation was conducted alongside a two-centre randomised controlled trial (AMIGOS). 433 patients (aged 70 or over) at risk of future health problems, discharged from acute medical units within 72 hours of attending hospital, were recruited in two general hospitals in Nottingham and Leicester, UK. Participants were randomised to the intervention, comprising geriatrician assessment in acute units and further specialist management, or to control where patients received no additional intervention over and above standard care. Primary outcome was incremental cost per quality adjusted life year (QALY) gained. Results We undertook cost-effectiveness analysis for 417 patients (intervention: 205). The difference in mean adjusted QALYs gained between groups at 3 months was -0.001 (95% confidence interval [CI]: -0.009, 0.007). Total adjusted secondary and social care costs, including direct costs of the intervention, at 3 months were £4412 (€5624, $6878) and £4110 (€5239, $6408) for the intervention and standard care groups, the incremental cost was £302 (95% CI: 193, 410) [€385, $471]. The intervention was dominated by standard care with probability of 62%, and with 0% probability of cost-effectiveness (at £20,000/QALY threshold). Conclusions The specialist geriatric medical intervention for frail older people discharged from acute medical unit was not cost-effective. Further research on

  12. Wavelength-Division Multiplexing Of Avionic Digital Control Signals

    NASA Technical Reports Server (NTRS)

    Patterson, James D.; Palumbo, Daniel L.

    1993-01-01

    Proposed wavelength-division multiplexing optoelectronic system aboard aircraft transmits digital control signals from central flight-control computer via optical fibers to multiple distributed processors, actuators, and sensors. In comparison with serial TDM communication systems, this system offers potentially higher data throughput, greater tolerance to transient induced faults, and lower bit-error rates. Also immune to electromagnetic interference at suboptical frequencies.

  13. Digital robust control law synthesis using constrained optimization

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivekananda

    1989-01-01

    Development of digital robust control laws for active control of high performance flexible aircraft and large space structures is a research area of significant practical importance. The flexible system is typically modeled by a large order state space system of equations in order to accurately represent the dynamics. The active control law must satisy multiple conflicting design requirements and maintain certain stability margins, yet should be simple enough to be implementable on an onboard digital computer. Described here is an application of a generic digital control law synthesis procedure for such a system, using optimal control theory and constrained optimization technique. A linear quadratic Gaussian type cost function is minimized by updating the free parameters of the digital control law, while trying to satisfy a set of constraints on the design loads, responses and stability margins. Analytical expressions for the gradients of the cost function and the constraints with respect to the control law design variables are used to facilitate rapid numerical convergence. These gradients can be used for sensitivity study and may be integrated into a simultaneous structure and control optimization scheme.

  14. Relationships between digital signal processing and control and estimation theory

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1978-01-01

    Research directions in the fields of digital signal processing and modern control and estimation theory are discussed. Stability theory, linear prediction and parameter identification, system synthesis and implementation, two-dimensional filtering, decentralized control and estimation, and image processing are considered in order to uncover some of the basic similarities and differences in the goals, techniques, and philosophy of the disciplines.

  15. A Digital Self Excited Loop for Accelerating Cavity Field Control

    SciTech Connect

    Curt Hovater; Trent Allison; Jean Delayen; John Musson; Tomasz Plawski

    2007-06-22

    We have developed a digital process that emulates an analog oscillator and ultimately a self excited loop (SEL) for field control. The SEL, in its analog form, has been used for many years for accelerating cavity field control. In essence the SEL uses the cavity as a resonant circuit -- much like a resonant (tank) circuit is used to build an oscillator. An oscillating resonant circuit can be forced to oscillate at different, but close, frequencies to resonance by applying a phase shift in the feedback path. This allows the circuit to be phased-locked to a master reference, which is crucial for multiple cavity accelerators. For phase and amplitude control the SEL must be forced to the master reference frequency, and feedback provided for in both dimensions. The novelty of this design is in the way digital signal processing (DSP) is structured to emulate an analog system. While the digital signal processing elements are not new, to our knowledge this is the first time that the digital SEL concept has been designed and demonstrated. This paper reports on the progress of the design and implementation of the digital SEL for field control of superconducting accelerating cavities.

  16. Progress in multirate digital control system design

    NASA Technical Reports Server (NTRS)

    Berg, Martin C.; Mason, Gregory S.

    1991-01-01

    A new methodology for multirate sampled-data control design based on a new generalized control law structure, two new parameter-optimization-based control law synthesis methods, and a new singular-value-based robustness analysis method are described. The control law structure can represent multirate sampled-data control laws of arbitrary structure and dynamic order, with arbitrarily prescribed sampling rates for all sensors and update rates for all processor states and actuators. The two control law synthesis methods employ numerical optimization to determine values for the control law parameters. The robustness analysis method is based on the multivariable Nyquist criterion applied to the loop transfer function for the sampling period equal to the period of repetition of the system's complete sampling/update schedule. The complete methodology is demonstrated by application to the design of a combination yaw damper and modal suppression system for a commercial aircraft.

  17. Digital control of high-intensity acoustic testing. [for spacecraft

    NASA Technical Reports Server (NTRS)

    Slusser, R. A.

    1975-01-01

    Three systems for the control of acoustic testing are compared: a hybrid digital/analog system, a digital vibration system, and the same digital vibration system modified by a software change. The hybrid system was constructed to control the 1/3-octaves from 50 to 1000 Hz. The vibration system was equipped with programs for sine and random vibration tests, shock analysis and synthesis, and signal analysis. For the modified vibration system, the random-vibration control program of the unmodified unit was changed so that acoustic tests could be performed. The performance of the three systems is compared by conducting probability-density and time-history analyses of the proposed test spectrum for the Mariner Jupiter/Saturn 1977 program. The results of the analyses show that the hybrid and modified vibration systems perform almost equally, but the modified vibration system is easier to use and produces better test documentation.

  18. Research into the efficacy and cost-effectiveness of brief, free of charge and anonymous sex counselling to improve (mental) health in youth: Design of a randomised controlled trial

    PubMed Central

    2009-01-01

    Background The capacity to form romantic relationships and sexual health of adolescents in the Netherlands are compromised by several factors, including young age of first intercourse and adolescent depression. Several thresholds like own expenses, trust and embarrassment prevent adolescents to seek help for their sexual problems. To overcome these thresholds, brief sex counselling has been developed. It has been used since 2006 within the Rotterdam-Rijnmond Public Health Service, but there is lack of information about the (cost-) effectiveness. In the current study we will evaluate the (cost-) effectiveness of brief sex counselling for sexual problems in adolescents and young adults between 18 and 25 years of age. Methods In a randomised controlled trial we will compare (1) brief sex counselling with (2) intensive sexological treatment, and (3) delayed treatment (waiting list). Embedded in this RCT will be a trial-based economic evaluation, looking at the cost-effectiveness and cost-utility of brief sex counselling versus the two other interventions. Four hundred fifty adolescents (aged 18-25) with sexual problems will be recruited among the persons who visit the Public Health Service (PHS) and through various websites. After a screening procedure, eligible participants will be randomly allocated to one of the three intervention groups. Primary outcome measure of the clinical evaluation is the severity of sexual problems. Other outcomes include psychological distress, especially depression. The economic evaluation will be performed from a societal perspective. Costs will be assessed continuously by a retrospective questionnaire covering the last 3 month. All outcome assessments (including those for the economic evaluation) will take place via the internet at baseline, and at 3, 6, 9, and 12 months after baseline. Discussion The proposed research project will be the first study to provide preliminary data about the effect and cost-effectiveness of brief sex

  19. Evaluation of a high response electrohydraulic digital control valve

    NASA Technical Reports Server (NTRS)

    Anderson, R. L.

    1973-01-01

    The application is described of a digital control valve on an electrohydraulic servo actuator. The digital control problem is discussed in general as well as the design and evaluation of a breadboard actuator. The evaluation revealed a number of problems associated with matching the valve to a hydraulic load. The problems were related to lost motion resulting from bulk modulus and leakage. These problems were effectively minimized in the breadboard actuator by maintaining a 1000 psi back pressure on the valve circuit and thereby improving the effective bulk modulus.

  20. Lymphatic Filariasis in Nigeria; Micro-stratification Overlap Mapping (MOM) as a Prerequisite for Cost-Effective Resource Utilization in Control and Surveillance

    PubMed Central

    Okorie, Patricia N.; Ademowo, George O.; Saka, Yisa; Davies, Emmanuel; Okoronkwo, Chukwu; Bockarie, Moses J.; Molyneux, David H.; Kelly-Hope, Louise A.

    2013-01-01

    Background Nigeria has a significant burden of lymphatic filariasis (LF) caused by the parasite Wuchereria bancrofti. A major concern to the expansion of the LF elimination programme is the risk of serious adverse events (SAEs) associated with the use of ivermectin in areas co-endemic with Loa filariasis. To better understand this, as well as other factors that may impact on LF elimination, we used Micro-stratification Overlap Mapping (MOM) to highlight the distribution and potential impact of multiple disease interventions that geographically coincide in LF endemic areas and which will impact on LF and vice versa. Methodology/Principal findings LF data from the literature and Federal Ministry of Health (FMoH) were collated into a database. LF prevalence distributions; predicted prevalence of loiasis; ongoing onchocerciasis community-directed treatment with ivermectin (CDTi); and long-lasting insecticidal mosquito net (LLIN) distributions for malaria were incorporated into overlay maps using geographical information system (GIS) software. LF was prevalent across most regions of the country. The mean prevalence determined by circulating filarial antigen (CFA) was 14.0% (n = 134 locations), and by microfilaria (Mf) was 8.2% (n = 162 locations). Overall, LF endemic areas geographically coincided with CDTi priority areas, however, LLIN coverage was generally low (<50%) in areas where LF prevalence was high or co-endemic with L. loa. Conclusions/Significance The extensive database and series of maps produced in this study provide an important overview for the LF Programme and will assist to maximize existing interventions, ensuring cost effective use of resources as the programme scales up. Such information is a prerequisite for the LF programme, and will allow for other factors to be included into planning, as well as monitoring and evaluation activities given the broad spectrum impact of the drugs used. PMID:24040432

  1. Real Time Digital Control of a Magnetostrictive Actuator

    NASA Technical Reports Server (NTRS)

    Zrostlik, Rick L.; Hall, David L.; Flatau, Alison B.

    1996-01-01

    The use of the magnetostrictive material Terfenol-D as a motion source in active vibration control (AVC) systems are being studied. Currently it is of limited use due to the nonlinear nature of the strain versus magnetization curve and the magnetic hysteresis in the Terfenol-D. One manifestation of these nonlinearities is waveform distortion in the output velocity of the transducer. For Terfenol-D to be used in ever greater numbers of AVC systems, these nonlinearities must be addressed. In this study the nonlinearities are treated as disturbances to a linear system. The acceleration output is used in simple analog and digital feedback control schemes to improve linearity of the transducer. In addition, the use of a Terfenol-D actuator in an AVC system is verified. Both analog and digital controllers are implemented and results compared. A cantilever beam system is considered for AVC applications. The second thrust of this presentation is the reduction of harmonic distortions. Two conclusions can be reached from this work. One, the linearization of Terfenol-D transducers is possible with the use of feedback controllers, both digital and analog. Second, Terfenol-D is a viable motion source in active vibration control systems utilizing either analog or digital controllers.

  2. Digital control of diode laser for atmospheric spectroscopy

    NASA Technical Reports Server (NTRS)

    Menzies, R. T.; Rutledge, C. W. (Inventor)

    1985-01-01

    A system is described for remote absorption spectroscopy of trace species using a diode laser tunable over a useful spectral region of 50 to 200 cm(-1) by control of diode laser temperature over range from 15 K to 100 K, and tunable over a smaller region of typically 0.1 to 10 cm(-1) by control of the diode laser current over a range from 0 to 2 amps. Diode laser temperature and current set points are transmitted to the instrument in digital form and stored in memory for retrieval under control of a microprocessor during measurements. The laser diode current is determined by a digital to analog converter through a field effect transistor for a high degree of ambient temperature stability, while the laser diode temperature is determined by set points entered into a digital to analog converter under control of the microprocessor. Temperature of the laser diode is sensed by a sensor diode to provide negative feedback to the temperature control circuit that responds to the temperature control digital to analog converter.

  3. An Inexpensive Digital Gradient Controller for HPLC.

    ERIC Educational Resources Information Center

    Brady, James E.; Carr, Peter W.

    1983-01-01

    Use of gradient elution techniques in high performance liquid chromatography (HPLC) is often essential for direct separation of complex mixtures. Since most commercial controllers have features that are of marginal value for instructional purposes, a low-cost controller capable of illustrating essential features of gradient elution was developed.…

  4. Digital Control and Identification of Distributed Systems.

    DTIC Science & Technology

    1990-08-14

    for example, problems in which a Schrodinger equation is coupled with a diffusion equation . In this paper, we are particularly interested in second...control of systems represented by partial differential equations , and adaptive control and tracking problems for flexible structures and manipulators...and functional differential equations . The primary class of applications is large flexible space structures. Papers dealing mainly with approximation

  5. Digital regulation of a phase controlled power converter

    SciTech Connect

    Schultheiss, C.; Haque, T.

    1995-12-01

    The Relativistic Heavy Ion Collider, now in construction at Brookhaven National Laboratory, will use phase controlled power converters for the main dipole and quadrupole magnet strings. The rectifiers in these power supplies will be controlled by a digital regulator based on the TI 320C30 Digital Signal Processor (DSP). The DSP implements the current loop, the voltage loop, and a system to actively reduce the sub-harmonic ripple components. Digital firing circuits consisting of a phase locked lop and counters are used to fire the SCRs. Corrections for the sub-harmonic reduction are calculated by the DSP and stored in registers in the firing circuit. These corrections are added in hardware, to the over-all firing count provided by the DSP. the resultant count is compared to a reference counter to fire the SCRs. This combination of a digital control system and the digital firing circuits allows the correction of the sub-harmonics in a real-time sense. A prototype of the regulator has been constructed, and the preliminary testing indicates a sub-harmonic reduction of 60 dB.

  6. Guidelines for Cost-Effective Training Product Development.

    ERIC Educational Resources Information Center

    Awotua-Efebo, Ebi Bio

    1984-01-01

    Presents guidelines for cost effective product development for training managers charged with quality control of products and training specialists who design materials. Discusses phases of educational product development--diagnosis, design, development, and evaluation. (MBR)

  7. HVDC control system based on parallel digital signal processors

    SciTech Connect

    Maharsi, Y.; Do, V.Q.; Sood, V.K.; Casoria, S.; Belanger, J.

    1995-05-01

    A numerical HVDC control system operating in real time has been developed for a simulator to be used for operator training. The control system, implemented with digital signal processors (DSPs), consists of typical HVDC control functions such as the synchronizing unit, the regulation unit, the protection unit, the firing unit, the tap changer and the reactive power regulation unit. Results from the steady-state and the transient performance validation tests carried out on the IREQ power system simulator are provided.

  8. The design of multirate digital control systems

    NASA Technical Reports Server (NTRS)

    Berg, M. C.

    1986-01-01

    The successive loop closures synthesis method is the only method for multirate (MR) synthesis in common use. A new method for MR synthesis is introduced which requires a gradient-search solution to a constrained optimization problem. Some advantages of this method are that the control laws for all control loops are synthesized simultaneously, taking full advantage of all cross-coupling effects, and that simple, low-order compensator structures are easily accomodated. The algorithm and associated computer program for solving the constrained optimization problem are described. The successive loop closures , optimal control, and constrained optimization synthesis methods are applied to two example design problems. A series of compensator pairs are synthesized for each example problem. The succesive loop closure, optimal control, and constrained optimization synthesis methods are compared, in the context of the two design problems.

  9. Digital computer control of a 30-cm mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Low, C. A., Jr.

    1975-01-01

    The major objective was to define the exact role of an onboard spacecraft computer in the control of ion thrusters. An initial computer control system with accurate high speed capability was designed, programmed, and tested with the computer as the sole control element for an operating ion thruster. The command functions and a code format for a spacecraft digital control system were established. A second computer control system was constructed to operate with these functions and format. A throttle program sequence was established and tested. A two thruster array was tested with these computer control systems and the results reported.

  10. Experience with synchronous and asynchronous digital control systems

    NASA Technical Reports Server (NTRS)

    Regenie, V. A.; Chacon, C. V.; Lock, W. P.

    1986-01-01

    Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

  11. Digital control circuitry of cancer cell and its apoptosis.

    PubMed

    Ardito Marretta, R M; Barbaraci, G

    2009-09-01

    This study, through a typical aerospace systems architecture, suggests an engineering design of a human cancer cell circuitry in which a digital optimal control matrix is assigned to repair the DNA damage level and/or to trigger its apoptosis. Here, the conceived machinery is proposed taking into account the state of the art in cancer investigation. However, it could be further generalized. The most recent studies on cancer pathologies give a predominant role to the oncosuppressor protein p53 and its antagonist, the oncogene Mdm2. Experimental and theoretical approaches are in agreement in deducing a "digital" response of the p53 when genomic integrity is damaged. Once DNA damage is present, the mutual influence of p53 and its antagonist, the Mdm2 oncogene, is closed in a feedback loop. In this work, starting from these current results, a novel molecular mechanism is proposed, based on a digital optimal control law, whereby p53 and Mdm2 proteins activities can be represented by appropriate circuitry and governed by the optimal control law of digital systems. This procedure obtains a real-time sequence evaluation of protein oscillations and an unexpected and relevant acceleration in the DNA repairing when suitable digital control matrix is implemented. Those effects suggest interesting perspectives for future scientific investigations. First of all, the proposed digital circuitry, receiving the p53 signal from a damaged cell, is able to repair the current level of genomic alteration. Moreover, the cell fate is newly conceived and bound by the modified pulsing mechanism of p53.

  12. Digitally Controlled High Availability Power Supply

    SciTech Connect

    MacNair, David; /SLAC

    2008-09-25

    This paper reports the design and test results on novel topology, high-efficiency, and low operating temperature, 1,320-watt power modules for high availability power supplies. The modules permit parallel operation for N+1 redundancy with hot swap capability. An embedded DSP provides intelligent start-up and shutdown, output regulation, general control and fault detection. PWM modules in the DSP drive the FET switches at 20 to 100 kHz. The DSP also ensures current sharing between modules, synchronized switching, and soft start up for hot swapping. The module voltage and current have dedicated ADCs (>200 kS/sec) to provide pulse-by-pulse output control. A Dual CAN bus interface provides for low cost redundant control paths. Over-rated module components provide high reliability and high efficiency at full load. Low on-resistance FETs replace conventional diodes in the buck regulator. Saturable inductors limit the FET reverse diode current during switching. The modules operate in a two-quadrant mode, allowing bipolar output from complimentary module groups. Controllable, low resistance FETs at the input and output provide fault isolation and allow module hot swapping.

  13. NASA develops new digital flight control system

    NASA Technical Reports Server (NTRS)

    Mewhinney, Michael

    1994-01-01

    This news release reports on the development and testing of a new integrated flight and propulsion automated control system that aerospace engineers at NASA's Ames Research Center have been working on. The system is being tested in the V/STOL (Vertical/Short Takeoff and Landing) Systems Research Aircraft (VSRA).

  14. 47 CFR 97.221 - Automatically controlled digital station.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... station. (a) This rule section does not apply to an auxiliary station, a beacon station, a repeater station, an earth station, a space station, or a space telecommand station. (b) A station may be... 47 Telecommunication 5 2013-10-01 2013-10-01 false Automatically controlled digital station....

  15. 47 CFR 97.221 - Automatically controlled digital station.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... station. (a) This rule section does not apply to an auxiliary station, a beacon station, a repeater station, an earth station, a space station, or a space telecommand station. (b) A station may be... 47 Telecommunication 5 2011-10-01 2011-10-01 false Automatically controlled digital station....

  16. 47 CFR 97.221 - Automatically controlled digital station.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... station. (a) This rule section does not apply to an auxiliary station, a beacon station, a repeater station, an earth station, a space station, or a space telecommand station. (b) A station may be... 47 Telecommunication 5 2012-10-01 2012-10-01 false Automatically controlled digital station....

  17. 47 CFR 97.221 - Automatically controlled digital station.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... station. (a) This rule section does not apply to an auxiliary station, a beacon station, a repeater station, an earth station, a space station, or a space telecommand station. (b) A station may be... 47 Telecommunication 5 2014-10-01 2014-10-01 false Automatically controlled digital station....

  18. 47 CFR 97.221 - Automatically controlled digital station.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... station. (a) This rule section does not apply to an auxiliary station, a beacon station, a repeater station, an earth station, a space station, or a space telecommand station. (b) A station may be... 47 Telecommunication 5 2010-10-01 2010-10-01 false Automatically controlled digital station....

  19. Digital Controller For Laser-Beam-Steering Subsystem: Part 2

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon; Voisinet, Leeann

    1995-01-01

    A report presents additional information about laser-beam-steering apparatus described in "Digital Controller for Laser-Beam-Steering Subsystem" (NPO-19193) and "More About Beam-Steering Subsystem for Laser Communication" (NPO-19381). Reiterates basic principles of operation of beam-steering subsystem, with emphasis on modes of operation, basic design concepts, and initial experiments on partial prototype of apparatus.

  20. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The annular suspension and pointing system (ASPS) a payload auxiliary pointing device of the space shuttle is briefly described along with the function of the digital controller. The equations of motion of a simplified plan planar model of the ASPS are derived. Results of computer simulations are discussed.

  1. Integrated assurance assessment of a reconfigurable digital flight control system

    NASA Technical Reports Server (NTRS)

    Ness, W. G.; Davis, R. M.; Benson, J. W.; Smith, M. K.; Eldredge, D.

    1983-01-01

    The integrated application of reliability, failure effects and system simulator methods in establishing the airworthiness of a flight critical digital flight control system (DFCS) is demonstrated. The emphasis was on the mutual reinforcement of the methods in demonstrating the system safety.

  2. Large-scale implementation of disease control programmes: a cost-effectiveness analysis of long-lasting insecticide-treated bed net distribution channels in a malaria-endemic area of western Kenya—a study protocol

    PubMed Central

    Gama, Elvis; Were, Vincent; Ouma, Peter; Desai, Meghna; Niessen, Louis; Buff, Ann M; Kariuki, Simon

    2016-01-01

    Introduction Historically, Kenya has used various distribution models for long-lasting insecticide-treated bed nets (LLINs) with variable results in population coverage. The models presently vary widely in scale, target population and strategy. There is limited information to determine the best combination of distribution models, which will lead to sustained high coverage and are operationally efficient and cost-effective. Standardised cost information is needed in combination with programme effectiveness estimates to judge the efficiency of LLIN distribution models and options for improvement in implementing malaria control programmes. The study aims to address the information gap, estimating distribution cost and the effectiveness of different LLIN distribution models, and comparing them in an economic evaluation. Methods and analysis Evaluation of cost and coverage will be determined for 5 different distribution models in Busia County, an area of perennial malaria transmission in western Kenya. Cost data will be collected retrospectively from health facilities, the Ministry of Health, donors and distributors. Programme-effectiveness data, defined as the number of people with access to an LLIN per 1000 population, will be collected through triangulation of data from a nationally representative, cross-sectional malaria survey, a cross-sectional survey administered to a subsample of beneficiaries in Busia County and LLIN distributors’ records. Descriptive statistics and regression analysis will be used for the evaluation. A cost-effectiveness analysis will be performed from a health-systems perspective, and cost-effectiveness ratios will be calculated using bootstrapping techniques. Ethics and dissemination The study has been evaluated and approved by Kenya Medical Research Institute, Scientific and Ethical Review Unit (SERU number 2997). All participants will provide written informed consent. The findings of this economic evaluation will be disseminated through

  3. Digital Flight Control System Redundancy Study

    DTIC Science & Technology

    1974-07-01

    microseconds to transfer the data to a memory location on DMA, 2 274 4P4 275 or to an accumulator if under program control. While it is possible, in principle ...March, 1973, to May, 1974, by the Flight Systems Division of The Bendix Corporation, Teterboro, New Jersey under Air Force Contract No. 333615-73-C...3035 AFFDL. The work was administered under the direction of the Air Force Flight Dynamics Laboratory, Wright-Patterson Air Force Base, Ohio, 45433, by

  4. F-8C digital CCV flight control laws

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Hauge, J. A.; Hendrick, R. C.

    1976-01-01

    A set of digital flight control laws were designed for the NASA F-8C digital fly-by-wire aircraft. The control laws emphasize Control Configured Vehicle (CCV) benefits. Specific pitch axis objectives were improved handling qualities, angle-of-attack limiting, gust alleviation, drag reduction in steady and maneuvering flight, and a capability to fly with reduced static stability. The lateral-directional design objectives were improved Dutch roll damping and turn coordination over a wide range in angle-of-attack. An overall program objective was to explore the use of modern control design methodilogy to achieve these specific CCV benefits. Tests for verifying system integrity, an experimental design for handling qualities evaluation, and recommended flight test investigations were specified.

  5. Digital electronic engine control fault detection and accommodation flight evaluation

    NASA Technical Reports Server (NTRS)

    Baer-Ruedhart, J. L.

    1984-01-01

    The capabilities and performance of various fault detection and accommodation (FDA) schemes in existing and projected engine control systems were investigated. Flight tests of the digital electronic engine control (DEEC) in an F-15 aircraft show discrepancies between flight results and predictions based on simulation and altitude testing. The FDA methodology and logic in the DEEC system, and the results of the flight failures which occurred to date are described.

  6. Design of a digital adaptive control system for reentry vehicles.

    NASA Technical Reports Server (NTRS)

    Picon-Jimenez, J. L.; Montgomery, R. C.; Grigsby, L. L.

    1972-01-01

    The flying qualities of atmospheric reentry vehicles experience considerable variations due to the wide changes in flight conditions characteristic of reentry trajectories. A digital adaptive control system has been designed to modify the vehicle's dynamic characteristics and to provide desired flying qualities for all flight conditions. This adaptive control system consists of a finite-memory identifier which determines the vehicle's unknown parameters, and a gain computer which calculates feedback gains to satisfy flying quality requirements.

  7. Modelling and designing digital control systems with averaged measurements

    NASA Technical Reports Server (NTRS)

    Polites, Michael E.; Beale, Guy O.

    1988-01-01

    An account is given of the control systems engineering methods applicable to the design of digital feedback controllers for aerospace deterministic systems in which the output, rather than being an instantaneous measure of the system at the sampling instants, instead represents an average measure of the system over the time interval between samples. The averaging effect can be included during the modeling of the plant, thereby obviating the iteration of design/simulation phases.

  8. Self-Administered Vidoetape Therapy for Families With Conduct-Problem Children: Comparison With Two Cost-Effective Treatments and a Control Group.

    ERIC Educational Resources Information Center

    Webster-Stratton, Carolyn; And Others

    1988-01-01

    Assigned parents of 114 conduct-problem young children to either individually administered videotape modeling treatment, group discussion videotape modeling treatment, group discussion treatment, or waiting-list control. Compared with controls, all three treatment groups of mothers reported significantly fewer child behavior problems, more…

  9. Digitally Controlled High Availability Power Supply

    SciTech Connect

    MacNair, David; /SLAC

    2009-05-07

    This paper will report on the test results of a prototype 1320 watt power module for a high availability power supply. The module will allow parallel operation for N+1 redundancy with hot swap capability. The two quadrant output of each module allows pairs of modules to provide a 4 quadrant (bipolar) operation. Each module employs a novel 4 FET buck regulator arranged in a bridge configuration. Each side of the bridge alternately conducts through a small saturable ferrite that limits the reverse current in the FET body diode during turn off. This allows hard switching of the FETs with low switching losses. The module is designed with over-rated components to provide high reliability and better then 97% efficiency at full load. The modules use a Microchip DSP for control, monitoring, and fault detection. The switching FETS are driven by PWM modules in the DSP at 60 KHz. A Dual CAN bus interface provides for low cost redundant control paths. The DSP will also provide current sharing between modules, synchronized switching, and soft start up for hot swapping. The input and output of each module have low resistance FETs to allow hot swapping and isolation of faulted units.

  10. Will joint regional air pollution control be more cost-effective? An empirical study of China's Beijing-Tianjin-Hebei region.

    PubMed

    Wu, Dan; Xu, Yuan; Zhang, Shiqiu

    2015-02-01

    By following an empirical approach, this study proves that joint regional air pollution control (JRAPC) in the Beijing-Tianjin-Hebei region will save the expense on air pollution control compared with a locally-based pollution control strategy. The evidences below were found. (A) Local pollutant concentration in some of the cities is significantly affected by emissions from their surrounding areas. (B) There is heterogeneity in the marginal pollutant concentration reduction cost among various districts as a result of the cities' varying contribution of unit emission reduction to the pollutant concentration reduction, and their diverse unit cost of emission reduction brought about by their different industry composition. The results imply that the cost-efficiency of air pollution control will be improved in China if the conventional locally based regime of air pollution control can shift to a regionally based one.

  11. Digital active control law synthesis for aeroservoelastic systems

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivekananda

    1988-01-01

    This paper presents a formulation for synthesis of digital active control laws for aeroservoelastic systems, which are typically modeled by large order equations in order to accurately represent the rigid and flexible body modes, unsteady aerodynamic forces, actuator dynamics, and gust spectra. The control law is expected to satisfy multiple design requirements on the dynamic loads, responses, actuator deflection and rate limitations, as well as maintain certain stability margins, yet should be simple enough to be implemented by an onboard digital microprocessor. The synthesis procedure minimizes a linear quadratic Gaussian type cost function, by updating selected free parameters of the control law, while satisfying a set of inequality constraints on the design loads, responses and stability margins. A stable classical control law or an estimator based full or reduced order control law can be used as an initial design starting point. The gradients of the cost function and the constraints, with respect to the digital control law design variables are derived analytically, to facilitate rapid convergence. Selected design responses can be treated as constraints instead of lumping them into the cost function, in order to satisfy individual root-mean-square load and response limitations. Constraints are also imposed on the minimum singular value requirements for stability robustness improvement.

  12. Digital frequency control of satellite frequency standards. [Defense Navigation Satellites

    NASA Technical Reports Server (NTRS)

    Nichols, S. A.

    1973-01-01

    In the Frequency and Time Standard Development Program of the TIMATION System, a new miniaturized rubidium vapor frequency standard has been tested and analyzed for possible use on the TIMATION 3A launch, as part of the Defense Navigation Satellite Development Program. The design and construction of a digital frequency control was required to remotely control this rubidium vapor frequency standard as well as the quartz oscillator in current use. This control must be capable of accepting commands from a satellite telemetry system, verify that the correct commands have been sent and control the frequency to the requirements of the system. Several modifications must be performed to the rubidium vapor frequency standard to allow it to be compatible with the digital frequency control. These include the addition of a varactor to voltage tune the coarse range of the flywheel oscillator, and a modification to supply the C field current externally. The digital frequency control for the rubidium vapor frequency standard has been successfully tested in prototype form.

  13. Cost-effectiveness of a Primary Care Depression Intervention

    PubMed Central

    Pyne, Jeffrey M; Rost, Kathryn M; Zhang, Mingliang; Williams, D Keith; Smith, Jeffrey; Fortney, John

    2003-01-01

    OBJECTIVE To determine the incremental cost-effectiveness of a quality improvement depression intervention (enhanced care) in primary care settings relative to usual care. DESIGN Following stratification, we randomized 12 primary care practices to enhanced or usual care conditions and followed patients for 12 months. SETTING Primary care practices located in 10 states across the United States. PATIENTS/PARTICIPANTS Two hundred eleven patients beginning a new treatment episode for major depression. INTERVENTIONS Training the primary care team to assess, educate, and monitor depressed patients during the acute and continuation stages of their depression treatment episode over 1 year. MEASUREMENTS AND MAIN RESULTS Cost-effectiveness was measured by calculating incremental (enhanced minus usual care) costs and quality-adjusted life years (QALYs) derived from SF-36 data. The mean incremental cost-effectiveness ratio in the main analysis was $15,463 per QALY. The mean incremental cost-effectiveness ratios for the sensitivity analyses ranged from $11,341 (using geographic block variables to control for pre-intervention service utilization) to $19,976 (increasing the cost estimates by 50%) per QALY. CONCLUSIONS This quality improvement depression intervention was cost-effective relative to usual care compared to cost-effectiveness ratios for common primary care interventions and commonly cited cost-effectiveness ratio thresholds for intervention implementation. PMID:12823650

  14. Digital tracking and control of retinal images

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Jerath, Maya R.; Rylander, Henry G., III; Welch, Ashley J.

    1993-06-01

    Laser induced retinal lesions are used to treat a variety of eye diseases such as diabetic retinopathy and retinal detachment. An instrumentation system has been developed to track a specific lesion coordinate on the retinal surface and provide corrective signals to maintain laser position on the coordinate. High resolution retinal images are acquired via a CCD camera coupled to a fundus camera and video frame grabber. Optical filtering and histogram modification are used to enhance the retinal vessel network against the lighter retinal background. Six distinct retinal landmarks are tracked on the high contrast image obtained from the frame grabber using two-dimensional blood vessel templates. The frame grabber is hosted on a 486 PC. The PC performs correction signal calculations using an exhaustive search on selected image portions. An X and Y laser correction signal is derived from the landmark tracking information and provided to a pair of galvanometer steered mirrors via a data acquisition and control subsystem. This subsystem also responds to patient inputs and the system monitoring lesion growth. This paper begins with an overview of the robotic laser system design followed by implementation and testing of a development system for proof of concept. The paper concludes with specifications for a real time system.

  15. Effectiveness and Cost-Effectiveness of Occupation-Based Occupational Therapy Using the Aid for Decision Making in Occupation Choice (ADOC) for Older Residents: Pilot Cluster Randomized Controlled Trial

    PubMed Central

    Nagayama, Hirofumi; Tomori, Kounosuke; Ohno, Kanta; Takahashi, Kayoko; Ogahara, Kakuya; Sawada, Tatsunori; Uezu, Sei; Nagatani, Ryutaro; Yamauchi, Keita

    2016-01-01

    Background Care-home residents are mostly inactive, have little interaction with staff, and are dependent on staff to engage in daily occupations. We recently developed an iPad application called the Aid for Decision-making in Occupation Choice (ADOC) to promote shared decision-making in activities and occupation-based goal setting by choosing from illustrations describing daily activities. This study aimed to evaluate if interventions based on occupation-based goal setting using the ADOC could focus on meaningful activities to improve quality of life and independent activities of daily living, with greater cost-effectiveness than an impairment-based approach as well as to evaluate the feasibility of conducting a large cluster, randomized controlled trial. Method In this single (assessor)-blind pilot cluster randomized controlled trial, the intervention group (ADOC group) received occupational therapy based on occupation-based goal setting using the ADOC, and the interventions were focused on meaningful occupations. The control group underwent an impairment-based approach focused on restoring capacities, without goal setting tools. In both groups, the 20-minute individualized intervention sessions were conducted twice a week for 4 months. Main Outcome Measures Short Form-36 (SF-36) score, SF-6D utility score, quality adjusted life years (QALY), Barthel Index, and total care cost. Results We randomized and analyzed 12 facilities (44 participants, 18.5% drop-out rate), with 6 facilities each allocated to the ADOC (n = 23) and control (n = 21) groups. After the 4-month intervention, the ADOC group had a significantly greater change in the BI score, with improved scores (P = 0.027, 95% CI 0.41 to 6.87, intracluster correlation coefficient = 0.14). No other outcome was significantly different. The incremental cost-effectiveness ratio, calculated using the change in BI score, was $63.1. Conclusion The results suggest that occupational therapy using the ADOC for older

  16. Comparison of digital controllers used in magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Kilgore, William A.

    1990-01-01

    Dynamic systems that were once controlled by analog circuits are now controlled by digital computers. Presented is a comparison of the digital controllers presently used with magnetic suspension and balance systems. The overall responses of the systems are compared using a computer simulation of the magnetic suspension and balance system and the digital controllers. The comparisons include responses to both simulated force and position inputs. A preferred digital controller is determined from the simulated responses.

  17. The Role of Controlled Vocabularies in Digital Archiving

    NASA Astrophysics Data System (ADS)

    Miller, S.; Clark, P. D.; Neiswender, C.

    2006-12-01

    Over the years, and across projects and disciplines, there is an unfortunate tendency for descriptive terminology to wander. Some of the variation is due to evolution in sensor technology, but some may be due to odd abbreviations, typographical errors on rolling decks, institutional practices, or a momentary inspiration to use a new term. As a consequence, we now face challenges in searching digital collections, and in designing re-usable tools that can be applied to multiple institutions. Practical experience with the SIOExplorer Digital Library of 700 SIO cruises has allowed us to develop techniques to assess variations in metadata values across collections of more than 100,000 digital objects, including datasets, documents and images spanning more than 50 years. The assessment helps to guide the development of controlled vocabularies, which in turn can be used to enable automatic detection of metadata errors, and in some cases automatic correction. Controlled vocabularies are playing an essential role in extending the technology to the collections of the Woods Hole Oceanographic Institution, including cruises, Alvin dives and ROV operations. Examples include the names of chief scientists, port names, operational areas, science themes, image types, sample types, data types, and processing steps. Controlled vocabularies underlie an emerging set of tools that support web user interfaces, large-scale automatic harvesting of metadata and data, project status assessment, workflow management and overall quality control. They are a key resource for user upload code in the IODP Site Survey Data Bank, prompting and enforcing appropriate metadata values for ocean drilling proposal support data. Compared to previous generations of hard-wired code, the access to controlled vocabularies allows a project to evolve with flexibility, and the code to be ported from one project to another. These efforts are supported by a Digital Archiving award from the Library of Congress and

  18. The Science of and Advanced Technology for Cost-Effective Manufacture of High Precision Engineering Products. Volume 4. Thermal Effects on the Accuracy of Numerically Controlled Machine Tools.

    DTIC Science & Technology

    1985-10-01

    Corporation ; Cummiins Engine Co.; Control - Data Corporation ; ALCOA. ." .." . .. .’ ... i . .v CHATE 1.ITOUTABEOF. CONENT LIS OF TeeABL..................o...2 2 - -a-c (a + X)t- G( ytl ’ ,y ,T E E e t nm ab -m ini sin(O x)sin(n Y)sin(B x )sin(n (4.37) in n in n 85 In Equation (4.37), 83 and nn are the

  19. Modern digital flight control system design for VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Broussard, J. R.; Berry, P. W.; Stengel, R. F.

    1979-01-01

    Methods for and results from the design and evaluation of a digital flight control system (DFCS) for a CH-47B helicopter are presented. The DFCS employed proportional-integral control logic to provide rapid, precise response to automatic or manual guidance commands while following conventional or spiral-descent approach paths. It contained altitude- and velocity-command modes, and it adapted to varying flight conditions through gain scheduling. Extensive use was made of linear systems analysis techniques. The DFCS was designed, using linear-optimal estimation and control theory, and the effects of gain scheduling are assessed by examination of closed-loop eigenvalues and time responses.

  20. Digital control of magnetic bearings in a cryogenic cooler

    NASA Technical Reports Server (NTRS)

    Feeley, J.; Law, A.; Lind, F.

    1990-01-01

    This paper describes the design of a digital control system for control of magnetic bearings used in a spaceborne cryogenic cooler. The cooler was developed by Philips Laboratories for the NASA Goddard Space Flight Center. Six magnetic bearing assemblies are used to levitate the piston, displacer, and counter-balance of the cooler. The piston and displacer are driven by linear motors in accordance with Stirling cycle thermodynamic principles to produce the desired cooling effect. The counter-balance is driven by a third linear motor to cancel motion induced forces that would otherwise be transmitted to the spacecraft. An analog control system is currently used for bearing control. The purpose of this project is to investigate the possibilities for improved performance using digital control. Areas for potential improvement include transient and steady state control characteristics, robustness, reliability, adaptability, alternate control modes, size, weight, and cost. The present control system is targeted for the Intel 80196 microcontroller family. The eventual introduction of application specific integrated circuit (ASIC) technology to this problem may produce a unique and elegant solution both here and in related industrial problems.

  1. A Cluster-Randomized Controlled Trial Evaluating the Effectiveness and Cost-Effectiveness of Tobacco Cessation on Prescription in Swedish Primary Health Care: A Protocol of the Motivation 2 Quit (M2Q) Study

    PubMed Central

    Lindgren, Peter; Sundberg, Carl Johan; Petzold, Max; Tomson, Tanja

    2016-01-01

    Background In Sweden, the prevalence of tobacco use is disproportionately high among socioeconomically disadvantaged groups. Previous research and clinical experience suggest that prescribed lifestyle interventions in the primary health care (PHC) setting such as Physical Activity on Prescription are effective in changing behavior. However, there is a lack of evidence for if and how such a prescription approach could be effectively transferred into the tobacco cessation context. Objective The aim of this trial is to evaluate the effectiveness and cost-effectiveness of Tobacco Cessation on Prescription (TCP) compared to current practice for tobacco cessation targeting socioeconomically disadvantaged groups in the PHC setting in Sweden. Methods The design is a pragmatic cluster-randomized controlled trial. The sample will consist of 928 daily tobacco users with Swedish social security numbers and permanent resident permits, recruited from 14-20 PHC centers located in socioeconomically disadvantaged areas in Stockholm County. The primary outcome will be measured in self-reported 7-day abstinence at 6 and 12 months after the intervention. The secondary outcomes will be measured in daily tobacco consumption, number of quit attempts, and health-related quality of life at 6 and 12 months after the intervention. Data will be collected through questionnaires and review of electronic medical records. Cost-effectiveness will be estimated through decision analytic modeling and measured by the incremental cost per quality-adjusted life year. Results In the first set of PHC centers participating in the study, eight centers have been included. Recruitment of individual study participants is currently ongoing. Inclusion of a second set of PHC centers is ongoing with expected study start in September 2016. Conclusions If TCP is found effective and cost-effective compared to standard treatment, the method could be implemented to facilitate tobacco cessation for socioeconomically

  2. Environment and health: Probes and sensors for environment digital control

    NASA Astrophysics Data System (ADS)

    Schettini, Chiara

    2014-05-01

    The idea of studying the environment using New Technologies (NT) came from a MIUR (Ministry of Education of the Italian Government) notice that allocated funds for the realization of innovative school science projects. The "Environment and Health" project uses probes and sensors for digital control of environment (water, air and soil). The working group was composed of 4 Science teachers from 'Liceo Statale G. Mazzini ', under the coordination of teacher Chiara Schettini. The Didactic Section of Naples City of Sciences helped the teachers in developing the project and it organized a refresher course for them on the utilization of digital control sensors. The project connects Environment and Technology because the study of the natural aspects and the analysis of the chemical-physical parameters give students and teachers skills for studying the environment based on the utilization of NT in computing data elaboration. During the practical project, samples of air, water and soil are gathered in different contexts. Sample analysis was done in the school's scientific laboratory with digitally controlled sensors. The data are elaborated with specific software and the results have been written in a booklet and in a computing database. During the first year, the project involved 6 school classes (age of the students 14—15 years), under the coordination of Science teachers. The project aims are: 1) making students more aware about environmental matters 2) achieving basic skills for evaluating air, water and soil quality. 3) achieving strong skills for the utilization of digitally controlled sensors. 4) achieving computing skills for elaborating and presenting data. The project aims to develop a large environmental conscience and the need of a ' good ' environment for defending our health. Moreover it would increase the importance of NT as an instrument of knowledge.

  3. A Flight Investigation of Digital Control Using Microprocessor Technology.

    DTIC Science & Technology

    1979-06-01

    DISPLAYS COTOSE IRF MOTIONS I I T EALATIONl PILOT FEPERIANTAL. Figure 3-2. Overview of the VRA/Micro- DFCS System. mechanical linkage connecting to the...April 1979 CELEC T E D 1 .... 3 OCT 23 1980 DISTRIBUTIOD Sor . D : - U Approved for public . Distribution Uniirnitcd - UNC LASS SECURITY CLASSIFICATION...CLASSIFICATION OF Ywl PAGE(IWhen Data Enterod) ABSTRACT A microprocessor-based digital flight control system (Micro- DFCS ) is implemented in Princeton’s

  4. Dried tube specimens: a simple and cost-effective method for preparation of HIV proficiency testing panels and quality control materials for use in resource-limited settings.

    PubMed

    Parekh, Bharat S; Anyanwu, Juliana; Patel, Hetal; Downer, Marie; Kalou, Mireille; Gichimu, Catherine; Keipkerich, Bera Steven; Clement, Nelly; Omondi, Michael; Mayer, Oren; Ou, Chin-Yih; Nkengasong, John N

    2010-02-01

    HIV testing has rapidly expanded worldwide, but proficiency testing (PT) programs to monitor and improve the quality of testing are often lacking in resource-limited settings (RLS). Traditional PT programs and quality control reagents use serum or plasma specimens requiring stringent conditions for storage and transportation. A novel, simple and easy to use approach, based on dried tube specimens (DTS), was developed that can help monitor the quality of HIV antibody testing in RLS. DTS were prepared by drying 20 microl of specimen overnight at room temperature. The addition of a green dye (0.1%) made the DTS pellets visible without affecting the test results. Before testing, the DTS were rehydrated with 200 microl of PBS-Tween buffer. A panel of 303 DTS samples (135 HIV positive and 168 HIV negative) was evaluated with two rapid tests. Sensitivity and specificity with the Determine HIV-1/2 test were 99.3% and 99.4%, respectively, and with OraQuick were 98.5% and 100%, respectively. Stability studies showed that HIV-specific antibodies in the DTS specimens were stable at 4 degrees C and 25 degrees C for 4 weeks, with only marginal decline at 37 degrees C and 45 degrees C over 4 weeks. The DTS-based PT program was piloted successfully in 24 testing sites in Kenya. Results demonstrate that the DTS is a simple to use, practical method to prepare and distribute PT panels and quality control specimens to monitor HIV testing practices in RLS.

  5. Real time digital control and controlled structures experiments

    NASA Technical Reports Server (NTRS)

    Rossi, Michael J.; Knowles, Gareth J.; Rauch, Frank

    1991-01-01

    Viewgraphs covering the following topics are given: controlled structures technology at Grumman Corporate Research Center, active and passive control technology, experiment plans, and vacuum chamber test experiment objectives and setup.

  6. A digital computer propulsion control facility: Description of capabilities and summary of experimental program results

    NASA Technical Reports Server (NTRS)

    Zeller, J. R.; Arpasi, D. J.; Lehtinen, B.

    1976-01-01

    Flight weight digital computers are being used today to carry out many of the propulsion system control functions previously delegated exclusively to hydromechanical controllers. An operational digital computer facility for propulsion control mode studies has been used successfully in several experimental programs. This paper describes the system and some of the results concerned with engine control, inlet control, and inlet engine integrated control. Analytical designs for the digital propulsion control modes include both classical and modern/optimal techniques.

  7. Screening strategies for active tuberculosis: focus on cost-effectiveness

    PubMed Central

    Dobler, Claudia Caroline

    2016-01-01

    In recent years, there has been renewed interest in screening for active tuberculosis (TB), also called active case-finding (ACF), as a possible means to achieve control of the global TB epidemic. ACF aims to increase the detection of TB, in order to diagnose and treat patients with TB earlier than if they had been diagnosed and treated only at the time when they sought health care because of symptoms. This will reduce or avoid secondary transmission of TB to other people, with the long-term goal of reducing the incidence of TB. Here, the history of screening for active TB, current screening practices, and the role of TB-diagnostic tools are summarized and the literature on cost-effectiveness of screening for active TB reviewed. Cost-effectiveness analyses indicate that community-wide ACF can be cost-effective in settings with a high incidence of TB. ACF among close TB contacts is cost-effective in settings with a low as well as a high incidence of TB. The evidence for cost-effectiveness of screening among HIV-infected persons is not as strong as for TB contacts, but the reviewed studies suggest that the intervention can be cost-effective depending on the background prevalence of TB and test volume. None of the cost-effectiveness analyses were informed by data from randomized controlled trials. As the results of randomized controlled trials evaluating different ACF strategies will become available in future, we will hopefully gain a better understanding of the role that ACF can play in achieving global TB control. PMID:27418848

  8. Fabrication and test of digital output interface devices for gas turbine electronic controls

    NASA Technical Reports Server (NTRS)

    Newirth, D. M.; Koenig, E. W.

    1978-01-01

    A program was conducted to develop an innovative digital output interface device, a digital effector with optical feedback of the fuel metering valve position, for future electronic controls for gas turbine engines. A digital effector (on-off solenoids driven directly by on-off signals from a digital electronic controller) with optical position feedback was fabricated, coupled with the fuel metering valve, and tested under simulated engine operating conditions. The testing indicated that a digital effector with optical position feedback is a suitable candidate, with proper development for future digital electronic gas turbine controls. The testing also identified several problem areas which would have to be overcome in a final production configuration.

  9. TRAPEZE: a randomised controlled trial of the clinical effectiveness and cost-effectiveness of chemotherapy with zoledronic acid, strontium-89, or both, in men with bony metastatic castration-refractory prostate cancer.

    PubMed Central

    James, Nicholas; Pirrie, Sarah; Pope, Ann; Barton, Darren; Andronis, Lazaros; Goranitis, Ilias; Collins, Stuart; McLaren, Duncan; O'Sullivan, Joe; Parker, Chris; Porfiri, Emilio; Staffurth, John; Stanley, Andrew; Wylie, James; Beesley, Sharon; Birtle, Alison; Brown, Janet; Chakraborti, Prabir; Russell, Martin; Billingham, Lucinda

    2016-01-01

    BACKGROUND: Bony metastatic castration-refractory prostate cancer is associated with a poor prognosis and high morbidity. TRAPEZE was a two-by-two factorial randomised controlled trial of zoledronic acid (ZA) and strontium-89 (Sr-89), each combined with docetaxel. All have palliative benefits, are used to control bone symptoms and are used with docetaxel to prolong survival. ZA, approved on the basis of reducing skeletal-related events (SREs), is commonly combined with docetaxel in practice, although evidence of efficacy and cost-effectiveness is lacking. Sr-89, approved for controlling metastatic pain and reducing need for subsequent bone treatments, is generally palliatively used in patients unfit for chemotherapy. Phase II analysis confirmed the safety and feasibility of combining these agents. TRAPEZE aimed to determine the clinical effectiveness and cost-effectiveness of each agent. METHODS: Patients were randomised to receive six cycles of docetaxel plus prednisolone: alone, with ZA, with a single Sr-89 dose after cycle 6, or with both. Primary outcomes were clinical progression-free survival (CPFS: time to pain progression, SRE or death) and cost-effectiveness. Secondary outcomes were SRE-free interval (SREFI), total SREs, overall survival (OS) and quality of life (QoL). Log-rank test and Cox regression modelling were used to determine clinical effectiveness. Cost-effectiveness was assessed from the NHS perspective and expressed as cost per additional quality-adjusted life-year (QALY). An additional analysis was carried out for ZA to reflect the availability of generic ZA. RESULTS: PATIENTS: 757 randomised (median age 68.7 years; Eastern Cooperative Oncology Group scale score 0, 40%; 1, 52%; 2, 8%; prior radiotherapy, 45%); median prostate-specific antigen 143.78 ng/ml (interquartile range 50.8-353.9 ng/ml). Stratified log-rank analysis of CPFS was statistically non-significant for either agent (Sr-89, p = 0.11; ZA, p = 0.45). Cox regression

  10. Direct drive digital servo press with high parallel control

    NASA Astrophysics Data System (ADS)

    Murata, Chikara; Yabe, Jun; Endou, Junichi; Hasegawa, Kiyoshi

    2013-12-01

    Direct drive digital servo press has been developed as the university-industry joint research and development since 1998. On the basis of this result, 4-axes direct drive digital servo press has been developed and in the market on April of 2002. This servo press is composed of 1 slide supported by 4 ball screws and each axis has linearscale measuring the position of each axis with high accuracy less than μm order level. Each axis is controlled independently by servo motor and feedback system. This system can keep high level parallelism and high accuracy even with high eccentric load. Furthermore the 'full stroke full power' is obtained by using ball screws. Using these features, new various types of press forming and stamping have been obtained by development and production. The new stamping and forming methods are introduced and 'manufacturing' need strategy of press forming with high added value and also the future direction of press forming are also introduced.

  11. Cost-effectiveness of Early Surgery versus Conservative Treatment with Optional Delayed Meniscectomy for Patients over 45 years with non-obstructive meniscal tears (ESCAPE study): protocol of a randomised controlled trial

    PubMed Central

    van de Graaf, Victor A; Scholtes, Vanessa A B; Wolterbeek, Nienke; Noorduyn, Julia C A; Neeter, Camille; van Tulder, Maurits W; Saris, Daniël B F; de Gast, Arthur; Poolman, Rudolf W

    2016-01-01

    Introduction Recent studies show similar outcome between surgery and conservative treatment in patients with non-obstructive meniscal tears. However, surgery is still often preferred over conservative treatment. When conservative treatment is non-inferior to surgery, shifting the current standard treatment choice to conservative treatment alone could save over €30 millions of direct medical costs on an annual basis. Economic evaluation studies comparing surgery to conservative treatment are lacking. Methods and analysis A multicentre randomised controlled trial (RCT) with an economic evaluation alongside was performed to assess the (cost)-effectiveness of surgery and conservative treatment for meniscal tears. We will include 402 participants between 45 and 70 years with an MRI-confirmed symptomatic, non-obstructive meniscal tears to prove non-inferiority of conservative treatment. Block randomisation will be web-based. The primary outcome measure is a physical function, measured by the International Knee Documentation Committee ‘Subjective Knee Form’. Furthermore, we will perform a cost-effectiveness and cost-utility analysis from societal perspective and a budget impact analysis from a societal, government and insurer perspective. Secondary outcomes include general health, quality of life, activity level, knee pain, physical examination, progression of osteoarthritis and the occurrence of adverse events. Ethics and dissemination This RCT will be performed in accordance with the Declaration of Helsinki and has been approved by the Ethics Committee (number NL44188.100.13). The results of this study will be reported in peer-reviewed journals and at international conferences. We further aim to disseminate our results to guideline committees. Trial registration number NCT01850719. PMID:28003302

  12. The Community In-reach Rehabilitation and Care Transition (CIRACT) clinical and cost-effectiveness randomisation controlled trial in older people admitted to hospital as an acute medical emergency

    PubMed Central

    Pulikottil-Jacob, Ruth; Marshall, Fiona; Montgomery, Alan; Tan, Wei; Sach, Tracey; Logan, Pip; Kendrick, Denise; Watson, Alison; Walker, Maria; Waring, Justin

    2017-01-01

    Abstract Objective to compare the clinical and cost-effectiveness of a Community In-reach Rehabilitation and Care Transition (CIRACT) service with the traditional hospital-based rehabilitation (THB-Rehab) service. Design pragmatic randomised controlled trial with an integral health economic study. Settings large UK teaching hospital, with community follow-up. Subjects frail older people aged 70 years and older admitted to hospital as an acute medical emergency. Measurements Primary outcome: hospital length of stay; secondary outcomes: readmission, day 91-super spell bed days, functional ability, co-morbidity and health-related quality of life; cost-effectiveness analysis. Results a total of 250 participants were randomised. There was no significant difference in length of stay between the CIRACT and THB-Rehab service (median 8 versus 9 days; geometric mean 7.8 versus 8.7 days, mean ratio 0.90, 95% confidence interval (CI) 0.74–1.10). Of the participants who were discharged from hospital, 17% and 13% were readmitted within 28 days from the CIRACT and THB-Rehab services, respectively (risk difference 3.8%, 95% CI −5.8% to 13.4%). There were no other significant differences in any of the other secondary outcomes between the two groups. The mean costs (including NHS and personal social service) of the CIRACT and THB-Rehab service were £3,744 and £3,603, respectively (mean cost difference £144; 95% CI −1,645 to 1,934). Conclusion the CIRACT service does not reduce major hospital length of stay nor reduce short-term readmission rates, compared to the standard THB-Rehab service; however, a modest (<2.3 days) effect cannot be excluded. Further studies are necessary powered with larger sample sizes and cluster randomisation. Trial registration ISRCTN 94393315, 25th April 2013 PMID:28180236

  13. Start2quit: a randomised clinical controlled trial to evaluate the effectiveness and cost-effectiveness of using personal tailored risk information and taster sessions to increase the uptake of the NHS Stop Smoking Services.

    PubMed Central

    Gilbert, Hazel; Sutton, Stephen; Morris, Richard; Petersen, Irene; Wu, Qi; Parrott, Steve; Galton, Simon; Kale, Dimitra; Magee, Molly Sweeney; Gardner, Leanne; Nazareth, Irwin

    2017-01-01

    BACKGROUND The NHS Stop Smoking Services (SSSs) offer help to smokers who want to quit. However, the proportion of smokers attending the SSSs is low and current figures show a continuing downward trend. This research addressed the problem of how to motivate more smokers to accept help to quit. OBJECTIVES To assess the relative effectiveness, and cost-effectiveness, of an intervention consisting of proactive recruitment by a brief computer-tailored personal risk letter and an invitation to a 'Come and Try it' taster session to provide information about the SSSs, compared with a standard generic letter advertising the service, in terms of attendance at the SSSs of at least one session and validated 7-day point prevalent abstinence at the 6-month follow-up. DESIGN Randomised controlled trial of a complex intervention with follow-up 6 months after the date of randomisation. SETTING SSSs and general practices in England. PARTICIPANTS All smokers aged ≥ 16 years identified from medical records in participating practices who were motivated to quit and who had not attended the SSS in the previous 12 months. Participants were randomised in the ratio 3 : 2 (intervention to control) by a computer program. INTERVENTIONS Intervention - brief personalised and tailored letter sent from the general practitioner using information obtained from the screening questionnaire and from medical records, and an invitation to attend a taster session, run by the local SSS. Control - standard generic letter from the general practice advertising the local SSS and the therapies available, and asking the smoker to contact the service to make an appointment. MAIN OUTCOME MEASURES (1) Proportion of people attending the first session of a 6-week course over a period of 6 months from the receipt of the invitation letter, measured by records of attendance at the SSSs; (2) 7-day point prevalent abstinence at the 6-month follow-up, validated by salivary cotinine analysis; and (3) cost-effectiveness

  14. [Intensified insulin treatment is cost-effective].

    PubMed

    Reichard, P; Alm, C; Andersson, E; Wärn, I; Rosenqvist, U

    1999-01-20

    Both the Diabetes Control and Complications Trial (DCCT) in USA/Canada, and Stockholm Diabetes Intervention Study (SDIS) showed intensified insulin treatment and reduced glycaemia to prevent complications in patients with insulin-dependent (type I) diabetes mellitus. In the DCCT, the intensified treatment was considered cost-effective. In the SDIS, investigation of the direct increase in costs due to the intensified insulin treatment showed the saving in direct costs due to the reduction in photocoagulation requirements, and in the prevalence of renal insufficiency and of amputation, to correspond to 10 years' intensive insulin treatment. Thus, as intensified insulin treatment in type I diabetes reduces direct suffering at a low cost, it may be regarded as 'evidence-based' and mandatory.

  15. Analyses of Blood Bank Efficiency, Cost-Effectiveness and Quality

    NASA Astrophysics Data System (ADS)

    Lam, Hwai-Tai Chen

    In view of the increasing costs of hospital care, it is essential to investigate methods to improve the labor efficiency and the cost-effectiveness of the hospital technical core in order to control costs while maintaining the quality of care. This study was conducted to develop indices to measure efficiency, cost-effectiveness, and the quality of blood banks; to identify factors associated with efficiency, cost-effectiveness, and quality; and to generate strategies to improve blood bank labor efficiency and cost-effectiveness. Indices developed in this study for labor efficiency and cost-effectiveness were not affected by patient case mix and illness severity. Factors that were associated with labor efficiency were identified as managerial styles, and organizational designs that balance workload and labor resources. Medical directors' managerial involvement was not associated with labor efficiency, but their continuing education and specialty in blood bank were found to reduce the performance of unnecessary tests. Surprisingly, performing unnecessary tests had no association with labor efficiency. This suggested the existence of labor slack in blood banks. Cost -effectiveness was associated with workers' benefits, wages, and the production of high-end transfusion products by hospital-based donor rooms. Quality indices used in this study included autologous transfusion rates, platelet transfusion rates, and the check points available in an error-control system. Because the autologous transfusion rate was related to patient case mix, severity of illness, and possible inappropriate transfusion, it was not recommended to be used for quality index. Platelet-pheresis transfusion rates were associated with the transfusion preferences of the blood bank medical directors. The total number of check points in an error -control system was negatively associated with government ownership and workers' experience. Recommendations for improving labor efficiency and cost-effectiveness

  16. A pragmatic randomised controlled trial of the effectiveness and cost-effectiveness of screening older women for the prevention of fractures: rationale, design and methods for the SCOOP study.

    PubMed

    Shepstone, L; Fordham, R; Lenaghan, E; Harvey, I; Cooper, C; Gittoes, N; Heawood, A; Peters, T J; O'Neill, T; Torgerson, D; Holland, R; Howe, A; Marshall, T; Kanis, J A; McCloskey, E

    2012-10-01

    SCOOP is a UK seven-centre, pragmatic, randomised controlled trial with 5-year follow-up, including 11,580 women aged 70 to 85 years, to assess the effectiveness and cost-effectiveness of a community-based screening programme to reduce fractures. It utilises the FRAX algorithm and DXA to assess the 10-year probability of fracture. Introduction Osteoporotic, or low-trauma, fractures present a considerable burden to the National Health Service and have major adverse effects on quality of life, disability and mortality for the individual. Methods Given the availability of efficacious treatments and a risk assessment tool based upon clinical risk factors and bone mineral density, a case exists to undertake a community-based controlled evaluation of screening for subjects at high risk of fracture, under the hypothesis that such a screening programme would reduce fractures in this population. Results This study is a UK seven-centre, unblinded, pragmatic, randomised controlled trial with a 5-year follow-up period. A total of 11,580 women, aged 70 to 85 years and not on prescribed bone protective therapy will be consented to the trial by post via primary care providing 90% power to detect an 18% decrease in fractures. Conclusions Participants will be randomised to either a screening arm or control. Those undergoing screening will have a 10-year fracture probability computed from baseline risk factors together with bone mineral density measured by DXA in selected subjects. Individuals above an age-dependent threshold of fracture probability will be recommended for treatment for the duration of the trial. Subjects in the control arm will receive 'usual care'. Participants will be followed up 6 months after randomisation and annually by postal questionnaires with independent checking of hospital and primary care records. The primary outcome will be the proportion of individuals sustaining fractures in each group. An economic analysis will be carried out to assess cost-effectiveness

  17. Digital Signal Processing and Control for the Study of Gene Networks

    PubMed Central

    Shin, Yong-Jun

    2016-01-01

    Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks. PMID:27102828

  18. Digital Signal Processing and Control for the Study of Gene Networks.

    PubMed

    Shin, Yong-Jun

    2016-04-22

    Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

  19. Digital Signal Processing and Control for the Study of Gene Networks

    NASA Astrophysics Data System (ADS)

    Shin, Yong-Jun

    2016-04-01

    Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

  20. Propulsion control experience used in the Highly Integrated Digital Electronic Control (HIDEC) program

    NASA Technical Reports Server (NTRS)

    Myers, L. P.; Burcham, F. W., Jr.

    1984-01-01

    The highly integrated digital electronic control (HIDEC) program will integrate the propulsion and flight control systems on an F-15 airplane at NASA Ames Research Center's Dryden Flight Research Facility. Ames-Dryden has conducted several propulsion control programs that have contributed to the HIDEC program. The digital electronic engine control (DEEC) flight evaluation investigated the performance and operability of the F100 engine equipped with a full-authority digital electronic control system. Investigations of nozzle instability, fault detection and accommodation, and augmentor transient capability provided important information for the HIDEC program. The F100 engine model derivative (EMD) was also flown in the F-15 airplane, and airplane performance was significantly improved. A throttle response problem was found and solved with a software fix to the control logic. For the HIDEC program, the F100 EMD engines equipped with DEEC controls will be integrated with the digital flight control system. The control modes to be implemented are an integrated flightpath management mode and an integrated adaptive engine control system mode. The engine control experience that will be used in the HIDEC program is discussed.

  1. Digital feedwater and recirculation flow control for GPUN Oyster Creek

    SciTech Connect

    Burjorjee, D. ); Gan, B. )

    1992-01-01

    This paper describes the digital system for feedwater and recirculation control that GPU Nuclear will be installing at Oyster Creek during its next outage - expected circa December 1992. The replacement was motivated by considerations of reliability and obsolescence - the analog equipment was aging and reaching the end of its useful life. The new system uses Atomic Energy of Canada Ltd.'s software platform running on dual, redundant, industrial-grade 386 computers with opto-isolated field input/output (I/O) accessed through a parallel bus. The feedwater controller controls three main feed regulating valves, two low flow regulating valves, and two block valves. The recirculation controller drives the five scoop positioners of the hydraulic couplers. The system also drives contacts that lock up the actuators on detecting an open circuit in their current loops.

  2. A comparison of digital flight control design methods

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E.; Tashker, M. G.

    1976-01-01

    Many variations in design methods for aircraft digital flight control have been proposed in the literature. In general, the methods fall into two categories: those where the design is done in the continuous domain (or s-plane), and those where the design is done in the discrete domain (or z-plane). This paper evaluates several variations of each category and compares them for various flight control modes of the Langley TCV Boeing 737 aircraft. Design method fidelity is evaluated by examining closed loop root movement and the frequency response of the discretely controlled continuous aircraft. It was found that all methods provided acceptable performance for sample rates greater than 10 cps except the 'uncompensated s-plane design' method which was acceptable above 20 cps. A design procedure based on optimal control methods was proposed that provided the best fidelity at very slow sample rates and required no design iterations for changing sample rates.

  3. Direct digital control of air washer cooling system

    SciTech Connect

    Elben, T.; Roseblock, R.; Lawler, R.; McCord, J.

    1990-01-01

    The purpose of this project was to make a practical evaluation of using new technology to extend the life of obsolete HVAC mechanical equipment. The specific exercises in this project involved the application of software driven control algorithms to operate and manage open loop air washer cooling systems in the air handling units located in the Municipal Auditorium in Kansas City, Missouri. The specific opportunity evaluated in this project involved eight air handling units at the Municipal Auditorium. The air handling systems utilize outdated air washer cooling systems that provide air conditioning and dehumidification to the areas they serve. We utilized direct digital control to assume total control of the operation of the air handling units. We also found it necessary to upgrade some components of the air handling units in order to allow the new control applications to execute their functions. This report describes the plan used to execute the project and the results. 20 tabs.

  4. Digital adaptive controllers for VTOL vehicles. Volume 1: Concept evaluation

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Stein, G.; Pratt, S. G.

    1979-01-01

    A digital self-adaptive flight control system was developed for flight test in the VTOL approach and landing technology (VALT) research aircraft (a modified CH-47 helicopter). The control laws accept commands from an automatic on-board guidance system. The primary objective of the control laws is to provide good command-following with a minimum cross-axis response. Three attitudes and vertical velocity are separately commanded. Adaptation of the control laws is based on information from rate and attitude gyros and a vertical velocity measurement. The final design resulted from a comparison of two different adaptive concepts--one based on explicit parameter estimates from a real-time maximum-likelihood estimation algorithm, the other based on an implicit model reference adaptive system. The two designs were compared on the basis of performance and complexity.

  5. Nonlinear and Digital Man-machine Control Systems Modeling

    NASA Technical Reports Server (NTRS)

    Mekel, R.

    1972-01-01

    An adaptive modeling technique is examined by which controllers can be synthesized to provide corrective dynamics to a human operator's mathematical model in closed loop control systems. The technique utilizes a class of Liapunov functions formulated for this purpose, Liapunov's stability criterion and a model-reference system configuration. The Liapunov function is formulated to posses variable characteristics to take into consideration the identification dynamics. The time derivative of the Liapunov function generate the identification and control laws for the mathematical model system. These laws permit the realization of a controller which updates the human operator's mathematical model parameters so that model and human operator produce the same response when subjected to the same stimulus. A very useful feature is the development of a digital computer program which is easily implemented and modified concurrent with experimentation. The program permits the modeling process to interact with the experimentation process in a mutually beneficial way.

  6. A task-based quality control metric for digital mammography

    NASA Astrophysics Data System (ADS)

    Maki Bloomquist, A. K.; Mainprize, J. G.; Mawdsley, G. E.; Yaffe, M. J.

    2014-11-01

    A reader study was conducted to tune the parameters of an observer model used to predict the detectability index (dʹ ) of test objects as a task-based quality control (QC) metric for digital mammography. A simple test phantom was imaged to measure the model parameters, namely, noise power spectrum, modulation transfer function and test-object contrast. These are then used in a non-prewhitening observer model, incorporating an eye-filter and internal noise, to predict dʹ. The model was tuned by measuring dʹ of discs in a four-alternative forced choice reader study. For each disc diameter, dʹ was used to estimate the threshold thicknesses for detectability. Data were obtained for six types of digital mammography systems using varying detector technologies and x-ray spectra. A strong correlation was found between measured and modeled values of dʹ, with Pearson correlation coefficient of 0.96. Repeated measurements from separate images of the test phantom show an average coefficient of variation in dʹ for different systems between 0.07 and 0.10. Standard deviations in the threshold thickness ranged between 0.001 and 0.017 mm. The model is robust and the results are relatively system independent, suggesting that observer model dʹ shows promise as a cross platform QC metric for digital mammography.

  7. Digital redesign of anti-wind-up controller for cascaded analog system.

    PubMed

    Chen, Y S; Tsai, J S H; Shieh, L S; Moussighi, M M

    2003-01-01

    The cascaded conventional anti-wind-up (CAW) design method for integral controller is discussed. Then, the prediction-based digital redesign methodology is utilized to find the new pulse amplitude modulated (PAM) digital controller for effective digital control of the analog plant with input saturation constraint. The desired digital controller is determined from existing or pre-designed CAW analog controller. The proposed method provides a novel methodology for indirect digital design of a continuous-time unity output-feedback system with a cascaded analog controller as in the case of PID controllers for industrial control processes with the presence of actuator saturations. It enables us to implement an existing or pre-designed cascaded CAW analog controller via a digital controller effectively.

  8. Clinical effectiveness and cost-effectiveness of the Rehabilitation Enablement in Chronic Heart Failure (REACH-HF) facilitated self-care rehabilitation intervention in heart failure patients and caregivers: rationale and protocol for a multicentre randomised controlled trial

    PubMed Central

    Taylor, R S; Hayward, C; Eyre, V; Austin, J; Davies, R; Doherty, P; Jolly, K; Wingham, J; Van Lingen, R; Abraham, C; Green, C; Warren, FC; Britten, N; Greaves, C J; Singh, S; Buckingham, S; Paul, K; Dalal, H

    2015-01-01

    Introduction The Rehabilitation EnAblement in CHronic Heart Failure (REACH-HF) trial is part of a research programme designed to develop and evaluate a health professional facilitated, home-based, self-help rehabilitation intervention to improve self-care and health-related quality of life in people with heart failure and their caregivers. The trial will assess the clinical effectiveness and cost-effectiveness of the REACH-HF intervention in patients with systolic heart failure and impact on the outcomes of their caregivers. Methods and analysis A parallel two group randomised controlled trial with 1:1 individual allocation to the REACH-HF intervention plus usual care (intervention group) or usual care alone (control group) in 216 patients with systolic heart failure (ejection fraction <45%) and their caregivers. The intervention comprises a self-help manual delivered by specially trained facilitators over a 12-week period. The primary outcome measure is patients’ disease-specific health-related quality of life measured using the Minnesota Living with Heart Failure questionnaire at 12 months’ follow-up. Secondary outcomes include survival and heart failure related hospitalisation, blood biomarkers, psychological well-being, exercise capacity, physical activity, other measures of quality of life, patient safety and the quality of life, psychological well-being and perceived burden of caregivers at 4, 6 and 12 months’ follow-up. A process evaluation will assess fidelity of intervention delivery and explore potential mediators and moderators of changes in health-related quality of life in intervention and control group patients. Qualitative studies will describe patient and caregiver experiences of the intervention. An economic evaluation will estimate the cost-effectiveness of the REACH-HF intervention plus usual care versus usual care alone in patients with systolic heart failure. Ethics and dissemination The study is approved by the North West

  9. In Search of Cost-Effective Schools.

    ERIC Educational Resources Information Center

    Raywid, Mary Anne; Shaheen, Thomas A.

    1994-01-01

    Examines major cost-effectiveness proposals, describing developments that highlight concerns over making schools cost effective. The article discusses ways to blend the concerns of educational quality, equity, and costs (district consolidations, shared service and facilities arrangements, new accountability strategies, new information systems,…

  10. Cost-effectiveness thresholds: pros and cons.

    PubMed

    Bertram, Melanie Y; Lauer, Jeremy A; De Joncheere, Kees; Edejer, Tessa; Hutubessy, Raymond; Kieny, Marie-Paule; Hill, Suzanne R

    2016-12-01

    Cost-effectiveness analysis is used to compare the costs and outcomes of alternative policy options. Each resulting cost-effectiveness ratio represents the magnitude of additional health gained per additional unit of resources spent. Cost-effectiveness thresholds allow cost-effectiveness ratios that represent good or very good value for money to be identified. In 2001, the World Health Organization's Commission on Macroeconomics in Health suggested cost-effectiveness thresholds based on multiples of a country's per-capita gross domestic product (GDP). In some contexts, in choosing which health interventions to fund and which not to fund, these thresholds have been used as decision rules. However, experience with the use of such GDP-based thresholds in decision-making processes at country level shows them to lack country specificity and this - in addition to uncertainty in the modelled cost-effectiveness ratios - can lead to the wrong decision on how to spend health-care resources. Cost-effectiveness information should be used alongside other considerations - e.g. budget impact and feasibility considerations - in a transparent decision-making process, rather than in isolation based on a single threshold value. Although cost-effectiveness ratios are undoubtedly informative in assessing value for money, countries should be encouraged to develop a context-specific process for decision-making that is supported by legislation, has stakeholder buy-in, for example the involvement of civil society organizations and patient groups, and is transparent, consistent and fair.

  11. Anticipatory planning and control of grasp positions and forces for dexterous two-digit manipulation.

    PubMed

    Fu, Qiushi; Zhang, Wei; Santello, Marco

    2010-07-07

    Dexterous object manipulation requires anticipatory control of digit positions and forces. Despite extensive studies on sensorimotor learning of digit forces, how humans learn to coordinate digit positions and forces has never been addressed. Furthermore, the functional role of anticipatory modulation of digit placement to object properties remains to be investigated. We addressed these questions by asking human subjects (12 females, 12 males) to grasp and lift an inverted T-shaped object using precision grip at constrained or self-chosen locations. The task requirement was to minimize object roll during lift. When digit position was not constrained, subjects could have implemented many equally valid digit position-force coordination patterns. However, choice of digit placement might also have resulted in large trial-to-trial variability of digit position, hence challenging the extent to which the CNS could have relied on sensorimotor memories for anticipatory control of digit forces. We hypothesized that subjects would modulate digit placement for optimal force distribution and digit forces as a function of variable digit positions. All subjects learned to minimize object roll within the first three trials, and the unconstrained device was associated with significantly smaller grip forces but larger variability of digit positions. Importantly, however, digit load force modulation compensated for position variability, thus ensuring consistent object roll minimization on each trial. This indicates that subjects learned object manipulation by integrating sensorimotor memories with sensory feedback about digit positions. These results are discussed in the context of motor equivalence and sensorimotor integration of grasp kinematics and kinetics.

  12. Selection of sampling rate for digital control of aircrafts

    NASA Technical Reports Server (NTRS)

    Katz, P.; Powell, J. D.

    1974-01-01

    The considerations in selecting the sample rates for digital control of aircrafts are identified and evaluated using the optimal discrete method. A high performance aircraft model which includes a bending mode and wind gusts was studied. The following factors which influence the selection of the sampling rates were identified: (1) the time and roughness response to control inputs; (2) the response to external disturbances; and (3) the sensitivity to variations of parameters. It was found that the time response to a control input and the response to external disturbances limit the selection of the sampling rate. The optimal discrete regulator, the steady state Kalman filter, and the mean response to external disturbances are calculated.

  13. Holographic digital microscopy in on-line process control

    NASA Astrophysics Data System (ADS)

    Osanlou, Ardeshir

    2011-09-01

    This article investigates the feasibility of real-time three-dimensional imaging of microscopic objects within various emulsions while being produced in specialized production vessels. The study is particularly relevant to on-line process monitoring and control in chemical, pharmaceutical, food, cleaning, and personal hygiene industries. Such processes are often dynamic and the materials cannot be measured once removed from the production vessel. The technique reported here is applicable to three-dimensional characterization analyses on stirred fluids in small reaction vessels. Relatively expensive pulsed lasers have been avoided through the careful control of the speed of the moving fluid in relation to the speed of the camera exposure and the wavelength of the continuous wave laser used. The ultimate aim of the project is to introduce a fully robust and compact digital holographic microscope as a process control tool in a full size specialized production vessel.

  14. A self-reorganizing digital flight control system for aircraft

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.; Caglayan, A. K.

    1974-01-01

    This paper presents a design method for digital self-reorganizing control systems which is optimally tolerant of failures in aircraft sensors. The functions of this system are accomplished with software instead of the popular and costly technique of hardware duplication. The theoretical development, based on M-ary hypothesis testing, results in a bank of M Kalman filters operating in parallel in the failure detection logic. A moving window of the innovations of each Kalman filter drives the detection logic to decide the failure state of the system. The detection logic also selects the optimal state estimate (for control logic) from the bank of Kalman filters. The design process is applied to the design of a self-reorganizing control system for a current configuration of the space shuttle orbiter at Mach 5 and 120,000 feet. The failure detection capabilities of the system are demonstrated using a real-time simulation of the system with noisy sensors.

  15. Gimballing magnetic bearing reaction wheel with digital controller

    NASA Astrophysics Data System (ADS)

    Gerlach, Bernd; Ehinger, Markus; Raue, Hans Knut; Seiler, René

    2005-07-01

    Magnetic bearing reaction wheels provide a number of interesting advantages over ball bearing wheels. They allow high-speed operation with minimum loss torque and generate substantially less micro-vibrations. However, they require dedicated, demanding control electronics. A conroller based on a Digital Signal Processor has been developed. The controller was tested with an 87 Nms wheel prototype equipped with a magnetic bearing allowing active control in five axes. The wheel provides low-noise operation from 0 to 8000 rpm with a rotor gimballing capability of up to ±1.7°. The paper reviews the design principles and presents relevant test results, e.g. regarding the active suppression of micro-vibrations.

  16. Efficacy and cost-effectiveness of a web-based intervention with mobile phone support to treat depressive symptoms in adults with diabetes mellitus type 1 and type 2: design of a randomised controlled trial

    PubMed Central

    2013-01-01

    Background A diagnosis of diabetes mellitus types 1 or 2 doubles the odds of a comorbid depressive disorder. The combined diseases have a wide range of adverse outcomes, such as a lower quality of life, poorer diabetes outcomes and increased healthcare utilisation. Diabetes patients with depression can be treated effectively with psychotherapy, but access to psychological care is limited. In this study we will examine the efficacy and cost-effectiveness of a newly developed web-based intervention (GET.ON Mood Enhancer Diabetes) for people with diabetes and comorbid depressive symptoms. Methods/Design A two-arm randomised controlled trial will be conducted. Adults with diabetes (type 1 or type 2) with increased depression scores (> 22 on the German version of the Center for Epidemiological Studies Depression Scale (CES-D)) will be included. Eligible participants will be recruited through advertisement in diabetes patient journals and via a large-scale German health insurance company. The participants will be randomly assigned to either a 6-week minimally guided web-based self-help program or an online psychoeducation program on depression. The study will include 260 participants, which will enable us to detect a statistically significant difference with a group effect size of d = 0.35 at a power of 80% and a significance level of p = 0.05. The primary outcome measure will be the level of depression as assessed by the CES-D. The secondary outcome measures will be: diabetes-specific emotional distress, glycaemic control, self-management behaviour and the participants’ satisfaction with the intervention. Online self-assessments will be collected at baseline and after a 2 months period, with additional follow-up measurements 6 and 12 months after randomisation. The data will be analysed on an intention-to-treat basis and per protocol. In addition, we will conduct an economic evaluation from a societal perspective. Discussion If this intervention is shown to be

  17. Integrated Digital Flight Control System for the Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives of the integrated digital flight control system (DFCS) is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the computer complex and is equally insensitive to characteristics of the processor configuration. The integrated structure is described of the control system and the DFCS executive routine which embodies that structure. The input and output, including jet selection are included. Specific estimation and control algorithm are shown for the various mission phases: cruise (including horizontal powered flight), entry, on-orbit, and boost. Attitude maneuver routines that interface with the DFCS are included.

  18. Digital flight control software design requirements. [for space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objective of the integrated digital flight control system is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effects by using an executive routine/function subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the GN and C computer complex and is equally insensitive to the characteristics of the processor configuration. The integrated structure of the control system and the DFCS executive routine which embodies that structure are described. The specific estimation and control algorithms used in the various mission phases are shown. Attitude maneuver routines that interface with the DFCS are also described.

  19. Digital Control Technologies for Modular DC-DC Converters

    NASA Technical Reports Server (NTRS)

    Button, Robert M.; Kascak, Peter E.; Lebron-Velilla, Ramon

    2002-01-01

    Recent trends in aerospace Power Management and Distribution (PMAD) systems focus on using commercial off-the-shelf (COTS) components as standard building blocks. This move to more modular designs has been driven by a desire to reduce costs and development times, but is also due to the impressive power density and efficiency numbers achieved by today's commercial DC-DC converters. However, the PMAD designer quickly learns of the hidden "costs" of using COTS converters. The most significant cost is the required addition of external input filters to meet strict electromagnetic interference (MIAMI) requirements for space systems. In fact, the high power density numbers achieved by the commercial manufacturers are greatly due to the lack of necessary input filters included in the COTS module. The NASA Glenn Research Center is currently pursuing a digital control technology that addresses this problem with modular DC-DC converters. This paper presents the digital control technologies that have been developed to greatly reduce the input filter requirements for paralleled, modular DC-DC converters. Initial test result show that the input filter's inductor size was reduced by 75 percent, and the capacitor size was reduced by 94 percent while maintaining the same power quality specifications.

  20. Stand-alone digital data storage control system including user control interface

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth D. (Inventor); Gray, David L. (Inventor)

    1994-01-01

    A storage control system includes an apparatus and method for user control of a storage interface to operate a storage medium to store data obtained by a real-time data acquisition system. Digital data received in serial format from the data acquisition system is first converted to a parallel format and then provided to the storage interface. The operation of the storage interface is controlled in accordance with instructions based on user control input from a user. Also, a user status output is displayed in accordance with storage data obtained from the storage interface. By allowing the user to control and monitor the operation of the storage interface, a stand-alone, user-controllable data storage system is provided for storing the digital data obtained by a real-time data acquisition system.

  1. Impact of Smoke Exposure on Digital Instrumentation and Control

    SciTech Connect

    Tanaka, Tina J.; Nowlen, Steven P.; Korsah, Kofi; Wood, Richard T.; Antonescu, Christina E.

    2003-08-15

    Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The results of previous smoke exposure studies have been reported in various publications. The major immediate effect of smoke has been to increase leakage currents and to cause momentary upsets and failures in digital systems. This paper presents new results from conformal coatings, memory chips, and hard drive tests.The best conformal coatings were found to be polyurethane, parylene, and acrylic (when applied by dipping). Conformal coatings can reduce smoke-induced leakage currents and protect against metal loss through corrosion. However conformal coatings are typically flammable, so they do increase material flammability. Some of the low-voltage biased memory chips failed during a combination of high smoke and high humidity. Typically, smoke along with heat and humidity is expected during fire, rather than smoke alone. Thus, due to high sensitivity of digital circuits to heat and humidity, it is hypothesized that the impact of smoke may be secondary.Low-voltage (3.3-V) static random-access memory (SRAMs) were found to be the most vulnerable to smoke. Higher bias voltages decrease the likelihood of failure. Erasable programmable read-only memory (EPROMs) and nonvolatile SRAMs were very smoke tolerant. Failures of the SRAMs occurred when two conditions were present: high density of smoke and high humidity. As the high humidity was present for only part of the test, the failures were intermittent. All

  2. CollAborative care and active surveillance for Screen-Positive EldeRs with subthreshold depression (CASPER): a multicentred randomised controlled trial of clinical effectiveness and cost-effectiveness.

    PubMed Central

    Lewis, Helen; Adamson, Joy; Atherton, Katie; Bailey, Della; Birtwistle, Jacqueline; Bosanquet, Katharine; Clare, Emily; Delgadillo, Jaime; Ekers, David; Foster, Deborah; Gabe, Rhian; Gascoyne, Samantha; Haley, Lesley; Hargate, Rebecca; Hewitt, Catherine; Holmes, John; Keding, Ada; Lilley-Kelly, Amanda; Maya, Jahnese; McMillan, Dean; Meer, Shaista; Meredith, Jodi; Mitchell, Natasha; Nutbrown, Sarah; Overend, Karen; Pasterfield, Madeline; Richards, David; Spilsbury, Karen; Torgerson, David; Traviss-Turner, Gemma; Trépel, Dominic; Woodhouse, Rebecca; Ziegler, Friederike; Gilbody, Simon

    2017-01-01

    BACKGROUND Efforts to reduce the burden of illness and personal suffering associated with depression in older adults have focused on those with more severe depressive syndromes. Less attention has been paid to those with mild disorders/subthreshold depression, but these patients also suffer significant impairments in their quality of life and level of functioning. There is currently no clear evidence-based guidance regarding treatment for this patient group. OBJECTIVES To establish the clinical effectiveness and cost-effectiveness of a low-intensity intervention of collaborative care for primary care older adults who screened positive for subthreshold depression. DESIGN A pragmatic, multicentred, two-arm, parallel, individually randomised controlled trial with a qualitative study embedded within the pilot. Randomisation occurred after informed consent and baseline measures were collected. SETTING Thirty-two general practitioner (GP) practices in the north of England. PARTICIPANTS A total of 705 participants aged ≥ 75 years during the pilot phase and ≥ 65 years during the main trial with subthreshold depression. INTERVENTIONS Participants in the intervention group received a low-intensity intervention of collaborative care, which included behavioural activation delivered by a case manager for an average of six sessions over 7-8 weeks, alongside usual GP care. Control-arm participants received only usual GP care. MAIN OUTCOME MEASURES The primary outcome measure was a self-reported measure of depression severity, the Patient Health Questionnaire-9 items PHQ-9 score at 4 months post randomisation. Secondary outcome measures included the European Quality of Life-5 Dimensions, Short Form questionnaire-12 items, Patient Health Questionnaire-15 items, Generalised Anxiety Disorder seven-item scale, Connor-Davidson Resilience Scale two-item version, a medication questionnaire and objective data. Participants were followed up for 12 months. RESULTS In total, 705

  3. Space Shuttle Main Engine control system. [hydraulic actuator with digital control

    NASA Technical Reports Server (NTRS)

    Seitz, P. F.; Searle, R. F.

    1973-01-01

    The Space Shuttle Main Engine is a reusable, high-performance rocket engine being developed by the Rocketdyne Div. of Rockwell International to satisfy the operational requirements of the Space Shuttle Orbiter Vehicle. The design incorporates a hydraulically actuated, closed-loop servosystem controlled and monitored by a programmable electronic digital controller. The controller accepts vehicle commands for the various engine operational phases, positions the appropriate valves, monitors the engine for the required performance precisions and conditions, and provides redundancy management.

  4. 7 CFR 1755.522 - RUS general specification for digital, stored program controlled central office equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... requirements for a digital telephone central office switching system, which is fully electronic and controlled by stored program processors. A digital switching system transfers information which is digitally encoded from any input port to a temporarily addressed exit port. The information may enter the system...

  5. 7 CFR 1755.522 - RUS general specification for digital, stored program controlled central office equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... requirements for a digital telephone central office switching system, which is fully electronic and controlled by stored program processors. A digital switching system transfers information which is digitally encoded from any input port to a temporarily addressed exit port. The information may enter the system...

  6. 7 CFR 1755.522 - RUS general specification for digital, stored program controlled central office equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... requirements for a digital telephone central office switching system, which is fully electronic and controlled by stored program processors. A digital switching system transfers information which is digitally encoded from any input port to a temporarily addressed exit port. The information may enter the system...

  7. Randomised controlled trial evaluating the effectiveness and cost-effectiveness of 'Families for Health', a family-based childhood obesity treatment intervention delivered in a community setting for ages 6 to 11 years.

    PubMed Central

    Robertson, Wendy; Fleming, Joanna; Kamal, Atiya; Hamborg, Thomas; Khan, Kamran A; Griffiths, Frances; Stewart-Brown, Sarah; Stallard, Nigel; Petrou, Stavros; Simkiss, Douglas; Harrison, Elizabeth; Kim, Sung Wook; Thorogood, Margaret

    2017-01-01

    BACKGROUND Effective programmes to help children manage their weight are required. 'Families for Health' focuses on a parenting approach, designed to help parents develop their parenting skills to support lifestyle change within the family. Families for Health version 1 showed sustained reductions in mean body mass index (BMI) z-score after 2 years in a pilot project. OBJECTIVE The aim was to evaluate its effectiveness and cost-effectiveness in a randomised controlled trial (RCT). DESIGN The trial was a multicentre, investigator-blind RCT, with a parallel economic and process evaluation, with follow-up at 3 and 12 months. Randomisation was by family unit, using a 1 : 1 allocation by telephone registration, stratified by three sites, with a target of 120 families. SETTING Three sites in the West Midlands, England, UK. PARTICIPANTS Children aged 6-11 years who were overweight (≥ 91st centile BMI) or obese (≥ 98th centile BMI), and their parents/carers. Recruitment was via referral or self-referral. INTERVENTIONS Families for Health version 2 is a 10-week, family-based community programme with parallel groups for parents and children, addressing parenting, lifestyle, social and emotional development. Usual care was the treatment for childhood obesity provided within each locality. MAIN OUTCOME MEASURES Joint primary outcome measures were change in children's BMI z-score and incremental cost per quality-adjusted life-year (QALY) gained at 12 months' follow-up (QALYs were calculated using the European Quality of Life-5 Dimensions Youth version). Secondary outcome measures included changes in children's waist circumference, percentage body fat, physical activity, fruit/vegetable consumption and quality of life. Parents' BMI and mental well-being, family eating/activity, parent-child relationships and parenting style were also assessed. The process evaluation documented recruitment, reach, dose delivered, dose received and fidelity, using mixed methods

  8. Formulation of a strategy for monitoring control integrity in critical digital control systems

    NASA Technical Reports Server (NTRS)

    Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

    1991-01-01

    Advanced aircraft will require flight critical computer systems for stability augmentation as well as guidance and control that must perform reliably in adverse, as well as nominal, operating environments. Digital system upset is a functional error mode that can occur in electromagnetically harsh environments, involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. A strategy is presented for dynamic upset detection to be used in the evaluation of critical digital controllers during the design and/or validation phases of development. Critical controllers must be able to be used in adverse environments that result from disturbances caused by an electromagnetic source such as lightning, high intensity radiated field (HIRF), and nuclear electromagnetic pulses (NEMP). The upset detection strategy presented provides dynamic monitoring of a given control computer for degraded functional integrity that can result from redundancy management errors and control command calculation error that could occur in an electromagnetically harsh operating environment. The use is discussed of Kalman filtering, data fusion, and decision theory in monitoring a given digital controller for control calculation errors, redundancy management errors, and control effectiveness.

  9. Quality control measurements for digital x-ray detectors.

    PubMed

    Marshall, N W; Mackenzie, A; Honey, I D

    2011-02-21

    This paper describes a digital radiography (DR) quality control protocol for DR detectors from the forthcoming report from the Institute of Physics and Engineering in Medicine (IPEM). The protocol was applied to a group of six identical caesium iodide (CsI) digital x-ray detectors to assess reproducibility of methods, while four further detectors were assessed to examine the wider applicability. Twelve images with minimal spatial frequency processing are required, from which the detector response, lag, modulation transfer function (MTF), normalized noise power spectrum (NNPS) and threshold contrast-detail (c-d) detectability are calculated. The x-ray spectrum used was 70 kV and 1 mm added copper filtration, with a target detector air kerma of 2.5 µGy for the NNPS and c-d results. In order to compare detector performance with previous imaging technology, c-d data from four screen/film systems were also acquired, at a target optical density of 1.5 and an average detector air kerma of 2.56 µGy. The DR detector images were typically acquired in 20 min, with a further 45 min required for image transfer and analysis. The average spatial frequency for the 50% point of the MTF for six identical detectors was 1.29 mm(-1) ± 0.05 (3.9% coefficient of variation (cov)). The air kerma set for the six systems was 2.57 µGy ± 0.13 (5.0% cov) and the NNPS at this air kerma was 1.42 × 10(-5) mm(2) (6.5% cov). The detective quantum efficiency (DQE) measured for the six identical detectors was 0.60 at 0.5 mm(-1), with a maximum cov of 10% at 2.9 mm(-1), while the average DQE was 0.56 at 0.5 mm(-1) for three CsI detectors from three different manufacturers. Comparable c-d performance was found for these detectors (5.9% cov) with an average threshold contrast of 0.46% for 11 mm circular discs. The average threshold contrast for the S/F systems was 0.70% at 11 mm, indicating superior imaging performance for the digital systems. The protocol was found to be quick, reproducible and

  10. Quality control measurements for digital x-ray detectors

    NASA Astrophysics Data System (ADS)

    Marshall, N. W.; Mackenzie, A.; Honey, I. D.

    2011-02-01

    This paper describes a digital radiography (DR) quality control protocol for DR detectors from the forthcoming report from the Institute of Physics and Engineering in Medicine (IPEM). The protocol was applied to a group of six identical caesium iodide (CsI) digital x-ray detectors to assess reproducibility of methods, while four further detectors were assessed to examine the wider applicability. Twelve images with minimal spatial frequency processing are required, from which the detector response, lag, modulation transfer function (MTF), normalized noise power spectrum (NNPS) and threshold contrast-detail (c-d) detectability are calculated. The x-ray spectrum used was 70 kV and 1 mm added copper filtration, with a target detector air kerma of 2.5 µGy for the NNPS and c-d results. In order to compare detector performance with previous imaging technology, c-d data from four screen/film systems were also acquired, at a target optical density of 1.5 and an average detector air kerma of 2.56 µGy. The DR detector images were typically acquired in 20 min, with a further 45 min required for image transfer and analysis. The average spatial frequency for the 50% point of the MTF for six identical detectors was 1.29 mm-1 ± 0.05 (3.9% coefficient of variation (cov)). The air kerma set for the six systems was 2.57 µGy ± 0.13 (5.0% cov) and the NNPS at this air kerma was 1.42 × 10-5 mm2 (6.5% cov). The detective quantum efficiency (DQE) measured for the six identical detectors was 0.60 at 0.5 mm-1, with a maximum cov of 10% at 2.9 mm-1, while the average DQE was 0.56 at 0.5 mm-1 for three CsI detectors from three different manufacturers. Comparable c-d performance was found for these detectors (5.9% cov) with an average threshold contrast of 0.46% for 11 mm circular discs. The average threshold contrast for the S/F systems was 0.70% at 11 mm, indicating superior imaging performance for the digital systems. The protocol was found to be quick, reproducible and gave an in

  11. Cost-Effective Stress Management Training.

    ERIC Educational Resources Information Center

    Shea, Gordon F.

    1980-01-01

    Stress management training can be a cost effective way to improve productivity and job performance. Among many relaxation techniques, the most effective in terms of teachability, participant motivation, and profitability are self-hypnosis, progressive relaxation, and transcendental meditation. (SK)

  12. Digital phase-locked-loop speed sensor for accuracy improvement in analog speed controls. [feedback control and integrated circuits

    NASA Technical Reports Server (NTRS)

    Birchenough, A. G.

    1975-01-01

    A digital speed control that can be combined with a proportional analog controller is described. The stability and transient response of the analog controller were retained and combined with the long-term accuracy of a crystal-controlled integral controller. A relatively simple circuit was developed by using phase-locked-loop techniques and total error storage. The integral digital controller will maintain speed control accuracy equal to that of the crystal reference oscillator.

  13. Design and Evaluation of a Digital Flight Control System for the FROG Unmanned Aerial Vehicle

    DTIC Science & Technology

    2001-09-01

    DIGITAL FLIGHT CONTROL SYSTEM FOR THE FROG UNMANNED AERIAL VEHICLE by Christopher H. Flood September 2001 Thesis Advisor: Isaac I. Kaminer...Subtitle Design and Evaluation of a Digital Flight Control System for the FROG Unmanned Aerial Vehicle Contract Number Grant Number Program Element...REPORT TYPE AND DATES COVERED Aeronautical Engineers Thesis 4. TITLE AND SUBTITLE: Design and Evaluation of a Digital Flight Control System for

  14. Development of ARMS-PCR assay for genotyping of Pro12Ala SNP of PPARG gene: a cost effective way for case-control studies of type 2 diabetes in developing countries.

    PubMed

    Islam, Mehboob; Awan, Fazli Rabbi; Baig, Shahid Mahmood

    2014-09-01

    Type 2 diabetes (T2D) is a prevalent metabolic disorder across the globe. Research is underway on various aspects including genetics to understand and control the global epidemic of diabetes. Recently, several SNPs in various genes have been associated with T2D. These association studies are mainly carried out in the developed countries through Genome Wide Association Scans, with follow-up replication/validation studies by high-throughput genotyping techniques (e.g. Taqman Technology). Although, similar studies could be conducted in developing countries, however, the limiting factors are the associated cost and expertise. These factors hamper research into the genetic association and replication studies from low-income countries to figure out the role of putatively associated SNPs in diabetes. Although, there are several SNP detection methods (e.g. Taqman assay, Dot-blot, PCR-RFLP, DGGE, SSCP) but these are either expensive or labor intensive or less sensitive. Hence, our aim was to develop a low-cost method for the validation of PPARG (Pro12Ala, CCA>GCA) SNP (rs1801282) for its association with T2D. Here, we developed a cost-effective and rapid amplification refractory mutation specific-PCR (ARMS-PCR) method for this SNP detection. We successfully genotyped PPARG SNPs (Pro12Ala) in human samples and the validity of this method was confirmed by DNA sequencing of a few representative samples for the three different genotypes. Furthermore, ARMS-PCR was applied to T2D patients and control samples for the screening of this SNP.

  15. Usability evaluation of remote controllers for digital television receivers

    NASA Astrophysics Data System (ADS)

    Komine, Kazuteru; Hiruma, Nobuyuki; Ishihara, Tatsuya; Makino, Eiji; Tsuda, Takao; Ito, Takayuki; Isono, Haruo

    2000-06-01

    In order to develop a useful and ergonomically attractive remote controller for ISDB (Integrated Services Digital Broadcasting), which will begin very soon in Japan, we performed experiments with elderly and young subjects to evaluate the usability and the training effects of four types of remote controller: a button type, a trackball, a touch panel and a voice recognition system. We set the subjects the task of selecting an icon on a HDTV monitor as quickly and as accurately as possible using each remote controller. Semantic differential and ranked order questionnaire surveys were also conducted, and these results were analyzed statistically. The results showed that the trackball type was the most preferred, with no major differences in preference among the other three types especially for elderly subjects. From the analyses of the questionnaire surveys and operation time, we conclude that the reasons for the rankings obtained are as follows: Users preferred devices which they could operate without having to look down; Users preferred devices with which there was a significant learning effect in a relatively short period. It is considered that these are necessary conditions for an ergonomically attractive remote controller which users will want to use.

  16. Markov reliability models for digital flight control systems

    NASA Technical Reports Server (NTRS)

    Mcgough, John; Reibman, Andrew; Trivedi, Kishor

    1989-01-01

    The reliability of digital flight control systems can often be accurately predicted using Markov chain models. The cost of numerical solution depends on a model's size and stiffness. Acyclic Markov models, a useful special case, are particularly amenable to efficient numerical solution. Even in the general case, instantaneous coverage approximation allows the reduction of some cyclic models to more readily solvable acyclic models. After considering the solution of single-phase models, the discussion is extended to phased-mission models. Phased-mission reliability models are classified based on the state restoration behavior that occurs between mission phases. As an economical approach for the solution of such models, the mean failure rate solution method is introduced. A numerical example is used to show the influence of fault-model parameters and interphase behavior on system unreliability.

  17. More on exact state reconstruction in deterministic digital control systems

    NASA Technical Reports Server (NTRS)

    Polites, Michael E.

    1988-01-01

    Presented is a special form of the Ideal State Reconstructor for deterministic digital control systems which is simpler to implement than the most general form. The Ideal State Reconstructor is so named because, if the plant parameters are known exactly, its output will exactly equal, not just approximate, the true state of the plant and accomplish this without any knowledge of the plant's initial state. Besides this, it adds no new states or eigenvalues to the system. Nor does it affect the plant equation for the system in any way; it affects the measurement equation only. It is characterized by the fact that discrete measurements are generated every T/N seconds and input into a multi-input/multi-output moving-average (MA) process. The output of this process is sampled every T seconds and utilized in reconstructing the state of the system.

  18. High-side Digitally Current Controlled Biphasic Bipolar Microstimulator

    PubMed Central

    Hanson, Timothy L.; Ómarsson, Björn; O'Doherty, Joseph E.; Peikon, Ian D.; Lebedev, Mikhail; Nicolelis, Miguel AL.

    2012-01-01

    Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. With the realized device and standard recording hardware - without active artifact rejection - we are able to observe stimulus artifacts of less than 2 ms in duration. PMID:22328184

  19. Selecting a software development methodology. [of digital flight control systems

    NASA Technical Reports Server (NTRS)

    Jones, R. E.

    1981-01-01

    The state of the art analytical techniques for the development and verification of digital flight control software is studied and a practical designer oriented development and verification methodology is produced. The effectiveness of the analytic techniques chosen for the development and verification methodology are assessed both technically and financially. Technical assessments analyze the error preventing and detecting capabilities of the chosen technique in all of the pertinent software development phases. Financial assessments describe the cost impact of using the techniques, specifically, the cost of implementing and applying the techniques as well as the relizable cost savings. Both the technical and financial assessment are quantitative where possible. In the case of techniques which cannot be quantitatively assessed, qualitative judgements are expressed about the effectiveness and cost of the techniques. The reasons why quantitative assessments are not possible will be documented.

  20. High-side digitally current controlled biphasic bipolar microstimulator.

    PubMed

    Hanson, Timothy L; Ómarsson, Björn; O'Doherty, Joseph E; Peikon, Ian D; Lebedev, Mikhail A; Nicolelis, Miguel A L

    2012-05-01

    Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. With the realized device and standard recording hardware-without active artifact rejection-we are able to observe stimulus artifacts of less than 2 ms in duration.

  1. The Digital Motion Control System for the Submillimeter Array Antennas

    NASA Astrophysics Data System (ADS)

    Hunter, T. R.; Wilson, R. W.; Kimberk, R.; Leiker, P. S.; Patel, N. A.; Blundell, R.; Christensen, R. D.; Diven, A. R.; Maute, J.; Plante, R. J.; Riddle, P.; Young, K. H.

    2013-09-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error function. Calibration factors and software filters are applied to the tachometer feedback prior to the application of the servo gains in the torque computations. All of these parameters are remotely adjustable in the software. The three layers of the control system monitor each other and are capable of shutting down the system safely if a failure or anomaly occurs. The Unix system continuously relays the antenna status to the central observatory computer via reflective memory. In each antenna, a Palm Vx hand controller displays the complete system status and allows full local control of the drives in an intuitive touchscreen user interface. The hand controller can also be connected outside the cabin, a major convenience during the frequent reconfigurations of the interferometer. Excellent tracking performance ( 0.3‧‧ rms) is achieved with this system. It has been in reliable operation on 8 antennas for over 10 years and has required minimal maintenance.

  2. Cost Effectiveness Analysis for Nursing Research

    PubMed Central

    Bensink, Mark E.; Eaton, Linda H.; Morrison, Megan L.; Cook, Wendy A.; Curtis, R. Randall; Kundu, Anjana; Gordon, Deborah B.; Doorenbos, Ardith Z.

    2013-01-01

    Background With ever increasing pressure to reduce costs and increase quality, nurses are faced with the challenge of producing evidence that their interventions and care provide value. Cost effectiveness analysis (CEA) is a tool that can be used to provide this evidence by comparative evaluation of the costs and consequences of two or more alternatives. Objectives The aim of this article is to introduce the essential components of CEA to nurses and nurse researchers with the protocol of a recently funded cluster randomized controlled trial as an example. Methods This article provides: (a) a description of the main concepts and key steps in CEA, and (b) a summary of the background and objectives of a CEA designed to evaluate a nursing led pain and symptom management intervention in rural communities compared to current usual care. Discussion As the example highlights, incorporating CEA into nursing research studies is feasible. The burden of the additional data collection required is off-set by quantitative evidence of the given intervention's cost and impact using humanistic and economic outcomes. At a time when US health care is moving toward accountable care, the information provided by CEA will be an important additional component of the evidence produced by nursing research. PMID:23817285

  3. A Digital Motion Control System for Large Telescopes

    NASA Astrophysics Data System (ADS)

    Hunter, T. R.; Wilson, R. W.; Kimberk, R.; Leiker, P. S.

    2001-05-01

    We have designed and programmed a digital motion control system for large telescopes, in particular, the 6-meter antennas of the Submillimeter Array on Mauna Kea. The system consists of a single robust, high-reliability microcontroller board which implements a two-axis velocity servo while monitoring and responding to critical safety parameters. Excellent tracking performance has been achieved with this system (0.3 arcsecond RMS at sidereal rate). The 24x24 centimeter four-layer printed circuit board contains a multitude of hardware devices: 40 digital inputs (for limit switches and fault indicators), 32 digital outputs (to enable/disable motor amplifiers and brakes), a quad 22-bit ADC (to read the motor tachometers), four 16-bit DACs (that provide torque signals to the motor amplifiers), a 32-LED status panel, a serial port to the LynxOS PowerPC antenna computer (RS422/460kbps), a serial port to the Palm Vx handpaddle (RS232/115kbps), and serial links to the low-resolution absolute encoders on the azimuth and elevation axes. Each section of the board employs independent ground planes and power supplies, with optical isolation on all I/O channels. The processor is an Intel 80C196KC 16-bit microcontroller running at 20MHz on an 8-bit bus. This processor executes an interrupt-driven, scheduler-based software system written in C and assembled into an EPROM with user-accessible variables stored in NVSRAM. Under normal operation, velocity update requests arrive at 100Hz from the position-loop servo process running independently on the antenna computer. A variety of telescope safety checks are performed at 279Hz including routine servicing of a 6 millisecond watchdog timer. Additional ADCs onboard the microcontroller monitor the winding temperature and current in the brushless three-phase drive motors. The PID servo gains can be dynamically changed in software. Calibration factors and software filters can be applied to the tachometer readings prior to the application of

  4. Direct Digital Boiler Control Systems for the Navy Small Boiler Equipment.

    DTIC Science & Technology

    1983-02-01

    codes , parity and dropout checks, check sums, high level data link control (HDLC) and keyboard response checking. 3. Display types-Typical are overview...Distributed Control can be cost-effective for as few as 8 control loops. Operator Mini-Station: Video Display The high scan-rate CRT otters a corn... high ana "* low alarm limits, the configurationfication-automatic ("A") or manual data than a Group Display (and is re- code and the filter time

  5. Digital control of working fluid flow rate for an OTEC plant

    SciTech Connect

    Nakamura, M.; Egashira, N.; Uehara, H.

    1986-05-01

    The role of control in operating an OTEC plant efficiently is of great importance. This paper describes digital control of working fluid rate based on an adaptive control theory for the ''Imari2'' OTEC plant at Saga University. Provisions have been made for linkage between the software of the adaptive control theory and the hardware of the OTEC plant. The authors can obtain satisfactory control performance using this digital control system.

  6. Computer aided design of digital controller for radial active magnetic bearings

    NASA Technical Reports Server (NTRS)

    Cai, Zhong; Shen, Zupei; Zhang, Zuming; Zhao, Hongbin

    1992-01-01

    A five degree of freedom Active Magnetic Bearing (AMB) system is developed which is controlled by digital controllers. The model of the radial AMB system is linearized and the state equation is derived. Based on the state variables feedback theory, digital controllers are designed. The performance of the controllers are evaluated according to experimental results. The Computer Aided Design (CAD) method is used to design controllers for magnetic bearings. The controllers are implemented with a digital signal processing (DSP) system. The control algorithms are realized with real-time programs. It is very easy to change the controller by changing or modifying the programs. In order to identify the dynamic parameters of the controlled magnetic system, a special experiment was carried out. Also, the online Recursive Least Squares (RLS) parameter identification method is studied. It can be realized with the digital controllers. Online parameter identification is essential for the realization of an adaptive controller.

  7. A Long-Term Experimental Case Study of the Ecological Effectiveness and Cost Effectiveness of Invasive Plant Management in Achieving Conservation Goals: Bitou Bush Control in Booderee National Park in Eastern Australia

    PubMed Central

    Lindenmayer, David B.; Wood, Jeff; MacGregor, Christopher; Buckley, Yvonne M.; Dexter, Nicholas; Fortescue, Martin; Hobbs, Richard J.; Catford, Jane A.

    2015-01-01

    Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at

  8. A long-term experimental case study of the ecological effectiveness and cost effectiveness of invasive plant management in achieving conservation goals: bitou bush control in booderee national park in eastern australia.

    PubMed

    Lindenmayer, David B; Wood, Jeff; MacGregor, Christopher; Buckley, Yvonne M; Dexter, Nicholas; Fortescue, Martin; Hobbs, Richard J; Catford, Jane A

    2015-01-01

    Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at

  9. Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

    NASA Astrophysics Data System (ADS)

    Quenzer-Hohmuth, Samuel; Rosahl, Thoralf; Ritzmann, Steffen; Wicht, Bernhard

    2016-09-01

    Switched-mode power supplies (SMPS) convert an input DC-voltage into a higher or lower output voltage. In automotive, analog control is mostly used in order to keep the required output voltages constant and resistant to disturbances. The design of robust analog control for SMPS faces parameter variations of integrated and external passive components. Using digital control, parameter variations can be eliminated and the required area for the integrated circuit can be reduced at the same time. Digital control design bears challenges like the prevention of limit cycle oscillations and controller-wind-up. This paper reviews how to prevent these effects. Digital control loops introduce new sources for dead times in the control loop, for example the latency of the analog-to-digital-converter (ADC). Dead times have negative influence on the stability of the control loop, because they lead to phase delays. Consequently, low latency is one of the key requirements for analog-to-digital-converters in digitally controlled SMPS. Exploiting the example of a 500 kHz-buck converter with a crossover frequency of 70 kHz, this paper shows that the 5 µs-latency of a ΔΣ-analog-to-digital-converter leads to a reduction in phase margin of 126°. The latency is less critical for boost converters because of their inherent lower crossover frequencies. Finally, the paper shows a comparison between analog and digital control of SMPS with regard to chip area and test costs.

  10. Evaluation of automatic exposure control options in digital mammography.

    PubMed

    Zhou, Yifang; Scott, Alexander; Allahverdian, Janet; Frankel, Steve

    2014-01-01

    To quantify the trade-offs of dose and image quality among pre-loaded automatic exposure control (AEC) options in digital mammography, two AEC tables from the Hologic Selenia digital mammography system were compared: the default AEC "table 0" and AEC "table 1". Realistically-shaped phantoms consisting of tissue-equivalent material of various thicknesses (4.5 cm-7 cm) were imaged to obtain a figure of merit (FOM), the squared contrast-to-noise ratio per mean glandular dose. To relate the results to pathological findings and to evaluate the overall performance, the measured contrast-to-noise ratios were applied to simulated lesions on the anthropomorphic breast phantom images, producing various lesion configurations which were blindly scored. It was found that the AEC table 1 improves the low contrast FOM by 11% to 20% for the breast thicknesses of 4.5-6 cm. However, for the 7 cm thick breast, the AEC table 1 decreases the low contrast FOM by 17%. For microcalcifications, the AEC table 1 improves the FOM slightly for the breast thicknesses of 4.5--6 cm and decreases it by 18% at a thickness of 7 cm. The lesion simulation showed enhanced contrast due to the AEC table 1 for the breast thicknesses of 5 cm, 6 cm, and 7 cm, but the enhancement gradually reduces as the thickness increases. The lesion reading showed that the microcalcification detection was scored significantly higher from the AEC table 1 for the thicknesses 5 cm, 6 cm, and 7 cm. The corresponding improvement of mass detection scores was also observed but not consistently significant over the thickness range.

  11. Anticipatory Planning and Control of Grasp Positions and Forces for Dexterous Two-Digit Manipulation

    PubMed Central

    Fu, Qiushi; Zhang, Wei; Santello, Marco

    2010-01-01

    Dexterous object manipulation requires anticipatory control of digit positions and forces. Despite extensive studies on sensorimotor learning of digit forces, how humans learn to coordinate digit positions and forces has never been addressed. Furthermore, the functional role of anticipatory modulation of digit placement to object properties remains to be investigated. We addressed these questions by asking human subjects (12 females, 12 males) to grasp and lift an inverted T-shaped object using precision grip at constrained or self-chosen locations. The task requirement was to minimize object roll during lift. When digit position was not constrained, subjects could have implemented many equally valid digit position-force coordination patterns. However, choice of digit placement might also have resulted in large trial-to-trial variability of digit position, hence challenging the extent to which the Central Nervous System could have relied on sensorimotor memories for anticipatory control of digit forces. We hypothesized that subjects would modulate (1) digit placement for optimal force distribution and (2) digit forces as a function of variable digit positions. While all subjects learned to minimize object roll within the first three trials, the unconstrained device was associated with significantly smaller grip forces but larger variability of digit positions. Importantly, however, digit load force modulation compensated for position variability, thus ensuring consistent object roll minimization on each trial. This indicates that subjects learned object manipulation by integrating sensorimotor memories with sensory feedback about digit positions. These results are discussed in the context of motor equivalence and sensorimotor integration of grasp kinematics and kinetics. PMID:20610745

  12. Modeling and Cost-Effectiveness in HIV Prevention

    PubMed Central

    Jacobsen, Margo M.; Walensky, Rochelle P.

    2016-01-01

    With HIV funding plateauing and the number of people living with HIV increasing due to the roll-out of life-saving antiretroviral therapy, policy makers are faced with increasingly tighter budgets to manage the ongoing HIV epidemic. Cost-effectiveness and modeling analyses can help determine which HIV interventions may be of best value. Incidence remains remarkably high in certain populations and countries, making prevention key to controlling the spread of HIV. This paper briefly reviews concepts in modeling and cost-effectiveness methodology, then examines results of recently published cost-effectiveness analyses on the following HIV prevention strategies: condoms and circumcision, behavioral or community-based interventions, prevention of mother to child transmission, HIV testing, pre-exposure prophylaxis, and treatment as prevention. We find that the majority of published studies demonstrate cost-effectiveness; however, not all interventions are affordable. We urge continued research on combination strategies and methodologies that take into account willingness to pay and budgetary impact. PMID:26830283

  13. Modeling and Cost-Effectiveness in HIV Prevention.

    PubMed

    Jacobsen, Margo M; Walensky, Rochelle P

    2016-02-01

    With HIV funding plateauing and the number of people living with HIV increasing due to the rollout of life-saving antiretroviral therapy, policy makers are faced with increasingly tighter budgets to manage the ongoing HIV epidemic. Cost-effectiveness and modeling analyses can help determine which HIV interventions may be of best value. Incidence remains remarkably high in certain populations and countries, making prevention key to controlling the spread of HIV. This paper briefly reviews concepts in modeling and cost-effectiveness methodology and then examines results of recently published cost-effectiveness analyses on the following HIV prevention strategies: condoms and circumcision, behavioral- or community-based interventions, prevention of mother-to-child transmission, HIV testing, pre-exposure prophylaxis, and treatment as prevention. We find that the majority of published studies demonstrate cost-effectiveness; however, not all interventions are affordable. We urge continued research on combination strategies and methodologies that take into account willingness to pay and budgetary impact.

  14. A gallium-arsenide digital phase shifter for clock and control signal distribution in high-speed digital systems

    NASA Technical Reports Server (NTRS)

    Fouts, Douglas J.

    1992-01-01

    The design, implementation, testing, and applications of a gallium-arsenide digital phase shifter and fan-out buffer are described. The integrated circuit provides a method for adjusting the phase of high-speed clock and control signals in digital systems, without the need for pruning cables, multiplexing between cables of different lengths, delay lines, or similar techniques. The phase of signals distributed with the described chip can be dynamically adjusted in eight different steps of approximately 60 ps per step. The IC also serves as a fan-out buffer and provides 12 in-phase outputs. The chip is useful for distributing high-speed clock and control signals in synchronous digital systems, especially if components are distributed over a large physical area or if there is a large number of components.

  15. 47 CFR 73.9001 - Redistribution control of digital television broadcasts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Redistribution control of digital television broadcasts. 73.9001 Section 73.9001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Digital Broadcast Television Redistribution Control §...

  16. Cyber secure systems approach for NPP digital control systems

    SciTech Connect

    McCreary, T. J.; Hsu, A.

    2006-07-01

    Whether fossil or nuclear power, the chief operations goal is to generate electricity. The heart of most plant operations is the I and C system. With the march towards open architecture, the I and C system is more vulnerable than ever to system security attacks (denial of service, virus attacks and others), thus jeopardizing plant operations. Plant staff must spend large amounts of time and money setting up and monitoring a variety of security strategies to counter the threats and actual attacks to the system. This time and money is a drain on the financial performance of a plant and distracts valuable operations resources from their real goals: product. The pendulum towards complete open architecture may have swung too far. Not all aspects of proprietary hardware and software are necessarily 'bad'. As the aging U.S. fleet of nuclear power plants starts to engage in replacing legacy control systems, and given the on-going (and legitimate) concern about the security of present digital control systems, decisions about how best to approach cyber security are vital to the specification and selection of control system vendors for these upgrades. The authors maintain that utilizing certain resources available in today's digital technology, plant control systems can be configured from the onset to be inherently safe, so that plant staff can concentrate on the operational issues of the plant. The authors postulate the concept of the plant I and C being bounded in a 'Cyber Security Zone' and present a design approach that can alleviate the concern and cost at the plant level of dealing with system security strategies. Present approaches through various IT cyber strategies, commercial software, and even postulated standards from various industry/trade organizations are almost entirely reactive and simply add to cost and complexity. This Cyber Security Zone design demonstrates protection from the four classes of cyber security attacks: 1)Threat from an intruder attempting to

  17. Assessing the effectiveness and cost effectiveness of subcutaneous nerve stimulation in patients with predominant back pain due to failed back surgery syndrome (SubQStim study): study protocol for a multicenter randomized controlled trial

    PubMed Central

    2013-01-01

    Background Chronic radicular pain can be effectively treated with spinal cord stimulation, but this therapy is not always sufficient for chronic back pain. Subcutaneous nerve stimulation (SQS) refers to the placement of percutaneous leads in the subcutaneous tissue within the area of pain. Case series data show that failed back surgery syndrome (FBSS) patients experience clinically important levels of pain relief following SQS and may also reduce their levels of analgesic therapy and experience functional well-being. However, to date, there is no randomized controlled trial evidence to support the use of SQS in FBSS. Methods/Design The SubQStim study is a multicenter randomized controlled trial comparing SQS plus optimized medical management (‘SQS arm’) versus optimized medical management alone (‘OMM arm’) in patients with predominant back pain due to FBSS. Up to 400 patients will be recruited from approximately 33 centers in Europe and Australia and will be randomized 1:1 to the SQS or OMM arms. After 9 months, patients who fail to reach the primary outcome will be allowed to switch treatments. Patients will be evaluated at baseline (prior to randomization) and at 1, 3, 6, 9, 12, 18, 24, and 36 months after randomization. The primary outcome is the proportion of patients at 9 months with a ≥50% reduction in back pain intensity compared to baseline. The secondary outcomes are: back and leg pain intensity score, functional disability, health-related quality of life, patient satisfaction, patient global impression of change, healthcare resource utilization/costs, cost-effectiveness analysis and adverse events. Outcomes arms will be compared between SQS and OMM arms at all evaluation points up to and including 9 months. After the 9-month assessment visit, the main analytic focus will be to compare within patient changes in outcomes relative to baseline. Discussion The SubQStim trial began patient recruitment in November 2012. Recruitment is expected to close

  18. Multimodal Supervision Programme to Reduce Catheter Associated Urinary Tract Infections and Its Analysis to Enable Focus on Labour and Cost Effective Infection Control Measures in a Tertiary Care Hospital in India

    PubMed Central

    Jaggi, Namita; Sissodia, Pushpa

    2012-01-01

    Background Catheter Associated Urinary Tract Infections (CAUTI) contribute 30%-40% of all the nosocomial infections and they are associated with substantially increased institutional death rates. A multimodal supervision program which incorporates training of the staff with respect to infection control measures can be effective in reducing the CAUTIs in hospitals. Aim To assess the impact of a multimodal UTI supervision program on the CAUTI rates over a year, from January 2009 to December 2009, in a tertiary care hospital in India. Setting A 215 bedded tertiary care private hospital. Materials and Methods The CAUTI rates were analyzed for the first 6 months (January 2009-June 2009). A UTI supervision program was instituted in the month of July 2009, which included training with respect to the standard protocols for the sample collection and diagnosis, the bundle components of the urinary catheter checklist and hand hygiene practices. The impact was assessed as per the CAUTI rates in the subsequent months. Results The average CAUTI rate was reduced by 47.1% (from 10.6 to 5.6) after the introduction of the supervision program. This study presented the mean age of the patients with CAUTIs as 54.5 years and it showed an approximately equal contribution of both the sexes (52.94% in males and 47.05% in females). The impact analysis of the supervision program showed a reduction of 8.7% (from 23 days to 21 days) during the average duration of the catheterization. The adherence to the components of the urinary catheter check list was increased by 44.4% (p=0.069) and the hand hygiene compliance was increased by 56.4% (p=0.004) respectively after the interventions. Components like bladder irrigation and practising perineal cleaning were found to show no effect on the CAUTI rates. Conclusion The most common labour and cost effective infection control measures as revealed by the supervision programme were adherence to the urinary catheter checklist components (indication for

  19. Effects of nurse-led motivational interviewing of patients with chronic musculoskeletal pain in preparation of rehabilitation treatment (PREPARE) on societal participation, attendance level, and cost-effectiveness: study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    of the pre-treatment intervention, productivity losses, and healthcare utilization. Potential moderators and active ingredients of MI are explored. For the process evaluation, parameters such as MI fidelity, feasibility, and experiences are explored. Discussion The results of this study will provide evidence on the effectiveness of this MI-based pre-treatment in pain rehabilitation. Furthermore, a cost-effectiveness analysis and exploration of moderating and working mechanisms of MI and an extensive process evaluation takes place. Trial registration Nederlands trial register NTR3065 PMID:23548195

  20. A multicentre, pragmatic, parallel group, randomised controlled trial to compare the clinical and cost-effectiveness of three physiotherapy-led exercise interventions for knee osteoarthritis in older adults: the BEEP trial protocol (ISRCTN: 93634563)

    PubMed Central

    2014-01-01

    Background Exercise is consistently recommended for older adults with knee pain related to osteoarthritis. However, the effects from exercise are typically small and short-term, likely linked to insufficient individualisation of the exercise programme and limited attention to supporting exercise adherence over time. The BEEP randomised trial aims to improve patients’ short and long-term outcomes from exercise. It will test the overall effectiveness and cost-effectiveness of two physiotherapy-led exercise interventions (Individually Tailored Exercise and Targeted Exercise Adherence) to improve the individual tailoring of, and adherence to exercise, compared with usual physiotherapy care. Methods/design Based on the learning from a pilot study (ISRCTN 23294263), the BEEP trial is a multi-centre, pragmatic, parallel group, individually randomised controlled trial, with embedded longitudinal qualitative interviews. 500 adults in primary care, aged 45 years and over with knee pain will be randomised to 1 of 3 treatment groups delivered by fully trained physiotherapists in up to 6 NHS services. These are: Usual Physiotherapy Care (control group consisting of up to 4 treatment sessions of advice and exercise), Individually Tailored Exercise (an individualised, supervised and progressed lower-limb exercise programme) or Targeted Exercise Adherence (supporting patients to adhere to exercise and to engage in general physical activity over the longer-term). The primary outcomes are pain and function as measured by the Western Ontario and McMaster Osteoarthritis index. A comprehensive range of secondary outcomes are also included. Outcomes are measured at 3, 6 (primary outcome time-point), 9, 18 and 36 months. Data on adverse events will also be collected. Semi-structured, qualitative interviews with a subsample of 30 participants (10 from each treatment group) will be undertaken at two time-points (end of treatment and 12 to 18 months later) and analysed thematically

  1. Learning in the Digital Age: Control or Connection?

    ERIC Educational Resources Information Center

    Van Galen, Jane

    2013-01-01

    In October 2011, 200 state school officers and legislators gathered at a hotel in San Francisco to learn how to "revolutionize" learning by "personalizing" instruction. The occasion was former Florida Gov. Jeb Bush's second annual National Summit on Education Reform. The topic was digital learning. The vision of digitally managed curriculum and…

  2. Digital controller design: Continuous and discrete describing function analysis of the IPS system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The digital IPS with wire cable and flex pivot nonlinearity is simulated on the digital computer to determine the effects of varying the sampling period T on the system stability, and to determine a range of optimal values of the parameters of the digital controller. The listing of the computer program is shown as well as the Dahl model for the flex pivot nonlinearity. For the wire cable nonlinearity, two ranges of values were used and the nominal values of the digital controller parameters are included.

  3. Long-term cost-effectiveness of collaborative care (vs usual care) for people with depression and comorbid diabetes or cardiovascular disease: a Markov model informed by the COINCIDE randomised controlled trial

    PubMed Central

    Camacho, Elizabeth M; Ntais, Dionysios; Coventry, Peter; Bower, Peter; Lovell, Karina; Chew-Graham, Carolyn; Baguley, Clare; Gask, Linda; Dickens, Chris; Davies, Linda M

    2016-01-01

    Objectives To evaluate the long-term cost-effectiveness of collaborative care (vs usual care) for treating depression in patients with diabetes and/or coronary heart disease (CHD). Setting 36 primary care general practices in North West England. Participants 387 participants completed baseline assessment (collaborative care: 191; usual care: 196) and full or partial 4-month follow-up data were captured for 350 (collaborative care: 170; usual care: 180). 62% of participants were male, 14% were non-white. Participants were aged ≥18 years, listed on a Quality and Outcomes Framework register for CHD and/or type 1 or 2 diabetes mellitus, with persistent depressive symptoms. Patients with psychosis or type I/II bipolar disorder, actively suicidal, in receipt of services for substance misuse, or already in receipt of psychological therapy for depression were excluded. Intervention Collaborative care consisted of evidence-based low-intensity psychological treatments, delivered over 3 months and case management by a practice nurse and a Psychological Well Being Practitioner. Outcome measures As planned, the primary measure of cost-effectiveness was the incremental cost-effectiveness ratio (cost per quality-adjusted life year (QALY)). A Markov model was constructed to extrapolate the trial results from short-term to long-term (24 months). Results The mean cost per participant of collaborative care was £317 (95% CI 284 to 350). Over 24 months, it was estimated that collaborative care was associated with greater healthcare usage costs (net cost £674 (95% CI −30 953 to 38 853)) and QALYs (net QALY gain 0.04 (95% CI −0.46 to 0.54)) than usual care, resulting in a cost per QALY gained of £16 123, and a likelihood of being cost-effective of 0.54 (willingness to pay threshold of £20 000). Conclusions Collaborative care is a potentially cost-effective long-term treatment for depression in patients with comorbid physical and mental illness. The estimated

  4. Mars Digital Image Model 2.1 Control Network

    NASA Technical Reports Server (NTRS)

    Archinal, B. A.; Kirk, R. L.; Duxbury, T. C.; Lee, E. M.; Sucharski, R.; Cook, D.

    2003-01-01

    USGS is currently preparing a new version of its global Mars digital image mosaic, which will be known as MDIM 2.1. As part of this process we are completing a new photogrammetric solution of the global Mars control network. This is an improved version of the network established earlier by RAND and USGS personnel, as partially described previously. MDIM 2.1 will have many improvements over earlier Viking Orbiter (VO) global mosaics. Geometrically, it will be an orthoimage product, draped on Mars Orbiter Laser Altimeter (MOLA) derived topography, thus accounting properly for the commonly oblique VO imagery. Through the network being described here it will be tied to the newly defined IAU/IAG 2000 Mars coordinate system via ties to MOLA data. Thus, MDIM 2.1 will provide complete global orthorectified imagery coverage of Mars at the resolution of 1/256 deg of MDIM 2.0, and be compatible with MOLA and other products produced in the current coordinate system.

  5. Cost effectiveness of the implantable cardioverter defibrillator: a preliminary analysis

    PubMed Central

    O'Brien, Bernie J; Buxton, Martin J; Rushby, Julia A

    1992-01-01

    Background—An implantable cardioverter defibrillator (ICD) may be effective in reducing the risk of sudden cardiac death. The high cost of ICD treatment, however, compared with alternatives raises the question of whether this new technology is an efficient use of scarce health care resources. Objective—To estimate the incremental cost effectiveness of the implantable cardioverter defibrillator compared with drug treatment with amiodarone in the management of patients at high risk of sudden cardiac death. Design—A cost effectiveness model was constructed from data already published and other secondary sources. Differences in patient survival were calculated from life tables for comparable ICD and amiodarone patient series. Costs were based on typical patient management protocols derived from current United Kingdom practice and interviews with physicians. Main outcome measures—Cost effectiveness of ICD treatment was computed over 20 years; all future costs and effects were discounted at 6% per year. Results—Estimated life expectancy was 11·1 and 6·7 years with ICD and amiodarone respectively; the discounted 20 year difference lies in the range 1·7 to 3·7 years. Discounted 20 year treatment costs were £28 400 for the ICD and £2300 for amiodarone. Cost effectiveness of ICD treatment lies in the range of £15 400 to £8200 per life-year gained. Conclusions—Cost effectiveness of ICD treatment is similar to some existing cardiac programmes funded under the NHS but uncertainty exists due to limitations of the data. Costs of ICD treatment may fall in the future as the life of the device increases and less invasive implantation methods are needed. The effectivess of ICD compared with amiodarone is currently being studied by a randomised controlled trial. PMID:1389748

  6. Effect of day-case unilateral cochlear implantation in adults on general and disease-specific quality of life, postoperative complications and hearing results, tinnitus, vertigo and cost-effectiveness: protocol for a randomised controlled trial

    PubMed Central

    Derks, Laura S M; Wegner, Inge; Smit, Adriana L; Thomeer, Hans G X M; Topsakal, Vedat; Grolman, Wilko

    2016-01-01

    Introduction Cochlear implantation is an increasingly common procedure in the treatment of severe to profound sensorineural hearing loss (SNHL) in children and adults. It is often performed as a day-case procedure. The major drive towards day-case surgery has been from a logistical, economical and societal perspective, but we also speculate that the patient's quality of life (QoL) is at least equal to inpatient surgery if not increased as a result of rapid discharge and rehabilitation. Even though cochlear implantation seems well suited to a day-case approach and this even seems to be common practice in some countries, evidence is scarce and of low quality to guide us towards the preferred treatment option. Methods and analysis A single-centre, non-blinded, randomised, controlled trial was designed to (primarily) investigate the effect on general QoL of day-case cochlear implantation compared to inpatient cochlear implantation and (secondarily) the effect of both methods on (subjective) hearing improvement, disease-specific QoL, tinnitus, vertigo and cost-effectiveness. 30 adult patients with severe to profound bilateral postlingual SNHL who are eligible for unilateral cochlear implantation will be randomly assigned to either the day-case or inpatient treatment group. The outcome measures will be assessed using auditory evaluations, questionnaires (preoperatively, at 1-week, 3-week, 3-month and 1-year follow-up) and costs diaries (weekly during the first month postoperatively, after which once in a month until 1-year follow-up). Preoperative and postoperative outcomes will be compared. The difference in costs and benefit will be represented using the incremental cost utility/effectiveness ratio. The analyses will be carried out on an intention-to-treat basis. Ethics and dissemination This research protocol was approved by the Institutional Review Board of the UMC Utrecht (NL45590.041.13; V.5, November 2015). The trial results will be disseminated through peer

  7. Establishing the effectiveness, cost-effectiveness and student experience of a Simulation-based education Training program On the Prevention of Falls (STOP-Falls) among hospitalised inpatients: a protocol for a randomised controlled trial

    PubMed Central

    Williams, Cylie; Kiegaldie, Debra; Kaplonyi, Jessica; Haines, Terry

    2016-01-01

    Introduction Simulation-based education (SBE) is now commonly used across health professional disciplines to teach a range of skills. The evidence base supporting the effectiveness of this approach for improving patient health outcomes is relatively narrow, focused mainly on the development of procedural skills. However, there are other simulation approaches used to support non-procedure specific skills that are in need of further investigation. This cluster, cross-over randomised controlled trial with a concurrent economic evaluation (cost per fall prevented) trial will evaluate the effectiveness, cost-effectiveness and student experience of health professional students undertaking simulation training for the prevention of falls among hospitalised inpatients. This research will target the students within the established undergraduate student placements of Monash University medicine, nursing and allied health across Peninsula Health acute and subacute inpatient wards. Methods and analysis The intervention will train the students in how to provide the Safe Recovery program, the only single intervention approach demonstrated to reduce falls in hospitals. This will involve redevelopment of the Safe Recovery program into a one-to-many participant SBE program, so that groups of students learn the communication skills and falls prevention knowledge necessary for delivery of the program. The primary outcome of this research will be patient falls across participating inpatient wards, with secondary outcomes including student satisfaction with the SBE and knowledge gain, ward-level practice change and cost of acute/rehabilitation care for each patient measured using clinical costing data. Ethics and dissemination The Human Research Ethics Committees of Peninsula Health (LRR/15/PH/11) and Monash University (CF15/3523-2015001384) have approved this research. The participant information and consent forms provide information on privacy, storage of results and dissemination

  8. Dynamical beam manipulation based on 2-bit digitally-controlled coding metasurface

    PubMed Central

    Huang, Cheng; Sun, Bo; Pan, Wenbo; Cui, Jianhua; Wu, Xiaoyu; Luo, Xiangang

    2017-01-01

    Recently, a concept of digital metamaterials has been proposed to manipulate field distribution through proper spatial mixtures of digital metamaterial bits. Here, we present a design of 2-bit digitally-controlled coding metasurface that can effectively modulate the scattered electromagnetic wave and realize different far-field beams. Each meta-atom of this metasurface integrates two pin diodes, and by tuning their operating states, the metasurface has four phase responses of 0, π/2, π, and 3π/2, corresponding to four basic digital elements “00”, “01”, “10”, and “11”, respectively. By designing the coding sequence of the above digital element array, the reflected beam can be arbitrarily controlled. The proposed 2-bit digital metasurface has been demonstrated to possess capability of achieving beam deflection, multi-beam and beam diffusion, and the dynamical switching of these different scattering patterns is completed by a programmable electric source. PMID:28176870

  9. Dynamical beam manipulation based on 2-bit digitally-controlled coding metasurface

    NASA Astrophysics Data System (ADS)

    Huang, Cheng; Sun, Bo; Pan, Wenbo; Cui, Jianhua; Wu, Xiaoyu; Luo, Xiangang

    2017-02-01

    Recently, a concept of digital metamaterials has been proposed to manipulate field distribution through proper spatial mixtures of digital metamaterial bits. Here, we present a design of 2-bit digitally-controlled coding metasurface that can effectively modulate the scattered electromagnetic wave and realize different far-field beams. Each meta-atom of this metasurface integrates two pin diodes, and by tuning their operating states, the metasurface has four phase responses of 0, π/2, π, and 3π/2, corresponding to four basic digital elements “00”, “01”, “10”, and “11”, respectively. By designing the coding sequence of the above digital element array, the reflected beam can be arbitrarily controlled. The proposed 2-bit digital metasurface has been demonstrated to possess capability of achieving beam deflection, multi-beam and beam diffusion, and the dynamical switching of these different scattering patterns is completed by a programmable electric source.

  10. Dynamical beam manipulation based on 2-bit digitally-controlled coding metasurface.

    PubMed

    Huang, Cheng; Sun, Bo; Pan, Wenbo; Cui, Jianhua; Wu, Xiaoyu; Luo, Xiangang

    2017-02-08

    Recently, a concept of digital metamaterials has been proposed to manipulate field distribution through proper spatial mixtures of digital metamaterial bits. Here, we present a design of 2-bit digitally-controlled coding metasurface that can effectively modulate the scattered electromagnetic wave and realize different far-field beams. Each meta-atom of this metasurface integrates two pin diodes, and by tuning their operating states, the metasurface has four phase responses of 0, π/2, π, and 3π/2, corresponding to four basic digital elements "00", "01", "10", and "11", respectively. By designing the coding sequence of the above digital element array, the reflected beam can be arbitrarily controlled. The proposed 2-bit digital metasurface has been demonstrated to possess capability of achieving beam deflection, multi-beam and beam diffusion, and the dynamical switching of these different scattering patterns is completed by a programmable electric source.

  11. Cost-effectiveness analysis and innovation.

    PubMed

    Jena, Anupam B; Philipson, Tomas J

    2008-09-01

    While cost-effectiveness (CE) analysis has provided a guide to allocating often scarce resources spent on medical technologies, less emphasis has been placed on the effect of such criteria on the behavior of innovators who make health care technologies available in the first place. A better understanding of the link between innovation and cost-effectiveness analysis is particularly important given the large role of technological change in the growth in health care spending and the growing interest of explicit use of CE thresholds in leading technology adoption in several Westernized countries. We analyze CE analysis in a standard market context, and stress that a technology's cost-effectiveness is closely related to the consumer surplus it generates. Improved CE therefore often clashes with interventions to stimulate producer surplus, such as patents. We derive the inconsistency between technology adoption based on CE analysis and economic efficiency. Indeed, static efficiency, dynamic efficiency, and improved patient health may all be induced by the cost-effectiveness of the technology being at its worst level. As producer appropriation of the social surplus of an innovation is central to the dynamic efficiency that should guide CE adoption criteria, we exemplify how appropriation can be inferred from existing CE estimates. For an illustrative sample of technologies considered, we find that the median technology has an appropriation of about 15%. To the extent that such incentives are deemed either too low or too high compared to dynamically efficient levels, CE thresholds may be appropriately raised or lowered to improve dynamic efficiency.

  12. Cost Effectiveness of On-Orbit Servicing

    DTIC Science & Technology

    2009-06-30

    distribution unlimited 1 AAS 09- XXX COST EFFECTIVENESS OF ON-ORBIT SERVICING Tiffany Rexius* This study was performed to model on...4,6 of total spacecraft failures and the pink line represents the model prediction of all failures. The pink “all failures” line is slightly higher

  13. Digit Position and Forces Covary during Anticipatory Control of Whole-Hand Manipulation.

    PubMed

    Marneweck, Michelle; Lee-Miller, Trevor; Santello, Marco; Gordon, Andrew M

    2016-01-01

    Theoretical perspectives on anticipatory planning of object manipulation have traditionally been informed by studies that have investigated kinematics (hand shaping and digit position) and kinetics (forces) in isolation. This poses limitations on our understanding of the integration of such domains, which have recently been shown to be strongly interdependent. Specifically, recent studies revealed strong covariation of digit position and load force during the loading phase of two-digit grasping. Here, we determined whether such digit force-position covariation is a general feature of grasping. We investigated the coordination of digit position and forces during five-digit whole-hand manipulation of an object with a variable mass distribution. Subjects were instructed to prevent object roll during the lift. As found in precision grasping, there was strong trial-to-trial covariation of digit position and force. This suggests that the natural variation of digit position that is compensated for by trial-to-trial variation in digit forces is a fundamental feature of grasp control, and not only specific to precision grasp. However, a main difference with precision grasping was that modulation of digit position to the object's mass distribution was driven predominantly by the thumb, with little to no modulation of finger position. Modulation of thumb position rather than fingers is likely due to its greater range of motion and therefore adaptability to object properties. Our results underscore the flexibility of the central nervous system in implementing a range of solutions along the digit force-to-position continuum for dexterous manipulation.

  14. Digit forces bias sensorimotor transformations underlying control of fingertip position.

    PubMed

    Shibata, Daisuke; Kappers, Astrid M L; Santello, Marco

    2014-01-01

    Humans are able to modulate digit forces as a function of position despite changes in digit placement that might occur from trial to trial or when changing grip type for object manipulation. Although this phenomenon is likely to rely on sensing the position of the digits relative to each other and the object, the underlying mechanisms remain unclear. To address this question, we asked subjects (n = 30) to match perceived vertical distance between the center of pressure (CoP) of the thumb and index finger pads (dy ) of the right hand ("reference" hand) using the same hand ("test" hand). The digits of reference hand were passively placed collinearly (dy = 0 mm). Subjects were then asked to exert different combinations of normal and tangential digit forces (Fn and Ftan , respectively) using the reference hand and then match the memorized dy using the test hand. The reference hand exerted Ftan of thumb and index finger in either same or opposite direction. We hypothesized that, when the tangential forces of the digits are produced in opposite directions, matching error (1) would be biased toward the directions of the tangential forces; and (2) would be greater when the remembered relative contact points are matched with negligible digit force production. For the test hand, digit forces were either negligible (0.5-1 N, 0 ± 0.25 N; Experiment 1) or the same as those exerted by the reference hand (Experiment 2).Matching error was biased towards the direction of digit tangential forces: thumb CoP was placed higher than the index finger CoP when thumb and index finger Ftan were directed upward and downward, respectively, and vice versa (p < 0.001). However, matching error was not dependent on whether the reference and test hand exerted similar or different forces. We propose that the expected sensory consequence of motor commands for tangential forces in opposite directions overrides estimation of fingertip position through haptic sensory feedback.

  15. Digit forces bias sensorimotor transformations underlying control of fingertip position

    PubMed Central

    Shibata, Daisuke; Kappers, Astrid M. L.; Santello, Marco

    2014-01-01

    Humans are able to modulate digit forces as a function of position despite changes in digit placement that might occur from trial to trial or when changing grip type for object manipulation. Although this phenomenon is likely to rely on sensing the position of the digits relative to each other and the object, the underlying mechanisms remain unclear. To address this question, we asked subjects (n = 30) to match perceived vertical distance between the center of pressure (CoP) of the thumb and index finger pads (dy) of the right hand (“reference” hand) using the same hand (“test” hand). The digits of reference hand were passively placed collinearly (dy = 0 mm). Subjects were then asked to exert different combinations of normal and tangential digit forces (Fn and Ftan, respectively) using the reference hand and then match the memorized dy using the test hand. The reference hand exerted Ftan of thumb and index finger in either same or opposite direction. We hypothesized that, when the tangential forces of the digits are produced in opposite directions, matching error (1) would be biased toward the directions of the tangential forces; and (2) would be greater when the remembered relative contact points are matched with negligible digit force production. For the test hand, digit forces were either negligible (0.5–1 N, 0 ± 0.25 N; Experiment 1) or the same as those exerted by the reference hand (Experiment 2).Matching error was biased towards the direction of digit tangential forces: thumb CoP was placed higher than the index finger CoP when thumb and index finger Ftan were directed upward and downward, respectively, and vice versa (p < 0.001). However, matching error was not dependent on whether the reference and test hand exerted similar or different forces. We propose that the expected sensory consequence of motor commands for tangential forces in opposite directions overrides estimation of fingertip position through haptic sensory feedback. PMID:25136304

  16. Low cost space operations - Empty promise or future reality. [cost effectiveness problems of NASA programs

    NASA Technical Reports Server (NTRS)

    Bader, M.

    1976-01-01

    Organizational obstacles to the achievement of a cost-effective Space Shuttle service are examined. Among the factors considered are the difficulties of fostering concern for cost-effectiveness among the NASA research and development team and elimination of unnecessary systems and personnel. The effect of foreign or commercial competition and the extent to which governmental funding and control should be implemented are considered.

  17. Manual on Cost-Effectiveness of Training Modalities in Population Education. Population Education Programme Service Series.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific and Cultural Organization, Bangkok (Thailand). Principal Regional Office for Asia and the Pacific.

    This manual is the result of a regional training workshop on the cost-effectiveness of different training strategies in population education by Unesco in Kathmandu, Nepal, June 1-8, 1987. The purpose of the manual is to enable project staff to initiate studies to determine cost-effective training strategies in population growth control education.…

  18. Digitally Controlled Four Harmonic Buncher for FSU LINAC

    NASA Astrophysics Data System (ADS)

    Moerland, Daniel S.; Wiedenhoever, Ingo; Baby, Lagy T.; Caussyn, David; Spingler, David

    2012-03-01

    Florida State University's John D. Fox Superconducting Accelerator Laboratory is operating a Tandem-Linac system for heavy ion beams at energies of 5-10 MeV/u. Recently, the accelerator has been used as the driver for the radioactive beam facility RESOLUT, which poses new demands on its high-intensity performance and time-resolution. These demands motivated us to optimize the RF bunching system and to switch the bunch frequency from 48.5 to 12.125 MHz. We installed a four-harmonic resonant transformer to create 3-4 kV potential oscillations across a pair of wire-mesh grids. This setup is modulating the energy of the beam injected into the tandem accelerator, with the aim to create short bunches of beam particles. Asawtooth-like wave-form is created using the Fourier series method, by combining the basis sinusoidal wave of 12.125MHz and its 3 higher order harmonics, in a manner similar to the systems used at ATLAS [1] and other RF-accelerators. A new aspect of our setup is the use of a digital 1GHz function generator, which allows us to optimize and stabilize the synthesized waveform. The control system was realized using labview and integrated into the recently updated controls of the accelerator. We characterize the bunching quality achievedand discuss the optimization of the bunching wave-form. The bunching system has been successfully used in a number of Linac-experiments performed during 2011.[4pt][1] S. Sharamentov, J. Bogaty, B.E. Clifft, R. Pardo, UPGRADE OF THE ATLAS POSITIVE ION INJECTOR BUNCHING SYSTEM, Proceedings of 2005 Particle Accelerator Conference, Knoxville, Tennessee

  19. Flight test of a full authority Digital Electronic Engine Control system in an F-15 aircraft

    NASA Technical Reports Server (NTRS)

    Barrett, W. J.; Rembold, J. P.; Burcham, F. W.; Myers, L.

    1981-01-01

    The Digital Electronic Engine Control (DEEC) system considered is a relatively low cost digital full authority control system containing selectively redundant components and fault detection logic with capability for accommodating faults to various levels of operational capability. The DEEC digital control system is built around a 16-bit, 1.2 microsecond cycle time, CMOS microprocessor, microcomputer system with approximately 14 K of available memory. Attention is given to the control mode, component bench testing, closed loop bench testing, a failure mode and effects analysis, sea-level engine testing, simulated altitude engine testing, flight testing, the data system, cockpit, and real time display.

  20. Digital controller design: Analysis of the annular suspension pointing system. [analog controllers with feedback

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.

    1978-01-01

    The analog controllers of the annular suspension pointing system are designed for control of the chi, phi sub 1, and phi sub 2 bandwidth dynamics through decoupling and pole placement. Since it is virtually impossible to find an equivalent bandwidth of the overall system and establish a general eigenvalue requirement for the system, the subsystem dynamics are decoupled through state feedback and the poles are placed simultaneously to realize the desired bandwidths for the three system components. Decoupling and pole placement are also used to design the closed-loop digital system through approximation.

  1. Field Programmable Gate Array for Implementation of Redundant Advanced Digital Feedback Control

    NASA Technical Reports Server (NTRS)

    King, K. D.

    2003-01-01

    The goal of this effort was to develop a digital motor controller using field programmable gate arrays (FPGAs). This is a more rugged approach than a conventional microprocessor digital controller. FPGAs typically have higher radiation (rad) tolerance than both the microprocessor and memory required for a conventional digital controller. Furthermore, FPGAs can typically operate at higher speeds. (While speed is usually not an issue for motor controllers, it can be for other system controllers.) Other than motor power, only a 3.3-V digital power supply was used in the controller; no analog bias supplies were used. Since most of the circuit was implemented in the FPGA, no additional parts were needed other than the power transistors to drive the motor. The benefits that FPGAs provide over conventional designs-lower power and fewer parts-allow for smaller packaging and reduced weight and cost.

  2. What can formal methods offer to digital flight control systems design

    NASA Technical Reports Server (NTRS)

    Good, Donald I.

    1990-01-01

    Formal methods research begins to produce methods which will enable mathematic modeling of the physical behavior of digital hardware and software systems. The development of these methods directly supports the NASA mission of increasing the scope and effectiveness of flight system modeling capabilities. The conventional, continuous mathematics that is used extensively in modeling flight systems is not adequate for accurate modeling of digital systems. Therefore, the current practice of digital flight control system design has not had the benefits of extensive mathematical modeling which are common in other parts of flight system engineering. Formal methods research shows that by using discrete mathematics, very accurate modeling of digital systems is possible. These discrete modeling methods will bring the traditional benefits of modeling to digital hardware and hardware design. Sound reasoning about accurate mathematical models of flight control systems can be an important part of reducing risk of unsafe flight control.

  3. Analysis and design of digital output interface devices for gas turbine electronic controls

    NASA Technical Reports Server (NTRS)

    Newirth, D. M.; Koenig, E. W.

    1976-01-01

    A trade study was performed on twenty-one digital output interface schemes for gas turbine electronic controls to select the most promising scheme based on criteria of reliability, performance, cost, and sampling requirements. The most promising scheme, a digital effector with optical feedback of the fuel metering valve position, was designed.

  4. 42 CFR 457.1015 - Cost-effectiveness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of the cost-effectiveness of family coverage in the aggregate reveals that it is not cost-effective... 42 Public Health 4 2010-10-01 2010-10-01 false Cost-effectiveness. 457.1015 Section 457.1015... Waivers: General Provisions § 457.1015 Cost-effectiveness. (a) Definition. For purposes of this...

  5. Discussion on software aging management of nuclear power plant safety digital control system.

    PubMed

    Liang, Huihui; Gu, Pengfei; Tang, Jianzhong; Chen, Weihua; Gao, Feng

    2016-01-01

    Managing the aging of digital control systems ensures that nuclear power plant systems are in adequate safety margins during their life cycles. Software is a core component in the execution of control logic and differs between digital and analog control systems. The hardware aging management for the digital control system is similar to that for the analog system, which has matured over decades of study. However, software aging management is still in the exploratory stage. Software aging evaluation is critical given the higher reliability and safety requirements of nuclear power plants. To ensure effective inputs for reliability assessment, this paper provides the required software aging information during the life cycle. Moreover, the software aging management scheme for safety digital control system is proposed on the basis of collected aging information.

  6. Digital controller for the Wave Propagation Laboratory's VHF and UHF wind-profiling radars

    NASA Astrophysics Data System (ADS)

    Moran, K.

    1984-09-01

    Principles are described for operation of a digital system that is used to control the operations of a multiple beam stratospheric-tropospheric (ST) radar system. The digital system, referred to as the radar controller, contains the digital logic for generating the necessary pulse sequences for modulation of the radar transmitter, gating the radar's receiver channels, and sequencing the antenna beams. The radar controller also performs digital-to-analog conversion and coherent averaging of the receiver necessary for signal detection in ST radars. The radar controller is controlled internally by a Z80 microprocessor, and the entire system functions as a peripheral device to a host minicomputer. Block diagrams and detailed circuit schematics for all the custom designed electronics are included.

  7. Cost-effective FITL technologies for small business and residential customers

    NASA Astrophysics Data System (ADS)

    Andersen, Niels E.; Woolnough, Peter; Seidenberg, Juergen; Ferreira, Mario F. S.

    1995-02-01

    FIRST is a RACE project where 5 main European telecoms operators, 4 equipment manufacturers and one university have joined up to define and test in a field trial in Portugal a cost effective Optical Access Network. The main design target has been a system which gives cost effective provision of wideband services for small and medium business customers. The system however, incorporates provision of telephone, ISDN and analog and digital video for residential customers as well. Technologies have been chosen with the objective of providing a simple, robust and flexible system where initial deployment costs are low and closely related to the service take up. The paper describes the main technical features of the system and network applications which shows how the system may be introduced in network planning. The system is based on Passive Optical Network technology where video is distributed in the 1550 nm window and telecoms services transmitted at 1300 nm in full duplex mode. The telecoms system provides high capacity, flexibility in loop length and robustness towards outside plant performance. The Subcarrier Multiple Access (SCMA) method is used for upstream transmission of bi-directional telecoms services. SCMA has advantages compared to the Time Division Multiple Access technology used in other systems. Bandwidth/cost tradeoff is better and the lower requirements to the outside plant increases the overall cost benefit. Optical beat noise due to overlapping of laser spectra which may be a problem for this technology has been addressed with success through the use of a suitable modulation and control technique. This technology is further validated in the field trial. The video system provides cost effective long distance transmission on standard fiber with externally modulated lasers and cascaded amplifiers. Coexistence of analog and digital video on one fiber with different modulation schemes i.e. BPSK, QPSK and 64 QAM have been validated. Total life cycle cost

  8. Theater SBI cost-effectiveness ratios

    SciTech Connect

    Canavan, G.H.

    1993-11-01

    To address M missiles spaced at intervals longer than the constillation reconstitution time t, the defense needs at the absentee ratio N{sub a} of SBIs to fill the belt plus the M SBIs needed for the intercepts; the resulting cost effectiveness scales as M/(M + N{sub a}). N{sub a} is large and CER small for small ranges and numbers of missiles. For several-hundred missile threats, CERs are greater than unity for ranges of interest.

  9. Are Certified Breast Centers Cost-Effective?

    PubMed Central

    Beckmann, Matthias W.; Bani, Mayada R.; Loehberg, Christian R.; Hildebrandt, Thomas; Schrauder, Michael G.; Wagner, Stefanie; Fasching, Peter A.; Lux, Michael Patrick

    2009-01-01

    Summary The German health care system has entered an era of specialist centers and certification. Hospitals are required to introduce quality management with external monitoring, refining and improving their quality of treatment. These statutory requirements can only be met through specialization, centralization, and establishing centers and networks with internal and external interdisciplinary collaboration. The breast centers certified according to the criteria of the German Cancer Society (DKG) and German Society for Mastology (DGS) are pioneers here. Simultaneously, there are increasing demands for more cost-effective medical services despite limited resources – making economic analysis of health care provision necessary. Few economic studies of the centers and certification system have been conducted, however. General long-term quality data, particularly for results, are not yet available from certified breast centers. At present, a certified breast center is not itself a proven independent prognostic parameter for treatment results. However, the individual criteria required for breast center certification show a significant positive influence on clinical efficacy. Certified breast centers involve substantial extra costs that are not reimbursed by funding bodies, so the slightest potential benefit for patients from certified centers already appears cost-effective. When the actual costs, currently usually subsidized by other departments, are considered, it is unclear whether certified breast centers remain cost-effective. PMID:20877662

  10. Coordination between digit forces and positions: interactions between anticipatory and feedback control.

    PubMed

    Fu, Qiushi; Santello, Marco

    2014-04-01

    Humans adjust digit forces to compensate for trial-to-trial variability in digit placement during object manipulation, but the underlying control mechanisms remain to be determined. We hypothesized that such digit position/force coordination was achieved by both visually guided feed-forward planning and haptic-based feedback control. The question arises about the time course of the interaction between these two mechanisms. This was tested with a task in which subjects generated torque (± 70 N·mm) on a virtual object to control a cursor moving to target positions to catch a falling ball, using a virtual reality environment and haptic devices. The width of the virtual object was varied between large (L) and small (S). These object widths result in significantly different horizontal digit relative positions and require different digit forces to exert the same task torque. After training, subjects were tested with random sequences of L and S widths with or without visual information about object width. We found that visual cues allowed subjects to plan manipulation forces before contact. In contrast, when visual cues were not available to predict digit positions, subjects implemented a "default" digit force plan that was corrected after digit contact to eventually accomplish the task. The time course of digit forces revealed that force development was delayed in the absence of visual cues. Specifically, the appropriate digit force adjustments were made 250-300 ms after initial object contact. This result supports our hypothesis and further reveals that haptic feedback alone is sufficient to implement digit force-position coordination.

  11. The use of minimum order state observers in digital flight-control systems.

    NASA Technical Reports Server (NTRS)

    Montgomery, R. C.; Hatch, H. G., Jr.

    1972-01-01

    This paper deals with the problem of selecting the 'arbitrary' design parameters of digital state observers when they are being used as a part of a digital flight-control system. A cost index is developed which indicates the output noise caused by input quantization due to analog-to-digital conversion. The cost index assumes that the input quantization error is uniformly distributed over the least-significant-bit of the conversion. Formulas relating the cost index to the observer design parameters are presented. The cost index is minimized with respect to the design parameters using a conjugate gradient algorithm. An example of the theory is presented in which a digital observer is designed so that a satisfactory digital flight-control system is obtained starting from an unacceptable one.

  12. Digital Control Analysis and Design of a Field-Sensed Magnetic Suspension System

    PubMed Central

    Li, Jen-Hsing; Chiou, Juing-Shian

    2015-01-01

    Magnetic suspension systems are mechatronic systems and crucial in several engineering applications, such as the levitation of high-speed trains, frictionless bearings, and wind tunnels. Magnetic suspension systems are nonlinear and unstable systems; therefore, they are suitable educational benchmarks for testing various modeling and control methods. This paper presents the digital modeling and control of magnetic suspension systems. First, the magnetic suspension system is stabilized using a digital proportional-derivative controller. Subsequently, the digital model is identified using recursive algorithms. Finally, a digital mixed linear quadratic regulator (LQR)/H∞ control is adopted to stabilize the magnetic suspension system robustly. Simulation examples and a real-world example are provided to demonstrate the practicality of the study results. In this study, a digital magnetic suspension system model was developed and reviewed. In addition, equivalent state and output feedback controls for magnetic suspension systems were developed. Using this method, the controller design for magnetic suspension systems was simplified, which is the novel contribution of this study. In addition, this paper proposes a complete digital controller design procedure for magnetic suspension systems. PMID:25781508

  13. Digital control analysis and design of a field-sensed magnetic suspension system.

    PubMed

    Li, Jen-Hsing; Chiou, Juing-Shian

    2015-03-13

    Magnetic suspension systems are mechatronic systems and crucial in several engineering applications, such as the levitation of high-speed trains, frictionless bearings, and wind tunnels. Magnetic suspension systems are nonlinear and unstable systems; therefore, they are suitable educational benchmarks for testing various modeling and control methods. This paper presents the digital modeling and control of magnetic suspension systems. First, the magnetic suspension system is stabilized using a digital proportional-derivative controller. Subsequently, the digital model is identified using recursive algorithms. Finally, a digital mixed linear quadratic regulator (LQR)/H∞ control is adopted to stabilize the magnetic suspension system robustly. Simulation examples and a real-world example are provided to demonstrate the practicality of the study results. In this study, a digital magnetic suspension system model was developed and reviewed. In addition, equivalent state and output feedback controls for magnetic suspension systems were developed. Using this method, the controller design for magnetic suspension systems was simplified, which is the novel contribution of this study. In addition, this paper proposes a complete digital controller design procedure for magnetic suspension systems.

  14. Supported employment: cost-effectiveness across six European sites

    PubMed Central

    Knapp, Martin; Patel, Anita; Curran, Claire; Latimer, Eric; Catty, Jocelyn; Becker, Thomas; Drake, Robert E; Fioritti, Angelo; Kilian, Reinhold; Lauber, Christoph; Rössler, Wulf; Tomov, Toma; van Busschbach, Jooske; Comas-Herrera, Adelina; White, Sarah; Wiersma, Durk; Burns, Tom

    2013-01-01

    A high proportion of people with severe mental health problems are unemployed but would like to work. Individual Placement and Support (IPS) offers a promising approach to establishing people in paid employment. In a randomized controlled trial across six European countries, we investigated the economic case for IPS for people with severe mental health problems compared to standard vocational rehabilitation. Individuals (n=312) were randomized to receive either IPS or standard vocational services and followed for 18 months. Service use and outcome data were collected. Cost-effectiveness analysis was conducted with two primary outcomes: additional days worked in competitive settings and additional percentage of individuals who worked at least 1 day. Analyses distinguished country effects. A partial cost-benefit analysis was also conducted. IPS produced better outcomes than alternative vocational services at lower cost overall to the health and social care systems. This pattern also held in disaggregated analyses for five of the six European sites. The inclusion of imputed values for missing cost data supported these findings. IPS would be viewed as more cost-effective than standard vocational services. Further analysis demonstrated cost-benefit arguments for IPS. Compared to standard vocational rehabilitation services, IPS is, therefore, probably cost-saving and almost certainly more cost-effective as a way to help people with severe mental health problems into competitive employment. PMID:23471803

  15. Cost-effectiveness of lowering the aflatoxin tolerance level.

    PubMed

    Dichter, C R; Weinstein, M C

    1984-06-01

    The cost-effectiveness of adopting aflatoxin tolerance levels of 15, 10 and 5 ppb for peanuts and peanut products was assessed. Estimates of the annual cost to manufacturers of monitoring and controlling peanut aflatoxin levels at the current 20-ppb action level, and estimates of the projected increase in costs of establishing lower tolerances were elicited from producers by questionnaire. Exposures to peanut products were derived from the HANES I survey and from peanut production statistics. The risk of liver cancer at each tolerance level was estimated using both epidemiological and extrapolated experimental data assuming that exposure would be reduced in direct proportion to the decrease in the tolerance. It was found that the 15-ppb tolerance would cost $60,000 per cancer death averted (range $20,000-$1,700,000) and is therefore relatively cost-effective. The marginal costs per life saved for both the 10-ppb and 5-ppb levels were found to be $1.7 million (range $0.6 million-$11.4 million) and $1.6 million (range +0.6 million-$31.1 million), respectively. Conclusions on the optimal regulatory approach should be guided by comparisons of these figures with corresponding cost-effectiveness ratios for alternative regulatory uses of national resources in the interests of public health.

  16. Optimization of Control Processes of Digital Electrical Drive Systems

    NASA Astrophysics Data System (ADS)

    Dochviri, J.

    2010-01-01

    The aim of the work is solution of the problems associated with synthesis of the digital speed regulators both for DC and AC thyristor electrical drives. The investigation is realized based on the parameters of continuous technological equipment (e.g. paper-making machine) by taking into account elastic transmission links of the drive systems. Appropriate frequency characteristics and transient processes are described.

  17. Collaborative Corrections with Spelling Control: Digital Resources and Peer Assistance

    ERIC Educational Resources Information Center

    Cekaite, Asta

    2009-01-01

    The present study has explored how pairs of students deployed digital tools (spelling software) as resources in spontaneously occurring corrections of spelling errors. Drawing on the sociocultural theory of learning and ethnomethodological (Conversation Analytic) insights into social interaction, it has identified a range of consistent practices…

  18. Digital servo control of random sound test excitation. [in reverberant acoustic chamber

    NASA Technical Reports Server (NTRS)

    Nakich, R. B. (Inventor)

    1974-01-01

    A digital servocontrol system for random noise excitation of a test object in a reverberant acoustic chamber employs a plurality of sensors spaced in the sound field to produce signals in separate channels which are decorrelated and averaged. The average signal is divided into a plurality of adjacent frequency bands cyclically sampled by a time division multiplex system, converted into digital form, and compared to a predetermined spectrum value stored in digital form. The results of the comparisons are used to control a time-shared up-down counter to develop gain control signals for the respective frequency bands in the spectrum of random sound energy picked up by the microphones.

  19. Modular system for data acquisition and control of experiments with digital output

    NASA Astrophysics Data System (ADS)

    Calabria, Mauro F.; Deza, Roberto R.

    2010-11-01

    In the present work, the design of an efficient, modular, and scalable data acquisition and control system is described. It consists of an array of microcontrollers and memories, which feed a single concentrating unit whose information can be accessed by means of a universal series bus (USB) interface to be processed later on. Signal levels can be controlled through a set of digital potentiometers. This system is ideal for experiments with a large number of digital outputs.

  20. Cost-effectiveness of reducing sulfur emissions from ships.

    PubMed

    Wang, Chengfeng; Corbett, James J; Winebrake, James J

    2007-12-15

    We model cost-effectiveness of control strategies for reducing SO2 emissions from U.S. foreign commerce ships traveling in existing European or hypothetical U.S. West Coast SO(x) Emission Control Areas (SECAs) under international maritime regulations. Variation among marginal costs of control for individual ships choosing between fuel-switching and aftertreatment reveals cost-saving potential of economic incentive instruments. Compared to regulations prescribing low sulfur fuels, a performance-based policy can save up to $260 million for these ships with 80% more emission reductions than required because least-cost options on some individual ships outperform standards. Optimal simulation of a market-based SO2 control policy for approximately 4,700 U.S. foreign commerce ships traveling in the SECAs in 2002 shows that SECA emissions control targets can be achieved by scrubbing exhaust gas of one out of ten ships with annual savings up to $480 million over performance-based policy. A market-based policy could save the fleet approximately $63 million annually under our best-estimate scenario. Spatial evaluation of ship emissions reductions shows that market-based instruments can reduce more SO2 closer to land while being more cost-effective for the fleet. Results suggest that combining performance requirements with market-based instruments can most effectively control SO2 emissions from ships.

  1. A satellite digital controller or 'play that PID tune again, Sam'. [Position, Integral, Derivative feedback control algorithm for design strategy

    NASA Technical Reports Server (NTRS)

    Seltzer, S. M.

    1976-01-01

    The problem discussed is to design a digital controller for a typical satellite. The controlled plant is considered to be a rigid body acting in a plane. The controller is assumed to be a digital computer which, when combined with the proposed control algorithm, can be represented as a sampled-data system. The objective is to present a design strategy and technique for selecting numerical values for the control gains (assuming position, integral, and derivative feedback) and the sample rate. The technique is based on the parameter plane method and requires that the system be amenable to z-transform analysis.

  2. Development of a digital guidance and control law for steep approach automatic landings using modern control techniques

    NASA Technical Reports Server (NTRS)

    Halyo, N.

    1979-01-01

    The development of a digital automatic control law for a small jet transport to perform a steep final approach in automatic landings is reported along with the development of a steady-state Kalman filter used to provide smooth estimates to the control law. The control law performs the functions of localizer and glides capture, localizer and glideslope track, decrab, and place. The control law uses the microwave landing system position data, and aircraft body-mounted accelerators, attitude and attitude rate information. The results obtained from a digital simulation of the aircraft dynamics, wind conditions, and sensor noises using the control law and filter developed are described.

  3. Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Flight evaluation in an F-15 aircraft by digital electronic engine control (DEEC) was investigated. Topics discussed include: system description, F100 engine tests, effects of inlet distortion on static pressure probe, flight tests, digital electronic engine control fault detection and accommodation flight evaluation, flight evaluation of a hydromechanical backup control, augmentor transient capability of an F100 engine, investigation of nozzle instability, real time in flight thrust calculation, and control technology for future aircraft propulsion systems. It is shown that the DEEC system is a powerful and flexible controller for the F100 engine.

  4. Status of a digital integrated propulsion/flight control system for the YF-12 airplane

    NASA Technical Reports Server (NTRS)

    Reukauf, P. J.; Burcham, F. W., Jr.; Holzman, J. K.

    1975-01-01

    The NASA Flight Research Center is engaged in a program with the YF-12 airplane to study the control of interactions between the airplane and the propulsion system. The existing analog air data computer, autothrottle, autopilot, and inlet control system are to be converted to digital systems by using a general purpose airborne computer and interface unit. First, the existing control laws will be programmed in the digital computer and flight tested. Then new control laws are to be derived from a dynamic propulsion model and a total force and moment aerodynamic model to integrate the systems. These control laws are to be verified in a real time simulation and flight tested.

  5. Low-to-Medium Power Single Chip Digital Controlled DC-DC Regulator for Point-of-Load Applications

    NASA Technical Reports Server (NTRS)

    Adell, Philippe C. (Inventor); Bakkaloglu, Bertan (Inventor); Vermeire, Bert (Inventor); Liu, Tao (Inventor)

    2015-01-01

    A DC-DC converter for generating a DC output voltage includes: a digitally controlled pulse width modulator (DPWM) for controlling a switching power stage to supply a varying voltage to an inductor; and a digital voltage feedback circuit for controlling the DPWM in accordance with a feedback voltage corresponding to the DC output voltage, the digital voltage feedback circuit including: a first voltage controlled oscillator for converting the feedback voltage into a first frequency signal and to supply the first frequency signal to a first frequency discriminator; a second voltage controlled oscillator for converting a reference voltage into a second frequency signal and to supply the second frequency signal to a second frequency discriminator; a digital comparator for comparing digital outputs of the first and second frequency discriminators and for outputting a digital feedback signal; and a controller for controlling the DPWM in accordance with the digital feedback signal.

  6. Digital TV-echelle spectrograph for simultaneous multielemental analysis using microcomputer control

    SciTech Connect

    Davidson, J.B.; Case, A.L.

    1980-12-01

    A digital TV-echelle spectrograph with microcomputer control was developed for simultaneous multielemental analysis. The optical system is a commercially available unit originally equipped for film and photomultiplier (single element) readout. The film port was adapted for the intensifier camera. The camera output is digitized and stored in a microcomputer-controlled, 512 x 512 x 12 bit memory and image processor. Multiple spectra over the range of 200 to 800 nm are recorded in a single exposure. Spectra lasting from nanoseconds to seconds are digitized and stored in 0.033 s and displayed on a TV monitor. An inexpensive microcomputer controls the exposure, reads and displays the intensity of predetermined spectral lines, and calculates wavelengths of unknown lines. The digital addresses of unknown lines are determined by superimposing a cursor on the TV display. The microcomputer also writes into memory wavelength fiducial marks for alignment of the TV camera.

  7. Tremor suppression using functional electrical stimulation: a comparison between digital and analog controllers.

    PubMed

    Gillard, D M; Cameron, T; Prochazka, A; Gauthier, M J

    1999-09-01

    In this study, we compared digital and analog versions of a functional electrical stimulator designed to suppress tremor. The device was based on a closed-loop control system designed to attenuate movements in the tremor frequency range, without significantly affecting slower, voluntary movements. Testing of the digital filter was done on three patients with Parkinsonian tremor and the results compared to those of a functional electrical stimulation device based on an analog filter evaluated in a previous study. Additional testing of both the analog and digital filters was done on three subjects with no neurological impairment performing tremor-like movements and slow voluntary movements. We found that the digital controller provided a mean attenuation of 84%, compared to 65% for the analog controller.

  8. Test and control computer user's guide for a digital beam former test system

    NASA Technical Reports Server (NTRS)

    Alexovich, Robert E.; Mallasch, Paul G.

    1992-01-01

    A Digital Beam Former Test System was developed to determine the effects of noise, interferers and distortions, and digital implementations of beam forming as applied to the Tracking and Data Relay Satellite 2 (TDRS 2) architectures. The investigation of digital beam forming with application to TDRS 2 architectures, as described in TDRS 2 advanced concept design studies, was conducted by the NASA/Lewis Research Center for NASA/Goddard Space Flight Center. A Test and Control Computer (TCC) was used as the main controlling element of the digital Beam Former Test System. The Test and Control Computer User's Guide for a Digital Beam Former Test System provides an organized description of the Digital Beam Former Test System commands. It is written for users who wish to conduct tests of the Digital Beam forming Test processor using the TCC. The document describes the function, use, and syntax of the TCC commands available to the user while summarizing and demonstrating the use of the commands wtihin DOS batch files.

  9. The second Randomised Evaluation of the Effectiveness, cost-effectiveness and Acceptability of Computerised Therapy (REEACT-2) trial: does the provision of telephone support enhance the effectiveness of computer-delivered cognitive behaviour therapy? A randomised controlled trial.

    PubMed Central

    Brabyn, Sally; Araya, Ricardo; Barkham, Michael; Bower, Peter; Cooper, Cindy; Duarte, Ana; Kessler, David; Knowles, Sarah; Lovell, Karina; Littlewood, Elizabeth; Mattock, Richard; Palmer, Stephen; Pervin, Jodi; Richards, David; Tallon, Debbie; White, David; Walker, Simon; Worthy, Gillian; Gilbody, Simon

    2016-01-01

    BACKGROUND Computerised cognitive behaviour therapy (cCBT) is an efficient form of therapy potentially improving access to psychological care. Indirect evidence suggests that the uptake and effectiveness of cCBT can be increased if facilitated by telephone, but this is not routinely offered in the NHS. OBJECTIVES To compare the clinical effectiveness and cost-effectiveness of telephone-facilitated free-to-use cCBT [e.g. MoodGYM (National Institute for Mental Health Research, Australian National University, Canberra, ACT, Australia)] with minimally supported cCBT. DESIGN This study was a multisite, pragmatic, open, two-arm, parallel-group randomised controlled trial with a concurrent economic evaluation. SETTING Participants were recruited from GP practices in Bristol, Manchester, Sheffield, Hull and the north-east of England. PARTICIPANTS Potential participants were eligible to participate in the trial if they were adults with depression scoring ≥ 10 on the Patient Health Questionnaire-9 (PHQ-9). INTERVENTIONS Participants were randomised using a computer-generated random number sequence to receive minimally supported cCBT or telephone-facilitated cCBT. Participants continued with usual general practitioner care. MAIN OUTCOME MEASURES The primary outcome was self-reported symptoms of depression, as assessed by the PHQ-9 at 4 months post randomisation. SECONDARY OUTCOMES Secondary outcomes were depression at 12 months and anxiety, somatoform complaints, health utility (as assessed by the European Quality of Life-5 Dimensions questionnaire) and resource use at 4 and 12 months. RESULTS Clinical effectiveness: 182 participants were randomised to minimally supported cCBT and 187 participants to telephone-facilitated cCBT. There was a difference in the severity of depression at 4 and 12 months, with lower levels in the telephone-facilitated group. The odds of no longer being depressed (defined as a PHQ-9 score of < 10) at 4 months were twice as high in the

  10. The digital implementation of control compensators: The coefficient wordlength issue

    NASA Technical Reports Server (NTRS)

    Moroney, P.; Willsky, A. S.; Houpt, P. K.

    1979-01-01

    There exists a number of mathematical procedures for designing discrete-time compensators. However, the digital implementation of these designs, with a microprocessor for example, has not received nearly as thorough an investigation. The finite-precision nature of the digital hardware makes it necessary to choose an algorithm (computational structure) that will perform 'well-enough' with regard to the initial objectives of the design. This paper describes a procedure for estimating the required fixed-point coefficient wordlength for any given computational structure for the implementation of a single-input single-output LOG design. The results are compared to the actual number of bits necessary to achieve a specified performance index.

  11. Backup control airstart performance on a digital electronic engine control-equipped F100-engine

    NASA Technical Reports Server (NTRS)

    Johnson, J. B.

    1984-01-01

    The air start capability of a backup control (BUC) was tested for a digital electronic engine control (DEEC) equipped F100 engine, which was installed in an F-15 aircraft. Two air start schedules were tested. Using the group 1 start schedule, based on a 40 sec timer, an air speed of 300 knots was required to ensure successful 40 and 25% BUC mode spooldown airstarts. If core rotor speed (N2) was less than 40% a stall would occur when the start bleed closed, 40 sec after initiation of the air start. All jet fuel starter (JFS) assisted air starts were successful with the group 1 start schedule. For the group 2 schedule, the time between pressurization and start bleed closure ranged between 50 sec and 72 sec. Idle rps was lower than the desired 65% for air starts at higher altitudes and lower air speeds.

  12. A Nonlinear Digital Control Solution for a DC/DC Power Converter

    NASA Technical Reports Server (NTRS)

    Zhu, Minshao

    2002-01-01

    A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

  13. Development and flight test experiences with a flight-crucial digital control system

    NASA Technical Reports Server (NTRS)

    Mackall, Dale A.

    1988-01-01

    Engineers and scientists in the advanced fighter technology integration (AFTI) F-16 program investigated the integration of emerging technologies into an advanced fighter aircraft. AFTI's three major technologies included: flight-crucial digital control, decoupled aircraft flight control, and integration of avionics, flight control, and pilot displays. In addition to investigating improvements in fighter performance, researchers studied the generic problems confronting the designers of highly integrated flight-crucial digital control. An overview is provided of both the advantages and problems of integration digital control systems. Also, an examination of the specification, design, qualification, and flight test life-cycle phase is provided. An overview is given of the fault-tolerant design, multimoded decoupled flight control laws, and integrated avionics design. The approach to qualifying the software and system designs is discussed, and the effects of design choices on system qualification are highlighted.

  14. A Nonlinear Digital Control Solution for a DC/DC Power Converter

    NASA Astrophysics Data System (ADS)

    Zhu, Minshao

    2002-02-01

    A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

  15. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2006-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted into digital signals and transmitted back to the controller. In one embodiment, the bus controller sends commands and data a defined bit rate, and the network device interface senses this bit rate and sends data back to the bus controller using the defined bit rate.

  16. Digit Position and Forces Covary during Anticipatory Control of Whole-Hand Manipulation

    PubMed Central

    Marneweck, Michelle; Lee-Miller, Trevor; Santello, Marco; Gordon, Andrew M.

    2016-01-01

    Theoretical perspectives on anticipatory planning of object manipulation have traditionally been informed by studies that have investigated kinematics (hand shaping and digit position) and kinetics (forces) in isolation. This poses limitations on our understanding of the integration of such domains, which have recently been shown to be strongly interdependent. Specifically, recent studies revealed strong covariation of digit position and load force during the loading phase of two-digit grasping. Here, we determined whether such digit force-position covariation is a general feature of grasping. We investigated the coordination of digit position and forces during five-digit whole-hand manipulation of an object with a variable mass distribution. Subjects were instructed to prevent object roll during the lift. As found in precision grasping, there was strong trial-to-trial covariation of digit position and force. This suggests that the natural variation of digit position that is compensated for by trial-to-trial variation in digit forces is a fundamental feature of grasp control, and not only specific to precision grasp. However, a main difference with precision grasping was that modulation of digit position to the object’s mass distribution was driven predominantly by the thumb, with little to no modulation of finger position. Modulation of thumb position rather than fingers is likely due to its greater range of motion and therefore adaptability to object properties. Our results underscore the flexibility of the central nervous system in implementing a range of solutions along the digit force-to-position continuum for dexterous manipulation. PMID:27695406

  17. Seminar on Understanding Digital Control and Analysis in Vibration Test Systems

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The advantages of the digital methods over the analog vibration methods are demonstrated. The following topics are covered: (1) methods of computer-controlled random vibration and reverberation acoustic testing, (2) methods of computer-controlled sinewave vibration testing, and (3) methods of computer-controlled shock testing. General algorithms are described in the form of block diagrams and flow diagrams.

  18. A quality control system for digital elevation data

    NASA Astrophysics Data System (ADS)

    Knudsen, Thomas; Kokkendorf, Simon; Flatman, Andrew; Nielsen, Thorbjørn; Rosenkranz, Brigitte; Keller, Kristian

    2015-04-01

    In connection with the introduction of a new version of the Danish national coverage Digital Elevation Model (DK-DEM), the Danish Geodata Agency has developed a comprehensive quality control (QC) and metadata production (MP) system for LiDAR point cloud data. The architecture of the system reflects its origin in a national mapping organization where raw data deliveries are typically outsourced to external suppliers. It also reflects a design decision of aiming at, whenever conceivable, doing full spatial coverage tests, rather than scattered sample checks. Hence, the QC procedure is split in two phases: A reception phase and an acceptance phase. The primary aim of the reception phase is to do a quick assessment of things that can typically go wrong, and which are relatively simple to check: Data coverage, data density, strip adjustment. If a data delivery passes the reception phase, the QC continues with the acceptance phase, which checks five different aspects of the point cloud data: Vertical accuracy Vertical precision Horizontal accuracy Horizontal precision Point classification correctness The vertical descriptors are comparatively simple to measure: The vertical accuracy is checked by direct comparison with previously surveyed patches. The vertical precision is derived from the observed variance on well defined flat surface patches. These patches are automatically derived from the road centerlines registered in FOT, the official Danish map data base. The horizontal descriptors are less straightforward to measure, since potential reference material for direct comparison is typically expected to be less accurate than the LiDAR data. The solution selected is to compare photogrammetrically derived roof centerlines from FOT with LiDAR derived roof centerlines. These are constructed by taking the 3D Hough transform of a point cloud patch defined by the photogrammetrical roof polygon. The LiDAR derived roof centerline is then the intersection line of the two primary

  19. Tailoring automatic exposure control toward constant detectability in digital mammography

    SciTech Connect

    Salvagnini, Elena; Bosmans, Hilde; Struelens, Lara; Marshall, Nicholas W.

    2015-07-15

    Purpose: The automatic exposure control (AEC) modes of most full field digital mammography (FFDM) systems are set up to hold pixel value (PV) constant as breast thickness changes. This paper proposes an alternative AEC mode, set up to maintain some minimum detectability level, with the ultimate goal of improving object detectability at larger breast thicknesses. Methods: The default “OPDOSE” AEC mode of a Siemens MAMMOMAT Inspiration FFDM system was assessed using poly(methyl methacrylate) (PMMA) of thickness 20, 30, 40, 50, 60, and 70 mm to find the tube voltage and anode/filter combination programmed for each thickness; these beam quality settings were used for the modified AEC mode. Detectability index (d′), in terms of a non-prewhitened model observer with eye filter, was then calculated as a function of tube current-time product (mAs) for each thickness. A modified AEC could then be designed in which detectability never fell below some minimum setting for any thickness in the operating range. In this study, the value was chosen such that the system met the achievable threshold gold thickness (T{sub t}) in the European guidelines for the 0.1 mm diameter disc (i.e., T{sub t} ≤ 1.10 μm gold). The default and modified AEC modes were compared in terms of contrast-detail performance (T{sub t}), calculated detectability (d′), signal-difference-to-noise ratio (SDNR), and mean glandular dose (MGD). The influence of a structured background on object detectability for both AEC modes was examined using a CIRS BR3D phantom. Computer-based CDMAM reading was used for the homogeneous case, while the images with the BR3D background were scored by human observers. Results: The default OPDOSE AEC mode maintained PV constant as PMMA thickness increased, leading to a reduction in SDNR for the homogeneous background 39% and d′ 37% in going from 20 to 70 mm; introduction of the structured BR3D plate changed these figures to 22% (SDNR) and 6% (d′), respectively

  20. Estimating 'costs' for cost-effectiveness analysis.

    PubMed

    Miners, Alec

    2008-01-01

    Since 1999, the National Institute for Health and Clinical Excellence (NICE) Technology Appraisal Programme has been charged with producing guidance for the NHS in England and Wales on the appropriate use of new and existing healthcare programmes. Guidance is based on an assessment of a number of factors, including cost effectiveness. The identification, measurement and valuation of costs are important components of any cost-effectiveness analysis. However, working through these steps raises a number of important methodological questions. For example, how should 'future' resource use be estimated, and is there a need to consider all 'future' costs? Given that NICE produces national guidance, should national unit cost data be used to value resources or should local variations in negotiated prices be taken into account? This paper was initially prepared as a briefing paper as part of the process of updating NICE's 2004 Guide to the Methods of Technology Appraisal for a workshop on 'costs'. It outlines the issues that were raised in the original briefing paper and the subsequent questions that were discussed at the workshop.

  1. Deregulation and Nuclear Training: Cost Effective Alternatives

    SciTech Connect

    Richard P. Coe; Patricia A. Lake

    2000-11-12

    Training is crucial to the success of any organization. It is also expensive, with some estimates exceeding $50 billion annually spent on training by U.S. corporations. Nuclear training, like that of many other highly technical organizations, is both crucial and costly. It is unlikely that the amount of training can be significantly reduced. If anything, current trends indicate that training needs will probably increase as the industry and workforce ages and changes. With the advent of energy deregulation in the United States, greater pressures will surface to make the costs of energy more cost-competitive. This in turn will drive businesses to more closely examine existing costs and find ways to do things in a more cost-effective way. The commercial nuclear industry will be no exception, and nuclear training will be equally affected. It is time for nuclear training and indeed the entire nuclear industry to begin using more aggressive techniques to reduce costs. This includes the need for nuclear training to find alternatives to traditional methods for the delivery of cost-effective high-quality training that meets regulatory requirements and produces well-qualified personnel capable of working in an efficient and safe manner. Computer-based and/or Web-based training are leading emerging technologies.

  2. Description of a digital computer simulation of an Annular Momentum Control Device (AMCD) laboratory test model

    NASA Technical Reports Server (NTRS)

    Woolley, C. T.; Groom, N. J.

    1981-01-01

    A description of a digital computer simulation of an Annular Momentum Control Device (AMCD) laboratory model is presented. The AMCD is a momentum exchange device which is under development as an advanced control effector for spacecraft attitude control systems. The digital computer simulation of this device incorporates the following models: six degree of freedom rigid body dynamics; rim warp; controller dynamics; nonlinear distributed element axial bearings; as well as power driver and power supply current limits. An annotated FORTRAN IV source code listing of the computer program is included.

  3. Development of the HIDEC inlet integration mode. [Highly Integrated Digital Electronic Control

    NASA Technical Reports Server (NTRS)

    Chisholm, J. D.; Nobbs, S. G.; Stewart, J. F.

    1990-01-01

    The Highly Integrated Digital Electronic Control (HIDEC) development program conducted at NASA-Ames/Dryden will use an F-15 test aircraft for flight demonstration. An account is presently given of the HIDEC Inlet Integration mode's design concept, control law, and test aircraft implementation, with a view to its performance benefits. The enhancement of performance is a function of the use of Digital Electronic Engine Control corrected engine airflow computations to improve the scheduling of inlet ramp positions in real time; excess thrust can thereby be increased by 13 percent at Mach 2.3 and 40,000 ft. Aircraft supportability is also improved through the obviation of inlet controllers.

  4. Reducing Wildlife Damage with Cost-Effective Management Programmes.

    PubMed

    Krull, Cheryl R; Stanley, Margaret C; Burns, Bruce R; Choquenot, David; Etherington, Thomas R

    2016-01-01

    Limiting the impact of wildlife damage in a cost effective manner requires an understanding of how control inputs change the occurrence of damage through their effect on animal density. Despite this, there are few studies linking wildlife management (control), with changes in animal abundance and prevailing levels of wildlife damage. We use the impact and management of wild pigs as a case study to demonstrate this linkage. Ground disturbance by wild pigs has become a conservation issue of global concern because of its potential effects on successional changes in vegetation structure and composition, habitat for other species, and functional soil properties. In this study, we used a 3-year pig control programme (ground hunting) undertaken in a temperate rainforest area of northern New Zealand to evaluate effects on pig abundance, and patterns and rates of ground disturbance and ground disturbance recovery and the cost effectiveness of differing control strategies. Control reduced pig densities by over a third of the estimated carrying capacity, but more than halved average prevailing ground disturbance. Rates of new ground disturbance accelerated with increasing pig density, while rates of ground disturbance recovery were not related to prevailing pig density. Stochastic simulation models based on the measured relationships between control, pig density and rate of ground disturbance and recovery indicated that control could reduce ground disturbance substantially. However, the rate at which prevailing ground disturbance was reduced diminished rapidly as more intense, and hence expensive, pig control regimes were simulated. The model produced in this study provides a framework that links conservation of indigenous ecological communities to control inputs through the reduction of wildlife damage and suggests that managers should consider carefully the marginal cost of higher investment in wildlife damage control, relative to its marginal conservation return.

  5. Reducing Wildlife Damage with Cost-Effective Management Programmes

    PubMed Central

    Krull, Cheryl R.; Stanley, Margaret C.; Burns, Bruce R.; Choquenot, David; Etherington, Thomas R.

    2016-01-01

    Limiting the impact of wildlife damage in a cost effective manner requires an understanding of how control inputs change the occurrence of damage through their effect on animal density. Despite this, there are few studies linking wildlife management (control), with changes in animal abundance and prevailing levels of wildlife damage. We use the impact and management of wild pigs as a case study to demonstrate this linkage. Ground disturbance by wild pigs has become a conservation issue of global concern because of its potential effects on successional changes in vegetation structure and composition, habitat for other species, and functional soil properties. In this study, we used a 3-year pig control programme (ground hunting) undertaken in a temperate rainforest area of northern New Zealand to evaluate effects on pig abundance, and patterns and rates of ground disturbance and ground disturbance recovery and the cost effectiveness of differing control strategies. Control reduced pig densities by over a third of the estimated carrying capacity, but more than halved average prevailing ground disturbance. Rates of new ground disturbance accelerated with increasing pig density, while rates of ground disturbance recovery were not related to prevailing pig density. Stochastic simulation models based on the measured relationships between control, pig density and rate of ground disturbance and recovery indicated that control could reduce ground disturbance substantially. However, the rate at which prevailing ground disturbance was reduced diminished rapidly as more intense, and hence expensive, pig control regimes were simulated. The model produced in this study provides a framework that links conservation of indigenous ecological communities to control inputs through the reduction of wildlife damage and suggests that managers should consider carefully the marginal cost of higher investment in wildlife damage control, relative to its marginal conservation return. PMID

  6. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2009-01-01

    A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

  7. Design and flight testing of a digital optimal control general aviation autopilot

    NASA Technical Reports Server (NTRS)

    Broussard, J. R.; Downing, D. R.; Bryant, W. H.

    1982-01-01

    This paper presents the designs of Proportional-Integral-Filter (PIF) autopilots for a General Aviation (NAVION) aircraft. The PIF autopilots use modern control theory to determine heading select and altitude select and hold autopilot modes. The PIF control law uses typical General Aviation sensors for state feedback; command error integration for command tracking; digital complimentary filtering and analog prefiltering for sensor noise suppression; a control filter for computation delay accommodation; and the incremental form to eliminate trim values in implementation. Theoretical developments for the control law are described which combine the sampled-data regulator with command generator tracking for use as a digital flight control system. The digital PIF autopilots are evaluated using closed-loop eigenvalues and simulations. Successful flight test results for the PIF autopilots are presented for different turbulence conditions and quadratic weights.

  8. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2006-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface is a state machine, such as an ASIC, that operates independent of a processor in communicating with the bus controller and data channels.

  9. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2007-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. In some embodiments, network device interfaces associated with different data channels coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

  10. F-8 digital fly-by-wire flight test results viewed from an active controls perspective

    NASA Technical Reports Server (NTRS)

    Zalai, K. J.; Deets, D. A.

    1975-01-01

    The results of the NASA F-8 digital fly-by-wire flight test program are presented, along with the implications for active controls applications. The closed loop performance of the digital control system agreed well with the sampled-data system design predictions. The digital fly-by-wire mechanization also met pilot flying qualities requirements. The advantages of mechanizing the control laws in software became apparent during the flight program and were realized without sacrificing overall system reliability. This required strict software management. The F-8 flight test results are shown to be encouraging in light of the requirements that must be met by control systems for flight-critical active controls applications.

  11. A monitor for the laboratory evaluation of control integrity in digital control systems operating in harsh electromagnetic environments

    NASA Technical Reports Server (NTRS)

    Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

    1992-01-01

    This paper presents a strategy for dynamically monitoring digital controllers in the laboratory for susceptibility to electromagnetic disturbances that compromise control integrity. The integrity of digital control systems operating in harsh electromagnetic environments can be compromised by upsets caused by induced transient electrical signals. Digital system upset is a functional error mode that involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. The motivation for this work is the need to develop tools and techniques that can be used in the laboratory to validate and/or certify critical aircraft controllers operating in electromagnetically adverse environments that result from lightning, high-intensity radiated fields (HIRF), and nuclear electromagnetic pulses (NEMP). The detection strategy presented in this paper provides dynamic monitoring of a given control computer for degraded functional integrity resulting from redundancy management errors, control calculation errors, and control correctness/effectiveness errors. In particular, this paper discusses the use of Kalman filtering, data fusion, and statistical decision theory in monitoring a given digital controller for control calculation errors.

  12. Validation of MTF measurement for digital mammography quality control

    SciTech Connect

    Carton, Ann-Katherine; Vandenbroucke, Dirk; Struye, Luc; Maidment, Andrew D.A.; Kao, Y.-H.; Albert, Michael; Bosmans, Hilde; Marchal, Guy

    2005-06-15

    The modulation transfer function (MTF) describes the spatial resolution properties of imaging systems. In this work, the accuracy of our implementation of the edge method for calculating the presampled MTF was examined. Synthetic edge images with known MTF were used as gold standards for determining the robustness of the edge method. These images simulated realistic data from clinical digital mammography systems, and contained intrinsic system factors that could affect the MTF accuracy, such as noise, scatter, and flat-field nonuniformities. Our algorithm is not influenced by detector dose variations for MTF accuracy up to 1/2 the sampling frequency. We investigated several methods for noise reduction, including truncating the supersampled line spread function (LSF), windowing the LSF, applying a local exponential fit to the LSF, and applying a monotonic constraint to the supersampled edge spread function. Only the monotonic constraint did not introduce a systematic error; the other methods could result in MTF underestimation. Overall, our edge method consistently computed MTFs which were in good agreement with the true MTF. The edge method was then applied to images from a commercial storage-phosphor based digital mammography system. The calculated MTF was affected by the size (sides of 2.5, 5, or 10 cm) and the composition (lead or tungsten) of the edge device. However, the effects on the MTF were observed only with regard to the low frequency drop (LFD). Scatter nonuniformity was dependent on edge size, and could lead to slight underestimation of LFD. Nevertheless, this negative effect could be minimized by using an edge of 5 cm or larger. An edge composed of lead is susceptible to L-fluorescence, which causes overestimation of the LFD. The results of this work are intended to underline the need for clear guidelines if the MTF is to be given a more crucial role in acceptance tests and routine assessment of digital mammography systems: the MTF algorithm and edge

  13. A digital control system for external magnetohydrodynamic modes in tokamak plasmas

    SciTech Connect

    Hanson, J. M.; Klein, A. J.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. Sunn

    2009-04-15

    A feedback system for controlling external, long-wavelength magnetohydrodynamic activity is described. The system is comprised of a network of localized magnetic pickup and control coils driven by four independent, low-latency field-programable gate array controllers. The control algorithm incorporates digital spatial filtering to resolve low mode number activity, temporal filtering to correct for frequency-dependent amplitude and phase transfer effects in the control hardware, and a Kalman filter to distinguish the unstable plasma mode from noise.

  14. A digital control system for external magnetohydrodynamic modes in tokamak plasmas.

    PubMed

    Hanson, J M; Klein, A J; Mauel, M E; Maurer, D A; Navratil, G A; Pedersen, T Sunn

    2009-04-01

    A feedback system for controlling external, long-wavelength magnetohydrodynamic activity is described. The system is comprised of a network of localized magnetic pickup and control coils driven by four independent, low-latency field-programable gate array controllers. The control algorithm incorporates digital spatial filtering to resolve low mode number activity, temporal filtering to correct for frequency-dependent amplitude and phase transfer effects in the control hardware, and a Kalman filter to distinguish the unstable plasma mode from noise.

  15. Guidance, Navigation and Control Digital Emulation Technology Laboratory

    NASA Astrophysics Data System (ADS)

    Alford, Cecil O.; Chamdani, J. I.; Huang, T. C.; Kubota, T.; Ghannadian, F.

    1994-09-01

    The contract began with seven tasks: (1) Digital Emulation Facility; (2) FPA Seeker Emulator Development; (3) Special Studies; (4) Software Development; (5) Automated Input; (6) PFP Technology; and (7) GN and C Processor Development. These tasks were developed through the first two years of the contract when virtually all funding was removed. Two additional tasks have been developed since the funding cut. The first was a speed test on the rad-hard FPU chip developed by Harris. A summary of this testing and the associated report is given in Section 2. The second task is the development of an FPA Test System.

  16. Digital-computer normal shock position and restart control of a Mach 2.5 axisymmetric mixed-compression inlet

    NASA Technical Reports Server (NTRS)

    Neiner, G. H.; Cole, G. L.; Arpasi, D. J.

    1972-01-01

    Digital computer control of a mixed-compression inlet is discussed. The inlet was terminated with a choked orifice at the compressor face station to dynamically simulate a turbojet engine. Inlet diffuser exit airflow disturbances were used. A digital version of a previously tested analog control system was used for both normal shock and restart control. Digital computer algorithms were derived using z-transform and finite difference methods. Using a sample rate of 1000 samples per second, the digital normal shock and restart controls essentially duplicated the inlet analog computer control results. At a sample rate of 100 samples per second, the control system performed adequately but was less stable.

  17. Cost-Effective Fuel Treatment Planning

    NASA Astrophysics Data System (ADS)

    Kreitler, J.; Thompson, M.; Vaillant, N.

    2014-12-01

    The cost of fighting large wildland fires in the western United States has grown dramatically over the past decade. This trend will likely continue with growth of the WUI into fire prone ecosystems, dangerous fuel conditions from decades of fire suppression, and a potentially increasing effect from prolonged drought and climate change. Fuel treatments are often considered the primary pre-fire mechanism to reduce the exposure of values at risk to wildland fire, and a growing suite of fire models and tools are employed to prioritize where treatments could mitigate wildland fire damages. Assessments using the likelihood and consequence of fire are critical because funds are insufficient to reduce risk on all lands needing treatment, therefore prioritization is required to maximize the effectiveness of fuel treatment budgets. Cost-effectiveness, doing the most good per dollar, would seem to be an important fuel treatment metric, yet studies or plans that prioritize fuel treatments using costs or cost-effectiveness measures are absent from the literature. Therefore, to explore the effect of using costs in fuel treatment planning we test four prioritization algorithms designed to reduce risk in a case study examining fuel treatments on the Sisters Ranger District of central Oregon. For benefits we model sediment retention and standing biomass, and measure the effectiveness of each algorithm by comparing the differences among treatment and no treat alternative scenarios. Our objective is to maximize the averted loss of net benefits subject to a representative fuel treatment budget. We model costs across the study landscape using the My Fuel Treatment Planner software, tree list data, local mill prices, and GIS-measured site characteristics. We use fire simulations to generate burn probabilities, and estimate fire intensity as conditional flame length at each pixel. Two prioritization algorithms target treatments based on cost-effectiveness and show improvements over those

  18. Understanding Cost-Effectiveness of Energy Efficiency Programs

    EPA Pesticide Factsheets

    This paper discusses the five standard tests used to assess the cost-effectiveness of energy efficiency, how states are using these tests, and how the tests can be used to determine the cost-effectiveness of energy efficiency measures.

  19. Report on Disclosure Issues Related to the Use of Copy Control and Digital Rights Management Technologies. OECD Digital Economy Papers, No. 115

    ERIC Educational Resources Information Center

    OECD Publishing (NJ1), 2006

    2006-01-01

    This report analyses the disclosure issues raised by technically-imposed restrictions on the use of digital content. It focuses on the application of copy control and digital rights management technologies in three areas: copy-protected CDs; online music, and DVD regional coding. In each of these areas, the report examines the kinds of…

  20. Apparatus for externally controlled closed-loop feedback digital epitaxy

    DOEpatents

    Eres, Djula; Sharp, Jeffrey W.

    1996-01-01

    A method and apparatus for digital epitaxy. The apparatus includes a pulsed gas delivery assembly that supplies gaseous material to a substrate to form an adsorption layer of the gaseous material on the substrate. Structure is provided for measuring the isothermal desorption spectrum of the growth surface to monitor the active sites which are available for adsorption. The vacuum chamber housing the substrate facilitates evacuation of the gaseous material from the area adjacent the substrate following exposure. In use, digital epitaxy is achieved by exposing a substrate to a pulse of gaseous material to form an adsorption layer of the material on the substrate. The active sites on the substrate are monitored during the formation of the adsorption layer to determine if all the active sites have been filled. Once the active sites have been filled on the growth surface of the substrate, the pulse of gaseous material is terminated. The unreacted portion of the gas pulse is evacuated by continuous pumping. Subsequently, a second pulse is applied when availability of active sites is determined by studying the isothermal desorption spectrum. These steps are repeated until a thin film of sufficient thickness is produced.

  1. Apparatus for externally controlled closed-loop feedback digital epitaxy

    DOEpatents

    Eres, D.; Sharp, J.W.

    1996-07-30

    A method and apparatus for digital epitaxy are disclosed. The apparatus includes a pulsed gas delivery assembly that supplies gaseous material to a substrate to form an adsorption layer of the gaseous material on the substrate. Structure is provided for measuring the isothermal desorption spectrum of the growth surface to monitor the active sites which are available for adsorption. The vacuum chamber housing the substrate facilitates evacuation of the gaseous material from the area adjacent the substrate following exposure. In use, digital epitaxy is achieved by exposing a substrate to a pulse of gaseous material to form an adsorption layer of the material on the substrate. The active sites on the substrate are monitored during the formation of the adsorption layer to determine if all the active sites have been filled. Once the active sites have been filled on the growth surface of the substrate, the pulse of gaseous material is terminated. The unreacted portion of the gas pulse is evacuated by continuous pumping. Subsequently, a second pulse is applied when availability of active sites is determined by studying the isothermal desorption spectrum. These steps are repeated until a thin film of sufficient thickness is produced. 5 figs.

  2. Flight evaluation of modifications to a digital electronic engine control system in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Zeller, J. R.

    1983-01-01

    The third phase of a flight evaluation of a digital electronic engine control system in an F-15 has recently been completed. It was found that digital electronic engine control software logic changes and augmentor hardware improvements resulted in significant improvements in engine operation. For intermediate to maximum power throttle transients, an increase in altitude capability of up to 8000 ft was found, and for idle to maximum transients, an increase of up to 4000 ft was found. A nozzle instability noted in earlier flight testing was investigated on a test engine at NASA Lewis Research Center, a digital electronic engine control software logic change was developed and evaluated, and no instability occurred in the Phase 3 flight evaluation. The backup control airstart modification was evaluated, and gave an improvement of airstart capability by reducing the minimum airspeed for successful airstarts by 50 to 75 knots.

  3. Digital controller for a Baum folding machine. [providing automatic counting and machine shutoff

    NASA Technical Reports Server (NTRS)

    Bryant, W. H. (Inventor)

    1974-01-01

    A digital controller for controlling the operation of a folding machine enables automatic folding of a desired number of sheets responsive to entry of that number into a selector. The controller includes three decade counter stages for corresponding rows of units, tens and hundreds push buttons. Each stage including a decimal-to-BCD encoder, a buffer register, and a digital or binary counter. The BCD representation of the selected count for each digit is loaded into the respective decade down counters. Pulses generated by a sensor and associated circuitry are used to decrease the count in the decade counters. When the content of the decade counter reaches either 0 or 1, a solenoid control valve is actuated which interrupts operation of the machine. A repeat switch, when actuated, prevents clearing of the buffer registers so that multiple groups of the same number of sheets can be folded without reentering the number into the selector.

  4. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2005-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

  5. Network device interface for digitally interfacing data channels to a controller via a network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2004-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

  6. Flight evaluation of a digital electronic engine control system in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Myers, L. P.; Mackall, K. G.; Burcham, F. W., Jr.; Walter, W. A.

    1982-01-01

    Benefits provided by a full-authority digital engine control are related to improvements in engine efficiency, performance, and operations. An additional benefit is the capability of detecting and accommodating failures in real time and providing engine-health diagnostics. The digital electronic engine control (DEEC), is a full-authority digital engine control developed for the F100-PW-100 turbofan engine. The DEEC has been flight tested on an F-15 aircraft. The flight tests had the objective to evaluate the DEEC hardware and software over the F-15 flight envelope. A description is presented of the results of the flight tests, which consisted of nonaugmented and augmented throttle transients, airstarts, and backup control operations. The aircraft, engine, DEEC system, and data acquisition and reduction system are discussed.

  7. Is nuclear medicine cost-effective?

    PubMed

    Ripley, S

    1991-03-01

    Clearly, there is currently no consensus on the cost-effectiveness of nuclear medicine--or in fact any other aspect of medicine. It is hoped that common sense prevails in clinical medicine today. An appropriate case history and physical examination may negate the need for any additional investigation. From the perspective of the capital cost of equipment and supply costs, ultrasound is clearly the most cost-effective diagnostic imaging modality. But while it is useful, it does not always provide definitive answers, and other modalities must be used to arrive at a diagnosis. In comparison, the capital cost of general radiology equipment and nuclear medicine equipment is relatively equal. Radiology has more operating costs per case than nuclear medicine and requires a lower staffing component per given volume of examinations. In any given diagnostic imaging procedure, the practitioner and imagist must maintain a dialogue to ascertain the appropriateness of the study and to use the available resources in the most effective manner. This is even more imperative when CT scanning and MRI are included in the equation. The development of an investigative protocol that makes the most efficient use of the various imaging modalities without compromising the quality of care makes sense for the patient, the physician and the insurance provider. It is unreasonable to expect the physician to be aware of the optimal protocol for the diagnostic workup of every patient. The guidance of the imaging department is required to maximize the efficient use of the available facilities. A critical and exhaustive appraisal of the medical literature may be required to determine the optimal diagnostic protocol.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Cost-effective ultrasound PACS solution

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice C.; Frost, Meryll M.; Staab, Edward V.

    1995-05-01

    Picture archiving and communication systems (PACS) have been quite successful at the University of Florida in the areas of CT, MR, and nuclear medicine. In each case, although we have not always been able to provide the optimal level of performance, we have been able to solve a problem and the systems are used extensively. Ultrasound images are required in a number of locations and the multiformat camera print capability was no longer adequate for the growing volume in the ultrasound section. Although we were certain we could successfully implement PACS for ultrasound, new forces in health care dictate that we justify our system in terms of cost. We analyzed the feasibility of a PACS solution for ultrasound and designed a system that meets our needs and is cost effective. We evaluated the ultrasound operation in terms of image acquisition patterns and throughput requirements. An inventory of existing and PACS equipment was made to determine the feasibility of interfacing the two systems. Commercial systems were evaluated for functionality and cost and a system was designed to meet our needs. The only way to achieve our goal of installing a cost effective ultrasound PACS was to eliminate film and use the cost savings to offset the cost of new equipment and development. We designed a system that could be produced using inexpensive components and existing hardware and software to meet our needs. A commercial vendor was chosen to provide the ultrasound acquisition. The Radiology Information System interface used at the University provides the necessary data to build a DICOM header, and an existing DICOM server routes the images to the appropriate workstations, archives, and printers. Additional storage is added to an existing archive to accommodate the ultrasound images and two existing workstations are evaluated for use in ultrasound.

  9. Flight testing the digital electronic engine control in the F-15 airplane

    NASA Technical Reports Server (NTRS)

    Myers, L. P.

    1984-01-01

    The digital electronic engine control (DEEC) is a full-authority digital engine control developed for the F100-PW-100 turbofan engine which was flight tested on an F-15 aircraft. The DEEC hardware and software throughout the F-15 flight envelope was evaluated. Real-time data reduction and data display systems were implemented. New test techniques and stronger coordination between the propulsion test engineer and pilot were developed which produced efficient use of test time, reduced pilot work load, and greatly improved quality data. The engine pressure ratio (EPR) control mode is demonstrated. It is found that the nonaugmented throttle transients and engine performance are satisfactory.

  10. Direct current pulse train actuation to enhance droplet control in digital microfluidics

    NASA Astrophysics Data System (ADS)

    Murran, Miguel A.; Najjaran, Homayoun

    2012-10-01

    The effective operation of a digital microfluidic (DMF) device depends on its ability to actuate droplets. Pulse width modulation of actuating signals (DC pulse train actuation) is proposed as a practical digital implementation and enhanced droplet manipulation technique. Experimental and simulation results demonstrate the efficacy of droplet incremental displacement and velocity control by modulating the width of each actuation pulse. This will in turn enable the control of the non-linear droplet transport dynamics to minimize droplet position overshoot, deformation, and fragmentation. As a result, DCPT actuation offers unparalleled control over droplet position and speed in DMF devices.

  11. Application of digital control to a magnetic model suspension and balance model

    NASA Technical Reports Server (NTRS)

    Luh, P. B.; Covert, E. E.; Whitaker, H. P.; Haldeman, C. W.

    1978-01-01

    The feasibility of using a digital computer for performing the automatic control functions for a magnetic suspension and balance system (MSBS) for use with wind tunnel models was investigated. Modeling was done using both a prototype MSBS and a one dimensional magnetic balance. A microcomputer using the Intel 8080 microprocessor is described and results are given using this microprocessor to control the one dimensional balance. Hybrid simulations for one degree of freedom of the MSBS were also performed and are reported. It is concluded that use of a digital computer to control the MSBS is eminently feasible and should extend both the accuracy and utility of the system.

  12. 23 CFR 635.205 - Finding of cost effectiveness.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Finding of cost effectiveness. 635.205 Section 635.205... CONSTRUCTION AND MAINTENANCE Force Account Construction § 635.205 Finding of cost effectiveness. (a) It may be found cost effective for a State transportation department or county to undertake a federally...

  13. 49 CFR 639.21 - Determination of cost-effectiveness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Determination of cost-effectiveness. 639.21... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CAPITAL LEASES Cost-Effectiveness § 639.21 Determination of cost-effectiveness. (a) To qualify a lease for capital assistance, a recipient must— (1) Make a written comparison...

  14. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    ERIC Educational Resources Information Center

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  15. Proceedings of the Fourth Annual Workshop on the Use of Digital Computers in Process Control.

    ERIC Educational Resources Information Center

    Smith, Cecil L., Ed.

    Contents: Computer hardware testing (results of vendor-user interaction); CODIL (a new language for process control programing); the design and implementation of control systems utilizing CRT display consoles; the systems contractor - valuable professional or unnecessary middle man; power station digital computer applications; from inspiration to…

  16. Seminar on Understanding Digital Control and Analysis in Vibration Test Systems, part 2

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A number of techniques for dealing with important technical aspects of the random vibration control problem are described. These include the generation of pseudo-random and true random noise, the control spectrum estimation problem, the accuracy/speed tradeoff, and control correction strategies. System hardware, the operator-system interface, safety features, and operational capabilities of sophisticated digital random vibration control systems are also discussed.

  17. NASA's advanced control law program for the F-8 digital fly-by-wire aircraft

    NASA Technical Reports Server (NTRS)

    Elliott, J. R.

    1977-01-01

    This paper briefly describes the NASA F-8 Digital Fly-By-Wire (DFBW) and Langley Research Center's role in investigating and promoting advanced control laws for possible flight experimentation and also provides a brief description of the Phase II DFBW F-8 aircraft and its control system. Some of the advanced control law study objectives and guidelines are discussed, and some mathematical models which are useful in the control analysis problem are provided.

  18. Results and Insights on the Impact of Smoke on Digital Instrumentation and Control

    SciTech Connect

    Tanaka, T. J.; Nowlen, S. P.

    2001-01-31

    Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The major effect of smoke has been to increase leakage currents (through circuit bridging across contacts and leads) and to cause momentary upsets and failures in digital systems. This report summarizes two previous reports and presents new results from conformal coating, memory chip, and hard drive tests. The report describes practices for mitigation of smoke damage through digital system design, fire barriers, ventilation, fire suppressants, and post fire procedures.

  19. Using Cost-Effectiveness Tests to Design CHP Incentive Programs

    SciTech Connect

    Tidball, Rick

    2014-11-01

    This paper examines the structure of cost-effectiveness tests to illustrate how they can accurately reflect the costs and benefits of CHP systems. This paper begins with a general background discussion on cost-effectiveness analysis of DER and then describes how cost-effectiveness tests can be applied to CHP. Cost-effectiveness results are then calculated and analyzed for CHP projects in five states: Arkansas, Colorado, Iowa, Maryland, and North Carolina. Based on the results obtained for these five states, this paper offers four considerations to inform regulators in the application of cost-effectiveness tests in developing CHP programs.

  20. BacNet and Analog/Digital Interfaces of the Building Controls Virtual Testbed

    SciTech Connect

    Nouidui, Thierry Stephane; Wetter, Michael; Li, Zhengwei; Pang, Xiufeng; Bhattacharya, Prajesh; Haves, Philip

    2011-11-01

    This paper gives an overview of recent developments in the Building Controls Virtual Test Bed (BCVTB), a framework for co-simulation and hardware-in-the-loop. First, a general overview of the BCVTB is presented. Second, we describe the BACnet interface, a link which has been implemented to couple BACnet devices to the BCVTB. We present a case study where the interface was used to couple a whole building simulation program to a building control system to assess in real-time the performance of a real building. Third, we present the ADInterfaceMCC, an analog/digital interface that allows a USB-based analog/digital converter to be linked to the BCVTB. In a case study, we show how the link was used to couple the analog/digital converter to a building simulation model for local loop control.

  1. Cost-Effectiveness of Hypertension Therapy According to 2014 Guidelines

    PubMed Central

    Moran, Andrew E.; Odden, Michelle C.; Thanataveerat, Anusorn; Tzong, Keane Y.; Rasmussen, Petra W.; Guzman, David; Williams, Lawrence; Bibbins-Domingo, Kirsten; Coxson, Pamela G.; Goldman, Lee

    2015-01-01

    BACKGROUND On the basis of the 2014 guidelines for hypertension therapy in the United States, many eligible adults remain untreated. We projected the cost-effectiveness of treating hypertension in U.S. adults according to the 2014 guidelines. METHODS We used the Cardiovascular Disease Policy Model to simulate drug-treatment and monitoring costs, costs averted for the treatment of cardiovascular disease, and quality-adjusted life-years (QALYs) gained by treating previously untreated adults between the ages of 35 and 74 years from 2014 through 2024. We assessed cost-effectiveness according to age, hypertension level, and the presence or absence of chronic kidney disease or diabetes. RESULTS The full implementation of the new hypertension guidelines would result in approximately 56,000 fewer cardiovascular events and 13,000 fewer deaths from cardiovascular causes annually, which would result in overall cost savings. The projections showed that the treatment of patients with existing cardiovascular disease or stage 2 hypertension would save lives and costs for men between the ages of 35 and 74 years and for women between the ages of 45 and 74 years. The treatment of men or women with existing cardiovascular disease or men with stage 2 hypertension but without cardiovascular disease would remain cost-saving even if strategies to increase medication adherence doubled treatment costs. The treatment of stage 1 hypertension was cost-effective (defined as <$50,000 per QALY) for all men and for women between the ages of 45 and 74 years, whereas treating women between the ages of 35 and 44 years with stage 1 hypertension but without cardiovascular disease had intermediate or low cost-effectiveness. CONCLUSIONS The implementation of the 2014 hypertension guidelines for U.S. adults between the ages of 35 and 74 years could potentially prevent about 56,000 cardiovascular events and 13,000 deaths annually, while saving costs. Controlling hypertension in all patients with

  2. Digital control of force microscope cantilevers using a field programmable gate array.

    PubMed

    Jacky, Jonathan P; Garbini, Joseph L; Ettus, Matthew; Sidles, John A

    2008-12-01

    This report describes a cantilever controller for magnetic resonance force microscopy based on a field programmable gate array, along with the hardware and software used to integrate the controller into an experiment. The controller is assembled from a low-cost commercially available software defined radio device and libraries of open-source software. The controller includes a digital filter comprising two cascaded second-order sections ("biquads"), which together can implement transfer functions for optimal cantilever controllers. An appendix in this report shows how to calculate filter coefficients for an optimal controller from measured cantilever characteristics. The controller also includes an input multiplexer and adder used in calibration protocols. Filter coefficients and multiplexer settings can be set and adjusted by control software while an experiment is running. The input is sampled at 64 MHz; the sampling frequency in the filters can be divided down under software control to achieve a good match with filter characteristics. Data reported here were sampled at 500 kHz, chosen for acoustic cantilevers with resonant frequencies near 8 kHz. Inputs are digitized with 12 bit resolution, and outputs are digitized with 14 bits. The experiment software is organized as a client and server to make it easy to adapt the controller to different experiments. The server encapsulates the details of controller hardware organization, connection technology, filter architecture, and number representation. The same server could be used in any experiment, while a different client encodes the particulars of each experiment.

  3. A Digital Control Algorithm for Magnetic Suspension Systems

    NASA Technical Reports Server (NTRS)

    Britton, Thomas C.

    1996-01-01

    An ongoing program exists to investigate and develop magnetic suspension technologies and modelling techniques at NASA Langley Research Center. Presently, there is a laboratory-scale large air-gap suspension system capable of five degree-of-freedom (DOF) control that is operational and a six DOF system that is under development. Those systems levitate a cylindrical element containing a permanent magnet core above a planar array of electromagnets, which are used for levitation and control purposes. In order to evaluate various control approaches with those systems, the Generic Real-Time State-Space Controller (GRTSSC) software package was developed. That control software package allows the user to implement multiple control methods and allows for varied input/output commands. The development of the control algorithm is presented. The desired functionality of the software is discussed, including the ability to inject noise on sensor inputs and/or actuator outputs. Various limitations, common issues, and trade-offs are discussed including data format precision; the drawbacks of using either Direct Memory Access (DMA), interrupts, or program control techniques for data acquisition; and platform dependent concerns related to the portability of the software, such as memory addressing formats. Efforts to minimize overall controller loop-rate and a comparison of achievable controller sample rates are discussed. The implementation of a modular code structure is presented. The format for the controller input data file and the noise information file is presented. Controller input vector information is available for post-processing by mathematical analysis software such as MATLAB1.

  4. Flight Testing a Digital Flight Control System. Issues and Results

    DTIC Science & Technology

    1984-07-01

    Program is primarily oriented to the development, integration, and I - evaluation of new flight control technologies . The testbed used in this program is...will be tested for safe operations to give confidence in case of non-rUettable automatic IBU engagement. ISSUE: CONTROL LAW AND REDUNDANCY MAGEMENT CO...were available. Being an advanced development program evaluating new aspects of integrated flight control technology , the latter approach was chosen

  5. Pipeline length optimization in a digital asynchronous trigger controller

    NASA Astrophysics Data System (ADS)

    D'Antone, I.

    2000-09-01

    This report describes the pipelined architecture of an asynchronous controller designed for a trigger board. To evaluate the suitable depth of the pipelines, the controller has been modelled as a priority queuing system. Some useful parameters have been introduced to estimate the optimal configuration in the static and dynamic priority cases. Nowadays, the hardware controllers are realised into programmable components where, usually, the internal memory resources are limited; to save space the design has been addressed towards the pipeline length optimization. Some analytic results have been reported for the static priority queueing system and, furthermore, the dynamic control of the priorities has been added. The implemented service discipline is a rate-controlled priority queueing discipline; the service rate is controlled with a negative feedback. The stability of this control system has been investigated and some parameters have been highlighted to solve the compromise between the minimum average length of the controlled queues and a suitable margin from the instability. The dynamic scheme requires the design of a more sophisticated system controller, but it shows better performances; it allows to reduce the pipeline depth with the same input rate.

  6. On-line evaluation of multiloop digital controller performance

    NASA Technical Reports Server (NTRS)

    Wieseman, Carol D.

    1993-01-01

    The purpose of this presentation is to inform the Guidance and Control community of capabilities which were developed by the Aeroservoelasticity Branch to evaluate the performance of multivariable control laws, on-line, during wind-tunnel testing. The capabilities are generic enough to be useful for all kinds of on-line analyses involving multivariable control in experimental testing. Consequently, it was decided to present this material at this workshop even though it has been presented elsewhere. Topics covered include: essential on-line analysis requirements; on-line analysis capabilities; on-line analysis software; frequency domain procedures; controller performance evaluation frequency-domain flutter suppression; and plant determination.

  7. Digital Fly-By-Wire Flight Control Validation Experience

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.; Jarvis, C. R.; Krier, G. E.; Megna, V. A.; Brock, L. D.; Odonnell, R. N.

    1978-01-01

    The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.

  8. A Digitalized Gyroscope System Based on a Modified Adaptive Control Method.

    PubMed

    Xia, Dunzhu; Hu, Yiwei; Ni, Peizhen

    2016-03-04

    In this work we investigate the possibility of applying the adaptive control algorithm to Micro-Electro-Mechanical System (MEMS) gyroscopes. Through comparing the gyroscope working conditions with the reference model, the adaptive control method can provide online estimation of the key parameters and the proper control strategy for the system. The digital second-order oscillators in the reference model are substituted for two phase locked loops (PLLs) to achieve a more steady amplitude and frequency control. The adaptive law is modified to satisfy the condition of unequal coupling stiffness and coupling damping coefficient. The rotation mode of the gyroscope system is considered in our work and a rotation elimination section is added to the digitalized system. Before implementing the algorithm in the hardware platform, different simulations are conducted to ensure the algorithm can meet the requirement of the angular rate sensor, and some of the key adaptive law coefficients are optimized. The coupling components are detected and suppressed respectively and Lyapunov criterion is applied to prove the stability of the system. The modified adaptive control algorithm is verified in a set of digitalized gyroscope system, the control system is realized in digital domain, with the application of Field Programmable Gate Array (FPGA). Key structure parameters are measured and compared with the estimation results, which validated that the algorithm is feasible in the setup. Extra gyroscopes are used in repeated experiments to prove the commonality of the algorithm.

  9. A Digitalized Gyroscope System Based on a Modified Adaptive Control Method

    PubMed Central

    Xia, Dunzhu; Hu, Yiwei; Ni, Peizhen

    2016-01-01

    In this work we investigate the possibility of applying the adaptive control algorithm to Micro-Electro-Mechanical System (MEMS) gyroscopes. Through comparing the gyroscope working conditions with the reference model, the adaptive control method can provide online estimation of the key parameters and the proper control strategy for the system. The digital second-order oscillators in the reference model are substituted for two phase locked loops (PLLs) to achieve a more steady amplitude and frequency control. The adaptive law is modified to satisfy the condition of unequal coupling stiffness and coupling damping coefficient. The rotation mode of the gyroscope system is considered in our work and a rotation elimination section is added to the digitalized system. Before implementing the algorithm in the hardware platform, different simulations are conducted to ensure the algorithm can meet the requirement of the angular rate sensor, and some of the key adaptive law coefficients are optimized. The coupling components are detected and suppressed respectively and Lyapunov criterion is applied to prove the stability of the system. The modified adaptive control algorithm is verified in a set of digitalized gyroscope system, the control system is realized in digital domain, with the application of Field Programmable Gate Array (FPGA). Key structure parameters are measured and compared with the estimation results, which validated that the algorithm is feasible in the setup. Extra gyroscopes are used in repeated experiments to prove the commonality of the algorithm. PMID:26959019

  10. Digital adaptive controllers using second order models with transport lag

    NASA Technical Reports Server (NTRS)

    Joshi, S.; Kaufman, H.

    1975-01-01

    Design of a discrete optimal regulator requires the a priori knowledge of a mathematical model for the system of interest. Because a second-order model with transport lag is very amenable to control computations and because this type of model has been used previously to represent certain high order single input-single output processes, an adaptive controller was designed based upon adjustment of controls computed for such a model. An extended Kalman filter was utilized for tracking the model parameters which were subsequently used to update a set of optimal control gains. Favorable results were obtained in applying this procedure to the control of several examples including a ninth order nonlinear process.

  11. Cost effectiveness of robotic mitral valve surgery

    PubMed Central

    2017-01-01

    Significant technological advances have led to an impressive evolution in mitral valve surgery over the last two decades, allowing surgeons to safely perform less invasive operations through the right chest. Most new technology comes with an increased upfront cost that must be measured against postoperative savings and other advantages such as decreased perioperative complications, faster recovery, and earlier return to preoperative level of functioning. The Da Vinci robot is an example of such a technology, combining the significant benefits of minimally invasive surgery with a “gold standard” valve repair. Although some have reported that robotic surgery is associated with increased overall costs, there is literature suggesting that efficient perioperative care and shorter lengths of stay can offset the increased capital and intraoperative expenses. While data on current cost is important to consider, one must also take into account future potential value resulting from technological advancement when evaluating cost-effectiveness. Future refinements that will facilitate more effective surgery, coupled with declining cost of technology will further increase the value of robotic surgery compared to traditional approaches. PMID:28203539

  12. Cost effectiveness of recycling: a systems model.

    PubMed

    Tonjes, David J; Mallikarjun, Sreekanth

    2013-11-01

    Financial analytical models of waste management systems have often found that recycling costs exceed direct benefits, and in order to economically justify recycling activities, externalities such as household expenses or environmental impacts must be invoked. Certain more empirically based studies have also found that recycling is more expensive than disposal. Other work, both through models and surveys, have found differently. Here we present an empirical systems model, largely drawn from a suburban Long Island municipality. The model accounts for changes in distribution of effort as recycling tonnages displace disposal tonnages, and the seven different cases examined all show that curbside collection programs that manage up to between 31% and 37% of the waste stream should result in overall system savings. These savings accrue partially because of assumed cost differences in tip fees for recyclables and disposed wastes, and also because recycling can result in a more efficient, cost-effective collection program. These results imply that increases in recycling are justifiable due to cost-savings alone, not on more difficult to measure factors that may not impact program budgets.

  13. Cost effectiveness of recycling: A systems model

    SciTech Connect

    Tonjes, David J.; Mallikarjun, Sreekanth

    2013-11-15

    Highlights: • Curbside collection of recyclables reduces overall system costs over a range of conditions. • When avoided costs for recyclables are large, even high collection costs are supported. • When avoided costs for recyclables are not great, there are reduced opportunities for savings. • For common waste compositions, maximizing curbside recyclables collection always saves money. - Abstract: Financial analytical models of waste management systems have often found that recycling costs exceed direct benefits, and in order to economically justify recycling activities, externalities such as household expenses or environmental impacts must be invoked. Certain more empirically based studies have also found that recycling is more expensive than disposal. Other work, both through models and surveys, have found differently. Here we present an empirical systems model, largely drawn from a suburban Long Island municipality. The model accounts for changes in distribution of effort as recycling tonnages displace disposal tonnages, and the seven different cases examined all show that curbside collection programs that manage up to between 31% and 37% of the waste stream should result in overall system savings. These savings accrue partially because of assumed cost differences in tip fees for recyclables and disposed wastes, and also because recycling can result in a more efficient, cost-effective collection program. These results imply that increases in recycling are justifiable due to cost-savings alone, not on more difficult to measure factors that may not impact program budgets.

  14. Development of a digital automatic control law for steep glideslope capture and flare

    NASA Technical Reports Server (NTRS)

    Halyo, N.

    1977-01-01

    A longitudinal digital guidance and control law for steep glideslopes using MLS (Microwave Landing System) data is developed for CTOL aircraft using modern estimation and control techniques. The control law covers the final approach phases of glideslope capture, glideslope tracking, and flare to touchdown for automatic landings under adverse weather conditions. The control law uses a constant gain Kalman filter to process MLS and body-mounted accelerometer data to form estimates of flight path errors and wind velocities including wind shear. The flight path error estimates and wind estimates are used for feedback in generating control surface commands. Results of a digital simulation of the aircraft dynamics and the guidance and control law are presented for various wind conditions.

  15. Fuels for urban transit buses: a cost-effectiveness analysis.

    PubMed

    Cohen, Joshua T; Hammitt, James K; Levy, Jonathan I

    2003-04-15

    Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental cost-effectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG (dollar 270 000 per QALY for ECD vs dollar 1.7 million to dollar 2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates.

  16. CSM digital autopilot testing in support of ASTP experiments control requirements

    NASA Technical Reports Server (NTRS)

    Rue, D. L.

    1975-01-01

    Results are presented of CSM digital autopilot (DAP) testing. The testing was performed to demonstrate and evaluate control modes which are currently planned or could be considered for use in support of experiments on the ASTP mission. The testing was performed on the Lockheed Guidance, Navigation, and Control System Functional Simulator (GNCFS). This simulator, which was designed to test the Apollo and Skylab DAP control system, has been used extensively and is a proven tool for CSM DAP analysis.

  17. Basic Research in Digital Stochastic Model Algorithmic Control.

    DTIC Science & Technology

    1980-11-01

    Richalet et al., 1978). The important differences are: (i) Robustness. Modern control techniques generally use full state feedback based on a parametric...state vector model. IDCOM, on the other hand, uses output feedback based on an impulse response model. It can be argued that the effect of modeling...lished between the stability and closed loop properties of optimizing type and feedback type of control laws. The organization of this section is as

  18. Digital controlling system to the set of high power LEDs

    NASA Astrophysics Data System (ADS)

    Gilewski, Marian; Gryko, Lukasz; Zajac, Andrzej

    2013-07-01

    In the paper is described the concept and architecture of the multi-channel control system for set of high-power LEDs. The broadband source of radiation for prototype illuminator is dedicated to the investigation of Low Level Laser Therapy procedures. The general scheme of the system, detailed schemes, control algorithm and its implementation description in FPGA structure is presented. The temperature conditions and the opportunity to work with a microcomputer are characterized.

  19. Anticipatory Modulation of Digit Placement for Grasp Control Is Affected by Parkinson's Disease

    PubMed Central

    Lukos, Jamie R.; Lee, Dongpyo; Poizner, Howard; Santello, Marco

    2010-01-01

    Background Successful object manipulation relies on the ability to form and retrieve sensorimotor memories of digit forces and positions used in previous object lifts. Past studies of patients affected by Parkinson's disease (PD) have revealed that the basal ganglia play a crucial role in the acquisition and/or retrieval of sensorimotor memories for grasp control. Whereas it is known that PD impairs anticipatory control of digit forces during grasp, learning deficits associated with the planning of digit placement have yet to be explored. This question is motivated by recent work in healthy subjects revealing that anticipatory control of digit placement plays a crucial role for successful manipulation. Methodology/Principal Findings We asked ten PD patients off medication and ten age-matched controls to reach, grasp and lift an object whose center of mass (CM) was on the left, right or center. The only task requirement was to minimize object roll during lift. The CM remained the same across consecutive trials (blocked condition) or was altered from trial to trial (random condition). We hypothesized that impairment of the basal ganglia-thalamo-cortical circuits in PD patients would reduce their ability to anticipate digit placement appropriate to the CM location. Consequently, we predicted that PD patients would exhibit similar digit placement in the blocked vs. random conditions and produce larger peak object rolls than that of control subjects. In the blocked condition, PD patients exhibited significantly weaker modulation of fingertip contact points to CM location and larger object roll than controls (p<0.05 and p<0.01, respectively). Nevertheless, both controls and PD patients minimized object roll more in the blocked than in the random condition (p<0.01). Conclusions/Significance Our findings indicate that, even though PD patients may have a residual ability of anticipatory control of digit contact points and forces, they fail to implement a motor plan with the

  20. Cost-effectiveness of cervical cancer prevention in Central and Eastern Europe and Central Asia.

    PubMed

    Berkhof, Johannes; Bogaards, Johannes A; Demirel, Erhan; Diaz, Mireia; Sharma, Monisha; Kim, Jane J

    2013-12-31

    -resource settings, low vaccine pricing is essential for strategies of combined vaccination and screening to be cost-effective. This article forms part of a regional report entitled "Comprehensive Control of HPV Infections and Related Diseases in the Central and Eastern Europe and Central Asia Region" Vaccine Volume 31, Supplement 7, 2013. Updates of the progress in the field are presented in a separate monograph entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

  1. Design and evaluation of a sensor fail-operational control system for a digitally controlled turbofan engine

    NASA Technical Reports Server (NTRS)

    Hrach, F. J.; Arpasi, D. J.; Bruton, W. M.

    1975-01-01

    A self-learning, sensor fail-operational, control system for the TF30-P-3 afterburning turbofan engine was designed and evaluated. The sensor fail-operational control system includes a digital computer program designed to operate in conjunction with the standard TF30-P-3 bill-of-materials control. Four engine measurements and two compressor face measurements are tested. If any engine measurements are found to have failed, they are replaced by values synthesized from computer-stored information. The control system was evaluated by using a realtime, nonlinear, hybrid computer engine simulation at sea level static condition, at a typical cruise condition, and at several extreme flight conditions. Results indicate that the addition of such a system can improve the reliability of an engine digital control system.

  2. A factorial-design cluster randomised controlled trial investigating the cost-effectiveness of a nutrition supplement and an exercise programme on pneumonia incidence, walking capacity and body mass index in older people living in Santiago, Chile: the CENEX study protocol

    PubMed Central

    Dangour, Alan D; Albala, Cecilia; Aedo, Cristian; Elbourne, Diana; Grundy, Emily; Walker, Damian; Uauy, Ricardo

    2007-01-01

    Background Chile is currently undergoing a period of rapid demographic transition which has led to an increase in the proportion of older people in the population; the proportion aged 60 years and over, for example, increased from 8% of the population in 1980 to 12% in 2005. In an effort to promote healthy ageing and preserve function, the government of Chile has formulated a package of actions into the Programme of Complementary Feeding for the Older Population (PACAM) which has been providing a nutritional supplement to older people since 1998. PACAM distributes micronutrient fortified foods to individuals aged 70 years and over registered at Primary Health Centres and enrolled in the programme. The recommended serving size (50 g/day) of these supplements provides 50% of daily micronutrient requirements and 20% of daily energy requirements of older people. No information is currently available on the cost-effectiveness of the supplementation programme. Aim The aim of the CENEX cluster randomised controlled trial is to evaluate the cost-effectiveness of an ongoing nutrition supplementation programme, and a specially designed physical exercise intervention for older people of low to medium socio-economic status living in Santiago, Chile. Methods The study has been conceptualised as a public health programme effectiveness study and has been designed as a 24-month factorial cluster-randomised controlled trial conducted among 2800 individuals aged 65.0–67.9 years at baseline attending 28 health centres in Santiago. The main outcomes are incidence of pneumonia, walking capacity and change in body mass index over 24 months of intervention. Costing data (user and provider), collected at all levels, will enable the determination of the cost-effectiveness of the two interventions individually and in combination. The study is supported by the Ministry of Health in Chile, which is keen to expand and improve its national programme of nutrition for older people based on

  3. Weight loss referrals for adults in primary care (WRAP): protocol for a multi-centre randomised controlled trial comparing the clinical and cost-effectiveness of primary care referral to a commercial weight loss provider for 12 weeks, referral for 52 weeks, and a brief self-help intervention [ISRCTN82857232

    PubMed Central

    2014-01-01

    Background Recent trials demonstrate the acceptability and short term efficacy of primary care referral to a commercial weight loss provider for weight management. Commissioners now need information on the optimal duration of intervention and the longer term outcomes and cost effectiveness of such treatment to give best value for money. Methods/Design This multicentre, randomised controlled trial with a parallel design will recruit 1200 overweight adults (BMI ≥28 kg/m2) through their primary care provider. They will be randomised in a 2:5:5 allocation to: Brief Intervention, Commercial Programme for 12 weeks, or Commercial Programme for 52 weeks. Participants will be followed up for two years, with assessments at 0, 3, 12 and 24 months. The sequential primary research questions are whether the CP interventions achieve significantly greater weight loss from baseline to 12 months than BI, and whether CP52 achieves significantly greater weight loss from baseline to 12 months than CP12. The primary outcomes will be an intention to treat analysis of between treatment differences in body weight at 12 months. Clinical effectiveness will be also be assessed by measures of weight, fat mass, and blood pressure at each time point and biochemical risk factors at 12 months. Self-report questionnaires will collect data on psychosocial factors associated with adherence, weight-loss and weight-loss maintenance. A within-trial and long-term cost-effectiveness analysis will be conducted from an NHS perspective. Qualitative methods will be used to examine the participant experience. Discussion The current trial compares the clinical and cost effectiveness of referral to a commercial provider with a brief intervention. This trial will specifically examine whether providing longer weight-loss treatment without altering content or intensity (12 months commercial referral vs. 12 weeks) leads to greater weight loss at one year and is sustained at 2 years. It will also

  4. Network device interface for digitally interfacing data channels to a controller a via network

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

    2006-01-01

    The present invention provides a network device interface and method for digitally connecting a plurality of data channels to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. In one embodiment, the bus controller transmits messages to the network device interface containing a plurality of bits having a value defined by a transition between first and second states in the bits. The network device interface determines timing of the data sequence of the message and uses the determined timing to communicate with the bus controller.

  5. Singular perturbations and time scales in the design of digital flight control systems

    NASA Technical Reports Server (NTRS)

    Naidu, Desineni S.; Price, Douglas B.

    1988-01-01

    The results are presented of application of the methodology of Singular Perturbations and Time Scales (SPATS) to the control of digital flight systems. A block diagonalization method is described to decouple a full order, two time (slow and fast) scale, discrete control system into reduced order slow and fast subsystems. Basic properties and numerical aspects of the method are discussed. A composite, closed-loop, suboptimal control system is constructed as the sum of the slow and fast optimal feedback controls. The application of this technique to an aircraft model shows close agreement between the exact solutions and the decoupled (or composite) solutions. The main advantage of the method is the considerable reduction in the overall computational requirements for the evaluation of optimal guidance and control laws. The significance of the results is that it can be used for real time, onboard simulation. A brief survey is also presented of digital flight systems.

  6. Relative Cost-Effectiveness of Treatments for Adolescent Depression: 36-Week Results from the TADS Randomized Trial

    ERIC Educational Resources Information Center

    Domino, Marisa Elena; Foster, E. Michael; Vitiello, Benedetto; Kratochvil, Christopher J.; Burns, Barbara J.; Silva, Susan G.; Reinecke, Mark A.; March, John S.

    2009-01-01

    Randomized controlled trials that involve 327 participants aged 12 to 18 who were diagnosed with major depression were given either fluoxetine alone, cognitive-behavioral therapy, or a combination of both. Cost-effectiveness acceptability curves suggest that combination treatment is highly likely to be the most cost-effective treatment than…

  7. A Cost Effective System Design Approach for Critical Space Systems

    NASA Technical Reports Server (NTRS)

    Abbott, Larry Wayne; Cox, Gary; Nguyen, Hai

    2000-01-01

    NASA-JSC required an avionics platform capable of serving a wide range of applications in a cost-effective manner. In part, making the avionics platform cost effective means adhering to open standards and supporting the integration of COTS products with custom products. Inherently, operation in space requires low power, mass, and volume while retaining high performance, reconfigurability, scalability, and upgradability. The Universal Mini-Controller project is based on a modified PC/104-Plus architecture while maintaining full compatibility with standard COTS PC/104 products. The architecture consists of a library of building block modules, which can be mixed and matched to meet a specific application. A set of NASA developed core building blocks, processor card, analog input/output card, and a Mil-Std-1553 card, have been constructed to meet critical functions and unique interfaces. The design for the processor card is based on the PowerPC architecture. This architecture provides an excellent balance between power consumption and performance, and has an upgrade path to the forthcoming radiation hardened PowerPC processor. The processor card, which makes extensive use of surface mount technology, has a 166 MHz PowerPC 603e processor, 32 Mbytes of error detected and corrected RAM, 8 Mbytes of Flash, and I Mbytes of EPROM, on a single PC/104-Plus card. Similar densities have been achieved with the quad channel Mil-Std-1553 card and the analog input/output cards. The power management built into the processor and its peripheral chip allows the power and performance of the system to be adjusted to meet the requirements of the application, allowing another dimension to the flexibility of the Universal Mini-Controller. Unique mechanical packaging allows the Universal Mini-Controller to accommodate standard COTS and custom oversized PC/104-Plus cards. This mechanical packaging also provides thermal management via conductive cooling of COTS boards, which are typically

  8. Choosing a sample rate for prime mover digital control systems

    SciTech Connect

    Schade, J.

    1995-09-01

    This paper explains the reasons and consequences of sample rate selection for gas turbine and steam turbine controls. Sample rate theory is important because there is often confusion about how to select the sample rate for different applications. Full-load rejection offspeeds, a common prime mover performance issue, will be used as an example. The effect of different sample rates will be shown.

  9. Modernizing Plunger Control with Low-Cost Digital Electronics

    NASA Astrophysics Data System (ADS)

    Fasano, Patrick; Kuta, Trenton; Aprahamian, Ani

    2014-09-01

    The plunger technique provides a valuable tool for measuring lifetimes of excited states in the 1-100 ps range. The plunger consists of a thin foil target and stopper foil separated by some controllable distance; beam-induced reactions occur in the target and the resulting nucleus of interest leaves the target foil and is completely stopped by the stopper foil. The Notre Dame Nuclear Science Laboratory has a plunger device which is approximately 30 years old. In the Notre Dame plunger apparatus, the separation between foils is measured via capacitance between the foils and is used to control the position of three servo motors. Our work this summer focused on a complete rebuild of the plunger control electronics including two major upgrades: (1) a precision capacitance-measuring circuit based on the phase-shift of a sinusoidal signal which follows a development in the mid 1990's, (2) and a low-cost microcontroller-based feedback loop for precisely controlling servo motors with quadrature encoder outputs. After demonstrating that the upgrades are successful, we will carry out reactions in the Nuclear Science Laboratory and measure the lifetimes of excited states in several rare earth nuclei.

  10. Vectored Thrust Digital Flight Control for Crew Escape. Volume 2.

    DTIC Science & Technology

    1985-12-01

    general the roll euler angle is essentially a " free " control variable since rotations about the velocity vector induce no injurious force and torque...400 +200 -200 - i +200 -200 radicl ion +1 - acceleration radical Figure 7.63 MIL 2 (Table 1) 339 u t=OUstt=S +2000 n *" Q ~ f 2 7- _7- dynornic

  11. Optimal digital control of a Stirling cycle cooler

    NASA Technical Reports Server (NTRS)

    Feeley, J.; Feeley, P.; Langford, G.

    1990-01-01

    This short paper describes work in progress on the conceptual design of a control system for a cryogenic cooler intended for use aboard spacecraft. The cooler will produce 5 watts of cooling at 65 K and will be used to support experiments associated with the following: earth observation; atmospheric measurements; infrared, x-ray, and gamma-ray astronomy; and magnetic field characterization. The cooler has been designed and constructed for NASA/GSFC by Philips Laboratories and is described in detail. The cooler has a number of unique design features intended to enhance long life and maintenance free operation in space including use of the high efficiency Stirling thermodynamic refrigeration cycle, linear magnetic motors, clearance-seals, and magnetic bearings. The proposed control system design is based on optimal control theory and is targeted for custom integrated circuit implementation. The resulting control system will meet the following mission requirements: efficiency, reliability, optimal thermodynamic, electrical, and mechanical performance; freedom from operator intervention; light weight; and small size.

  12. An Educational Laboratory for Digital Control and Rapid Prototyping of Power Electronic Circuits

    ERIC Educational Resources Information Center

    Choi, Sanghun; Saeedifard, M.

    2012-01-01

    This paper describes a new educational power electronics laboratory that was developed primarily to reinforce experimentally the fundamental concepts presented in a power electronics course. The developed laboratory combines theoretical design, simulation studies, digital control, fabrication, and verification of power-electronic circuits based on…

  13. Digital controller design for absolute value function constrained nonlinear systems via scalar sign function approach.

    PubMed

    Wu, Jian; Singla, Mithun; Olmi, Claudio; Shieh, Leang S; Song, Gangbing

    2010-07-01

    In this paper, a scalar sign function-based digital design methodology is developed for modeling and control of a class of analog nonlinear systems that are restricted by the absolute value function constraints. As is found to be not uncommon, many real systems are subject to the constraints which are described by the non-smooth functions such as absolute value function. The non-smooth and nonlinear nature poses significant challenges to the modeling and control work. To overcome these difficulties, a novel idea proposed in this work is to use a scalar sign function approach to effectively transform the original nonlinear and non-smooth model into a smooth nonlinear rational function model. Upon the resulting smooth model, a systematic digital controller design procedure is established, in which an optimal linearization method, LQR design and digital implementation through an advanced digital redesign technique are sequentially applied. The example of tracking control of a piezoelectric actuator system is utilized throughout the paper for illustrating the proposed methodology.

  14. Low power digitally controlled oscillator designs with a novel 3-transistor XNOR gate

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Arya, Sandeep K.; Pandey, Sujata

    2012-03-01

    Digital controlled oscillators (DCOs) are the core of all digital phase locked loop (ADPLL) circuits. Here, DCO structures with reduced hardware and power consumption having full digital control have been proposed. Three different DCO architectures have been proposed based on ring based topology. Three, four and five bit controlled DCO with NMOS, PMOS and NMOS & PMOS transistor switching networks are presented. A three-transistor XNOR gate has been used as the inverter which is used as the delay cell. Delay has been controlled digitally with a switch network of NMOS and PMOS transistors. The three bit DCO with one NMOS network shows frequency variations of 1.6141-1.8790 GHz with power consumption variations 251.9224-276.8591 μW. The four bit DCO with one NMOS network shows frequency variation of 1.6229-1.8868 GHz with varying power consumption of 251.9225-278.0740 μW. A six bit DCO with one NMOS switching network gave an output frequency of 1.7237-1.8962 GHz with power consumption of 251.928-278.998 μW. Output frequency and power consumption results for 4 & 6 bit DCO circuits with one PMOS and NMOS & PMOS switching network have also been presented. The phase noise parameter with an offset frequency of 1 MHz has also been reported for the proposed circuits. Comparisons with earlier reported circuits have been made and the present approach shows advantages over previous circuits.

  15. Development, simulation validation, and wind tunnel testing of a digital controller system for flutter suppression

    NASA Technical Reports Server (NTRS)

    Hoadley, Sherwood Tiffany; Buttrill, Carey S.; Mcgraw, Sandra M.; Houck, Jacob A.

    1991-01-01

    Flutter suppression (FS) is one of the active control concepts being investigated by the AFW program. The design goal for FS control laws was to increase the passive flutter dynamic pressure by 30 percent. In order to meet this goal, the FS control laws had to be capable of suppressing both symmetric and antisymmetric flutter instabilities simultaneously. In addition, the FS control laws had to be practical and low-order, robust and capable of real time execution within the 200 hz. sampling time. The purpose here is to present an overview of the development, simulation validation, and wind tunnel testing of a digital controller system for flutter suppression.

  16. Magnetophoretic circuits for digital control of single particles and cells

    NASA Astrophysics Data System (ADS)

    Lim, Byeonghwa; Reddy, Venu; Hu, Xinghao; Kim, Kunwoo; Jadhav, Mital; Abedini-Nassab, Roozbeh; Noh, Young-Woock; Lim, Yong Taik; Yellen, Benjamin B.; Kim, Cheolgi

    2014-05-01

    The ability to manipulate small fluid droplets, colloidal particles and single cells with the precision and parallelization of modern-day computer hardware has profound applications for biochemical detection, gene sequencing, chemical synthesis and highly parallel analysis of single cells. Drawing inspiration from general circuit theory and magnetic bubble technology, here we demonstrate a class of integrated circuits for executing sequential and parallel, timed operations on an ensemble of single particles and cells. The integrated circuits are constructed from lithographically defined, overlaid patterns of magnetic film and current lines. The magnetic patterns passively control particles similar to electrical conductors, diodes and capacitors. The current lines actively switch particles between different tracks similar to gated electrical transistors. When combined into arrays and driven by a rotating magnetic field clock, these integrated circuits have general multiplexing properties and enable the precise control of magnetizable objects.

  17. Magnetophoretic circuits for digital control of single particles and cells.

    PubMed

    Lim, Byeonghwa; Reddy, Venu; Hu, XingHao; Kim, KunWoo; Jadhav, Mital; Abedini-Nassab, Roozbeh; Noh, Young-Woock; Lim, Yong Taik; Yellen, Benjamin B; Kim, CheolGi

    2014-05-14

    The ability to manipulate small fluid droplets, colloidal particles and single cells with the precision and parallelization of modern-day computer hardware has profound applications for biochemical detection, gene sequencing, chemical synthesis and highly parallel analysis of single cells. Drawing inspiration from general circuit theory and magnetic bubble technology, here we demonstrate a class of integrated circuits for executing sequential and parallel, timed operations on an ensemble of single particles and cells. The integrated circuits are constructed from lithographically defined, overlaid patterns of magnetic film and current lines. The magnetic patterns passively control particles similar to electrical conductors, diodes and capacitors. The current lines actively switch particles between different tracks similar to gated electrical transistors. When combined into arrays and driven by a rotating magnetic field clock, these integrated circuits have general multiplexing properties and enable the precise control of magnetizable objects.

  18. Digital control of high performance aircraft using adaptive estimation techniques

    NASA Technical Reports Server (NTRS)

    Van Landingham, H. F.; Moose, R. L.

    1977-01-01

    In this paper, an adaptive signal processing algorithm is joined with gain-scheduling for controlling the dynamics of high performance aircraft. A technique is presented for a reduced-order model (the longitudinal dynamics) of a high performance STOL aircraft. The actual controller views the nonlinear behavior of the aircraft as equivalent to a randomly switching sequence of linear models taken from a preliminary piecewise-linear fit of the system nonlinearities. The adaptive nature of the estimator is necessary to select the proper sequence of linear models along the flight trajectory. Nonlinear behavior is approximated by effective switching of the linear models at random times, with durations reflecting aircraft motion in response to pilot commands.

  19. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.

    1979-01-01

    The Annular Suspension and Pointing System (ASPS) is a payload auxiliary pointing device of the Space Shuttle. The ASPS is comprised of two major subassemblies, a vernier and a coarse pointing subsystem. The experiment is attached to a mounting plate/rim combination which is suspended on magnetic bearing/actuators (MBA) strategically located about the rim. Fine pointing is achieved by gimballing the plate/rim within the MBA gaps. Control about the experiment line-of-sight is obtained through the use of a non-contacting rim drive and positioning torquer. All sensors used to close the servo loops on the vernier system are noncontacting elements. Therefore, the experiment is a free-flyer constrained only by the magnetic forces generated by the control loops.

  20. Analytical design of a parasitic-loading digital speed controller for a 400-hertz turbine driven alternator

    NASA Technical Reports Server (NTRS)

    Ingle, B. D.; Ryan, J. P.

    1972-01-01

    A design for a solid-state parasitic speed controller using digital logic was analyzed. Parasitic speed controllers are used in space power electrical generating systems to control the speed of turbine-driven alternators within specified limits. The analysis included the performance characteristics of the speed controller and the generation of timing functions. The speed controller using digital logic applies step loads to the alternator. The step loads conduct for a full half wave starting at either zero or 180 electrical degrees.