865 resultados para cost control


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This paper is concerned with the cost efficiency in achieving the Swedish national air quality objectives under uncertainty. To realize an ecologically sustainable society, the parliament has approved a set of interim and long-term pollution reduction targets. However, there are considerable quantification uncertainties on the effectiveness of the proposed pollution reduction measures. In this paper, we develop a multivariate stochastic control framework to deal with the cost efficiency problem with multiple pollutants. Based on the cost and technological data collected by several national authorities, we explore the implications of alternative probabilistic constraints. It is found that a composite probabilistic constraint induces considerably lower abatement cost than separable probabilistic restrictions. The trend is reinforced by the presence of positive correlations between reductions in the multiple pollutants.

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A constant-current stimulator for high-impedance loads using only low-cost standard high-voltage components Is presented. A voltage-regulator powers an oscillator built across the primary of a step-up transformer whose secondary supplies, after rectification, the high voltage to a switched current-mirror in the driving stage. Adjusting the regulated voltage controls the pulsed-current intensity. A prototype produces stimulus of amplitude and pulsewidth within 0 less than or equal to I-skin less than or equal to 20 mA and 50 mus less than or equal to T-pulse less than or equal to 1 ms, respectively. Pulse-repetition spans from 1 Hz to 10 Hz. Worst case ripple is 3.7% at I-skin = 1 mA. Overall consumption is 5.6 W at I-skin = 20 mA.

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Methicillin Resistant Staphylococcus aureus healthcare-associated infections (MRSA HAIs) are a major cause of morbidity in hospitalized patients. They pose great economic burden to hospitals caring for these patients. Intensified Interventions aim to control MRSA HAIs. Cost-effectiveness of Intensified Interventions is largely unclear. We performed a review of cost-effectiveness literature on Intensified Interventions , and provide a summary of study findings, the status of economic research in the area, and information that will help decision-makers at regional level and guide future research.^ We conducted literature search using electronic database PubMed, EBSCO, and The Cochrane Library. We limited our search to English articles published after 1999. We reviewed a total of 1,356 titles, and after applying our inclusion and exclusion criteria selected seven articles for our final review. We modified the Economic Evaluation Abstraction Form provided by CDC, and used this form to abstract data from studies.^ Of the seven selected articles two were cohort studies and the remaining five were modeling studies. They were done in various countries, in different study settings, and with different variations of the Intensified Intervention . Overall, six of the seven studies reported that Intensified Interventions were dominant or at least cost-effective in their study setting. This effect persisted on sensitivity testing.^ We identified many gaps in research in this field. The cost-effectiveness research in the field is mostly composed of modeling studies. The studies do not always clearly describe the intervention. The intervention and infection costs and the sources for these costs are not always explicit or are missing. In modeling studies, there is uncertainty associated with some key model inputs, but these inputs are not always identified. The models utilized in the modeling studies are not always tested for internal consistency or validity. Studies usually test the short term cost-effectiveness of Intensified Interventions but not the long results.^ Our study limitation was the inability to adjust for differences in study settings, intervention costs, disease costs, or effectiveness measures. Our study strength is the presentation of a focused literature review of Intensified Interventions in hospital settings. Through this study we provide information that will help decision makers at regional level, help guide future research, and might change clinical care and policies. ^

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The main objective of this work is the design and implementation of the digital control stage of a 280W AC/DC industrial power supply in a single low-cost microcontroller to replace the analog control stage. The switch-mode power supply (SMPS) consists of a PFC boost converter with fixed frequency operation and a variable frequency LLC series resonant DC/DC converter. Input voltage range is 85VRMS-550VRMS and the output voltage range is 24V-28V. A digital controller is especially suitable for this kind of SMPS to implement its multiple functionalities and to keep the efficiency and the performance high over the wide range of input voltages. Additional advantages of the digital control are reliability and size. The optimized design and implementation of the digital control stage it is presented. Experimental results show the stable operation of the controlled system and an estimation of the cost reduction achieved with the digital control stage.

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Solar drying is one of the important processes used for extending the shelf life of agricultural products. Regarding consumer requirements, solar drying should be more suitable in terms of curtailing total drying time and preserving product quality. Therefore, the objective of this study was to develop a fuzzy logic-based control system, which performs a ?human-operator-like? control approach through using the previously developed low-cost model-based sensors. Fuzzy logic toolbox of MatLab and Borland C++ Builder tool were utilized to develop a required control system. An experimental solar dryer, constructed by CONA SOLAR (Austria) was used during the development of the control system. Sensirion sensors were used to characterize the drying air at different positions in the dryer, and also the smart sensor SMART-1 was applied to be able to include the rate of wood water extraction into the control system (the difference of absolute humidity of the air between the outlet and the inlet of solar dryer is considered by SMART-1 to be the extracted water). A comprehensive test over a 3 week period for different fuzzy control models has been performed, and data, obtained from these experiments, were analyzed. Findings from this study would suggest that the developed fuzzy logic-based control system is able to tackle difficulties, related to the control of solar dryer process.

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Objectives: To estimate the economic efficiency of tight blood pressure control, with angiotensin converting enzyme inhibitors or β blockers, compared with less tight control in hypertensive patients with type 2 diabetes.

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This paper describes the development of a low-cost mini-robot that is controlled by visual gestures. The prototype allows a person with disabilities to perform visual inspections indoors and in domestic spaces. Such a device could be used as the operator's eyes obviating the need for him to move about. The robot is equipped with a motorised webcam that is also controlled by visual gestures. This camera is used to monitor tasks in the home using the mini-robot while the operator remains quiet and motionless. The prototype was evaluated through several experiments testing the ability to use the mini-robot’s kinematics and communication systems to make it follow certain paths. The mini-robot can be programmed with specific orders and can be tele-operated by means of 3D hand gestures to enable the operator to perform movements and monitor tasks from a distance.

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Mode of access: Internet.