924 resultados para Developments of Flood and Drought Early Warning Systems


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Introduction: Early warning of future hypoglycemic and hyperglycemic events can improve the safety of type 1 diabetes mellitus (T1DM) patients. The aim of this study is to design and evaluate a hypoglycemia / hyperglycemia early warning system (EWS) for T1DM patients under sensor-augmented pump (SAP) therapy. Methods: The EWS is based on the combination of data-driven online adaptive prediction models and a warning algorithm. Three modeling approaches have been investigated: (i) autoregressive (ARX) models, (ii) auto-regressive with an output correction module (cARX) models, and (iii) recurrent neural network (RNN) models. The warning algorithm performs postprocessing of the models′ outputs and issues alerts if upcoming hypoglycemic/hyperglycemic events are detected. Fusion of the cARX and RNN models, due to their complementary prediction performances, resulted in the hybrid autoregressive with an output correction module/recurrent neural network (cARN)-based EWS. Results: The EWS was evaluated on 23 T1DM patients under SAP therapy. The ARX-based system achieved hypoglycemic (hyperglycemic) event prediction with median values of accuracy of 100.0% (100.0%), detection time of 10.0 (8.0) min, and daily false alarms of 0.7 (0.5). The respective values for the cARX-based system were 100.0% (100.0%), 17.5 (14.8) min, and 1.5 (1.3) and, for the RNN-based system, were 100.0% (92.0%), 8.4 (7.0) min, and 0.1 (0.2). The hybrid cARN-based EWS presented outperforming results with 100.0% (100.0%) prediction accuracy, detection 16.7 (14.7) min in advance, and 0.8 (0.8) daily false alarms. Conclusion: Combined use of cARX and RNN models for the development of an EWS outperformed the single use of each model, achieving accurate and prompt event prediction with few false alarms, thus providing increased safety and comfort.

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The Education for All Handicapped Children Act of 1975, P.L. 94-142, created a new challenge for the nation's public school systems. During 1982-1983, a national study, called the "Collaborative Study of Children with Special Needs", was conducted in 5 metropolitan school districts to evaluate the effectiveness of education and health care services of children in kindergarten to 6th grade being provided under P.L. 94-142 programs. This dissertation (the Substudy) was undertaken to augment the findings of the Collaborative Study. The purpose of this study was to develop a database to provide descriptive information on the demographic, service and health characteristics of a small group of 3 and 4 year old handicapped children served by the Houston Independent School District (HISD) during 1982-1983.^ The study involved a stratified sample of 105 three and four year old children divided into 3 groups according to type of handicapping condition.^ The results of the study gave a clearer picture of the demographic characteristics of these Pre-K children. Specifically, sex ratio was approximately one, lower than the national norm. Family and socioeconomic characteristics were assessed.^ The study used an independence/dependence index composed of 11 items on the parent questionnaire to assess the level of functional independence of each child. An association was found between index scores and parent-reported effects of the child on family activity. Parents who said that their child's condition had affected the family's job situation, housing accomodations, vacation plans, marriage, choice of friends and social activities were also more likely to report less independence in the child. In addition, many of the Substudy children had extensive care-taking needs reflected in specific components of the index such as dressing, feeding, toileting or moving about the house.^ In general the results of the Pre-K Substudy indicate that at the early childhood level, the HISD special education program is functioning well in most areas and that parents are very satisfied with the program. (Abstract shortened with permission of author.)^

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There is increasing evidence for an important role of adverse early experience on the development of major psychiatric disorders in adulthood. Corticotropin-releasing factor (CRF), an endogenous neuropeptide, is the primary physiological regulator of the mammalian stress response. Grown nonhuman primates who were exposed as infants to adverse early rearing conditions were studied to determine if long-term alterations of CRF neuronal systems had occurred following the early stressor. In comparison to monkeys reared by mothers foraging under predictable conditions, infant monkeys raised by mothers foraging under unpredictable conditions exhibited persistently elevated cerebrospinal fluid (CSF) concentrations of CRF. Because hyperactivity of CRF-releasing neurons has been implicated in the pathophysiology of certain human affective and anxiety disorders, the present finding provides a potential neurobiological mechanism by which early-life stressors may contribute to adult psychopathology.

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Modern power networks incorporate communications and information technology infrastructure into the electrical power system to create a smart grid in terms of control and operation. The smart grid enables real-time communication and control between consumers and utility companies allowing suppliers to optimize energy usage based on price preference and system technical issues. The smart grid design aims to provide overall power system monitoring, create protection and control strategies to maintain system performance, stability and security. This dissertation contributed to the development of a unique and novel smart grid test-bed laboratory with integrated monitoring, protection and control systems. This test-bed was used as a platform to test the smart grid operational ideas developed here. The implementation of this system in the real-time software creates an environment for studying, implementing and verifying novel control and protection schemes developed in this dissertation. Phasor measurement techniques were developed using the available Data Acquisition (DAQ) devices in order to monitor all points in the power system in real time. This provides a practical view of system parameter changes, system abnormal conditions and its stability and security information system. These developments provide valuable measurements for technical power system operators in the energy control centers. Phasor Measurement technology is an excellent solution for improving system planning, operation and energy trading in addition to enabling advanced applications in Wide Area Monitoring, Protection and Control (WAMPAC). Moreover, a virtual protection system was developed and implemented in the smart grid laboratory with integrated functionality for wide area applications. Experiments and procedures were developed in the system in order to detect the system abnormal conditions and apply proper remedies to heal the system. A design for DC microgrid was developed to integrate it to the AC system with appropriate control capability. This system represents realistic hybrid AC/DC microgrids connectivity to the AC side to study the use of such architecture in system operation to help remedy system abnormal conditions. In addition, this dissertation explored the challenges and feasibility of the implementation of real-time system analysis features in order to monitor the system security and stability measures. These indices are measured experimentally during the operation of the developed hybrid AC/DC microgrids. Furthermore, a real-time optimal power flow system was implemented to optimally manage the power sharing between AC generators and DC side resources. A study relating to real-time energy management algorithm in hybrid microgrids was performed to evaluate the effects of using energy storage resources and their use in mitigating heavy load impacts on system stability and operational security.