10 resultados para Data acquisition

em Digital Commons at Florida International University


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The development cost of any civil infrastructure is very high; during its life span, the civil structure undergoes a lot of physical loads and environmental effects which damage the structure. Failing to identify this damage at an early stage may result in severe property loss and may become a potential threat to people and the environment. Thus, there is a need to develop effective damage detection techniques to ensure the safety and integrity of the structure. One of the Structural Health Monitoring methods to evaluate a structure is by using statistical analysis. In this study, a civil structure measuring 8 feet in length, 3 feet in diameter, embedded with thermocouple sensors at 4 different levels is analyzed under controlled and variable conditions. With the help of statistical analysis, possible damage to the structure was analyzed. The analysis could detect the structural defects at various levels of the structure.

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Governmental accountability is the requirement of government entities to be accountable to the citizenry in order to justify the raising and expenditure of public resources. The concept of service efforts and accomplishments measurement for government programs was introduced by the Governmental Accounting Standards Board (GASB) in Service Efforts and Accomplishments Reporting: Its Time Has Come (1990). This research tested the feasibility of implementing the concept for the Federal-aid highway construction program and identified factors affecting implementation with a case study of the District of Columbia. Changes in condition and performance ratings for specific highway segments in 15 projects, before and after construction expenditures, were evaluated using data provided by the Federal Highway Administration. The results of the evaluation indicated difficulty in drawing conclusions on the state program performance, as a whole. The state program reflects problems within the Federally administered program that severely limit implementation of outcome-oriented performance measurement. Major problems identified with data acquisition are: data reliability, availability, compatibility and consistency among states. Other significant factors affecting implementation are institutional barriers and political barriers. Institutional issues in the Federal Highway Administration include the lack of integration of the fiscal project specific database with the Highway Performance Monitoring System database. The Federal Highway Administration has the ability to resolve both of the data problems, however interviews with key Federal informants indicate this will not occur without external directives and changes to the Federal “stewardship” approach to program administration. ^ The findings indicate many issues must be resolved for successful implementation of outcome-oriented performance measures in the Federal-aid construction program. The issues are organizational and political in nature, however in the current environment resolution is possible. Additional research is desirable and would be useful in overcoming the obstacles to successful implementation. ^

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This dissertation is about the research carried on developing an MPS (Multipurpose Portable System) which consists of an instrument and many accessories. The instrument is portable, hand-held, and rechargeable battery operated, and it measures temperature, absorbance, and concentration of samples by using optical principles. The system also performs auxiliary functions like incubation and mixing. This system can be used in environmental, industrial, and medical applications. ^ Research emphasis is on system modularity, easy configuration, accuracy of measurements, power management schemes, reliability, low cost, computer interface, and networking. The instrument can send the data to a computer for data analysis and presentation, or to a printer. ^ This dissertation includes the presentation of a full working system. This involved integration of hardware and firmware for the micro-controller in assembly language, software in C and other application modules. ^ The instrument contains the Optics, Transimpedance Amplifiers, Voltage-to-Frequency Converters, LCD display, Lamp Driver, Battery Charger, Battery Manager, Timer, Interface Port, and Micro-controller. ^ The accessories are a Printer, Data Acquisition Adapter (to transfer the measurements to a computer via the Printer Port and expand the Analog/Digital conversion capability), Car Plug Adapter, and AC Transformer. This system has been fully evaluated for fault tolerance and the schemes will also be presented. ^

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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.

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Supervisory Control & Data Acquisition (SCADA) systems are used by many industries because of their ability to manage sensors and control external hardware. The problem with commercially available systems is that they are restricted to a local network of users that use proprietary software. There was no Internet development guide to give remote users out of the network, control and access to SCADA data and external hardware through simple user interfaces. To solve this problem a server/client paradigm was implemented to make SCADAs available via the Internet. Two methods were applied and studied: polling of a text file as a low-end technology solution and implementing a Transmission Control Protocol (TCP/IP) socket connection. Users were allowed to login to a website and control remotely a network of pumps and valves interfaced to a SCADA. This enabled them to sample the water quality of different reservoir wells. The results were based on real time performance, stability and ease of use of the remote interface and its programming. These indicated that the most feasible server to implement is the TCP/IP connection. For the user interface, Java applets and Active X controls provide the same real time access.

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The future power grid will effectively utilize renewable energy resources and distributed generation to respond to energy demand while incorporating information technology and communication infrastructure for their optimum operation. This dissertation contributes to the development of real-time techniques, for wide-area monitoring and secure real-time control and operation of hybrid power systems. ^ To handle the increased level of real-time data exchange, this dissertation develops a supervisory control and data acquisition (SCADA) system that is equipped with a state estimation scheme from the real-time data. This system is verified on a specially developed laboratory-based test bed facility, as a hardware and software platform, to emulate the actual scenarios of a real hybrid power system with the highest level of similarities and capabilities to practical utility systems. It includes phasor measurements at hundreds of measurement points on the system. These measurements were obtained from especially developed laboratory based Phasor Measurement Unit (PMU) that is utilized in addition to existing commercially based PMU’s. The developed PMU was used in conjunction with the interconnected system along with the commercial PMU’s. The tested studies included a new technique for detecting the partially islanded micro grids in addition to several real-time techniques for synchronization and parameter identifications of hybrid systems. ^ Moreover, due to numerous integration of renewable energy resources through DC microgrids, this dissertation performs several practical cases for improvement of interoperability of such systems. Moreover, increased number of small and dispersed generating stations and their need to connect fast and properly into the AC grids, urged this work to explore the challenges that arise in synchronization of generators to the grid and through introduction of a Dynamic Brake system to improve the process of connecting distributed generators to the power grid.^ Real time operation and control requires data communication security. A research effort in this dissertation was developed based on Trusted Sensing Base (TSB) process for data communication security. The innovative TSB approach improves the security aspect of the power grid as a cyber-physical system. It is based on available GPS synchronization technology and provides protection against confidentiality attacks in critical power system infrastructures. ^

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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.

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Few valid and reliable placement procedures are available to assess the English language proficiency of adults who enroll in English for Speakers of Other Languages (ESOL) programs. Whereas placement material exists for children and university ESOL students, the needs of students in adult community education programs have not been adequately addressed. Furthermore, the research suggests that a number of variables, such as, native language, age, prior schooling, length of residence, and employment are related to second language acquisition. Numerous studies contribute to our understanding of the relationship of these factors to second language acquisition of Spanish-speaking students. Again, there is a void in the research investigating the factors affecting second language acquisition and consequently, appropriate placement of Haitian Creole-speaking students. This study compared a standardized instrument, the NYS Place Test, used alone and in combination with a writing sample in English, to subjective judgement of a department coordinator for initial placement of Haitian adult ESOL students in a community education program. The study also investigated whether or not consideration of student profile data improved the accuracy of the test. Finally, the study sought to determine if a relationship existed between student profile data and those who withdrew from the program or did not enter a class after registering. Analysis of the data by crosstabulation and chi-square revealed that the standardized NYS Place Test was at least as accurate as subjective department coordinator placement and that one procedure could be substituted for li other. Although the writing sample in English improved accuracy of placement by the NYS test, the results were not significant. Of the profile variables, only length of residence was found to be significantly related to accuracy of placement using the NYS Place Test. The number of incorrect placements was higher for those students who lived in the host country from twenty-five to one hundred ten months. A post hoc analysis of NYS test scores according to level showed that those learners who placed in level three also had a significantly higher incidence of incorrect placements. No significant relationship was observed between the profile variables and those who withdrew from the program or registered but did not enter a class.

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Autism Spectrum Disorder () is defined as “the presence of severe and pervasive impairments in reciprocal social interaction and in verbal and nonverbal communication skills” (Diagnostic & Statistical Manual, 2000). It is estimated that 1 in 68 children across the United States are diagnosed with ASD. One of the most common delays that children diagnosed with ASD experience are language delays. Children with ASD that have a language delay will often develop maladaptive behaviors as a result of poor communication skills (Carr & Durand, 1985). The failure to develop mand acquisition in typical fashion results in behaviors ranging from social withdrawal to self-injurious behaviors (Cooper et. al, 2007). A lack of a strong tact repertoire can further impede and complicate the learning of other necessary components of language due to the inability to successfully label items and events in the physical environment of the child. The purpose of this study is to replicate with a reversal in verbal operant training of the procedures described in Wallace et al. (2006) in which two children with ASD underwent tact training to facilitate the formation of mands; essentially this study aims to accomplish mand training first to establish as tact. It is hypothesized that mand training will result in a greater repertoire of tacts due to strength of the relationship between mands and the control over the social environment (Cooper et al., 2007). The two children in the study will be taught to mand items that will be ranked in order of preference via stimulus preference assessment. This study is of great importance due to the indispensable value of effective social communication skills. Data gathered on improving communication skills is of great value to the ASD community as the implications for functional skills result in better communication with family and greater control of individual functioning.

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Autism Spectrum Disorder () is defined as “the presence of severe and pervasive impairments in reciprocal social interaction and in verbal and nonverbal communication skills” (Diagnostic & Statistical Manual, 2000). It is estimated that 1 in 68 children across the United States are diagnosed with ASD. One of the most common delays that children diagnosed with ASD experience are language delays. Children with ASD that have a language delay will often develop maladaptive behaviors as a result of poor communication skills (Carr & Durand, 1985). The failure to develop mand acquisition in typical fashion results in behaviors ranging from social withdrawal to self-injurious behaviors (Cooper et. al, 2007). A lack of a strong tact repertoire can further impede and complicate the learning of other necessary components of language due to the inability to successfully label items and events in the physical environment of the child. The purpose of this study is to replicate with a reversal in verbal operant training of the procedures described in Wallace et al. (2006) in which two children with ASD underwent tact training to facilitate the formation of mands; essentially this study aims to accomplish mand training first to establish as tact. It is hypothesized that mand training will result in a greater repertoire of tacts due to strength of the relationship between mands and the control over the social environment (Cooper et al., 2007). The two children in the study will be taught to mand items that will be ranked in order of preference via stimulus preference assessment. This study is of great importance due to the indispensable value of effective social communication skills. Data gathered on improving communication skills is of great value to the ASD community as the implications for functional skills result in better communication with family and greater control of individual functioning.