Simulation based design environment for multi-agent systems in buildings

With increasing experience and understanding of the behavior of users in buildings, it is very often difficult to properly build a control system that operates in the real world. To explore such a potential, this paper addresses a new approach to building automation systems that utilizes hybrids systems in order to model large scale systems typically arising in multi-agents. In fact hybrid systems are crucial for solving complex problems and for designing real-time controllers that can be used to automatically regulate HVAC (Heating, Ventilation and Air-Conditioning) systems and building components. A statechart formalism is also used for modelling of the entire building system behaviour in the structural analysis paradigm, in order to achieve a comfortable indoor climate while fulfilling operating constraints. Particularity, this paper concerns the relevance and reliability of integrating control and building performance simulation environments by run-time coupling, over TCP/IP protocol suite. In addition, this paper involves a case-study with two important steps; first consists of experiments obtained in TU Delft test-cell, and then simulation results are obtained with the use of run-time coupling approach

DESIGN OF REAL-TIME FUZZY LOGIC PSS BASED ON PMUs FOR DAMPING LOW FREQUENCY OSCILLATIONS

Poorly damped low frequency oscillations is one of the main problems threatening safe and stable operation of the interconnected power systems and reducing the capability of transmission the power. The generator's excitation system has been supplemented with the Power System Stabilizer (PSS) in order to improve the damping of these low oscillations. In the latest smart power grids, the Phasor Measurement Units (PMUs) become a fundamental element in the monitoring, protection and control applications as PMU signals are more accurate than the conventional measurement units and real time GPS stamped. In this study, Fuzzy Power System Stabilizer (FPSS) has been designed and its performance in damping inter-are oscillations compared with the conventional PSS (CPSS) based on the simulation with MATLAB/Simulink model. The results of the simulation with the Simulink model proved that the performance of the designed FPSS in damping inter-area oscillation is better than the CPSS. One of the main features of fuzzy controller is that it doesn't require mathematical modeling as it is designed based on the time-domain and the operator experience while, in contrast, the conventional PSS requires to be designed in the frequency domain. Real Time Digital Simulator (RTDS) has been used to develop the real-time models of the test systems. The time-domain simulations with the RTDS model when the system subjected to the large disturbance (three-phase to ground fault) have been performed to show that the designed FPSS improved the damping of the oscillations effectively. The simulation results have been verified by modal analysis

QUERY PERFORMANCE EVALUATION OVER HEALTH DATA

International audienceIn recent years, there has been a significant increase in the number and variety of application scenarios studied under the e-health. Each application generates an immense data that is growing constantly. In this context, it becomes an important challenge to store and analyze the data efficiently and economically via conventional database management tools. The traditional relational database systems may sometimes not answer the requirements of the increased type, volume, velocity and dynamic structure of the new datasets. Effective healthcare data management and its transformation into information/knowledge are therefore challenging issues. So, organizations especially hospitals and medical centers that deal with immense data, either have to purchase new systems or re-tool what they already have. The new data models so-called NOSQL, its management tool Hadoop Distributed File Systems is replacing RDBMs especially in real-time healthcare data analytics processes. It becomes a real challenge to perform complex reporting in these applications as the size of the data grows exponentially. Along with that, there is customers demand complex analysis and reporting on those data. Compared to the traditional DBs, Hadoop Framework is designed to process a large volume of data. In this study, we examine the query performance of a traditional DBs and Big Data platforms on healthcare data. In this paper, we try to explore whether it is really necessary to invest on big data environment to run queries on the high volume data or this can also be done with the current relational database management systems and their supporting hardware infrastructure. We present our experience and a comprehensive performance evaluation of data management systems in the context of application performance

An investigation into the development of an advanced ship performance monitoring and analysis system

PhD ThesisThe complete ban on TBT in marine antifouling coatings in 2008, rocketing fuel prices over the past six years, environmental concern and upcoming energy efficiency indices for ships have resulted in a strong interest of the shipping industry to monitor, evaluate and optimise ship performance. Furthermore, the complete ban on TBT in anti-fouling coatings resulted in new types of foul-release hull-coatings, based con silicon, whose effectiveness and performance still needs to be evaluated. Because of the difficulty of measuring coating roughness in service and the large effect of marine bio-fouling on ship performance, a research project was setup at Newcastle University in collaboration with a major paint company to investigate the ways to evaluate hull coating through ship performance monitoring. This thesis describes the details of this project which aimed to investigate the feasibility of a real-time ship performance monitoring and analysis (PM&A) system by implementation and evaluation onboard a 16m research vessel and 300.000dwt VLCC. The thesis starts with a review of the state of art of PM&A systems. The main weaknesses of existing PM&A systems is that often abstract logbook data is used as input and that too little attention is paid to data quality. Furthermore, the systems often act as a black box, showing little insight in data analysis, harming the reliability and trustworthiness of output indicators. Additionally, there are large differences in the way that performance data is corrected to standard conditions, resulting in contradicting and unreliable performance indicators. The thesis focuses therefore on theoretically sound, transparent data analysis and improved data collection. In the thesis, all performance affecting environmental and operational conditions have been reviewed including sensor characteristics and data acquisition aspects. Based on the experience from the analysis of the data collected from both vessels, it reveals that automatic, real-time data collection and rational filtering for periods of acceleration, deceleration, course deviation, drift, shallow water and ship motion is the way forward for accurate performance monitoring. Performance analysis is highly sensitive to errors in shaft torque and ship speed through water. A frequently calibrated/validated shaft torque & RPM sensor and Doppler speed log are therefore the most important sensors for performance monitoring. Speed logs are T.W.F. Hasselaar PhD thesis, 2010 ii affected by many environmental conditions and cannot be used directly for performance monitoring. Other ways to determine ship speed through water, e.g. using the propeller inflow speed, are however affected by hull fouling and loading deviations unless corrected for accordingly. Corrections using full scale trials are then necessary to avoid overestimation of the effects of hull fouling on ship performance. To avoid these errors, a method is described to use the speed log by evaluating its reliability and utilise its reading for performance analysis only in periods where it can be considered reliable. A new transparent analysis method is described to analyse ship performance based on conversion of torque and rpm at constant ship speed. The method differentiates between the hull and propeller performance by empirically correcting the propeller open water diagram for roughness (periodically measured by divers). Evaluation of the proposed PM&A system on both vessels indicates that reliable performance indicatgors can be calculated but that fluctuations in performance indicators of ±12% remain unavoidable due to inaccurate wave observations and errors from the speed log. Trials on the research vessel furthermore show that the system is able to identify fouling, but sensor accuracy requires further research so that fouling can be defined with less performance data and higher reliability. This thesis demonstrates for the first time in open literature that the design and implementation of a transparent and fully automatic, real-time, shipboard PM&A system is perfectly viable and can be installed on any ship with the use of reliable sensors.International Pain

Open-source tool for real-time and automated analysis of droplet-based microfluidic

Publisher Copyright: © 2023 The Royal Society of Chemistry.Droplet-based microfluidic technology is a powerful tool for generating large numbers of monodispersed nanoliter-sized droplets for ultra-high throughput screening of molecules or single cells. Yet further progress in the development of methods for the real-time detection and measurement of passing droplets is needed for achieving fully automated systems and ultimately scalability. Existing droplet monitoring technologies are either difficult to implement by non-experts or require complex experimentation setups. Moreover, commercially available monitoring equipment is expensive and therefore limited to a few laboratories worldwide. In this work, we validated for the first time an easy-to-use, open-source Bonsai visual programming language to accurately measure in real-time droplets generated in a microfluidic device. With this method, droplets are found and characterized from bright-field images with high processing speed. We used off-the-shelf components to achieve an optical system that allows sensitive image-based, label-free, and cost-effective monitoring. As a test of its use we present the results, in terms of droplet radius, circulation speed and production frequency, of our method and compared its performance with that of the widely-used ImageJ software. Moreover, we show that similar results are obtained regardless of the degree of expertise. Finally, our goal is to provide a robust, simple to integrate, and user-friendly tool for monitoring droplets, capable of helping researchers to get started in the laboratory immediately, even without programming experience, enabling analysis and reporting of droplet data in real-time and closed-loop experiments.publishersversionepub_ahead_of_prin

Improving Efficiency and Reliability of Building Systems Using Machine Learning and Automated Online Evaluation

A high percentage of newly-constructed commercial office buildings experience energy consumption that exceeds specifications and system failures after being put into use. This problem is even worse for older buildings. We present a new approach, 'predictive building energy optimization', which uses machine learning (ML) and automated online evaluation of historical and real-time building data to improve efficiency and reliability of building operations without requiring large amounts of additional capital investment. Our ML approach uses a predictive model to generate accurate energy demand forecasts and automated analyses that can guide optimization of building operations. In parallel, an automated online evaluation system monitors efficiency at multiple stages in the system workflow and provides building operators with continuous feedback. We implemented a prototype of this application in a large commercial building in Manhattan. Our predictive machine learning model applies Support Vector Regression (SVR) to the building's historical energy use and temperature and wet-bulb humidity data from the building's interior and exterior in order to model performance for each day. This predictive model closely approximates actual energy usage values, with some seasonal and occupant-specific variability, and the dependence of the data on day-of-the-week makes the model easily applicable to different types of buildings with minimal adjustment. In parallel, an automated online evaluator monitors the building's internal and external conditions, control actions and the results of those actions. Intelligent real-time data quality analysis components quickly detect anomalies and automatically transmit feedback to building management, who can then take necessary preventive or corrective actions. Our experiments show that this evaluator is responsive and effective in further ensuring reliable and energyefficient operation of building systems

kluwer

Introduction Modern communication systems are very complex heterogeneous systems realizing world-wide video and audio communication and using different networks and protocols with a specified quality of service. Such communication systems consist of servers and clients. Especially clients are very different user devices, from powerful personal computers to small cellular phones. A client can communicate with other clients and servers, using services like live video conferences or it can store and can demand video and audio records (see also One of the main challenges for configuration and structuring of such a heterogeneous system is to guarantee the specified quality of service with a minimum of costs. The designer may meet the challenge by using his practical knowledge or by building up prototypes or by utilising formal methods such as performance analysis and simulation. Object Oriented System Simulation of Large Heterogeneous Communication Systems Uwe Hatnik, Jürgen Haufe, Peter Schwarz Fraunhofer Institut für Integrierte Schaltungen, Germany email: [email protected] Abstract Communication systems consist of many soft-and hardware components with a wide range of parameters which affect mainly the provided quality of service. One of the main challenges for configuration and structuring such a heterogeneous system is to guarantee the specified quality of service with a minimum of costs. In this paper, we introduce a simulation based approach which helps the designer to determine the best fitting parameter values. Our approach combines prototyping and simulation in a common environment. Servers Network (WAN, LAN) Clients 186 In this contribution, we introduce a simulation based analysis approach which combines the fore-mentioned analysing methods. In our approach both simulation models and real hardware and real software prototypes can be executed in a common environment. Results of the application of formal methods may be integrated into the simulation models, e.g. distribution functions, profiling results as well as measured values. The approach was driven by our experience that only a mix of different analysis methods which complement one another may bridge the analysis gap of such huge heterogeneous systems. The text is organized as follows. Section 2 details the analysis requirements of the system we focus on. Section 3 gives an overview of our modelling approach. Implementation aspects are described in section 4. Requirements in communication system design analysis Clients and servers of a communication system consist of software and hardware components like real-time and non real-time operation systems Parameter determination: A lot of parameters influence the system behaviour. One goal of the system simulation is to find optimal parameter values for a special configuration. Some parameters are specified by the service demand, for example the video resolution, the number of colours, the net bandwidth, and the used network protocol. Other parameters depend on the computer used, like CPU performance, memory size and so on. Additionally there are software parameters like buffer size and the used algorithm for data processing. There is a large amount of parameters and the optimal configuration is very system specific. Therefore the parameters can not determined completely analytically. Performance analysis: Since optimal system parameters can hardly be determined only analytically, simulation is also important for examining system performance depending on the hard-and software parameters. Configuration analysis: The configuration of a server or client depends on the demanded service and the client system. For example a specific data compressing algorithm is used depending on system parameters of the client like CPU performance and memory size. There are a lot of possible hard-and software combinations. It would be useful to determine what combination is suitable for a special service and configuration. Relationships between the components: There is a more or less tight correlation between the components of a configuration. For that reason, the system has to be treated as a whole. For example, swapping out parts of the software to hardware would decrease the load of the CPU, bu