Real Time Systems

OCL is becoming an important means to formulate formal specifications in the context of object-oriented software development. The question is whether this approach is appropriate for real-time systems as well. This question is discussed from the point of view of UML/OCL itself but also from an applications point of view.

In this paper, we present a new vision-based multiple human tracking system. This novel 3D visual tracking system is capable of automatically identifying, labeling and tracking multiple humans in real-time even when they occlude each other. Furthermore, the multiple human tracker was implemented in a vision driven robot system for human robot interaction. The distributed system comprises of 4 subsystems: a)Multiple Human Tracking System, b) Robot Control System, c) 3D Visualization System and d) Remote Interface System. The Visual Tracking System performs real-time detection and tracking of humans in 3D within a large workspace. The Robot System uses the 3D position data of the targets obtained from the vision system to interact with the humans. The visual information is also used to monitor safe interaction within humans and robot. The Robot System is a 6DOF Stäubli TX90 industrial arm, controlled in real-time through a low-level interface. A real-time representation of the actual environment is rendered in 3D by the 3D Visualization System. The individual subsystems communicate with each other over a common communication engine based on TCP/IP. The complete system can be controlled and monitored through a wireless device.

A novel fiber optic sensor has been developed to be used in superconducting magnets for fusion reactors and other large cable-in-conduit superconductor (CICC) magnet applications. These large superconducting magnets need a diagnostic that can measure the temperature and strain throughout the magnet in real-time, which was not possible until now. Simultaneous temperature and strain measurements at cryogenic temperatures have been demonstrated, using spontaneous Brillouin scattering in an optical fiber. Using an extremely narrow (100 Hz) linewidth Brillouin laser with very low noise as a frequency shifted local oscillator, the frequency shift of spontaneous Brillouin scattered light was measured using heterodyne detection. A pulsed laser was used to probe the fiber using Optical Time Domain Reflectometry (OTDR) to determine spatial resolution. The spontaneous Brillouin frequency shift and linewidth as a function of temperature agree with previous literature on stimulated Brillouin scattering data from room temperature down to 4 K. For the first time, the spontaneous Brillouin frequency shift, linewidth, and intensity as a function of strain have been measured down to 4 K. Analyzing the frequency spectrum of the scattered light after an FFT gives the Brillouin frequency shift, linewidth, and intensity of the scattered light. 65,000 pulses, with 53 ns pulse widths, were averaged in under one second, providing a 5 meter spatial resolution along a fiber that was about 100 m long. Measuring these three parameters allow the simultaneous determination of temperature and strain in real-time throughout a fiber with a spatial resolution on the order of several meters.

In this work a robust, non-invasive and wearable micro-fluidic system was developed and employed to analyse pH of sweat in real time during exercise. The device is incorporated in an optical detection platform designed to provide real-time information on sweat composition. The device has been tested by monitoring the pH of sweat during 55 minutes of cycling activity. During these trials, the data obtained by the micro-fluidic system was compared to pH measurements obtained in parallel studies with a conventional electrochemical sensor.

The recent proliferation of computing devices and the contexts in which they are used demand diversity in collaborative applications as well. The objective of our research is to enable conferees to share applications that are adapted to their (heterogeneous) computing environments. This is achieved by using eXtensible Markup Language (XML) for the communication medium. The conferees share the same data or a subset of that data, represented in XML, but they may see it displayed in different ways as needed or desired. The framework adapts to the computing and network environment and transforms information so that it matches the client's local capabilities and resources.

The recent proliferation of computing devices and the contexts in which they are used demand diversity in collaborative applications as well. The objective of our research is to enable conferees to share applications that are adapted to their (heterogeneous) computing environments. This is achieved by using eXtensible Markup Language (XML) for the communication medium. The conferees share the same data or a subset of that data, represented in XML, but they may see it displayed in different ways as needed or desired. The framework adapts to the computing and network environment and transforms information so that it matches the client's local capabilities and resources.

The recent Facebook rebranding to Meta has drawn renewed attention to the metaverse. Technology giants, amongst others, are increasingly embracing the vision and opportunities of a hybrid social experience that mixes physical and virtual interactions. As the metaverse gains in traction, it is expected that everyday objects may soon connect more closely with virtual elements. However, discovering this "hidden" virtual world will be a crucial first step to interacting with it in this new augmented world. In this paper, we address the problem of connecting physical objects with their virtual counterparts, especially through connections built upon visual markers. We propose a unified recognition framework that guides approaches to the metaverse access points. We illustrate the use of the framework through experimental studies under different conditions, in which an interactive and visually attractive decoration pattern, an Artcode, is used as the approach to enable the connection. This paper will be of interest to, amongst others, researchers working in Interaction Design or Augmented Reality who are seeking techniques or guidelines for augmenting physical objects in an unobtrusive, complementary manner.

Contrast sensitivity has been extensively studied over the last decades and there are well-established models of early vision that were derived by presenting the visual system with synthetic stimuli such as sine-wave gratings near threshold contrasts. Natural scenes, however, contain a much wider distribution of orientations, spatial frequencies, and both luminance and contrast values. Furthermore, humans typically move their eyes two to three times per second under natural viewing conditions, but most laboratory experiments require subjects to maintain central fixation. We here describe a gaze-contingent display capable of performing real-time contrast modulations of video in retinal coordinates, thus allowing us to study contrast sensitivity when dynamically viewing dynamic scenes. Our system is based on a Laplacian pyramid for each frame that efficiently represents individual frequency bands. Each output pixel is then computed as a locally weighted sum of pyramid levels to introduce local contrast changes as a function of gaze. Our GPU implementation achieves real-time performance with more than 100 fps on high-resolution video (1920 by 1080 pixels) and a synthesis latency of only 1.5 ms. Psychophysical data show that contrast sensitivity is greatly decreased in natural videos and under dynamic viewing conditions. Synthetic stimuli therefore only poorly characterize natural vision.

systems, distributed systems. The use of component models such as Enterprise Java Beans and the CORBA Component Model (CCM) in application development is expanding rapidly. Even in real-time safetycritical and mission-critical domains, component-based development is beginning to take hold as a mechanism for incorporating non-functional aspects such as real-time, qualityof-service, and distribution. ∗ This work was supported in part by the U.S. Army Research Office (DAAD190110564), by DARPA/IXO’s PCES program (AFRL Contract F33615-00-C-3044), by Rockwell-Collins, by Lockheed-Martin, and by Intel Corporation (Grant 11462). Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requir...

This paper focuses on system monitoring and alarm processing and the use of those alarms for economic decision in the nodal electricity market. The task of an Intelligent Economic Alarm Processor (IEAP) is to analyze thousands of alarm messages and extract useful information that explains cause-effect sequences associated with the unexpected contingencies. A graphical Fuzzy Reasoning Petri-nets (FRPN) model that uses fuzzy logic parameters to effectively tackle the uncertainties is built. The economic alarm processor module then processes the fault event signal, analyzes the impact on the market operation activities and different participants, and gives recommendations to optimize the total economic impact under fault scenarios. A contingency-based strategic bidding model concept is proposed to help the market participants take advantages of the latest system operation information and maximize their benefits over the competitors.

The paper presents a formal development approach borrowing features from a specification method based on duration calculus CoD and verification method using the model checker UPPAAL. In this approach we translate CoD specification and required properties to be checked by UPPAAL, by introducing rules translating CoD formula to UPPAAL model which composed by automata system. Two classes of rules are introduced. The first is related to required properties and the second to behavioral ones.

The air-conditioning systems are important for providing optimal conditions for work, human health and quality of living. At the same time they are one of the greatest household energy consumers. Therefore the Building Energy Management System sets high demands to their control, aiming at the reduction of the energy consumption while ensuring the indoor comfort. The classic control technique cannot satisfactory deal with the energy-efficient stabilization of the basic interacting microclimate parameters. The fuzzy logic approach offers intelligent means for stabilization of the coupled temperature, humidity and fresh air supply at low energy required. The aim of the present research is to develop a model-free design method for a two-variable PI fuzzy controller for temperature and humidity control that ensures indoor comfort and reduces energy consumption by supervisory fuzzy tuning.

The Hiking Optimization Algorithm (HOA) has a simple structure and a small number of adjustable parameters, achieving desirable convergence speed and accuracy in singleobjective functions. However, it faces drawbacks such as premature convergence, slow convergence in the final stages, and low search accuracy in complex and diverse problems. To address these issues, this paper proposes a new hybrid optimization algorithm by integrating two algorithms: hill climbing and differential evolution, named DHOA. The search technique in the Differential Evolution (DE) algorithm has enhanced the global search capability of the algorithm and, through the use of combination and mutation operations, has prevented it from falling into local optima and premature convergence. The evaluation of the proposed algorithm through 23 classical benchmark functions, 10 test functions from CEC2020, and 12 benchmark functions from the CEC2022 set has shown that the DHOA algorithm has improved accuracy in finding global optima and convergence speed, effectively escaping local optima and surpassing the original HOA and other comparative algorithms in achieving global optima.

The paper presents a UML profile that overcomes the limitations of real-time solutions currently available on the market. Associations between classes are given a formal semantics. New temporal operators are introduced; they include a non deterministic delay and a time-limited offering. UML models can be validated against logical and timing constraints. The profile's semantics is given through a translation into the formal language RT-LOTOS. The latter is supported by a validation tool which generates reachability graphs from extended UML models. A coffee machine serves as example in the paper. The profile is under evaluation on a satellite-based software reconfiguration system. RÉSUMÉ. Face aux limitations des solutions UML temps réel actuellement sur le marché, l'article présente un profil UML qui donne une sémantique formelle aux associations entre classes, définit des opérateurs temporels de type délai non déterministe et d'offre limitée dans le temps et ajoute des facilités de validation de contraintes logiques et temporelles. La sémantique formelle de ce profil est donnée par la traduction dans le langage formel RT-LOTOS dont l'outil de validation permet de construire des graphes d'accessibilité à partir de diagrammes UML étendus. Outre l'exemple de la machine à café traité dans l'article, le profil proposé est en cours d'évaluation sur un système de reconfiguration dynamique de logiciel embarqué à bord de satellite.

UML solutions in competition on the real-time system market share three common drawbacks: an incomplete formal semantics, temporal operators with limited expression and analysis power, and implementation-oriented tools with limited verification capabilities. To overcome these limitations, the paper proposes a UML profile designed with real-time system validation in mind. Extended class diagrams with associations attributed by composition operators give an explicit semantics to associations between classes. Enhanced activity diagrams with a deterministic delay, a non deterministic delay and a timelimited offering make it possible to work with temporal intervals in lieu of timers with fixed duration. The UML profile is given a precise semantics via its translation into the Formal Description Technique RT-LOTOS. A RT-LOTOS validation tool generates simulation chronograms and reachability graphs for RT-LOTOS specifications derived from UML class and activity diagrams. A coffee machine serves as example. The proposed profile is under evaluation on a satellite-based software reconfiguration system.

Residential and small-scale solar photovoltaic systems require accessible monitoring tools to
detect performance degradation and maximize energy yield, yet existing solutions rely on
proprietary hardware, expensive commercial platforms, or technically complex web interfaces
inaccessible to non-expert users. This paper presents a real-time IoT-based solar panel
monitoring system that integrates a Flutter cross-platform mobile application with Firebase
Realtime Database and an ESP32 microcontroller equipped with three INA219 current-voltage
sensors for per-panel performance tracking. The system provides secure multi-user
authentication, device registration with database validation, real-time streaming of voltage,
current, and power metrics, and interactive multi-channel time-series visualization using the
fl_chart library. Experimental evaluation demonstrated 100% data collection reliability over a
seven-day monitoring period with 116 readings and sub-100-millisecond dashboard rendering
performance. Open-source architecture delivers comprehensive photovoltaic monitoring at a
fraction of commercial solution costs while maintaining real-time responsiveness and an
intuitive mobile interface.

This paper presents a simple Fuzzy Logic Controllers (FLC) based control strategy to solve the tracking and interception problem of a moving target by a mobile robot equipped with a pan-tilt camera. Before sending commands to the mobile robot, video acquisition and image processing techniques are employed to estimate the target’s position in the image plane. The estimate coordinates are used by a fuzzy logic controller to control the pan-tilt camera angles. The objective is to ensure that the moving target is always at the middle of the camera image plane. A second FLC is used to control the robot orientation and to guarantee the tracking and interception of the target. The proposed pan-tilt camera and robot orientation controllers’ efficiency has been validated by simulation under Matlab using Virtual Reality Toolbox

The main purpose of this paper is to present architecture of automated system that allows monitoring and tracking in real time (online) the possible occurrence of faults and electromagnetic transients observed in primary power distribution networks. Through the interconnection of this automated system to the utility operation center, it will be possible to provide an efficient tool that will assist in decisionmaking by the Operation Center. In short, the desired purpose aims to have all tools necessary to identify, almost instantaneously, the occurrence of faults and transient disturbances in the primary power distribution system, as well as to determine its respective origin and probable location. The compilations of results from the application of this automated system show that the developed techniques provide accurate results, identifying and locating several occurrences of faults observed in the distribution system.

The main purpose of this paper is to present architecture of automated system that allows monitoring and tracking in real time (online) the possible occurrence of faults and electromagnetic transients observed in primary power distribution networks. Through the interconnection of this automated system to the utility operation center, it will be possible to provide an efficient tool that will assist in decisionmaking by the Operation Center. In short, the desired purpose aims to have all tools necessary to identify, almost instantaneously, the occurrence of faults and transient disturbances in the primary power distribution system, as well as to determine its respective origin and probable location. The compilations of results from the application of this automated system show that the developed techniques provide accurate results, identifying and locating several occurrences of faults observed in the distribution system.

An Evolutionary Algorithm (EA) is a meta-heuristic and stochastic optimization search process that mimics Darwinian evolution theory and Mendel's Genetics. Each process facilitates (a) population(s) evolve into fittest and/or convergence by setting parameters of selection, mutation, crossover, population resizing, and/or many other variant operators. However, due to two primary identified factors, EAs are still a challenging research topic: (1) Value choices/ranges for parameters (i.e., parameter settings) will greatly influence the evolution performance of a search process in terms of fittest and/or convergence; and (2) Parameter settings that are good for one fitness function do not guarantee the same evolution performance of another fitness function. Namely, parameter settings are function-specific. Different functions may have various characteristics that request specific attention. In order to better organize and overcome the parameter setting problem, Eiben et al. have classified parameter settings into parameter tuning and parameter control : Parameter tuning determines parameter values before a search process begins while parameter control changes parameter values during a search process. More specifically, parameter control adjusts parameters on-the-fly using three different approaches: (1) Deterministic approach alters parameters based on certain pre-determined rules or formulae; (2) Adaptive approach strategically adjusts parameter values based on the feedbacks of a search process. Such feedbacks could be fitness, diversity, distance, among others; and (3) Self-adaptive approach encodes parameters to be adapted and evolves them along with a search process. Yet, even with such a classification, to our best knowledge there is no existing tool to assist researchers with conducting experiments of parameter settings with ease. Namely, researchers need to find out appropriate places out of thousand lines of EA source code to introduce and update specific parameters (including feedbacks) as well as formulae and adaptive strategies. Additionally, a number of revisions for EA source code will be also required for different kinds of experiments. To EA experimenters, such endeavor is time consuming and error prone. To EA developers, complex and tangling source code, resulted from different www.

a,b), A. Balboni (b), W. Fornaciari (a), D. Sciuto (c) (a) CEFRIEL, via Emanueli 15,20126 Milano (MI), Italy, E-mail: f -' er.cefiiel.it @) IT&T&SlT, Central Fbearch Labs, CLTE, 20019 Castelletto di Settimo nse 0, Italy (c) Politecnico di Milano, Dip. EleUrmica e Infarm.

A METHOD OF OBJECT-ORIENTED CONCURRENT PROGRAMMING hile there have been many attempts to provide objectoriented languages with a model of concurrency, few have dealt with reusability and methodology. Here we propose a concurrent model that takes into account such important concerns. Concept unifications are a necessity, and underlie the need to make object-oriented programming adaptable to concurrency. The model characteristics, especially reusability, permit definition of a concurrent object-oriented design method. The model, which makes extensive use of objectoriented techniques such as inheritance and polymorphism, is presented followed by development of the concurrent programming method. A real-time example of an automotive cruise control system illustrates and exercises the method. Our model of concurrency relies on a small set of basic concepts, which are often continuations of those existing in sequential programming--our focus is on such a unification of concepts. The concepts and ideas detailed here have been implemented as an extension of Eiffel I [1, which is named Eiffel//. The first choice encountered when designing a concurrent langnage is the.' process genesis: what language construct and concept permit the process definition? One of the "breakthrough,;" of object-oriented programming is the unification of module and type aspects into one construct: the class. When it comes to adding parallelism, another unification is to bring together the concepts of class and process:

We present TECTLK, a logic to specify knowledge and real time in multi-agent systems. We show that the TECTLK model checking problem is decidable, and we present an algorithm for bounded model checking based on a discretisation method. We exemplify the use of the technique by means of the "Railroad Crossing System", a popular example in the multi-agent systems literature.

The rapid advancement of technology across the globe resulted in an exponential growth of data production. The rate of data production is directly proportional to the volume of data generated and stored. A domain that adheres to the stated fact is transportation, as it heavily relies on real-time data for accurate traffic analysis and prediction. The satisfaction that accompanies the successful completion of the thesis would be incomplete without mentioning the people who made it possible. The constant guidance and encouragement of these people crown all the efforts with success. First and foremost, I am incredibly grateful to my supervisor, Professor Richard O. Sinnott of the Department of Computing and Information Systems at the University of Melbourne, whose expertise was invaluable in formulating the research questions and methodology. His insightful feedback pushed me to sharpen my thinking and brought my work to a higher level. I would also like to thank Mr. Luca Morandini of the Department of Computing and Information Systems at the University of Melbourne for his invaluable advice, technical guidance, continuous support, and patience throughout my project. His immense knowledge and ample experience have encouraged me throughout my academic research and daily life. In addition, I would like to thank Mr. Abdul Rehman Mohammad and Mr. Xiaolin Zhang for their efforts and cooperation when needed during this project. I would like to thank my parents for their wise counsel, tremendous understanding, encouragement, and support all through my life and studies. Finally, I could not have completed this dissertation without the support of my friends, who provided stimulating discussions and happy distractions to rest my mind outside of my research.

for a laptop client with a distant, rack-mounted server or for a head-mounted virtual reality client with a nearby PC server. Voxels are well-suited to amortizing illumination within a server farm for mobile clients. Photons offer the best quality for more powerful clients. We began this project at NVIDIA's industry research lab because we were skeptical about cloud-based real-time global illumination. We took the three popular rendering strategies and sought to demonstrate the show-stopping limitations of each under a distributed system. Our initial goal was due diligence in wrapping up an internal research project. We were surprised to find that all three strategies are in fact viable once properly adapted for the cloud. As detailed in this paper, there are bandwidth and client computation scaling limitations for different strategies, but these are not the overall "show stoppers" that we expected. Furthermore, each strategy is well-suited to a particular, practical scenario, so the methods complement each other well. We were the most surprised to discover that up to half a second of the latency in indirect illumination is visually acceptable and, in fact, hard to notice. This is a critical perceptual issue for any distributed real-time rendering system. It is an immediately obvious conclusion when viewing our videos, but we had no theoretical basis or previous experience that would have predicted it before performing these experiments. Collectively, these results have converted us from skeptics to proponents of distributed real-time rendering. We hope that some of our results will also surprise others and spur further research and development, and that our systems observations will assist in that.

The Multiple Input Multiple Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) is considered a key technology in modern wireless-access communication systems. The IEEE 802.16e standard, also denoted as mobile WiMAX, utilizes the MIMO-OFDM technology and it was one of the first initiatives towards the roadmap of fourth generation systems. This paper presents the PHY-layer design, implementation and validation of a high-performance real-time 2x2 MIMO mobile WiMAX transmitter that accounts for low-level deployment issues and signal impairments. The focus is mainly laid on the impact of the selected high bandwidth, which scales the implementation complexity of the baseband signal processing algorithms. The latter also requires an advanced pipelined memory architecture to timely address the datapath operations that involve high memory utilization. We present in this paper a first evaluation of the extracted results that demonstrate the performance of the system using a 2x2 MIMO channel emulation.

The IEEE 802.16e-2005 standard, also denoted as mobile WiMAX, was introduced as one of the first real efforts towards the deployment of fourth generation communication systems providing fixed and mobile broadband wireless access. Mobile WiMAX supports multiple input multiple output (MIMO) antenna techniques which are considered a key technology in wireless communication systems for increasing both data rates and system performance. This paper presents a real-time 2 Â 2 MIMO mobile WiMAX receiver with a detailed description of the architecture, design and implementation steps. The complexity of the real-time baseband signal processing has been scaled-up due to the high channel bandwidth that was adopted. Numerous equipment and instrumentation comprising our high performance experimental MIMO testbed were used to validate the operation of the mobile WiMAX receiver. The paper includes a subset of results that demonstrate the system-performance using standard 2 Â 2 MIMO mobile channels.

As technology improves, Virtual Reality interfaces based on body actions and expressions will become more and more important. In the domain of games, an evident application is the control of the hero by body actions.The robotics domain is another area where such an interface presents an attractive issue, especially because tele-presence is a hot topic nowadays. In this paper, we discuss an action model along with a real-time recognition system and show how it may be used in Virtual Environments.

We investigate how the movement measurement technologies developed for Virtual Reality applications can be applied to track in real-time the full body posture of a human being. The accuracy of this information is of definite importance to evaluate the feasibility of complex tasks involving human beings. We present a full body movement measurement approach. It provides a realistic conversion in real-time with a reasonable number of sensors. Associated with the hand movement measurement and correction algorithms we provide a pertinent visual and vibrotactile feedback to the performer.

Most of today's virtual environments are populated with some kind of autonomous life-like agents. Such agents follow a pre-programmed sequence of behaviours that exclude the user as a participating entity in the virtual society. In order to make inhabited virtual reality an attractive place for information exchange and social interaction, we need to equip the autonomous agents with some perception and interpretation skills. In this paper we present one skill: human action recognition. By opposition to human-computer interfaces (HCI) that focus on speech or hand gestures, we propose a full-body integration of the user. We present a model of human actions along with a real-time recognition system. To cover the bilateral aspect in human-computer interfaces, we also discuss some action response issues. In particular we describe a motion management library that solves animation continuity and mixing problems. Finally we illustrate our system with two examples and discuss what we have learned.

Emerging real-time communications and multimedia applications necessitate the provisioning of Quality of Service (QoS) in Internet. Recently, a new concept, referred to as service vector, has been introduced to enhance the end-to-end QoS granularity, and at the same time, maintain the simplicity and scalability feature of the current differentiated services (DiffServ) networks. This work extends this concept to wireless ad hoc networks and proposes a cross-layer architecture based on the combination of delay-bounded wireless link level scheduling and the network layer service vector concept, resulting in significant power savings and finer end-to-end QoS granularity. The impact of various traffic arrival distributions and flows with different QoS requirements on the performance of this cross-layer architecture is also investigated and evaluated.

Medical monitors are important for detecting and monitoring cardiovascular diseases, and precise heart rate monitoring is vital for treating patients. Electrocardiogram (ECG) monitors are popular devices in hospital and clinical settings for recording the electrical activity of the heart, and their accuracy must be verified through appropriate testing and calibration. Nevertheless, real patient signals are frequently inaccessible during development and testing, are intermittent or impractical, which necessitates a controlled, repeatable signal source. The project is thus proposed to design and develop an ECG signal simulator capable of generating realistic ECG signals for testing and validation of medical monitoring devices. The project scope centers around the design and implementation of an electronic circuit capable of simulating the most important ECG waveform parameters (the P wave, QRS complex, and T wave) with adjustable parameters (amplitude and frequency) to simulate various heart conditions. The system will be designed using analog and/or digital signal generation methods, ensuring the output signal closely matches the shape and timing of a real ECG signal. The simulator would generate controlled noise to test the performance, precision, and responsiveness of ECG monitoring devices under different simulated conditions. In addition, the project will ensure that the signals produced fall within normal physiological parameters, so that the generated and tested signals are safe and effective without involving any human subjects. This ECG signal simulator will help streamline testing, reduce reliance on the clinical setting, and improve the accuracy of medical equipment before implementation. Finally, the project will result in better health outcomes through assisting in the creation and sustenance of precise and reliable cardiac surveillance systems.

Real-time interactive software can be difficult to construct and debug. Aura is a software platform to facilitate highly interactive systems that combine audio signal processing, sophisticated control, sensors, computer animation, video processing, and graphical user interfaces. Moreover, Aura is open-ended, allowing diverse software components to be interconnected in a real-time framework. A recent assessment of Aura has motivated a redesign of the communication system to support remote procedure call. In addition, the audio signal processing framework has been altered to reduce programming errors. The motivation behind these changes is discussed, and measurements of run-time performance offer some general insights for system designers.

A novel Smart Pixel Opto-VLSI architecture to implement a complete 2-D wavelet transform of real-time captured images is presented. The Smart Pixel architecture enables the realisation of a highly parallel, compact, low power device capable of real-time capture, compression, decompression and display of images suitable for Mobile Multimedia Communication applications.

Recently Voice over IP (VoIP) is experiencing a phenomenal growth. Being a real-time service, VoIP is more susceptible to Denial-of-Service (DoS) attacks than regular Internet services. Moreover, VoIP uses multiple protocols for call control and data delivery, making it vulnerable to various DoS attacks at different protocol layers. An attacker can easily disrupt VoIP services by flooding TCP SYN packets, UDP-based RTP packets, or SIP-based INVITE messages, which pose a critical threat to IP telephony. In this paper, we present an online statistical detection mechanism, called vFDS, to detect DoS attacks in the context of VoIP. The core of vFDS is based on Hellinger distance method, which computes the variability between two probability measures. Using Hellinger distance, we characterize normal protocol behaviors and then detect the traffic anomalies caused by flooding attacks. Our experimental results show that vFDS achieves fast and accurate detection of DoS attacks.

A widely used approach to achieving service level objectives for a software system (e.g., an email server) is to add a controller that manipulates the target system's tuning parameters. We describe a methodology for designing such controllers for software systems that builds on classical control theory. The classical approach proceeds in two steps: system identi®cation and controller design. In system identi®cation, we construct mathematical models of the target system. Traditionally, this has been based on a ®rst-principles approach, using detailed knowledge of the target system. Such models can be complex and dif®cult to build, validate, use, and maintain. In our methodology, a statistical (ARMA) model is ®t to historical measurements of the target being controlled. These models are easier to obtain and use and allow us to apply control-theoretic design techniques to a larger class of systems. When applied to a Lotus Notes groupware server, we obtain model-®ts with R 2 no lower than 75% and as high as 98%. In controller design, an analysis of the models leads to a controller that will achieve the service level objectives. We report on an analysis of a closed-loop system using an integral control law with Lotus Notes as the target. The objective is to maintain a reference queue length. Using root-locus analysis from control theory, we are able to predict the occurrence (or absence) of controller-induced oscillations in the system's response. Such oscillations are undesirable since they increase variability, thereby resulting in a failure to meet the service level objective. We implement this controller for a real Lotus Notes system, and observe a remarkable correspondence between the behavior of the real system and the predictions of the analysis. This indicates that the control theoretic analysis is suf®cient to select controller parameters that meet the desired goals, and the need for simulations is reduced.

One of the main properties of today's distributed and parallel systems, such as mobile ad-hoc networks and grids, is their heterogeneity in the available resources. Further, many applications of such systems are subject to Time/Utility Function (TUF) time constraints for jobs, unavoidable variability in job characteristics and arrivals, and statistical assurance requirements on timeliness behaviors. In this paper, we propose an exact analytical solution for performance evaluation of dynamic policies used for routing of TUF-constrained Firm Real-Time (FRT) jobs among parallel single-processor queues with arbitrary processing rates and capacities. The analytical method can be used for the evaluation of the compliance of some important statistical assurance requirements. Furthermore, we present a utility-aware dynamic routing policy to improve the expected accrued utility of the parallel system. The policy called Maximum Expected Utility (MEU) behaves based on the information gathered from the analytical solution. MEU is compared with some well-known Dynamic Routing (DR) policies for different TUF shapes and both cases of homogeneous and heterogeneous processors of a two-queue system. The comparisons show the efficiency of MEU for the former case and its good behavior in most situations for the latter case.

The widespread use of microservices and event-driven architectures requires reliable tools to manage data structures in motion. A robust foundation for high-throughput data pipelines, Apache Kafka decouples event producers and consumers, which introduces complications regarding schema evolution ability within enterprise integrations. This research paper studies the critical Confluent Schema Registry and serialization formats, namely, Apache Avro, Protocol Buffers, and JSON Schema, for backward and forward compatibility in enterprise integrations. By combining academic literature on compatibility enforcement with industry case studies, the analysis investigates compatibility enforcement levels including transitive modes and their impact on system resilience. Additionally, schema validation in automated continuous integration continuous delivery (CI/CD) pipelines, the use of architectural patterns such as the Transactional Outbox and CQRS, and the governance frameworks needed for scalable data ecosystems will be examined. The results reveal that automatic schema management reduces operational overhead by more than 70% and prevents catastrophic integration failures enabling seamless evolution in heterogeneous environments.

The European Commission and the US Department of Education FIPSE Program have funded ATLANTIS initiative to promote collaboration in the higher education between European and American universities. The goal of the project was to create a new collaborative multinational model for interdisciplinary education in real-time software engineering. The project had not only created a framework for introducing new components to engineering programs but also had proposed a methodology for development of multinational, multidisciplinary engineering program. The purpose of this paper is to summarize the experience gained with this international project.

Imaging polarimetry can be used to accurately measure wave slopes of ocean waves in real time. An imaging polarimeter measures the polarization ellipse, and hence the degree of polarization and its orientation, by acquiring a number of images each of which analyzes a different polarization state. By knowing the geometry of the camera and its relationship to the sea surface and the measured polarization quantities, the wave slope can be extracted. We have developed and tested such an instrument with good results. For this talk, the four camera imaging polarimeter operating in the visible at 60 frames per second will be presented. The polarimeter design, calibration procedures, and the data from several data acquisition programs using the instrument will be presented.

SIR-5: Ordering Sound proposes that musical meaning does not reside in structure, but emerges from dynamic interaction between five domains: Structure, Intention, Interpretation, Reception, and Iteration. It frames composition and listening as a system of shifting relational forces, where meaning is produced through conflict, temporal transformation, and reconfiguration rather than fixed form. Central to the model is the idea of “nodal points”—threshold events where interacting domains reorganise into new states of musical meaning.

Interactive simulation environments constitute one of today's promising emerging technologies, with applications in areas such as education, manufacturing, entertainment and training. These environments are also rich domains for building and investigating intelligent automated agents, with requirements for the integration of a variety of agent capabilities, but without the costs and demands of low-level perceptual processing or robotic control. Our project is aimed at developing human-like, intelligent agents that can interact with each other, as well as with humans in such virtual environments. Our current target is intelligent automated pilots for battlefield simulation environments. These are dynamic, interactive, multi-agent environments that pose interesting challenges for research on specialized agent capabilities as well as on the integration of these capabilities in the development of "complete" pilot agents. We are addressing these challenges through development of a pilot agent, called TacAir-Soar, within the Soar architecture. The purpose of this article is to provide an overview of this domain and project by analyzing the challenges that automated pilots face in battlefield simulations, describing how TacAir-Soar is successfully able to address many of them  TacAir-Soar pilots have already successfully participated in constrained air-combat simulations against expert human pilots  and discussing the issues involved in resolving the remaining research challenges.

Obstacle detection and avoidance systems as a research area have been gaining attention lately, but the issues of blind areas and ground/small obstacle problems have received little interest, especially indoor autonomous navigation. In this work, we present an environment-sweep technique for obstacle detection and a fuzzy algorithm for ground obstacle avoidance, surface elevation estimation, and obstacle classification for indoor robots that eliminates the blind area problem. We employed an ultrasonic sensor on a servo for environmental sweep to eliminate blind areas. Results show that the issue of interference was mitigated by the servo sweep technique we propose. Fuzzy algorithms combined with a single ultrasonic sensor reduced the complexity of the robot, thereby improving the robot's performance in real-time. Fuzzy algorithms combined with a differential wheel driving mechanism speed up the inference and actuation process of the proposed system. This is due to fewer rules and a less complex yet effective algorithm design that converts steering angles to different wheel speeds, making the response time much less than the stipulated threshold of 2s as has been determined in previous literature.

Fuzzy set, since its advent has played an important role in control systems and many other area of applications. One of such area is the control of autonomous vehicle. There seem to be some difficulty however, for a new timer trying to get a clear picture of the autonomous navigation problem. To this end, this survey presents a panoramic view of the Intelligent Transportation Systems with some few example of the Advance Driver Assistance Systems and a good discussion on the autonomous systems with its eminent problems. More attention was focused on the fuzzy controllers designed for collision avoidance; as its performance has largely simplified and smoothens the collision avoidance process of an autonomous vehicular system.

The design of a virtual piano action composed of a keyboard of motorized keys and a realtime mechanical system simulation is presented. Using this simulator, we h a v e re-created certain aspects of the feel of the grand piano by numerically integrating the equations of motion of a simpli ed piano action in real time in a human-in-the-loop simulation scheme. In this paper, the simulation of the release and catch of the hammer is used to introduce the simulator architecture. The structure of a software module which manages the simulation of models with changing kinematic constraints is discussed, including a nite state machine driver which allows for the simulation of rigid-body systems which may take on various constraint conditions in a sequence dependent on run-time interaction.

Vulnerability exploits present in malformed messages are one of the major sources to remotely launch malicious activities in different protocols. Sometimes, a single malformed message could be enough to crash remote servers or to gain unfettered access over them. In this paper, we propose the design of a generic vulnerability exploits detection system xMiner to detect malformed messages in real time for avoiding any network hazard. The proposed xMiner exploits the information embedded within byte-sequences of network messages. xMiner applies multi-order Markov process and principal component analysis (PCA) to extract novel discriminative features and uses them to detect attacks launched through malicious packets in real-time. The novelty of xMiner lies in its light-weight design which requires less processing and memory resources and makes it easily deployable on resourceconstrained devices like smart phones. The system is evaluated on real-world datasets pertaining to three different protocols -HTTP, FTP and SIP. Five different classifiers are deployed to establish the effectiveness of the proposed system. On evaluation we found that the decision tree classifier performs well for HTTP and FTP datasets whereas, SVM shows highest performance in case of SIP packets.