We present a modular approach to implementing dynamic algorithm switching for parallel scientific simulations. Our approach leverages modem software engineering techniques to implement fine-grained control of algorith...
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We present a modular approach to implementing dynamic algorithm switching for parallel scientific simulations. Our approach leverages modem software engineering techniques to implement fine-grained control of algorithmic behavior in scientific simulations as well as to improve modularity in realizing the algorithm switching functionality onto existing application source code. Through fine-grained control of functional behavior in an application, our approach enables design and implementation of application specific dynamic algorithm switching scenarios. To ensure modularity, our approach considers dynamic algorithm switching as a separate concern with regard to a given application and encourages separate development and transparent integration of the switching functionality without directly modifying the original application code. By applying and evaluating our approach with a real-world scientific application to switch its simulation algorithms dynamically, we demonstrate the applicability and effectiveness of our approach to constructing efficient parallel simulations.
Odor source localization (OSL) robots are essential for safety and rescue teams to overcome the problem of human exposure to hazardous chemical plumes. However, owing to the complicated geometry of environments, it is...
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Odor source localization (OSL) robots are essential for safety and rescue teams to overcome the problem of human exposure to hazardous chemical plumes. However, owing to the complicated geometry of environments, it is almost impossible to construct the dispersion model of the odor plume in practical situations to be used for probabilistic odor source search algorithms. Additionally, as time is crucial in OSL tasks, dynamically modifying the robot's balance of emphasis between exploration and exploitation is desired. In this study, we addressed both the aforementioned problems by simplifying the environment with an obstacle region into multiple sub-environments with different resolutions. Subsequently, a framework was introduced to switch between the Infotaxis and Dijkstra algorithms to navigate the agent and enable it to reach the source swiftly. One algorithm was used to guide the agent in searching for clues about the source location, whereas the other facilitated the active movement of the agent between sub-environments. The proposed algorithm exhibited improvements in terms of success rate and search time. Furthermore, the implementation of the proposed framework on an autonomous mobile robot verified its effectiveness. Improvements were observed in our experiments with a robot when the success rate increased 3.5 times and the average moving steps of the robot were reduced by nearly 35%.
switching control algorithms is a method used successfully in non-linear processes or processes with different domains or working regimes. These control structures are also called multicontroller or multimodel (adjust...
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ISBN:
(纸本)9781665414968
switching control algorithms is a method used successfully in non-linear processes or processes with different domains or working regimes. These control structures are also called multicontroller or multimodel (adjustment) architectures. The literature offers several practical and theoretical elements in relation to these solutions. It is well known that a specific problem of these techniques is the shock of the command when switching the adjustment algorithms. The paper proposes and validates some criteria that are imposed on these algorithms from the design phase. The effects of applying these criteria are demonstrated on a laboratory installation controlled by a software application with operation over time.
switching the control algorithms is a widely used procedure within non-linear process control structures. However, this type of procedure is very sensitive, especially in the presence of disturbances, as it may cause ...
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ISBN:
(数字)9781728198095
ISBN:
(纸本)9781728198095
switching the control algorithms is a widely used procedure within non-linear process control structures. However, this type of procedure is very sensitive, especially in the presence of disturbances, as it may cause command control shocks which have negative effects on the system being controlled. This procedure is particularly found within the configuration of multiple model type control structures (MM). This paper proposes a practical solution for measuring the value of a shock caused by such a switchingalgorithm and a procedure that can avoid or reduce its effects. The solution can be directly applied in real-time applications, which is demonstrated by the example included at the end of this paper.
High speed Interior Permanent Magnet Synchronous Motors (IPMSM) are used in embedded applications for their high-power density and efficiency. Because of the voltage limit of the supply, operating at such speed requir...
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We present a modular approach to implementing dynamic algorithm switching for parallel scientific software. By using a compositional framework based on function call interception techniques, our proposed method transp...
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We present a modular approach to implementing dynamic algorithm switching for parallel scientific software. By using a compositional framework based on function call interception techniques, our proposed method transparently integrates algorithm switching code with a given program without directly modifying the original code structure. Through fine-grained control of algorithmic behavior of an application at the level of functions, our approach supports design and implementation of application-specific switching scenarios in a modular way. Our approach encourages algorithm switching to dynamically perform at the loop end of a parallel simulation, where cooperating processes in concurrent execution typically synchronize and intermediate computation results are consistent. In this way, newly added switching operations do not cause race conditions that may produce unreliable computation results in parallel simulations. By applying our method to a real-world scientific application and adapting its algorithmic behavior to the properties of input problems, we demonstrate the applicability and effectiveness of our approach to constructing efficient parallel simulations.
Recently, cloud-based data stream processing has emerged to process huge amounts of data. During such processing, the actual characteristics of data streams may vary, e.g., in terms of volume or velocity. For example,...
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ISBN:
(纸本)9783319721255;9783319721248
Recently, cloud-based data stream processing has emerged to process huge amounts of data. During such processing, the actual characteristics of data streams may vary, e.g., in terms of volume or velocity. For example, in the financial domain hectic markets can cause bursty streams of events leading to changes of the stream characteristics by several orders of magnitude. To handle such situations, adaptation of the data processing at runtime is desirable. While several techniques for changing data stream processing at runtime do exist, one specific challenge is to minimize the impact of runtime adaptation on the data processing, in particular for real-time data analytics. In this research work, we aim at performing runtime adaptation in cloud-based data stream processing, namely, dynamically switching alternative distributed algorithms, which have similar functionality, but operate at different characteristics (tradeoffs). The goal of this work is to provide a generic approach which can automatically determine the algorithm switch with minimized impact on the data processing. To achieve this goal, we introduce the concept of a "safe" (transparent, gap-free) switch, which takes the characteristics of alternative algorithms into account. For the actual switch, we combine stream re-routing with buffering and stream synchronization along with a support of dynamic deployment of alternative stream processing algorithms into the cloud.
Previous studies have shown that cardiac microacceleration signals, recorded either cutaneously, or embedded into the tip of an endocardial pacing lead, provide meaningful information to characterize the cardiac mecha...
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Previous studies have shown that cardiac microacceleration signals, recorded either cutaneously, or embedded into the tip of an endocardial pacing lead, provide meaningful information to characterize the cardiac mechanical function. This information may be useful to personalize and optimize the cardiac resynchronization therapy, delivered by a biventricular pacemaker, for patients suffering from chronic heart failure (HF). This paper focuses on the improvement of a previously proposed method for the estimation of the systole period from a signal acquired with a cardiac microaccelerometer (SonR sensor, Sorin CRM SAS, France). We propose an optimal algorithm switching approach, to dynamically select the best configuration of the estimation method, as a function of different control variables, such as the signal-to-noise ratio or heart rate. This method was evaluated on a database containing recordings from 31 patients suffering from chronic HF and implanted with a biventricular pacemaker, for which various cardiac pacing configurations were tested. Ultrasound measurements of the systole period were used as a reference and the improved method was compared with the original estimator. A reduction of 11% on the absolute estimation error was obtained for the systole period with the proposed algorithm switching approach.
Background maintenance is a complex problem due to varying scene conditions. Typically, a single algorithm cannot handle the complex scene changes that occur in visual surveillance applications. Also complex backgroun...
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ISBN:
(纸本)9781424426645
Background maintenance is a complex problem due to varying scene conditions. Typically, a single algorithm cannot handle the complex scene changes that occur in visual surveillance applications. Also complex background modelling techniques, for example mixture of Gaussians have a high computational and communication demand compared to simple techniques such as a uni-model background model or simple frame-differencing with an adaptive threshold. In this paper we present an algorithm switching approach that can handle multi-model background scenes. Starting with a less computational and less data intensive uni-model background subtraction algorithm the system switches to a complex multimodel background subtraction there by saving valuable software and hardware resources both in terms of power and computation time. Our results show this algorithm switching approach can be used to effectively handle various scene conditions encountered in real time surveillance systems with optimal use of system resources.
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