Current research work on the development of a nanohandling cell in a scanning electron microscope (SEM) is presented. An experimental setup is shown, in which two microrobots operate in the vacuum chamber of an SEM. I...
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Current research work on the development of a nanohandling cell in a scanning electron microscope (SEM) is presented. An experimental setup is shown, in which two microrobots operate in the vacuum chamber of an SEM. In order to enable automatic nanohandling, a modular control system architecture is proposed. Different microrobots can be integrated in a flexible manner using a common control interface. The system easily scales up for more complex robot and sensor setups. Parallel execution of open and closed-loop control tasks can be performed. The functionality of the robot cell is exemplified by handling and mechanical characterization of carbon nanotubes (CNT).
Numerical simulations involving multiple, physically different domains can be solved effectively by coupling simulation programs, or solvers. The coordination of the different solvers is commonly handled by a coupling...
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Image de-noising and enhancement form two fundamental problems in many engineering and biomedical applications. The paper is devoted to the study of the multi-resolution approach to this topic employing the Haar wavel...
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Image de-noising and enhancement form two fundamental problems in many engineering and biomedical applications. The paper is devoted to the study of the multi-resolution approach to this topic employing the Haar wavelet transform and its application to processing of volumetric magnetic resonance image sets corrupted with additional noise. The resulting coefficients are thresholded and exploited for subsequent reconstruction. The Haar transform is evaluated using both the two-dimensional approach applied individually to each image layer, and the three-dimensional technique performed on the image volume as a whole. In noise reduction, the latter approach profits from similarities between the neighbouring image layers and shows a considerable improvement over the former method. Results are presented in numerical and graphical forms using three-dimensional visualization tools.
In this paper we describe a design and implementation of an on-line scheduling algorithm for controller Area Network (CAN) messages that exploits properties of genetic algorithms (GA) to achieve global message through...
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Upcoming ubiquitous computing systems are required to operate in dynamic, diverse, unverified, and unpredictable operating environment. The OSGi (Open Service Gateway initiative) framework employs the service-oriented...
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Upcoming ubiquitous computing systems are required to operate in dynamic, diverse, unverified, and unpredictable operating environment. The OSGi (Open Service Gateway initiative) framework employs the service-oriented approach and the Java ClassLoader architecture for the runtime service deployment, that are well suited to the dynamic environment envisioned for home networking and ubiquitous computing. However, the current OSGi framework does not provide full reliability measures, especially for failure conditions, such as network, device, and application failures. This paper analyzes software reliability issues in OSGi framework and proposes a proxy-based reliable extensions. The design concept was implemented and partly tested on an open source OSGi platform, Oscar, for the smart home residential gateway test-bed.
This paper deals with an analysis of applicability, capabilities, benefits and pitfalls of using a virtual potential field approach to autonomously planning trajectories in non-communicating autonomous underwater vehi...
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This paper deals with an analysis of applicability, capabilities, benefits and pitfalls of using a virtual potential field approach to autonomously planning trajectories in non-communicating autonomous underwater vehicles (AUV-s). Virtual potentials represent an approach to this problem with cross-layer design features. Examples of different layers of control that can be achieved with the same fundamental approach are: obstacle-avoidance, energy-optimal trajectories, forming up with other moving agents, controlled formation fragmentation into well-posed sub-formation etc. This paper shows, on the basis of extensive simulated experiments, that such a trajectory planner based on virtual potentials, guarantees good extendibility, scalability and performance in a hard-real-time hardware-in-the-loop system.
The work presented in this paper deals with the process of transfer function identification by using self-oscillation method (autotuning identification method). The algorithm is given in a general matrix form and some...
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The work presented in this paper deals with the process of transfer function identification by using self-oscillation method (autotuning identification method). The algorithm is given in a general matrix form and some modifications are introduced. The modifications of the algorithm include augmentation of the initial algorithm for Type k systems, systems with delays and discrete-time systems. The paper also includes simulation examples which describe the introduced modifications. Apart from being rather simple, this method is applicable to real systems. Its greatest advantage is quick identification of a transfer function (depends on the system).
In this paper we present four carefully selected computationally intensive signal processing problems, which can serve as benchmark applications for efficiency testing of modern DSP's, FASIC's, and PLD's.
In this paper we present four carefully selected computationally intensive signal processing problems, which can serve as benchmark applications for efficiency testing of modern DSP's, FASIC's, and PLD's.
This paper presents a trajectory tracking control scheme for the human arm moving in sagittal plane. The arm is described by a musculoskeletal model with two degrees of freedom and six muscles, and the control signal ...
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This paper presents a trajectory tracking control scheme for the human arm moving in sagittal plane. The arm is described by a musculoskeletal model with two degrees of freedom and six muscles, and the control signal is applied directly in muscle space. To design the intelligent controller, an evolutionary diagonal recurrent neural network (EDRNN) is integrated with proper performance indices, which a genetic algorithm (GA) and evolutionary program (EP) strategy are effectively combined with the diagonal neural network (DRNN). The hybrid GA with EP strategy is applied to optimize the DRNN structure and a dynamic back-propagation algorithm (DBP) is used for training the network weights. The effectiveness of the control scheme is demonstrated through a simulated case study.
Collaboration is used for information sharing and activity coordinating, and it exists broadly in many fields. Group communication enables efficient communication between a set of processes logically organized into gr...
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Collaboration is used for information sharing and activity coordinating, and it exists broadly in many fields. Group communication enables efficient communication between a set of processes logically organized into groups and communicating via multicast in an asynchronous environment. One of the key technologies for collaborative applications is secure group communication. Current research on secure group communication scarcely considers the existing security mechanism in local systems. As a result, group communication systems couldn 't provide general support for collaborative applications running on a specific system. Based on the existing grid security technologies, we propose an authentication and access control framework at virtual organization (VO) level for group communication in grid environment. By introducing role-based access control (RBAC) and attribute-based approach, we define group management policies and design group control protocols. The protocols are analyzed from three aspects: compatibility, performance, and security. Finally, we implement a prototype based on GridShib.
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