18025478
Facilitate knowledge communications
With current multimedia information management techniques, the knowledge communications among users in multimedia e-Learning environments are still limited at a relative low single type media servicing level. New developments in multimedia knowledge discovery, representation and integration are needed to improve the intelligence of the knowledge management and communications at the semantic level. This paper proposes a novel contextual knowledge management framework to improve the current isolated learning information retrieval and communication status, by enabling flexible knowledge representation beyond heterogeneous multimedia learning resources and facilitating multilevel knowledge communications between instructors and learners. Based on knowledge communication model analysis in university e-Learning environments, a contextual knowledge representation model is presented. Corresponding knowledge retrieval techniques are discussed afterwards. To demonstrate the proposed concepts and techniques, a case study in a virtual scenario-based learning environment shows how the presented framework works with existing e-Learning content description standards and multimedia information retrieval techniques, and consequently enables a semantic-based interactive learning environment.
33589927
Towards Context-Aware Knowledge Management in e-Enterprises
21933462
Multi-media semantics contextualisation for knowledge-oriented e-learning
Existing e-learning technical solutions are more focused on content packaging rather than semantics management, which is one of the keys to knowledge-oriented e-learning. This paper presents a context-based approach to address the challenging semantics management issue by contextualising the semantics of multimedia learning resources at different levels. A prototype of semi-automatic multimedia semantics generation and editing tool - CONMAN shows the basic idea of the approach in practice.
6649130
Cartop manipulation
This paper explores a novel mode of mobile manipulation using a car-like robot whose chassis does not extend above the height of its wheels. It transports an object that rests on top of the wheels, so as the robot moves forwards, the object moves forward relative to the robot. The robot must maneuver so that the object stays on top of the robot, or a second robot must be in position to receive the robot as it rolls off the first one. We describe the mechanics of this system, its basic maneuvers and manipulation techniques, present a motion planner for generating plans to transport an object, and give results of our experimental implementation of this system.
11127837
Nomad: migrating OS-bypass networks in virtual machines
Virtual machine (VM) technology is experiencing a resurgence due to various benefits including ease of management, security and resource consolidation. Live migration of virtual machines allows transparent movement of OS instances and hosted applications across physical machines. It is one of the most useful features of VM technology because it provides a powerful tool for effective administration of modern cluster environments. Migrating network resources is one of the key problems that need to be addressed in the VM migration process. Existing studies of VM migration have focused on traditional I/O interfaces such as Ethernet. However, modern high-speed interconnects with intelligent NICs pose significantly more challenges as they have additional features including hardware level reliable services and direct I/O accesses. In this paper we present Nomad, a design for migrating modern interconnects with the aforementioned features, focusing on cluster environments running VMs. We introduce a thin namespace virtualization layer to efficiently address location dependent resource handles and a handshake protocol which transparently maintains reliable service semantics during migration. We demonstrate our design by implementing a prototype based on the Xen virtual machine monitor and InfiniBand. Our performance analysis shows that Nomad can achieve efficient migration of network resources, even in environments with stringent communication performance requirements.
29243423
Design Alternatives and Performance Trade-Offs for Implementing MPI-2 over InfiniBand
MPICH2 provides a layered architecture to achieve both portability and performance. For implementations of MPI-2 over InfiniBand, it provides the flexibility for researchers at the RDMA channel, CH3 or ADI3 layer. In this paper we analyze the performance and complexity trade-offs associated with implementations at these layers. We describe our designs and implementations, as well as optimizations at each layer. To show the performance impacts of these design schemes and optimizations, we evaluate our implementations with different micro-benchmarks, HPCC and NAS test suite. Our experiments show that although the ADI3 layers adds complexity in implementation, the benefits achieved through optimizations justify moving to the ADI layer to extract the best performance.
12648516
Experiments in impulsive manipulation
In this paper, we present the results of our experimental effort in one form of impulsive manipulation: tapping. Our previous work studied the mechanics of tapping a planar object which then slides on a support surface, coming to rest due to friction. This work addresses the practical issues in creating a system which uses this mode of manipulation. We begin with the design of tapping devices-end effecters designed to deliver an impulse to an object, and report some of the issues we have found to be important in their design. Our next step was to perform single-tap experiments in order to fit and evaluate the models of impact and sliding. These experiments have shown that objects rotate less than predicted; we have found that the addition of a scaling factor for the torque due to friction enables the models to predict object motion reasonably well. In order to do positioning experiments, we developed a number of planning methods (or feedback control strategies) to compensate for errors in modeling, parameters, and actuation. These planning methods were successfully used to demonstrate a positioning task. We also have experimentally demonstrated that tapping can be used to position an object more precisely than the manipulator can position the tapping device. We offer some sensitivity analysis in support of this result.
7757717
A kernel autoassociator approach to pattern classification
Autoassociators are a special type of neural networks which, by learning to reproduce a given set of patterns, grasp the underlying concept that is useful for pattern classification. In this paper, we present a novel nonlinear model referred to as kernel autoassociators based on kernel methods. While conventional non-linear autoassociation models emphasize searching for the non-linear representations of input patterns, a kernel autoassociator takes a kernel feature space as the nonlinear manifold, and places emphasis on the reconstruction of input patterns from the kernel feature space. Two methods are proposed to address the reconstruction problem, using linear and multivariate polynomial functions, respectively. We apply the proposed model to novelty detection with or without novelty examples and study it on the promoter detection and sonar target recognition problems. We also apply the model to mclass classification problems including wine recognition, glass recognition, handwritten digit recognition, and face recognition. The experimental results show that, compared with conventional autoassociators and other recognition systems, kernel autoassociators can provide better or comparable performance for concept learning and recognition in various domains.