The modelling of the educational processes and their operational support is a key aspect in the construction of more effective e-learning applications. Instructional models are usually described by means of an educati...
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The modelling of the educational processes and their operational support is a key aspect in the construction of more effective e-learning applications. Instructional models are usually described by means of an educational modelling language (EML). The EML used can be one of the available standards (e.g. IMS Learning Design), the customization of a standard to meet a specific application profile, or even a domain-specific EML specifically designed to best fit in the very particular needs of a learning scenario. In this paper we propose , a general authoring and operationalization architecture capable of dealing with all these possibilities in a highly modular and flexible way. We also outline a specific implementation of based on standard XML technologies and in the BPEL4WS workflow management language, and we describe how this implementation can be used to support IMS Learning Design.
Explorative research is a vital part of biological sciences. Biologists frequently have to examine and compare multiple (large) sets of biological data in an interactive and explorative manner. Exploring alternative w...
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In this paper the improvement in the performance obtained by a Time Interleaving applied to DVB-T scheme are analyzed in impulsive noise environments. The performance is evaluated in terms of bit error rate probabilit...
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This paper presents an advanced control structure exploiting a GPC master-slave solution to regulate the oxygen and nitrification process of a simulated water treatment plant. The slave controller regulates the proces...
This paper presents an advanced control structure exploiting a GPC master-slave solution to regulate the oxygen and nitrification process of a simulated water treatment plant. The slave controller regulates the process variable, whilst the master controller changes the set-point for the slave controller depending on the output behaviour of the system. The presented structure outperforms significantly the standard control structure. Different weather conditions are simulated and analysed for comparison
This work presents the performance of WLAN and MANET networks using the auto-configuration of Mobile IP Agents Protocol (DRMIPA). This scheme would allow groups of MIP nodes in WLANs or MANETs to enjoy IP mobility at ...
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ISBN:
(纸本)9781424436446
This work presents the performance of WLAN and MANET networks using the auto-configuration of Mobile IP Agents Protocol (DRMIPA). This scheme would allow groups of MIP nodes in WLANs or MANETs to enjoy IP mobility at any foreign or local network that doesn't implement MIP. To maintain a failure free MIP network, a passive agent is elected from an active agent if this active agent leaves or ceases its participation from current network. The DRMIPA protocol is implemented in WLAN and MANET. A performance analysis is done using a real world testbed scenario.
There is increasing awareness that planning and model checking are closely related fields. Abstraction means to perform search in an over-approximation of the original problem instance, with a potentially much smaller...
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There is increasing awareness that planning and model checking are closely related fields. Abstraction means to perform search in an over-approximation of the original problem instance, with a potentially much smaller state space. This is the most essential method in model checking. One would expect that it can also be made successful in planning. We show, however, that this is likely to not be the case. The main reason is that, while in model checking one traditionally uses blind search to exhaust the state space and prove the absence of solutions, in planning informed search is used to find solutions. We give an exhaustive theoretical and practical account of the use of abstraction in planning. For all abstraction (over-approximation) methods known in planning, we prove that they cannot improve the best-case behavior of informed search. While this is easy to see for heuristic search, we were quite surprised to find that it also holds, in most cases, for the resolution-style proofs of unsolvability underlying SAT-based optimal planners. This result is potentially relevant also for model checking, where SAT-based techniques have recently been combined with abstraction. Exploring the issue in planning practice, we find that even hand-made abstractions do not tend to improve the performance of planners, unless the attacked task contains huge amounts of irrelevance. We relate these findings to the kinds of application domains that are typically addressed in model checking.
By now, the concept of program slicing has been known in the research community for around 25 years. As a research topic, it has enjoyed a fair share of popularity, evidenced by the number of articles published on the...
Cyber theft is a serious threat to Internet security. It is one of the major security concerns by both network service providers and Internet users. Though sensitive information can be encrypted when stored in non-vol...
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Cyber theft is a serious threat to Internet security. It is one of the major security concerns by both network service providers and Internet users. Though sensitive information can be encrypted when stored in non-volatile memory such as hard disks, for many e-commerce and network applications, sensitive information is often stored as plaintext in main memory. Documented and reported exploits facilitate an adversary stealing sensitive information from an application's memory. These exploits include illegitimate memory scan, information theft oriented buffer overflow, invalid pointer manipulation, integer overflow, password stealing Trojans and so forth. Today's computing system and its hardware cannot address these exploits effectively in a coherent way. This paper presents a unified and lightweight solution, called InfoShield that can strengthen application protection against theft of sensitive information such as passwords, encryption keys, and other private data with a minimal performance impact. Unlike prior whole memory encryption and information flow based efforts, InfoShield protects the usage of information. InfoShield ensures that sensitive data are used only as defined by application semantics, preventing misuse of information. Comparing with prior art, InfoShield handles a broader range of information theft scenarios in a unified framework with less overhead. Evaluation using popular network client-server applications shows that InfoShield is sound for practical use and incurs little performance loss because InfoShield only protects absolute, critical sensitive information. Based on the profiling results, only 0.3% of memory accesses and 0.2% of executed codes are affected by InfoShield.
This work presents a Dynamic Reconfiguration of Mobile IP Agents (DRMIPA) and failure free architecture integrated with Mobile Ad hoc Networks (MANETs). Actual infra-structured networks do not implement the Mobile IP ...
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This work presents a Dynamic Reconfiguration of Mobile IP Agents (DRMIPA) and failure free architecture integrated with Mobile Ad hoc Networks (MANETs). Actual infra-structured networks do not implement the Mobile IP (MIP) protocol, all MIP agents are static and the cost of having redundancy of MIP agents is often high. We propose a solution that would allow the integration of MIP with MANET. Therefore, new algorithms and messages are presented for DRMIPA in MANET and, a performance analysis is done using the Network Simulator 2 (NS2) and a real world testbed scenario.
The algorithm of the dynamic control functions achieves a complex modeling regarding the behavior of any mechanical robot structure. First of all, considering the kinetic links dominated of stiffness hypothesis, on th...
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The algorithm of the dynamic control functions achieves a complex modeling regarding the behavior of any mechanical robot structure. First of all, considering the kinetic links dominated of stiffness hypothesis, on the basis of the new formulations with matrix exponentials, in this paper, the differentials expressions answerable to the forward kinematics of mechanical robot structures were presented. On the basis of these equations, in the following, the generalized dynamics forces were also analyzed for the robots with rigid and elastic structure
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