Earticle

Unique characteristics of biological systems are described, and similarities are made to certain computing architectures. The security challenges posed by these characteristics are discussed. A method of securely isolating portions of a design using introspective capabilities of a fine-grain self-configurable device is presented. Experimental results are discussed, and plans for future work are given.

One important but often overlooked aspect of human contexts of ubiquitous computing environment is human’s emotional status. And, there are no realistic and robust humancentric contents services so far, because there are few considers about combining context awareness computing with wearable computing for improving suitability of contents to each user’s needs. In this paper, we discuss combining context awareness computing with wearable computing to develop more effective personalized services. And we propose new algorithms to develop efficiently personalized emotion based content service system.

As ubiquitous computing technology convergences into many industrial domains, most museums want to apply this technique to their domain. However, most ubiquitous museums merely provide the simplest service giving visitors only static information of artifact. To resolve limitations of the existing ubiquitous museums, we had proposed Visitor Preference based Museum Viewing Search Algorithm that provides the best path for visitors to reflect their preferences. However, since the Visitor Preference based Museum Viewing Search Algorithm did not consider abnormal situations that occur while visitors look at the exhibit. So when abnormal situations occur, the exhibition may cause congestion problems that may make visitors feel very uncomfortable. In this paper, we propose an efficient congestion avoidance algorithm to solve these problems. This algorithm automatically re-finds proper alternative paths for avoiding congestion resulting from the abnormal ones occurring during the museum viewing. The proposed algorithm improves comfortable museum viewing services by preventing congestion in advance when exceptional conditions occur. For the experiment of the proposed algorithm, we show that the algorithm can provide the best path to reduce the impact of museum sightseeing crowdedness well even in exceptional conditions.

Online collaborative systems are popular communication channels as the systems allow people from various disciplines to interact and collaborate with ease. The systems provide communication tools and services that can be integrated on the web; consequently, the systems are more convenient to use and easier to install. Nevertheless, most of the currently available systems are designed according to some specific requirements and cannot be straightforwardly integrated into various applications. This paper provides the design of a new collaborative platform, which is component-based and re-con Figureurable. The platform is called the Modular Web-based Collaboration (MWC). MWC shares the same concept as computer supported collaborative work (CSCW) and computer-supported collaborative learning (CSCL), but it provides con Figureurable tools for online collaboration. Each tool module can be integrated into users’ web applications freely and easily. This makes collaborative system flexible, adaptable and suitable for online collaboration.

MANET security is becoming a challenge for researchers with the time. The lack of infrastructure gives rise to authentication problems in these networks. Most of the TTP and non-TTP based schemes seem to be impractical for being adopted in MANETs. A hybrid keymanagement scheme addressed these issues effectively by pre-assigned logins on offline basis and issuing certificates on its basis using 4G services. However, the scheme did not taken into account the CRL status of servers; if it is embedded the nodes need to check frequently the server’s CRL status for authenticating any node and place external messages outside MANET which leads to overheads. We have tried to reduce them by introducing an online MANET Authority responsible for issuing certificates by considering the CRL status of servers, renewing them and key verification within MANET that has greatly reduced the external messages.

The new generation mobile communication systems are very sensitive to the nonlinearities in their transmitting paths. The power amplifier is a key component which generates the nonlinear distortions. Power amplifier linearization techniques are very important to reduce the distortion of the transmitted signal and the adjacent band interference of users. As its facility of implementation, adaptive ability and high efficiency, the pre-distortion technology becomes the first choice to minimize the nonlinear distortions. In this paper, a new technique, based on the pre-distortion principle for linearizing a power amplifier, which is modeled by a Wiener model is proposed. The Wiener model is used to take into account the nonlinearities and the memory effects of the power amplifier. We also propose an efficient and original method for extracting the parameters of the power amplifier’s Wiener Model. Simulation results have been provided for showing the performances of this technique.

Real-Time (RT) applications, which manipulate important volumes of data, need to be managed with RT databases that deal with time-constrained data and time-constrained transactions. In spite of their numerous advantages, RT databases development remains a complex task, since developers must study many design issues related to the RT domain. In this paper, we tackle this problem by proposing RT design patterns that allow the modeling of structural and behavioral aspects of RT databases. We show how RT design patterns can provide design assistance through architecture reuse of reoccurring design problems. In addition, we present an UML profile that represents patterns and facilitates further their reuse. This profile proposes, on one hand, UML extensions allowing to model the variability of patterns in the RT context and, on another hand, extensions inspired from the MARTE (Modeling and Analysis of Real-Time Embedded systems) profile.