Abstract

On 26 December 2004 a devastating earthquake of magnitude 9.3 occurred in Sumatra region of Indonesia. This earthquake produced the world’s deadliest tsunami in the Indian Ocean region that claimed more than 300, 000 lives. This earthquake was quickly followed by another great one of magnitude 8.7 on 28 March 2005 in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession.

Abstract

The great devastating tsunamigenic earthquake of 26 December 2004 in sumatra was quickly followed by another great one on 28 march 2005 in the same region. This is for the first time in the known histroy of seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates in in generation of such great earthquakes.

Abstract

This article aims to understand the response of soil deposits underlying bedrock fault displacement in three dimensions. When an active bedrock fault ruptures, movement along the fault propagates through the overlying soil and produces zones of intense shear. Hence, it is important to study the surface behaviour based on fault characteristics. Hence we attempted to develop application of Ap- plied Element Method by modelling the fault rupture zone. In this article, we have modelled the fault rupture problem in three dimensions. First, a simple model is used to illustrate absorption of the bedrock deformation by the overlying soil in elastic case. In the later part, nonlinear analysis is car- ried out to study the complex failure propagation in three dimensions. Influence of mechanical properties of the material is also discussed.

Abstract

The great devastating tsunamigenic earthquake of 26 December 2004 (M9.0) in Sumatra was quickly followed by another great one on 28 March 2005 (M8.7) in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates, in generation of such great earthquakes. The 26 December 2004 and the 28 March 2005 earthquakes in the Andaman-Sumatra arc seem to have occurred on distinct India-Burma and Australia-Sunda mega-thrust segments possibly separated by a stress barrier or a lithospheric break at the junction that prevented stress transfer along the arc during both earthquakes. This is evidenced by the confinement of aftershock activity on either sides of the barrier during each of the earthquakes. It appears that the large impulsive co-seismic deformation during the first earthquake of 26 December 2004 triggered the already saturated adjoining segment of the Australia-Sunda plate boundary within a short period of 3 months, generating the second one on 28 March 2005. An examination of the locations of the world’s 12 largest earthquakes since the year 1900 indicates a strong correlation (>80%) with multiple plate junctions. Apart from the 2 great Sumatran earthquakes observed at the quadruple plate junction of India, Burma, Australia and Sunda, even the 2 greatest earthquakes in the Himalayas – the 1897 Shillong and the 1950 Assam earthquakes – each of magnitude 8.7, occurred at a quadruple junction near the eastern Himalayan syntaxis, comprising the India, Eurasia, Burma and Sunda plates. Finite element modeling of stress field at plate junctions indicates the mechanism of great stress build-up due to the plate geometry and variable plate velocities. In general, it is inferred that triple and quadruple plate junctions are potential targets for future great earthquakes.

Abstract

The great devastating tsunamigenic earthquake of 26 December 2004 (M9.0) in Sumatra was quickly followed by another great one on 28 March 2005 (M8.7) in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates, in generation of such great earthquakes. The 26 December 2004 and the 28 March 2005 earthquakes in the Andaman-Sumatra arc seem to have occurred on distinct India-Burma and Australia-Sunda mega-thrust segments possibly separated by a stress barrier or a lithospheric break at the junction that prevented stress transfer along the arc during both earthquakes. This is evidenced by the confinement of aftershock activity on either sides of the barrier during each of the earthquakes. It appears that the large impulsive co-seismic deformation during the first earthquake of 26 December 2004 triggered the already saturated adjoining segment of the Australia-Sunda plate boundary within a short period of 3 months, generating the second one on 28 March 2005. An examination of the locations of the world’s 12 largest earthquakes since the year 1900 indicates a strong correlation (>80%) w

Abstract

We present in this paper a methodology for computing the maximum velocity profile over a trajectory planned for a mobile robot. Environment and robot dynamics as well as the constraints of the robot sensors determine the profile. The planned profile is indicative of maximum speeds that can be possessed by the robot along its path without colliding with any of the mobile objects that could intercept its future trajectory. The mobile objects could be arbitrary in number and the only information available regarding them is their maximum possible velocity. The velocity profile also enables one to deform planned trajectories for better trajectory time. The methodology has been adopted for holonomic and nonholonomic motion planners. An extension of the approach to an online real-time scheme that modifies and adapts the path as well as velocities to changes in the environment such that both safety and execution time are not compromised is also presented for the holonomic case. Simulation and experimental results demonstrate the efficacy of this methodology.

Abstract

RS paths for a robot with both front and rear wheel steer. We call such robots as FR steer. The occurrence of such paths is due to the additional maneuver possible in such a robot which we call parallel steer, in addition to the ones already present in a vehicle with only front wheel steering. Hence we extend the optimal path set, containing only a single element to a set, containing n elements, thereby extending its configuration set along the optimal path from the initial to the final configuration. This extension of the set to set is made possible by introducing a special set, which we call the Parallel Steer (PS) Set. Such an extension of the configuration set would increase the size of the final configuration set achievable by a path that is optimal in free space. In the following discussion, we shall term all paths whose length is equal to an RS path as optimal.

Abstract

Different methodologies exist to direct the motion of sensors to detect targets moving across an environment in various scenarios. However, some of these do not model that navigation scenario in an environment in which obstacles are present. We extend our earlier algorithm for optimal target detection, as well as other algorithms reported in literature, to this case, and make a detailed comparison of their performance. This makes clear that the current algorithm is competitive in applications where target statistics are known in advance; otherwise, a heuristic technique by Sukhatme and Jung performs best.

Abstract

Digital Libraries have received wide attention in the recent years allowing access to digital information from anywhere across the world. They have become widely accepted and even preferred information sources in areas of education, science and others. When the full potential of digital libraries is realized, any citizen will for the first time be able to access all human knowledge immediately from any location. For a successful and useful Digital Library, the assurance of quality of the product from digitization process is quite essential. In this paper we discuss the major quality concerns of data from the digitization process, and how we assure for better quality before they are web enabled for the end-user to use. Also we discuss a Quality Management Framework that we applied for the improvement of both the Quality of the digital output and the efficiency of the processes.

Abstract

In this paper we propose a novel technique for robust visual servoing in presence of a large proportion of outliers in image measurements. The method employs robust statistical techniques and novel view prediction for improving the performance. We identify a set of points from initial and reference images and compute the essential matrix relating them. The selected points are predicted from the initial and reference images to the current frame using essential matrices. A function of the difference between the observed and predicted image point measurements is used to identify outliers. This technique is validated with many experiments and compared with other robust methods in a simulation framework.