No description available.

No description available.

No description available.

This paper presents algorithms for computing constraints on the position of an object due to the presence of obstacles. This problem arises in applications which require choosing how to arrange or move objects among other objects. The basis of the approach presented here is to characterize the position and orientation of the object of interest as a single point in a Configuration Space, in which each coordinate represents a degree of freedom in the position and/or orientation of the object. The configurations forbidden to this object, due to the presence of obstacles, can then be characterized as regions in the Configuration Space. The paper presents algorithms for computing these Configuration Space obstacles when the objects and obstacles are polygons or polyhedra. An approximation technique for high-dimensional Configuration Space obstacles, based on projections of obstacles slices, is described.

We use Particle-in-Cell Method¡]PIC¡^and Monte-Carlo-Collision Method¡]MCC¡^to model a plasma colliding system .By this way¡Awe can realize the behaviors and effects in the motion of plasma collision . Our mainly discuss is that the system will produce a thin layer¡]Sheath¡^between plasma and a workpiece ¡Aand the effects of colliding phenomenon in this thin layer¡]Sheath¡^ .

There are various kinds of creature living in the world and each kind of creatures has its own unique life habits and behavior patterns. For these reasons between the creature as well as the biology and the environment can have many interactions with each other, and we may observe these interactions easily in the frequently daily life. However the humanity may be the quantity hugest, and also have the most complex behavior at the fine race group in all kind of creatures on earth. So how could we penetrate into by observed and analysis to obtain the information which translates to the computer simulation realistically is a topic of the very hardship with challenge to presents the human behavior. Virtually all previous work has been agent-based, meaning that motion is computed separately for each individual. Such models can capture each person¡¦s unique situation. So the agent-based modeling will inevitably result in a large number of calculation and make poor efficiency. In addition, there are leader-follower system which consists of a leader and multiple followers. This leader will lead the entire group to the destination, and the followers will follow the motion of their leader closely. In our research apply the physical properties of electric charge to the simulation of pedestrians by using the basic concepts of electromagnetism. The simulation method contains the agent-based modeling and the leader-follower system at the same time. The agent-based modeling simulates pedestrian of the individual motion. The goal of the leader-follower system is to simulate the real world behavior that people in a community often move by following a specific object.

No description available.

No description available.

This thesis documents an investigation into the automatic provision of reasonably realistic motion for the computer generated target ships in a marine simulator. The thesis explores: automatic collision avoidance between the target ships; automatic track keeping for the target ships; the use of sea stabilised and land stabilised motion for the target ships; some issues of software fault tolerance in marine simulators; message frameworks for use in a Multi-Agent System (MAS) simulation; the opportunity to provide different manoeuvring characteristics for different target ships; and the use of autonomous agents to control the target ships. A software system has been developed to facilitate this research. Entitled "A Multi-Agent Realm for Investigating Navigators' Educational Simulators" (MARINES), the software is a MAS providing much of the functionality of a marine simulator instructor station; basic functions are encapsulated into the instructor environment and additional features are provided by processes that connect to the environment using Dynamic Data Exchange. The processes can also connect to each other and, in MARINES, co-operate to navigate the ships. These co-operative, autonomous processes are the agents that together form a MAS. A simple 3D view is also connected, enabling the view from the bridge of a specific target ship to be assessed. The MARINES software is written using C++ to run under Microsoft Windows v3.1. Therefore, the processes multi-task co-operatively. In MARINES each target ship can be made to perform in an individual manner; manoeuvring and performance characteristics can be customised to simulate a specific ship type. Additionally, the agents performing collision avoidance can be given rule sets that interpret the International Regulations for the Prevention of Collisions at Sea in subtly different ways, and the track-keeping agents can have different beliefs about the manoeuvring capabilities of the vessels they control. Automatic collision avoidance and track keeping is performed for two-ship situations even when the set and drift of a current is introduced. A comparison is made with the tracks of land stabilised targets. This shows how aspect, course and speed are affected by ignoring the effects of the current, and demonstrates the need for an accurate simulation.

The Himalaya provide the most significant example of present-day orogenesis and consequently have been extensively studied to gain an understanding of the principle controls on the response of the crust to continental collision. However, our understanding of the prograde metamorphic evolution of the orogen remains poor. This thesis builds on recent advances in the study of PTt paths, using garnet chronometry, to better constrain the thennobarometric evolution of the Garhwal section of the Indian Himalaya. Results show that the metamorphic core of the Garhwal Himalaya - the High Himalayan Crystalline Series (HHCS) - records a complex, continuous prograde thermal history from initial burial -10 Ma after continental collision at -50 Ma, up to cooling and exhumation at 20-16 Ma BP. PT paths obtained from garnets indicate that prograde metamorphism occurred during crustal thickening and "peak" thermobarometric estimates show that the presently exposed HHCS records temperatures of -700 °C throughout the section accompanied by a decrease in pressures from --13 kbar at the base to -6 kbar at the top. However, chronometric information shows that reorganisation of the orogenic wedge resulted in the juxtaposition of rocks which attained different PT conditions at different times and places during orogenesis. Additionally, temperatures were sufficient in the early stages of orogenesis for the development of small leucogranitic bodies to form by fluid-present melting. The HHCS in Garhwal, therefore, cannot be considered as a single coherent crustal slice. Furthermore, the continued reorganisation of the orogen since collision also means the heat generation within the overthickened orogenic wedge is sufficient for anatexis of the crust to form the well-studied melts intruding the upper levels of the HHCS. However, interpretation of the results is complicated by the isotopic systematics involved in garnet chronometry and by the role of small inclusions with high concentrations of the critical elements of- Nd, Pb, Sr. The systematics of the Sm-Nd system in garnet has been investigated by a comparison of concentrations obtained insitu by LA-ICP-MS with those obtained by isotope dilution. Results show that while such inclusions can pose a problem to chronometry, their effects can be identified and constrained. In the course of such work data was obtained on the trace-element zonation in garnet, which acts as a monitor of the chemical evolution of the rock. While the controls on such zonation are still poorly understood the data presented here emphasise the importance of fractionation of the chemical system from which the garnet grows by both accessory minerals and by garnet itself. Furthermore, different minerals fractionate distinctly different elements this can be recognised in the trace-element zonation preserved in garnet.