journal article
LitStream Collection
Home
Karplus, Walter J.; Shibata, Yoshitaka
doi: 10.1177/003754978604600602pmid: N/A
In the modeling of distributed parameter systems, it is sometimes necessary to utilize system observations to identify or estimate the boundary conditions of the field. For example, in dealing with water resources systems, it may be desired to identify and characterize sources of water pollution on the basis of measure ments of pollution concentrations downstream from suspected sources. A computational technique based on pattern recogni tion has been found to be relatively effective in this application. However, the algorithms involved are highly computation- intensive and therefore tend to place a considerable burden on most conventional digital computer facilities. Array processors, though primarily designed for signal processing are playing an increasingly important role in the modeling and simulation of physical systems. It is a purpose of this paper to describe the ap plication of a relatively small and inexpensive peripheral array processor to this problem and to evaluate its performance.
doi: 10.1177/003754978604600603pmid: N/A
PASION is a process and event-oriented simulation language designed for those who already know and use Pascal. The lan guage has a two-level (process/event) structure and permits all the Pascal structures. PASION provides all necessary facilities needed to handle sequences of random events, queues, and quasi-parallel processes, both discrete and continuous. A PASION program consists of a sequence of process declara tions. At run-time the program generates objects that represent model processes due to the process declarations. Compared with Simula, PASION is rather simple and offers similar compromise between simplicity and flexibility as does Pascal when compared to Algol.
Cheng, Shang-I.; Talbot, Guy Richard
doi: 10.1177/003754978604600604pmid: N/A
Dynamic simulation and phase plane analysis techniques were used to examine the stability of an entrained coal gasifier. The mathematical model consists of a set of algebraic and ordinary differential equations which represent the time-dependent in terrelationships among reaction kinetics, heat transfers and mass transports; and the variable physical properties of both gaseous mixture and coal particles. For simplicity, the shift-reaction and volatilization were not considered in the study. This model is expected to be valid for dynamic simulation of gasification of char with low iron content and negligible shift reaction.During simulation the coupled differential equations are solved by the Adams-Moulton numerical integration technique.After the simulation is run to a steady state, the temperatures and composition of this system were perturbed in many com binations. The trajectories of variable changes were plotted in phase planes. It was noted that the system was stable for all the variable combinations tested.The effects of pure proportional control on the dynamics of the gasifier were examined. Such control resulted in a faster return to the steady-state conditions.
Showing 1 to 6 of 6 Articles