Browsing by Author "Feustel, Edward A."
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Item An implementation model for a multiprocessor operating system on a descriptor oriented architecture(1977) Jagannathan, Anand; Feustel, Edward A.This thesis evolves a computer system which serves as the "basis for operating system design in a multiprocessor environment. The evolution presupposes the distinction between the 'mechanisms' and 'policies' which comprise an operating system and suggests an implementation for the set of mechanisms, which satisfy the criteria of flexibility and extensibility. The assumption is that the policy defining part of the operating system can be considered as a set of cooperating concurrent processes. The set of mechanisms, available to the system designer implementing the policy defining operating system, is termed as the 'nucleus' and is treated as a set of protected entities available to all processes in the system. The control of access is effected through a protection structure, which provides for the flexibility, extensibility and protected access. The protection structure uses a 'capability' model for protection and is supported by a descriptor oriented architecture. It is shown that the limited protection features of the supporting architecture cam be generalized to construct the protection structure, with respect to which, the nucleus can be appropriately specified. The nucleus is directed towards the delineation of as many features as possible, from a 'monitor' which is constrained to be used exclusively and which provides system wide functions.Item An implementation model for MADCAP VI(1973) McMahan, Larry Niel; Feustel, Edward A.An implementation model is specified for the MADCAP VI programming language on the Rice Research Computer. The features of the language and machine are examined and a theoretical model is developed based on the Contour Model of Johnson and Berry. The model is then expanded and detailed for the expression node structure of the language. A multienvironment access and control scheme is worked out using the features of the machine, and a working unit is described. A hybrid stack-access tree is used for the value implementation, and a tree of control word addressed segments for the algorithm. Finally some questions regarding language and machine design are considered and areas for future research presented.Item Deadlock free storage allocation policy(1973) Yang, Ay-fang E.; Feustel, Edward A.This thesis is concerned with the problem of determining optimal storage allocation strategies that are sensitive to the nature of the processes that request storage. It is intuitively obvious that such a strategy would be better than one which has been decided upon a priori, and does not take into account the local behavior of the entities it deals with. Efforts have been made to characterize the storage usages of computer users. Based on the techniques of Time Series Analysis, stochastic modles are constructed for the VSLM, SLRUM and IRM models of Denning and Spirn, It was found that the storage requirements of processes essentially stay on a certain level most of the time. An entity, called holding probability, is defined for a process to denote the probability that this process will change its storage need. Most programs under our studies have holding probabilities between .5 to .2. Also, experience from the experiments has shown us that the mean working set size of process can be determined quite accurately. In the second part of the thesis, a storage allocation policy called DFSA is discussed. The assumption that WS size as a function of time is normally distributed has been corroborated by our study of program behavior, GPSS/36 simulation has been used for the purpose of providing information about the performance of DFSA as compared with the currently used policies, The results show that roughly speaking, we need only half as much as channel activity while achieving a throughput rate not worse than the currently used strategies. The user's response time, under DFSA, however, is larger by 3%.Item Tagged Architecture and the Semantics Programming Languages: Extensible Types(1975-11-20) Feustel, Edward A.This research note suggests that before we design hardware or software for the task of problem solving, we re-evaluate the task of problem solving in terms of the linguistic constituents which will be required and the manner in which these linguistic constituents will be combined. Utilizing the principles of composition and abstraction-to-specifics, we conclude that all data and programs might be realized in a structured format called messages. We conclude with a few preliminary thoughts and questions as to how an architecture designed for such structured operands might be designed.Item Tagged Architectures and Protection: Message Systems(1975-10-20) Feustel, Edward A.Recent work in extensible programming languages and operating systems by Redell, Lampson, Hewitt, and others coupled with developments in distributed computer systems motivates a study in models of the implementation of protection on tagged architectures. an extension of the notions of message and actor as discussed in previous work provides and abstract framework which may lead to the development of a suitable virtual machine. We wish to show that such a system provides a good framework for representation and protection of types, data, and procedures.Item The development of a microprocessor based instrument for calculating mass, volume, and energy of natural gas(1977) Collins, Michael G.; Feustel, Edward A.This Thesis describes the design of a microprocessor based industrial instrument which is used for natural gas metering. It is named the PC-8. By using equations and standards of the American Gas Association (AGA) Reports numbers three and five, the FC-8 instrument calculates the volumetric flow rate, the mass flow rate and the energy flow rate of natural gas flowing in a pipeline. The primary volumetric metering standard is the orifice plate. The FC-8 dynamically calculates the modeling factors for the orifice plate i.e. Reynolds factor (Fp) and expansion factor (Y). This technique improves orifice metering over traditional volumetric metering methods because in the past Fr and Y were assumed constant at the time of meter design (AGA3). By measuring gas density and following the rules of AGA5 the FC-8 calculates the mass flow rate of natural gas. By measuring the specific gravity of natural gas and using Caldwell's equation also found in AGA5, the FC-8 derives the energy flow rate in dekatherms. A dekatherm is one million BTU's. The design of the FC-8 is followed from its conception to its inception by starting with the systems definition and following through to a working prototype. The system definition is anaylized so the hardware architecture may be formalized and the equations optimized for efficient execution. Several number formats are developed and a floating point arithmetic package is designed to manipulate thes formats. A study is performed on several microprocessing systems and the processor best suited is selected. After a processor is selected, the input/output structure and protocol is designed. The final element discussed is the development of the FC-8 executive program.