Browsing by Subject "Expert systems (Computer science)"
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Item A workplace design expert system(Texas Tech University, 1985-12) DeGreve, Thomas BlairNot availableItem An empirical investigation of the use of expert systems by groups(Texas Tech University, 1989-08) Rajkumar, T. MGroups make a large number of decisions in organizations. Incorporation of expert system concepts within GDSS has been suggested in the past as a means of supporting the decision-making activity of groups. This study aims to find what group factors affect the use of expert systems by groups within a decision-making setting. Specifically the study examined group commitment, satisfaction, past success and cohesion as variables of interest. Competing alternative models, incorporating these variables, are proposed to explain the group use of expert systems. An expert system that supports reasoning by analogy was developed for the business simulation game IMAGINIT. The use of the expert system was found to significantly increase the problem understanding, and the average and ending performance. The expert system was also found to help in the strategic decision-making phase by the groups. A laboratory study was conducted to measure the voluntary use of this expert system. Results show support for one of the models. In this model each of the variables (commitment, satisfaction, cohesion, and past success) were viewed as independently affecting the use of expert systems. Of the variables investigated, past success was the only variable to significantly affect the use of the expert system. Groups that performed better in the past tended to attribute their performance to the usage of the expert system. This attribution resulted in an increased usage of the expert system. The other variables (commitment, satisfaction, and cohesion) did not significantly affect the use of expert systems. Because many of the group variables did not significantly affect the usage of expert systems by groups, a data-driven model was developed to derive the relationships among the group variables, and usage of expert systems. The data suggests that the correlation between the variables (commitment, satisfaction, past success, and cohesion) is caused by a common second-order factor (group behavior). This second-order factor did not significantly affect the use of the expert system.Item An empirical study on the knowledge acquistition process for expert systems(Texas Tech University, 1995-12) Kiris, Esin ÖzarExpert systems, a form of artificial intelligence, are computer programs that enhance the problem-solving and decision-making performance of users. The power of these systems is dependent on the knowledge that is extracted from the experts. The process of extracting expertise is called knowledge acquisition. As a process, knowledge acquisition involves eliciting, analyzing and interpreting the knowledge that a human expert uses when solving a particular problem and then transforming this knowledge into a suitable machine representation. Several knowledge elicitation techniques have been reported in the literature. Despite the rapid development of techniques for knowledge acquisition, there has been little effort involved in evaluating the effectiveness of the techniques. The objective of this research was to determine how the knowledge source (domain expert), task features (domain), knowledge engineer (expert system developer) and knowledge acquisition technique affect the effort needed to develop a knowledge base, the time spent to develop a knowledge base and the quality of the elicited knowledge base. Nine librarians and six pilots (experts) and nine graduate university students (knowledge engineers) served as subjects in this study. Two types of domains were investigated, for which knowledge bases were created for each domain: (1) an aircraft flight maneuver task and (2) a librarian material selection task. In the experiment, each person serving as an expert participated in the study once using each of the three techniques: (1) interview, (2) verbal protocol and (3) concept mapping with three different knowledge engineers. Each knowledge engineer used each of the three techniques by conducting knowledge acquisition session with experts for each task. Time to elicit knowledge from an expert, time to analyze elicited knowledge, accuracy and completeness of the knowledge base, expert workload, and knowledge engineer workload were measured at the end of each knowledge acquisition session. Results of ANOVAs showed a significant effect of task type only for the completeness measure and not for all other measures. In addition, results of ANOVAs showed that the quality of the knowledge base was more dependent on the expert's and the knowledge engineer's personal characteristics and performance than a selected knowledge acquisition technique. However, the time spent on either the knowledge elicitation or knowledge analysis sub-tasks of the knowledge acquisition process was dependent on the knowledge acquisition technique. The verbal protocol technique shortened the time spent on knowledge elicitation, whereas the concept mapping technique shortened the time spent on analysis. From the point of the knowledge engineer, it is concluded that the concept mapping technique is the most efficient technique and requires the least effort spent On the other hand, the domain experts were split, with the librarians viewing the concept mapping technique as the most efficient and the pilots viewing the verbal protocol technique as the most efficient method. Overall, the selection of the knowledge engineer and expert is as important as the selection of a knowledge acquisition technique at least with these two tasks. Although there were not any quality or time differences using the different techniques, the concept mapping technique is recommended based on this study, as compared to both the interview and verbal protocol techniques as a means of reducing the knowledge engineer's workload.Item Automatic interpretation of loosely encoded knowledge(2006) Fan, James Junmin; Porter, Bruce, 1956-Knowledge is critical for a variety of artificial intelligence problems. A key challenge in using knowledge-based systems is how to align one's encoding with the idiosyncrasies in the existing knowledge base. We call such misalignments "loose speak". We found that loose-speak occurs frequently in knowledge base interactions with such regularity that it can be interpreted automatically by a machine. We created a loose-speak interpreter based on a unified approach that is capable of interpreting the different forms of loose speak, and we evaluated it through empirical studies in different domains and on different tasks.Item Design of inexact reasoning systems for management problem diagnosis(Texas Tech University, 1990-05) Jung, Dong-GillHuman decision-making becomes more complicated when decision problems arise in less-than-perfect situations-- situations with information imperfection. In these situations, decision quality degrades severely because of the limitation of a human's reasoning capabilities. Promoted by advances in modern computing technology, intelligent decision aid systems have surfaced as a solution to solve that problem. The core of such decision aid systems is an inexact reasoning system. The purpose of this research was to design a robust and efficient reasoning system that can handle the problems with information imperfection effectively. The problem domain of focus was managerial problem diagnosis at a strategic decision level. The research question was whether the new inexact reasoning architecture can help managers to diagnose their problems in a more robust and efficient way than existing inexact reasoning architectures. The task of designing a robust and efficient inexact reasoning architecture was performed by synthesizing the knowledge in two major fields of modern computing technology: the representation of imperfect knowledge and information, and the connectionist computational architectures. Design of the inexact reasoning system, named as GIROS, involved: i) formulation of design criteria; ii) conceptualization and functional specification; iii) architectural design; iv) detailed design; and v) coding and verification. Detailed design required designing a series of algorithms for the functional specification of GIROS. To accomplish the research purpose and to answer the research question, prototype system development was adopted as a base for the methodology of the research. A checklist of the functional capabilities of inexact reasoning systems was developed as a framework for the comparative evaluation of CIROS and the selected inexact reasoning systems. Then, a comparative evaluation was done based on the framework. The evaluation and a demonstration of the use of CIROS seemed sufficient to conclude that GIROS is a robust and efficient inexact reasoning architecture. Moreover, CIROS can handle more diverse types of information imperfection than the selected inexact reasoning systems. CIROS can perform inexact inferencing more efficiently than many other inexact reasoning architectures. And GIROS has its own justification/explanation facility, a capability that is nonexistent in the connectionist architectures.Item Determining the individual microeconomic demand for continuous online assurance given specific types of decisions(Texas Tech University, 2002-05) Daigle, Ronald JudeThe accounting profession is studying the viability of a new potential assurance service, continuous auditing (continuous online assurance [COA]). The ability to begin developing COA as a professional service is due to the proliferation of information technology, which has provided more timely information, as well as the potential for more timely assurance. The purpose of this study is to investigate the relative demand for COA by individual decision-makers given specific types of decision-making situations. This study provides a framework based on the information hypothesis and information microeconomics for explaining the demand for COA when making individual repetitive decisions. Using an experimental methodology, five decision aspects are studied: (1) the level of precision in the COA report, (2) choice versus judgment decisions, (3) the level of similarity or dissimilarity of options when making choice decisions, (4) the number of decision criteria and (5) the benefit/penalty to be earned/incurred from making decisions. Markets are developed and compared to determine which situations have relatively more significant and consistent demand for COA. Results indicate that (1) more precise COA reports are significantly demanded more than less precise COA reports when an equal economic benefit can be obtained from either option, (2) COA demand is significantly greater and more consistent for judgment decisions than choice decisions, (3) while no significant difference in COA demand is found for choice decisions based on the similarity/dissimilarity of options. COA purchase patterns differ with changes in the similarity/dissimilarity of options, (4) COA demand is significantly greater and more consistent with an increase in the number of decision criteria when making judgment decisions, but only more consistent when making choice decisions, (5) no significant difference is found in the level or consistency of COA demand with an increase in reward/penalty to be earned/incurred, whether the decisions are judgment or choice in nature. Based on the results, because judgment decisions are more indicative of internal decisions and choice decisions are more indicative of external decisions to an organization, the accounting profession should first develop COA towards meeting the needs of internal decision-makers.Item Determining the individual microeconomic demand for continuous online assurance given specific types of decisions(Texas Tech University, 2002-05) Daigle, Ronald JudeThe accounting profession is studying the viability of a new potential assurance service, continuous auditing (continuous online assurance [COA]). The ability to begin developing COA as a professional service is due to the proliferation of information technology, which has provided more timely information, as well as the potential for more timely assurance. The purpose of this study is to investigate the relative demand for COA by individual decision-makers given specific types of decision-making situations. This study provides a framework based on the information hypothesis and information microeconomics for explaining the demand for COA when making individual repetitive decisions. Using an experimental methodology, five decision aspects are studied: (1) the level of precision in the COA report, (2) choice versus judgment decisions, (3) the level of similarity or dissimilarity of options when making choice decisions, (4) the number of decision criteria and (5) the benefit/penalty to be earned/incurred from making decisions. Markets are developed and compared to determine which situations have relatively more significant and consistent demand for COA. Results indicate that (1) more precise COA reports are significantly demanded more than less precise COA reports when an equal economic benefit can be obtained from either option, (2) COA demand is significantly greater and more consistent for judgment decisions than choice decisions, (3) while no significant difference in COA demand is found for choice decisions based on the similarity/dissimilarity of options. COA purchase patterns differ with changes in the similarity/dissimilarity of options, (4) COA demand is significantly greater and more consistent with an increase in the number of decision criteria when making judgment decisions, but only more consistent when making choice decisions, (5) no significant difference is found in the level or consistency of COA demand with an increase in reward/penalty to be earned/incurred, whether the decisions are judgment or choice in nature. Based on the results, because judgment decisions are more indicative of internal decisions and choice decisions are more indicative of external decisions to an organization, the accounting profession should first develop COA towards meeting the needs of internal decision-makers.Item Expert system to retrieve optimal kinetic parameters for simple reactions(Texas Tech University, 1986-05) Jou, Chon-shinNot availableItem A generic memory module for events(2007) Tecuci, Dan Gabriel; Porter, Bruce, 1956-The ability to remember past experiences enables a system to improve its performance as well as its competence. For example, a system might be able solve problems faster by adapting previous solutions. Additional tasks, such as avoiding unwanted behavior by detecting potential problems, monitoring long-term goals by remembering what subgoals have been achieved, and reflection on past actions, become feasible. As the tasks that an intelligent system accomplishes become more and more complex, so does the experience it acquires in the process. Such experience has a temporal extent and is expressed in terms of concepts and relations with deep semantics associated to them. Memory systems should be able to deal with the temporal aspect of experience, exploit this semantic knowledge for storage and retrieval and do so in a scalable fashion. However, relying just on experience will not achieve a broad coverage, as it needs to be used in conjunction with other reasoning mechanisms. That is why we need the ability to add episodic memory functionality to intelligent systems. Today's knowledge-based systems are complex software applications and the ability to develop them in a modular fashion, using generic, reusable components is essential. We propose to separate the episodic memory from the system that uses it and to build a generic, reusable memory module that can be attached to a variety of applications in order to provide this functionality. Its goal is to provide accurate, scalable, efficient and content-addressable access to prior episodes. Having such a reusable memory module should allow research to focus on the generic aspects of memory representation, organization and retrieval and its interaction with the external application and it should also reduce the complexity of the overall system. In this dissertation we propose a set of general requirements that any memory module should provide regarding memory encoding, storage and retrieval. We present an implementation that satisfies these requirements and evaluate it on three different tasks: plan synthesis, plan recognition and Physics problem solving. The memory module proved easily adaptable to these tasks, providing fast, accurate and scalable retrieval.Item Integration of knowledge-based expert system and relational database to grade buildings for wind resistance: design and implementation(Texas Tech University, 1995-12) Godbole, Seemantini PThis research was aimed at designing and implementing a system which would be capable of providing decision support, information management and easy to use user interface. Among many other challenges, one of the main challenge was to combine these different branches of computer science into one unified system. Some of the significant design features of this system include a loosely coupled design, run time binding of various components, relational database design and object-oriented user interface. It is also worth mentioning that this complex system with different components constantly communicating with one another, presents a unified fi^ont to the user. The user interface of this system was built with Microsoft Visual Basic, the database was implemented in Microsoft Access and the decision support component was built around the M4 expert system shell. The loosely coupled design facilitated a parallel design and implementation of each of the components. A user survey was conducted as a part of this thesis. The aim of the user survey was to gather information and feedback from the users about the system. This system is at work at the Insurance Industry for property Loss Reduction at Boston, MA.Item Investigation of an advanced technique to select an optimal inhibition and removal method of paraffin deposition in oil wells(Texas Tech University, 2001-08) Baruah, Bikram M.From the very beginning of the business of hydrocarbon exploitation, the problem of paraffin deposition was encountered with varying degrees. With oil exploitation expanding into exotic frontiers like deep-water and the Arctic Circle, wax deposition became a greater challenge for the operators. Various mechanical, thermal and chemical methods are used to remove and prevent wax deposition. However, it is often difficult to select the most effective and economic remedial measure for a given situation. Due to uniqueness of every crude, there is no single technique that is most effective for all types of crude oils. The main objective of this thesis project is to explore the feasibilities of using computer-based consulting systems, commonly known as expert systems, to select the best remedial measure of wax deposition in a given situation. Extensive literature survey was carried out to understand and collect information on the phenomena of wax deposition and removal/prevention techniques. A separate survey was conducted to understand expert systems in general and also to find out the criteria and resources required for building one. Then a feasibility study of building an envisioned computer system was conducted. Steps were also taken to initiate the building of an expert system.Item Pipelined sigma-delta modulators with interstage scaling(Texas Tech University, 1997-12) Chandrasekaran, Ramesh M.Sigma-Delta analog-to-digital converters (lA ADC) are capable of achieving high resolution ( > 15 bits) for moderate signal frequencies (