This paper introduces a hybrid evolutionary system for globel path planning within unstructured environments. This hybrid system combines a novel representation for obstacles within an environment, the concept of evolutionary search and a new concept we refer to as visibility-based repair to form a hybrid which quickly transforms infeasible paths into feasible ones. Our hybrid evolutionary system differs from other evolutionary path planners in that (1) more emphasis is placed on repairing infeasible paths to develop feasible paths rather than using simulated evolution exclusively as a means of discovering feasible paths and (2) a continuous map of the environment is used rather than a discretized map. In this paper, we demonstrate the effectiveness of this new hybrid system by using three challenging path planning problems.
{"title":"Hybrid evolutionary path planning via visibility-based repair","authors":"G. Dozier, A. Esterline, A. Homaifar, M. Bikdash","doi":"10.1145/2817460.2817468","DOIUrl":"https://doi.org/10.1145/2817460.2817468","url":null,"abstract":"This paper introduces a hybrid evolutionary system for globel path planning within unstructured environments. This hybrid system combines a novel representation for obstacles within an environment, the concept of evolutionary search and a new concept we refer to as visibility-based repair to form a hybrid which quickly transforms infeasible paths into feasible ones. Our hybrid evolutionary system differs from other evolutionary path planners in that (1) more emphasis is placed on repairing infeasible paths to develop feasible paths rather than using simulated evolution exclusively as a means of discovering feasible paths and (2) a continuous map of the environment is used rather than a discretized map. In this paper, we demonstrate the effectiveness of this new hybrid system by using three challenging path planning problems.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115646502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Careful page placement policies are memory management heuristics that map virtual pages to physical memory in a manner that tends to reduce the average CPU cache conflict miss rate compared to random placement. Careful placement is particularly well-suited to large direct-mapped caches. Perfect page placement is the limiting case of careful placement and is achieved by a virtual page mapping that minimizes the conflict miss rate. Cache performance curves for perfect page placement are useful benchmarks for estimating the relative error of other careful placement policies. On-line perfect placement is not realizable because the computation requires future knowledge of the memory reference string. However, off-line perfect placement is a systems modeling tool analogous to the OPT page replacement policy for virtual memory systems; both policies are tools for computing upper bounds on memory system performance. In this paper, perfect page placement is presented and proved NP-hard for demand-paged virtual memory systems with direct-mapped caches and infinite physical memory capacity. A class of perfect placement approximation algorithms is also presented and proved NP-hard.
{"title":"Perfect page placement","authors":"Thomas J. Murray, A. A. McRae, A. W. Madison","doi":"10.1145/2817460.2817472","DOIUrl":"https://doi.org/10.1145/2817460.2817472","url":null,"abstract":"Careful page placement policies are memory management heuristics that map virtual pages to physical memory in a manner that tends to reduce the average CPU cache conflict miss rate compared to random placement. Careful placement is particularly well-suited to large direct-mapped caches. Perfect page placement is the limiting case of careful placement and is achieved by a virtual page mapping that minimizes the conflict miss rate. Cache performance curves for perfect page placement are useful benchmarks for estimating the relative error of other careful placement policies. On-line perfect placement is not realizable because the computation requires future knowledge of the memory reference string. However, off-line perfect placement is a systems modeling tool analogous to the OPT page replacement policy for virtual memory systems; both policies are tools for computing upper bounds on memory system performance. In this paper, perfect page placement is presented and proved NP-hard for demand-paged virtual memory systems with direct-mapped caches and infinite physical memory capacity. A class of perfect placement approximation algorithms is also presented and proved NP-hard.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116943738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Researchers have studied graphic analogies from a wide range of disciplines and have perceived them in different ways. However, to represent analogy-making in computer simulations was not sought after until 1968 by a programmer by the name of Thomas Evans. His implementation was more or less a traditional way of viewing analogy-making decisions. The goal of my research is to first introduce an algorithm called Genetic Algorithm (GA) and from there give insight on how I went about developing a system that uses a GA to solve the analogy-making problem.
{"title":"Discovering graphic analogies through the use of genetic algorithms","authors":"Henry Everett","doi":"10.1145/2817460.2817496","DOIUrl":"https://doi.org/10.1145/2817460.2817496","url":null,"abstract":"Researchers have studied graphic analogies from a wide range of disciplines and have perceived them in different ways. However, to represent analogy-making in computer simulations was not sought after until 1968 by a programmer by the name of Thomas Evans. His implementation was more or less a traditional way of viewing analogy-making decisions. The goal of my research is to first introduce an algorithm called Genetic Algorithm (GA) and from there give insight on how I went about developing a system that uses a GA to solve the analogy-making problem.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127112025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multidatabase systems are designed to integrate heterogeneous database systems under one schema while maintaining site autonomy. Discretionary access control is a method of database security that allows authorized users to give and remove privileges to the data they own. In this paper we translate discretionary access to multidatabases. The SQL2 syntax can be modified to accommodate multiple sites, while maintaining the proper site autonomy. Maintaining a strict local autonomy involves making sure that any changes that are made to a remote site are also made locally. The partial syntax is defined here with future plans for a complete syntax and simulation of the rules in practice.
{"title":"Stopping traffic: discretionary access control in a multidatabase system","authors":"D. Strickland, Susan V. Vrbsky","doi":"10.1145/2817460.2817527","DOIUrl":"https://doi.org/10.1145/2817460.2817527","url":null,"abstract":"Multidatabase systems are designed to integrate heterogeneous database systems under one schema while maintaining site autonomy. Discretionary access control is a method of database security that allows authorized users to give and remove privileges to the data they own. In this paper we translate discretionary access to multidatabases. The SQL2 syntax can be modified to accommodate multiple sites, while maintaining the proper site autonomy. Maintaining a strict local autonomy involves making sure that any changes that are made to a remote site are also made locally. The partial syntax is defined here with future plans for a complete syntax and simulation of the rules in practice.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126135150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathan D. Fouss, Kai-Hsiung Chang, L. Murphy, Timothy W. Dollar, B. Lee, Yifang Chang
Most of today's applications have been targeted at making individuals more productive. It is common, however, for several individuals to collaborate on a project. Computers support the individual work done by group members but provide only token support for group interaction. There is a need for new tools that provide an environment where a group can cooperate on a project. Most work done in this area has thus far been targeted toward office automation and communication. However, there has been very little done to provide a group tool that supports the engineering design process. The objective of the CSCW project is to provide an environment that supports this process. In particular, this environment provides collaborative tools that support CAD and CASE. A CSCW environment has been developed by a team of faculty and students at Auburn University. This system is an expansion of an earlier project that focused on collaborative writing, called Distributed Collaborative Writing Aid. The CSCW project has added support for CAD and CASE. This paper discusses the method used to implement the CASE support. In particular, it addresses how group members can simultaneously work on coding a program and then integrate their work.
{"title":"Computer-aided software engineering in a computer supported cooperative environment","authors":"Jonathan D. Fouss, Kai-Hsiung Chang, L. Murphy, Timothy W. Dollar, B. Lee, Yifang Chang","doi":"10.1145/2817460.2817529","DOIUrl":"https://doi.org/10.1145/2817460.2817529","url":null,"abstract":"Most of today's applications have been targeted at making individuals more productive. It is common, however, for several individuals to collaborate on a project. Computers support the individual work done by group members but provide only token support for group interaction. There is a need for new tools that provide an environment where a group can cooperate on a project. Most work done in this area has thus far been targeted toward office automation and communication. However, there has been very little done to provide a group tool that supports the engineering design process. The objective of the CSCW project is to provide an environment that supports this process. In particular, this environment provides collaborative tools that support CAD and CASE. A CSCW environment has been developed by a team of faculty and students at Auburn University. This system is an expansion of an earlier project that focused on collaborative writing, called Distributed Collaborative Writing Aid. The CSCW project has added support for CAD and CASE. This paper discusses the method used to implement the CASE support. In particular, it addresses how group members can simultaneously work on coding a program and then integrate their work.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116498720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many students find difficulty in grasping the abstract concepts that are introduced in a typical data structures course. The purpose of this study is to develop methods that would encourage students to use pictures and animation to visualize data structures concepts. We use the ideas and rules from two popular games, Pictionary and Jeopardy, as a way to create a learning environment that will assist students in thinking in a more visual manner. We have created a computerized version of these games that students can use after class to reinforce the classroom lectures.
{"title":"Game-based methods for teaching data structures","authors":"Kriston Carson","doi":"10.1145/2817460.2817490","DOIUrl":"https://doi.org/10.1145/2817460.2817490","url":null,"abstract":"Many students find difficulty in grasping the abstract concepts that are introduced in a typical data structures course. The purpose of this study is to develop methods that would encourage students to use pictures and animation to visualize data structures concepts. We use the ideas and rules from two popular games, Pictionary and Jeopardy, as a way to create a learning environment that will assist students in thinking in a more visual manner. We have created a computerized version of these games that students can use after class to reinforce the classroom lectures.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124133551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method for compression of one-dimensional signals using two-dimensional representations is investigated. In particular, this work focuses on compression of electrocardiogram (ECG) signals. Electrocardiograms measure the electrical activity of the heart. The pulse beat of the heart is reflected in the ECG by various waveforms. The morphology of the waveforms is useful in diagnosing heart abnormalities, therefore, it is important that the compression algorithm preserves these characteristics. Electrocardiograms exhibit periodic characteristics when observed in the time domain. A two-dimensional representation can be used to distinguish and exploit this periodicity which is not readily apparent in typical one-dimensional representations. By utilizing inter-period correlations of electrocardiogram signals, improved compression rates may be achieved. In this study, ECG compression is accomplished by creating a two-dimensional representation of the ECG. The approach involves dividing the ECG signal into short segments, each representing one pulse beat. The pulse beats are then stacked to form a two-dimensional matrix. The matrix is compressed with an Embedded Zerotree Wavelet (EZW) image encoder. Reconstructed signal quality has been evaluated in two ways: by the Percent Root-Mean-Squared Difference percentage (PRD) and by comparison with results produced by a one-dimensional wavelet encoder. Results indicate that the two-dimensional technique produces high quality results, particularly for very low bit-rates.
{"title":"Compression of one-dimensional ECG signals using two-dimensional representations","authors":"L. Christianson","doi":"10.1145/2817460.2817500","DOIUrl":"https://doi.org/10.1145/2817460.2817500","url":null,"abstract":"A new method for compression of one-dimensional signals using two-dimensional representations is investigated. In particular, this work focuses on compression of electrocardiogram (ECG) signals. Electrocardiograms measure the electrical activity of the heart. The pulse beat of the heart is reflected in the ECG by various waveforms. The morphology of the waveforms is useful in diagnosing heart abnormalities, therefore, it is important that the compression algorithm preserves these characteristics. Electrocardiograms exhibit periodic characteristics when observed in the time domain. A two-dimensional representation can be used to distinguish and exploit this periodicity which is not readily apparent in typical one-dimensional representations. By utilizing inter-period correlations of electrocardiogram signals, improved compression rates may be achieved. In this study, ECG compression is accomplished by creating a two-dimensional representation of the ECG. The approach involves dividing the ECG signal into short segments, each representing one pulse beat. The pulse beats are then stacked to form a two-dimensional matrix. The matrix is compressed with an Embedded Zerotree Wavelet (EZW) image encoder. Reconstructed signal quality has been evaluated in two ways: by the Percent Root-Mean-Squared Difference percentage (PRD) and by comparison with results produced by a one-dimensional wavelet encoder. Results indicate that the two-dimensional technique produces high quality results, particularly for very low bit-rates.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123912058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Process migration is the transfer of some significant part of the state of execution of a process from one machine (source) to another (destination), so that the process can resume execution on the destination machine from the point where it stopped execution on the source machine. When the source and destination machines differ significantly in their hardware and software configurations, the transferred process state needs to be translated to a correct state, valid on the destination machine, and such a migration is called a heterogeneous process migration. This paper discusses some of the motivations, problems and issues associated with architectural heterogeneity, especially the effects caused by having different number of registers on the source and destination machines, when doing heterogeneous process migration. It also describes an approach to accomplish heterogeneous process migration while addressing these effects of heterogeneity in register cardinality. The principal advantage of this approach is that it doesn't require any recompilation during the migration phase, and the migrated process can resume execution from a point very close to the point where it stopped execution on the source machine.
{"title":"Heterogeneous process migration: issues and an approach","authors":"Mallik V. Yalamanchili, R. Hyatt","doi":"10.1145/2817460.2817530","DOIUrl":"https://doi.org/10.1145/2817460.2817530","url":null,"abstract":"Process migration is the transfer of some significant part of the state of execution of a process from one machine (source) to another (destination), so that the process can resume execution on the destination machine from the point where it stopped execution on the source machine. When the source and destination machines differ significantly in their hardware and software configurations, the transferred process state needs to be translated to a correct state, valid on the destination machine, and such a migration is called a heterogeneous process migration. This paper discusses some of the motivations, problems and issues associated with architectural heterogeneity, especially the effects caused by having different number of registers on the source and destination machines, when doing heterogeneous process migration. It also describes an approach to accomplish heterogeneous process migration while addressing these effects of heterogeneity in register cardinality. The principal advantage of this approach is that it doesn't require any recompilation during the migration phase, and the migrated process can resume execution from a point very close to the point where it stopped execution on the source machine.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124743809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rules are an important part of any programming language and system. Rules can be employed either to enforce the correctness, integrity or admissibility of databases or database states, or to define requirements specified in the design phase of a software development process. A rule is more than just a simple IF ... THEN construction. Rules can be viewed as objects with distinctive properties and operations, constantly interacting and relating with other objects. Although research has been done on rules, the focus has been mainly on retrieval, activation and firing. Our focus is on the graphical representation and storage of rules and on event modeling in an object-oriented environment.
{"title":"Graphical representation and storage issues in object-oriented rule modeling","authors":"H. Vo, Jeffrey Peters","doi":"10.1145/2817460.2817479","DOIUrl":"https://doi.org/10.1145/2817460.2817479","url":null,"abstract":"Rules are an important part of any programming language and system. Rules can be employed either to enforce the correctness, integrity or admissibility of databases or database states, or to define requirements specified in the design phase of a software development process. A rule is more than just a simple IF ... THEN construction. Rules can be viewed as objects with distinctive properties and operations, constantly interacting and relating with other objects. Although research has been done on rules, the focus has been mainly on retrieval, activation and firing. Our focus is on the graphical representation and storage of rules and on event modeling in an object-oriented environment.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124844383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Home automation systems have been in development since the late seventies. However, the home automation market has not fully reached its potential. This can be attributed to a number of factors. Remote home automation systems, however, are quickly becoming more and more popular. Users like the ability to change their home environment while not at home. The remote home automation systems in existence, however, use the telephone as a medium for communication. These telephone user interfaces, unfortunately, are crude at best and often lead to a frustrating attempt to access the system. A better system would be one that could offer a graphical user interface, such as a homepage on the internet. Thus, if the user can access a web browser, the user can access the home automation system. In this paper, we discuss the design and implementation of such a system, an Internet Accessible Remote-control Home Automation System.
{"title":"An internet accessible remote controlled home automation system","authors":"Mave Houston, Richard O. Chapman, L. Moore","doi":"10.1145/2817460.2817482","DOIUrl":"https://doi.org/10.1145/2817460.2817482","url":null,"abstract":"Home automation systems have been in development since the late seventies. However, the home automation market has not fully reached its potential. This can be attributed to a number of factors. Remote home automation systems, however, are quickly becoming more and more popular. Users like the ability to change their home environment while not at home. The remote home automation systems in existence, however, use the telephone as a medium for communication. These telephone user interfaces, unfortunately, are crude at best and often lead to a frustrating attempt to access the system. A better system would be one that could offer a graphical user interface, such as a homepage on the internet. Thus, if the user can access a web browser, the user can access the home automation system. In this paper, we discuss the design and implementation of such a system, an Internet Accessible Remote-control Home Automation System.","PeriodicalId":274966,"journal":{"name":"ACM-SE 35","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133472409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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