Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200582
A. Hoffmann, M. Fathi
The goal-oriented modeling of a diagnosis problem in the VLSI-design domain, namely the VLSI chip-architecture selection, is presented. To realize a more flexible and goal-oriented approach to diagnosis the framework QBB is used. QBB is based on the blackboard model. The description of the blackboard framework QBB is organized according to the three organizational components of blackboard systems, namely the blackboard, the knowledge sources, and the control component. Special emphasis is laid on the control component that follows a qualitative goal-oriented approach to control. Quality goals, their priorities, the goal relationships, and the informal dependencies are an essential part of a dynamic control plan. Compared to most other blackboard systems an extended, more detailed goal structure is maintained providing for more flexible, more explainable, and more transparent control decisions.<>
{"title":"Control reasoning based on goal relationships within the blackboard framework QBB","authors":"A. Hoffmann, M. Fathi","doi":"10.1109/PCCC.1992.200582","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200582","url":null,"abstract":"The goal-oriented modeling of a diagnosis problem in the VLSI-design domain, namely the VLSI chip-architecture selection, is presented. To realize a more flexible and goal-oriented approach to diagnosis the framework QBB is used. QBB is based on the blackboard model. The description of the blackboard framework QBB is organized according to the three organizational components of blackboard systems, namely the blackboard, the knowledge sources, and the control component. Special emphasis is laid on the control component that follows a qualitative goal-oriented approach to control. Quality goals, their priorities, the goal relationships, and the informal dependencies are an essential part of a dynamic control plan. Compared to most other blackboard systems an extended, more detailed goal structure is maintained providing for more flexible, more explainable, and more transparent control decisions.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"838 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123294016","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200542
J. Myoupo
The authors present a fully pipelined modular linear systolic algorithm for dynamic programming. They use geometric considerations to design the array. Its characteristics make it fully-pipelined. It runs in 1.5n/sup 2/+O(n) time steps on an array of n/sup 2//6+O(n) processors.<>
{"title":"Solving dynamic programming problems efficiently on modular linear pipelines","authors":"J. Myoupo","doi":"10.1109/PCCC.1992.200542","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200542","url":null,"abstract":"The authors present a fully pipelined modular linear systolic algorithm for dynamic programming. They use geometric considerations to design the array. Its characteristics make it fully-pipelined. It runs in 1.5n/sup 2/+O(n) time steps on an array of n/sup 2//6+O(n) processors.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121110259","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200535
N. Ullah, R. K. Acree, M.J. Gonzalez, M. L. Weems
The authors study the limitations placed on performance by using a model known as the job profile model. They extend and generalize the job profile model to develop a performance model that can be used to determine a lower bound on performance for a class of scheduling policies for a specific architectural configuration. The extended model incorporates the effects of communication between subtasks of a job, and a contention for common resources into the job profile model. This new model provides performance equations that depict the performance impact of the synchronization demands and the algorithmic decomposition of a workload. The extended model is then used to study the effect of the communication to computation ratio on performance. The validity of the model was verified by comparing the theoretical results obtained from the model to experimental results obtained from simulation.<>
{"title":"Predicting the limits of multiple processor performance using job profiles","authors":"N. Ullah, R. K. Acree, M.J. Gonzalez, M. L. Weems","doi":"10.1109/PCCC.1992.200535","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200535","url":null,"abstract":"The authors study the limitations placed on performance by using a model known as the job profile model. They extend and generalize the job profile model to develop a performance model that can be used to determine a lower bound on performance for a class of scheduling policies for a specific architectural configuration. The extended model incorporates the effects of communication between subtasks of a job, and a contention for common resources into the job profile model. This new model provides performance equations that depict the performance impact of the synchronization demands and the algorithmic decomposition of a workload. The extended model is then used to study the effect of the communication to computation ratio on performance. The validity of the model was verified by comparing the theoretical results obtained from the model to experimental results obtained from simulation.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127104965","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 theory of the interaction among agents and a formal semantics for their interactions are presented. The semantics of the messages exchanged, not the process of exchanging them, is emphasized. A recent theory of communication that gives the object model-theoretic semantics for speech acts is applied to this problem. This allows the important properties of protocols to be formalized abstractly, i.e. at the level of the application, not of the implementation. Further constraints on good designs can also be stated, which simplify the requirements imposed on the member agents. The resulting theory not only provides some insights into designing distributed intelligence systems, but also helps in their validation. As an example, it is applied to a logical reconstruction of the classical Contract Net protocol.<>
{"title":"On the semantics of protocols among distributed intelligent agents","authors":"Munindar P. Singh","doi":"10.22028/D291-25027","DOIUrl":"https://doi.org/10.22028/D291-25027","url":null,"abstract":"A theory of the interaction among agents and a formal semantics for their interactions are presented. The semantics of the messages exchanged, not the process of exchanging them, is emphasized. A recent theory of communication that gives the object model-theoretic semantics for speech acts is applied to this problem. This allows the important properties of protocols to be formalized abstractly, i.e. at the level of the application, not of the implementation. Further constraints on good designs can also be stated, which simplify the requirements imposed on the member agents. The resulting theory not only provides some insights into designing distributed intelligence systems, but also helps in their validation. As an example, it is applied to a logical reconstruction of the classical Contract Net protocol.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126763741","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200601
V. Ramji, T. Gonsalves
Two enhanced versions of the Make utility compatible with the conventional version were developed, namely Distributed Make and Optimistic Make. Distributed Make uses the idle CPU cycles in a network of workstations to improve response time by running compilations concurrently on lightly loaded remote workstations. Optimistic Make runs in the background while the user is editing. When the user saves a file, any targets that are rendered out-of-date are recompiled even while the user continues editing. Thus, when the user finishes the editing session, most of the compilations have already been done. The performances of these two versions of Make were evaluated in a network of SUNs. Distributed Make was found to achieve a close to linear speedup in certain cases. Optimistic Make reduced response time by a factor of 2-7 with little degradation in editor response. Thus, both significantly reduce the program development cycle.<>
{"title":"Distributed and Optimistic Make: implementation and performance","authors":"V. Ramji, T. Gonsalves","doi":"10.1109/PCCC.1992.200601","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200601","url":null,"abstract":"Two enhanced versions of the Make utility compatible with the conventional version were developed, namely Distributed Make and Optimistic Make. Distributed Make uses the idle CPU cycles in a network of workstations to improve response time by running compilations concurrently on lightly loaded remote workstations. Optimistic Make runs in the background while the user is editing. When the user saves a file, any targets that are rendered out-of-date are recompiled even while the user continues editing. Thus, when the user finishes the editing session, most of the compilations have already been done. The performances of these two versions of Make were evaluated in a network of SUNs. Distributed Make was found to achieve a close to linear speedup in certain cases. Optimistic Make reduced response time by a factor of 2-7 with little degradation in editor response. Thus, both significantly reduce the program development cycle.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122280168","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200515
C. Espinosa, M. Perkowski
A hierarchical Hough transform (HT) based on pyramidal architecture is described, being a main component of the low-to-medium spatial vision subsystem for a mobile robot. The sequence of processing in the system originally conceived to be essential to the extraction of line features in indoor scenes consisted of: histogram equalization, smoothing with the use of a medial filter, edge detection using the Sobel edge detectors, binarization to extract the edges detected, labeling, rebinarization and thinning to refine the edges to thin lines, and line extraction using a hierarchical approach to the HT method. The task was to establish the importance of each step for the success of the hierarchical HT. It was implemented on a 386-based personal computer with 640 K memory and proved to give results of high quality as compared with the standard HT implementation.<>
{"title":"Hierarchical Hough transform based on pyramidal architecture","authors":"C. Espinosa, M. Perkowski","doi":"10.1109/PCCC.1992.200515","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200515","url":null,"abstract":"A hierarchical Hough transform (HT) based on pyramidal architecture is described, being a main component of the low-to-medium spatial vision subsystem for a mobile robot. The sequence of processing in the system originally conceived to be essential to the extraction of line features in indoor scenes consisted of: histogram equalization, smoothing with the use of a medial filter, edge detection using the Sobel edge detectors, binarization to extract the edges detected, labeling, rebinarization and thinning to refine the edges to thin lines, and line extraction using a hierarchical approach to the HT method. The task was to establish the importance of each step for the success of the hierarchical HT. It was implemented on a 386-based personal computer with 640 K memory and proved to give results of high quality as compared with the standard HT implementation.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122313821","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200562
F. Carden, B. Kopp
Minimum shift keying (MSK) is a modulation format that exhibits some spectral efficiency over currently used spacelink digital modulation techniques such as binary phase shift keying (BPSK) and offset quadrature phase shift keying (OQPSK). The authors present a novel design of an MSK modulator that is well suited for investigating MSK in the laboratory. MSK obtains its advantage over OQPSK through the use of some elaborate timing. One of the costs of this required timing is added complexities in the modulator circuitry. Phase locked loops and an extra phase shift are required to modify a simple OQPSK modulator to perform MSK. Digital timing circuitry, including digital phase shifting, can be used in conjunction with inexpensive laboratory function generators to construct a simple MSK modulator that avoids the complexities of the modified OQPSK design technique. These design techniques are described.<>
{"title":"A laboratory minimum shift key modulator","authors":"F. Carden, B. Kopp","doi":"10.1109/PCCC.1992.200562","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200562","url":null,"abstract":"Minimum shift keying (MSK) is a modulation format that exhibits some spectral efficiency over currently used spacelink digital modulation techniques such as binary phase shift keying (BPSK) and offset quadrature phase shift keying (OQPSK). The authors present a novel design of an MSK modulator that is well suited for investigating MSK in the laboratory. MSK obtains its advantage over OQPSK through the use of some elaborate timing. One of the costs of this required timing is added complexities in the modulator circuitry. Phase locked loops and an extra phase shift are required to modify a simple OQPSK modulator to perform MSK. Digital timing circuitry, including digital phase shifting, can be used in conjunction with inexpensive laboratory function generators to construct a simple MSK modulator that avoids the complexities of the modified OQPSK design technique. These design techniques are described.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124242979","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200561
J. Fonseka, T. R. Mao
A class of nonlinear continuous phase modulation (CPM) signals is introduced by extending nonlinear continuous phase frequency shift keying (CPFSK) signals. Coding is considered to further improve the performance of nonlinear CPM signals. Numerical results indicate that both uncoded and coded CPM signals achieve attractive minimum Euclidean distances. Gains of over 1.8 dB over previous schemes have been reported at the same number of states. The spectral properties of nonlinear CPM signals are kept close to those of full response linear CPM with a modulation index of 0.5. It is shown that both uncoded and coded nonlinear CPM signals can be realized by using a finite state machine and a standard FM modulator.<>
{"title":"Coded nonlinear continuous phase modulation","authors":"J. Fonseka, T. R. Mao","doi":"10.1109/PCCC.1992.200561","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200561","url":null,"abstract":"A class of nonlinear continuous phase modulation (CPM) signals is introduced by extending nonlinear continuous phase frequency shift keying (CPFSK) signals. Coding is considered to further improve the performance of nonlinear CPM signals. Numerical results indicate that both uncoded and coded CPM signals achieve attractive minimum Euclidean distances. Gains of over 1.8 dB over previous schemes have been reported at the same number of states. The spectral properties of nonlinear CPM signals are kept close to those of full response linear CPM with a modulation index of 0.5. It is shown that both uncoded and coded nonlinear CPM signals can be realized by using a finite state machine and a standard FM modulator.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124440001","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200585
Y. Hao, Jyh-Charn S. Liu, Junguk L. Kim
The authors propose a scheme for global scheduling in a distributed system using a bus network, which is shared by nodes in the system through a contention-free medium access protocol. Unlike existing solutions, the scheme does not require complete global state information to be collected for a node that has an unschedulable aperiodic task to find a node that can execute the task. The nodes are organized in the system in a logical ring fashion to synchronize the global scheduling process. To evaluate the performance of the scheme, two protocols are developed. Simulation results show that the performance of the scheme is close to an ideal distributed system, in which the centralized global scheduler takes care of aperiodic tasks without any communication and task migration overhead.<>
{"title":"Task scheduling in hard real-time distributed systems on a bus local area network","authors":"Y. Hao, Jyh-Charn S. Liu, Junguk L. Kim","doi":"10.1109/PCCC.1992.200585","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200585","url":null,"abstract":"The authors propose a scheme for global scheduling in a distributed system using a bus network, which is shared by nodes in the system through a contention-free medium access protocol. Unlike existing solutions, the scheme does not require complete global state information to be collected for a node that has an unschedulable aperiodic task to find a node that can execute the task. The nodes are organized in the system in a logical ring fashion to synchronize the global scheduling process. To evaluate the performance of the scheme, two protocols are developed. Simulation results show that the performance of the scheme is close to an ideal distributed system, in which the centralized global scheduler takes care of aperiodic tasks without any communication and task migration overhead.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131187986","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}
Pub Date : 1992-04-01DOI: 10.1109/PCCC.1992.200546
W. Fortune, R. Reinoso
An experimental prototype network was built to study the issues in interconnecting SNA token ring networks using packet-switched services. In particular, the effect of out-of-sequence frames on the Logical Link Control Type 2 (LLC-2) protocol was considered. LLC-2 is the link level protocol used in SNA token rings. The authors show that, if LLC-2 acknowledgement frames are out of sequence, then the logical link and the session(s) will be reset. Terminal access to hosts is not affected if the window size is one and the acknowledgement timer is set to match the wide area network (WAN) maximum packet lifetime. For application-to-application communications, other solutions are proposed and analyzed because the window one solution limits the performance of the applications.<>
{"title":"Effect of out-of-sequence frames on LLC Type 2 applications","authors":"W. Fortune, R. Reinoso","doi":"10.1109/PCCC.1992.200546","DOIUrl":"https://doi.org/10.1109/PCCC.1992.200546","url":null,"abstract":"An experimental prototype network was built to study the issues in interconnecting SNA token ring networks using packet-switched services. In particular, the effect of out-of-sequence frames on the Logical Link Control Type 2 (LLC-2) protocol was considered. LLC-2 is the link level protocol used in SNA token rings. The authors show that, if LLC-2 acknowledgement frames are out of sequence, then the logical link and the session(s) will be reset. Terminal access to hosts is not affected if the window size is one and the acknowledgement timer is set to match the wide area network (WAN) maximum packet lifetime. For application-to-application communications, other solutions are proposed and analyzed because the window one solution limits the performance of the applications.<<ETX>>","PeriodicalId":250212,"journal":{"name":"Eleventh Annual International Phoenix Conference on Computers and Communication [1992 Conference Proceedings]","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130280364","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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