Pub Date : 1994-11-17DOI: 10.1109/PHYCMP.1994.363676
S. Morgera, J.M. Hallik
Examines an efficient approach to the calculation of the entropy of long binary and nonbinary 1D information sequences. The entropy calculation is accomplished in a time which is linear in the sequence length. The method is expanded to estimate the entropy of grey-level images which, under raster scanning, may be represented as 1D information sequences. The entropy estimate obtained depends on the image scanning method employed, and consequently, in order to achieve a greater reduction in the bit rate, the scanning should be done in the direction of the highest adjacent pixel statistical dependence. Depending on the image statistics, it is shown that uniform luminance requantization of an image may not lead to an appreciable reduction in the bit rate. The algorithm discussed can be applied to areas such as image compression and string entropy estimation in genetics.<>
{"title":"A fast algorithm for entropy estimation of grey-level images","authors":"S. Morgera, J.M. Hallik","doi":"10.1109/PHYCMP.1994.363676","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363676","url":null,"abstract":"Examines an efficient approach to the calculation of the entropy of long binary and nonbinary 1D information sequences. The entropy calculation is accomplished in a time which is linear in the sequence length. The method is expanded to estimate the entropy of grey-level images which, under raster scanning, may be represented as 1D information sequences. The entropy estimate obtained depends on the image scanning method employed, and consequently, in order to achieve a greater reduction in the bit rate, the scanning should be done in the direction of the highest adjacent pixel statistical dependence. Depending on the image statistics, it is shown that uniform luminance requantization of an image may not lead to an appreciable reduction in the bit rate. The algorithm discussed can be applied to areas such as image compression and string entropy estimation in genetics.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"773 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120883575","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363699
R. Landauer
Our understanding of the fundamental physical limits of information handling has developed along a very convoluted path. Most of the initially plausible physical conjectures have turned out to be wrong. A participant's personal view of these events as not a disciplined contribution to the history of science. The author does, however, list his own mistakes along with those of others.<>
{"title":"Zig-zag path to understanding [physical limits of information handling]","authors":"R. Landauer","doi":"10.1109/PHYCMP.1994.363699","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363699","url":null,"abstract":"Our understanding of the fundamental physical limits of information handling has developed along a very convoluted path. Most of the initially plausible physical conjectures have turned out to be wrong. A participant's personal view of these events as not a disciplined contribution to the history of science. The author does, however, list his own mistakes along with those of others.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"264 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123033617","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363693
M. Manthey
Presents a chain of reasoning that makes an information mechanics a plausible goal. A radically new model of distributed computation that exceeds Turing's sequential model refutes the perception that quantum mechanics cannot be captured computationally. Our new model, called the 'phase web paradigm', is itself captured naturally by a physically relevant mathematics, that of a Clifford algebra. The basic features of the computational model are shown to have natural counterparts in current physical theory, and we close with a discussion of the implications of the framework presented for the fabrication of nano-scale hardware.<>
{"title":"Toward an information mechanics","authors":"M. Manthey","doi":"10.1109/PHYCMP.1994.363693","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363693","url":null,"abstract":"Presents a chain of reasoning that makes an information mechanics a plausible goal. A radically new model of distributed computation that exceeds Turing's sequential model refutes the perception that quantum mechanics cannot be captured computationally. Our new model, called the 'phase web paradigm', is itself captured naturally by a physically relevant mathematics, that of a Clifford algebra. The basic features of the computational model are shown to have natural counterparts in current physical theory, and we close with a discussion of the implications of the framework presented for the fabrication of nano-scale hardware.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122183110","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363705
C. Lent, P. Tougaw, W. Porod
We discuss the fundamental limits of computing using a new paradigm for quantum computation, cellular automata composed of arrays of coulombically coupled quantum dot molecules, which we term quantum cellular automata (QCA). Any logical or arithmetic operation can be performed in this scheme. QCA's provide a valuable concrete example of quantum computation in which a number of fundamental issues come to light. We examine the physics of the computing process in this paradigm. We show to what extent thermodynamic considerations impose limits on the ultimate size of individual QCA arrays. Adiabatic operation of the QCA is examined and the implications for dissipationless computing are explored.<>
{"title":"Quantum cellular automata: the physics of computing with arrays of quantum dot molecules","authors":"C. Lent, P. Tougaw, W. Porod","doi":"10.1109/PHYCMP.1994.363705","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363705","url":null,"abstract":"We discuss the fundamental limits of computing using a new paradigm for quantum computation, cellular automata composed of arrays of coulombically coupled quantum dot molecules, which we term quantum cellular automata (QCA). Any logical or arithmetic operation can be performed in this scheme. QCA's provide a valuable concrete example of quantum computation in which a number of fundamental issues come to light. We examine the physics of the computing process in this paradigm. We show to what extent thermodynamic considerations impose limits on the ultimate size of individual QCA arrays. Adiabatic operation of the QCA is examined and the implications for dissipationless computing are explored.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116507476","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363679
P. Gács
In the context of the dynamical systems of classical mechanics, we introduce two new notions called "algorithmic fine-grain and coarse-grain entropy". The fine-grain algorithmic entropy is, on the one hand, a simple variant of the Martin-Lof (and other) randomness tests, and, on the other hand, a connecting link between description (Kolmogorov) complexity, Gibbs entropy and Boltzmann entropy. The coarse-grain entropy is a slight correction to Boltzmann's coarse-grain entropy. Its main advantage is its less partition dependence, due to the fact that algorithmic entropies for different coarse-grainings are approximations of one and the same fine-grain entropy. It has the desirable properties of Boltzmann entropy in a somewhat wider range of systems, including those of interest in the "thermodynamics of computation".<>
{"title":"The Boltzmann entropy and randomness tests","authors":"P. Gács","doi":"10.1109/PHYCMP.1994.363679","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363679","url":null,"abstract":"In the context of the dynamical systems of classical mechanics, we introduce two new notions called \"algorithmic fine-grain and coarse-grain entropy\". The fine-grain algorithmic entropy is, on the one hand, a simple variant of the Martin-Lof (and other) randomness tests, and, on the other hand, a connecting link between description (Kolmogorov) complexity, Gibbs entropy and Boltzmann entropy. The coarse-grain entropy is a slight correction to Boltzmann's coarse-grain entropy. Its main advantage is its less partition dependence, due to the fact that algorithmic entropies for different coarse-grainings are approximations of one and the same fine-grain entropy. It has the desirable properties of Boltzmann entropy in a somewhat wider range of systems, including those of interest in the \"thermodynamics of computation\".<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130759779","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363681
Tad Hogg, Xerox
The statistical mechanics of combinatorial search problems is described using the example of the well-known NP-complete graph coloring problem. A simple parameter describing the problem structure predicts the difficulty of solving the problem, on average. However, because of the large variance associated with this prediction, it is of limited direct use for individual instances. Additional parameters, describing the problem structure as well as the heuristic effectiveness, are introduced to address this issue. This also highlights the distinction between the statistical mechanics of combinatorial search problems, with their exponentially large search spaces, and physical systems, whose interactions are often governed by a simple Euclidean metric.<>
{"title":"Statistical mechanics of combinatorial search","authors":"Tad Hogg, Xerox","doi":"10.1109/PHYCMP.1994.363681","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363681","url":null,"abstract":"The statistical mechanics of combinatorial search problems is described using the example of the well-known NP-complete graph coloring problem. A simple parameter describing the problem structure predicts the difficulty of solving the problem, on average. However, because of the large variance associated with this prediction, it is of limited direct use for individual instances. Additional parameters, describing the problem structure as well as the heuristic effectiveness, are introduced to address this issue. This also highlights the distinction between the statistical mechanics of combinatorial search problems, with their exponentially large search spaces, and physical systems, whose interactions are often governed by a simple Euclidean metric.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116138446","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363689
A. Tyagi
The CCD based implementations of reversible logic consume a constant amount of energy per switching event which depends only on the charge packet size and not on the interconnect length. Within this model of computation, it seems possible to leverage data, encoding to reduce the number of switching events for the computation, resulting in lower overall computation energy. We explore the applicability of encoding for different datapath functions. We also develop a lower bound on switching count in a model similar to the traditional VLSI model of computation. A notion of reversible communication complexity is also developed.<>
{"title":"Encoded arithmetic for reversible logic","authors":"A. Tyagi","doi":"10.1109/PHYCMP.1994.363689","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363689","url":null,"abstract":"The CCD based implementations of reversible logic consume a constant amount of energy per switching event which depends only on the charge packet size and not on the interconnect length. Within this model of computation, it seems possible to leverage data, encoding to reduce the number of switching events for the computation, resulting in lower overall computation energy. We explore the applicability of encoding for different datapath functions. We also develop a lower bound on switching count in a model similar to the traditional VLSI model of computation. A notion of reversible communication complexity is also developed.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116143152","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363682
V. Pratt
Chu spaces are a model of concurrent computation extending automata theory to express branching time and true concurrency. They exhibit in a primitive form the quantum mechanical phenomena of complementarity and uncertainty. The complementarity arises as the duality of information and time, automata and schedules, and states and events. Uncertainty arises when we define a measurement to be a morphism and notice that increasing structure in the observed object reduces clarity of observation. For a Chu space this uncertainty can be calculated numerically in an attractively simple way directly from its form factor to yield the usual Heisenberg uncertainty relation. Chu spaces correspond to wavefunctions as vectors of Hilbert space, whose inner product operation is realized for Chu spaces as right residuation and whose quantum logic becomes Girard's linear logic.<>
{"title":"Chu spaces: automata with quantum aspects","authors":"V. Pratt","doi":"10.1109/PHYCMP.1994.363682","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363682","url":null,"abstract":"Chu spaces are a model of concurrent computation extending automata theory to express branching time and true concurrency. They exhibit in a primitive form the quantum mechanical phenomena of complementarity and uncertainty. The complementarity arises as the duality of information and time, automata and schedules, and states and events. Uncertainty arises when we define a measurement to be a morphism and notice that increasing structure in the observed object reduces clarity of observation. For a Chu space this uncertainty can be calculated numerically in an attractively simple way directly from its form factor to yield the usual Heisenberg uncertainty relation. Chu spaces correspond to wavefunctions as vectors of Hilbert space, whose inner product operation is realized for Chu spaces as right residuation and whose quantum logic becomes Girard's linear logic.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124869039","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363686
J. Tomé
In this work it is proved that necessary and sufficient conditions for binary regular, non-bounded, one dimensional cellular automata do exist. These conditions are derived from the definition of sufficiency for non reversibility and using a well known property of Boolean algebra. These conditions are dependent on the relative neighbourhood of the considered automaton and a graph search algorithm is derived for the establishment of these conditions and the associated listing of solutions. It is shown, however, that this general solution has an exponential complexity nature, depending on the number of cell neighbours. A simple example is also presented.<>
{"title":"Necessary and sufficient conditions for reversibility in one dimensional cellular automata","authors":"J. Tomé","doi":"10.1109/PHYCMP.1994.363686","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363686","url":null,"abstract":"In this work it is proved that necessary and sufficient conditions for binary regular, non-bounded, one dimensional cellular automata do exist. These conditions are derived from the definition of sufficiency for non reversibility and using a well known property of Boolean algebra. These conditions are dependent on the relative neighbourhood of the considered automaton and a graph search algorithm is derived for the establishment of these conditions and the associated listing of solutions. It is shown, however, that this general solution has an exponential complexity nature, depending on the number of cell neighbours. A simple example is also presented.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129431004","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 : 1994-11-17DOI: 10.1109/PHYCMP.1994.363680
C. Williams, T. Hogg
Abstraction is a method for solving a variety of computational search problems that uses coarse-graining to simplify the search. When a coarse-grained, or abstract, solution is found, it is then refined to give a complete solution. We present a model of this abstraction process for constraint satisfaction problems, a well-known class of NP-complete search problems. This model is then used to identify phase transition-like behavior in the effectiveness of abstraction, as well as to determine the type of abstraction that is likely to be most useful for relatively hard instances of these search problems.<>
{"title":"Phase transitions and coarse-grained search","authors":"C. Williams, T. Hogg","doi":"10.1109/PHYCMP.1994.363680","DOIUrl":"https://doi.org/10.1109/PHYCMP.1994.363680","url":null,"abstract":"Abstraction is a method for solving a variety of computational search problems that uses coarse-graining to simplify the search. When a coarse-grained, or abstract, solution is found, it is then refined to give a complete solution. We present a model of this abstraction process for constraint satisfaction problems, a well-known class of NP-complete search problems. This model is then used to identify phase transition-like behavior in the effectiveness of abstraction, as well as to determine the type of abstraction that is likely to be most useful for relatively hard instances of these search problems.<<ETX>>","PeriodicalId":378733,"journal":{"name":"Proceedings Workshop on Physics and Computation. PhysComp '94","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128581671","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：