It is well known that the exponential function plays an extremely important role in many areas of science. In this study, a generator function-based mapping, called the generalized epsilon function is presented. Next, we demonstrate that the exponential function is an asymptotic generalized epsilon function. Exploiting this result and the fact that this new function is generator function-dependent, it can be utilized as a very flexible alternative to the exponential function in a wide range of applications. We should add that if the generator is a rational function, then the generalized epsilon function is rational as well. In this case, the generalized epsilon function is computationally simple and it may be treated as an easy-to-compute alternative to the exponential function. In this paper, we briefly present two applications of this novel function: an approximation to the exponential probability distribution, and an alternative to the sigmoid function on a bounded domain.
{"title":"The Generalized Epsilon Function","authors":"T. Jónás","doi":"10.14232/actacyb.294699","DOIUrl":"https://doi.org/10.14232/actacyb.294699","url":null,"abstract":"It is well known that the exponential function plays an extremely important role in many areas of science. In this study, a generator function-based mapping, called the generalized epsilon function is presented. Next, we demonstrate that the exponential function is an asymptotic generalized epsilon function. Exploiting this result and the fact that this new function is generator function-dependent, it can be utilized as a very flexible alternative to the exponential function in a wide range of applications. We should add that if the generator is a rational function, then the generalized epsilon function is rational as well. In this case, the generalized epsilon function is computationally simple and it may be treated as an easy-to-compute alternative to the exponential function. In this paper, we briefly present two applications of this novel function: an approximation to the exponential probability distribution, and an alternative to the sigmoid function on a bounded domain.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49491608","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}
Missing data is a large-scale challenge to research and investigate. It reduces the statistical power and produces negative consequences that may introduce selection bias on the data. Many approaches to handle this problem have been introduced. The main approaches suggested are either missing values to be ignored (removed) or imputed (filled in) with new values. This paper uses the second method. Possible worlds and possible and certain keyswere introduced in Köhler et.al., and by Levene et.al. Köhler and Link introduced certain functional dependencies (c-FD) as a natural complement to Lien's class of possible functional dependencies (p-FD). Weak and strong functional dependencies were studied by Levene and Loizou. We introduced the intermediate concept of strongly possible worlds that are obtained by imputing values already existing in the table in a preceding paper. This results in strongly possible keys (spKey's) and strongly possible functional dependencies (spFD's). We give a polynomial algorithm to verify a single spKey and show that in general, it is NP-complete to verify an arbitrary collection of spKeys. We give a graph-theoretical characterization of the validity of a given spFD X →sp Y.We show, that the complexity to verify a single strongly possible functional dependency is NP-complete in general, then we introduce some cases when verifying a single spFD can be done in polynomial time.As a step forward axiomatization of spFD's, the rules given for weak and strong functional dependencies are checked. Appropriate weakenings of those that are not sound for spFD's are listed. The interaction between spFD's and spKey's and certain keys is studied. Furthermore, a graph theoretical characterization of implication between singular attribute spFD's is given.
{"title":"Strongly Possible Functional Dependencies for SQL","authors":"Munqath Al-Atar, A. Sali","doi":"10.14232/actacyb.287523","DOIUrl":"https://doi.org/10.14232/actacyb.287523","url":null,"abstract":"Missing data is a large-scale challenge to research and investigate. It reduces the statistical power and produces negative consequences that may introduce selection bias on the data. Many approaches to handle this problem have been introduced. The main approaches suggested are either missing values to be ignored (removed) or imputed (filled in) with new values. This paper uses the second method. Possible worlds and possible and certain keyswere introduced in Köhler et.al., and by Levene et.al. Köhler and Link introduced certain functional dependencies (c-FD) as a natural complement to Lien's class of possible functional dependencies (p-FD). Weak and strong functional dependencies were studied by Levene and Loizou. We introduced the intermediate concept of strongly possible worlds that are obtained by imputing values already existing in the table in a preceding paper. This results in strongly possible keys (spKey's) and strongly possible functional dependencies (spFD's). We give a polynomial algorithm to verify a single spKey and show that in general, it is NP-complete to verify an arbitrary collection of spKeys. We give a graph-theoretical characterization of the validity of a given spFD X →sp Y.We show, that the complexity to verify a single strongly possible functional dependency is NP-complete in general, then we introduce some cases when verifying a single spFD can be done in polynomial time.As a step forward axiomatization of spFD's, the rules given for weak and strong functional dependencies are checked. Appropriate weakenings of those that are not sound for spFD's are listed. The interaction between spFD's and spKey's and certain keys is studied. Furthermore, a graph theoretical characterization of implication between singular attribute spFD's is given.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44723017","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 dynamic system models in population dynamics, physics and control involve temporally delayed state information in such a way that the evolution of future state trajectories depends not only on the current state as the initial condition but also on some previous state. In technical systems, such phenomena result, for example, from mass transport of incompressible fluids through finitely long pipelines, the transport of combustible material such as coal in power plants via conveyor belts, or information processing delays. Under the assumption of continuous dynamics, the corresponding delays can be treated either as constant and fixed, as uncertain but bounded and fixed, or even as state-dependent. In this paper, we restrict the discussion to the first two classes and provide suggestions on how interval-based verified approaches to solving ordinary differential equations can be extended to encompass such delay differential equations. Three close-to-life examples illustrate the theory.
{"title":"Verified Integration of Differential Equations with Discrete Delay","authors":"A. Rauh, E. Auer","doi":"10.14232/actacyb.290904","DOIUrl":"https://doi.org/10.14232/actacyb.290904","url":null,"abstract":"Many dynamic system models in population dynamics, physics and control involve temporally delayed state information in such a way that the evolution of future state trajectories depends not only on the current state as the initial condition but also on some previous state. In technical systems, such phenomena result, for example, from mass transport of incompressible fluids through finitely long pipelines, the transport of combustible material such as coal in power plants via conveyor belts, or information processing delays. Under the assumption of continuous dynamics, the corresponding delays can be treated either as constant and fixed, as uncertain but bounded and fixed, or even as state-dependent. In this paper, we restrict the discussion to the first two classes and provide suggestions on how interval-based verified approaches to solving ordinary differential equations can be extended to encompass such delay differential equations. Three close-to-life examples illustrate the theory.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46289458","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}
This paper is devoted to a new flexible two-parameter lower-truncated distribution, which is based on the inversion of the so-called epsilon distribution. It is called the inverse epsilon distribution. In some senses, it can be viewed as an alternative to the inverse exponential distribution, which has many applications in reliability theory and biology. Diverse properties of the new lower-truncated distribution are derived including relations with existing distributions, hazard and reliability functions, survival and reverse hazard rate functions, stochastic ordering, quantile function with related skewness and kurtosis measures, and moments. A demonstrative survival times data example is used to show the applicability of the new model.
{"title":"The Inverse Epsilon Distribution as an Alternative to Inverse Exponential Distribution with a Survival Times Data Example","authors":"T. Jónás, C. Chesneau, J. Dombi, H. Bakouch","doi":"10.14232/actacyb.292077","DOIUrl":"https://doi.org/10.14232/actacyb.292077","url":null,"abstract":"This paper is devoted to a new flexible two-parameter lower-truncated distribution, which is based on the inversion of the so-called epsilon distribution. It is called the inverse epsilon distribution. In some senses, it can be viewed as an alternative to the inverse exponential distribution, which has many applications in reliability theory and biology. Diverse properties of the new lower-truncated distribution are derived including relations with existing distributions, hazard and reliability functions, survival and reverse hazard rate functions, stochastic ordering, quantile function with related skewness and kurtosis measures, and moments. A demonstrative survival times data example is used to show the applicability of the new model.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43138796","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}
In this paper we investigate realizability of discrete time linear dynamical systems (LDSs) in fixed state space dimension. We examine whether there exist different Θ = (A,B,C,D) state space realizations of a given Markov parameter sequence Y with fixed B, C and D state space realization matrices. Full observation is assumed in terms of the invertibility of output mapping matrix C. We prove that the set of feasible state transition matrices associated to a Markov parameter sequence Y is convex, provided that the state space realization matrices B, C and D are known and fixed. Under the same conditions we also show that the set of feasible Metzler-type state transition matrices forms a convex subset. Regarding the set of Metzler-type state transition matrices we prove the existence of a structurally unique realization having maximal number of non-zero off-diagonal entries. Using an eigenvalue assignment procedure we propose linear programming based algorithms capable of computing different state space realizations. By using the convexity of the feasible set of Metzler-type state transition matrices and results from the theory of non-negative polynomial systems, we provide algorithms to determine structurally different realization. Computational examples are provided to illustrate structural non-uniqueness of network-based LDSs.
{"title":"Computing Different Realizations of Linear Dynamical Systems with Embedding Eigenvalue Assignment","authors":"Gergely Szlobodnyik, G. Szederkényi","doi":"10.14232/actacyb.291870","DOIUrl":"https://doi.org/10.14232/actacyb.291870","url":null,"abstract":"In this paper we investigate realizability of discrete time linear dynamical systems (LDSs) in fixed state space dimension. We examine whether there exist different Θ = (A,B,C,D) state space realizations of a given Markov parameter sequence Y with fixed B, C and D state space realization matrices. Full observation is assumed in terms of the invertibility of output mapping matrix C. We prove that the set of feasible state transition matrices associated to a Markov parameter sequence Y is convex, provided that the state space realization matrices B, C and D are known and fixed. Under the same conditions we also show that the set of feasible Metzler-type state transition matrices forms a convex subset. Regarding the set of Metzler-type state transition matrices we prove the existence of a structurally unique realization having maximal number of non-zero off-diagonal entries. Using an eigenvalue assignment procedure we propose linear programming based algorithms capable of computing different state space realizations. By using the convexity of the feasible set of Metzler-type state transition matrices and results from the theory of non-negative polynomial systems, we provide algorithms to determine structurally different realization. Computational examples are provided to illustrate structural non-uniqueness of network-based LDSs.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48928398","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 : 2014-01-01DOI: 10.14232/ACTACYB.21.3.2014.1
Ákos Kiss
{"title":"Symposium on Programming Languages and Software Tools - Preface","authors":"Ákos Kiss","doi":"10.14232/ACTACYB.21.3.2014.1","DOIUrl":"https://doi.org/10.14232/ACTACYB.21.3.2014.1","url":null,"abstract":"","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816523","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 : 2013-09-03DOI: 10.14232/actacyb.23.1.2017.15
A. Maletti
The expressive power of synchronous forest (tree-sequence) substitution grammars (SFSG) is studied in relation to multi bottom-up tree transducers (MBOT). It is proved that SFSG have exactly the same expressive power as compositions of an inverse MBOT with an MBOT. This result is used to derive complexity results for SFSG and the fact that compositions of an MBOT with an inverse MBOT can compute tree translations that cannot be computed by any SFSG, although the class of tree translations computable by MBOT is closed under composition.
{"title":"Synchronous Forest Substitution Grammars","authors":"A. Maletti","doi":"10.14232/actacyb.23.1.2017.15","DOIUrl":"https://doi.org/10.14232/actacyb.23.1.2017.15","url":null,"abstract":"The expressive power of synchronous forest (tree-sequence) substitution grammars (SFSG) is studied in relation to multi bottom-up tree transducers (MBOT). It is proved that SFSG have exactly the same expressive power as compositions of an inverse MBOT with an MBOT. This result is used to derive complexity results for SFSG and the fact that compositions of an MBOT with an inverse MBOT can compute tree translations that cannot be computed by any SFSG, although the class of tree translations computable by MBOT is closed under composition.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2013-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78596985","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 : 2013-01-01DOI: 10.14232/ACTACYB.21.1.2013.10
Péter Hegedűs
Both for software developers and managers it is crucial to have clues about different aspects of the quality of their systems. Maintainability is probably the most attractive, observed and evaluated quality characteristic of all. The importance of maintainability lies in its very obvious and direct connection with the costs of altering the behavior of the software. In this paper we present an existing approach and its adaptation to the C# language for estimating the maintainability of the source code. We used our model to assess the maintainability of the C# components of a large international company. We analyzed almost a million lines of code and evaluated the results with the help of IT professionals of our industrial partner. The application of our method and model was successful as the opinions of the developers showed a 0.92 correlation with the maintainability values produced by our C# maintainability model.
{"title":"A Probabilistic Quality Model for C# - an Industrial Case Study","authors":"Péter Hegedűs","doi":"10.14232/ACTACYB.21.1.2013.10","DOIUrl":"https://doi.org/10.14232/ACTACYB.21.1.2013.10","url":null,"abstract":"Both for software developers and managers it is crucial to have clues about different aspects of the quality of their systems. Maintainability is probably the most attractive, observed and evaluated quality characteristic of all. The importance of maintainability lies in its very obvious and direct connection with the costs of altering the behavior of the software. In this paper we present an existing approach and its adaptation to the C# language for estimating the maintainability of the source code. We used our model to assess the maintainability of the C# components of a large international company. We analyzed almost a million lines of code and evaluated the results with the help of IT professionals of our industrial partner. The application of our method and model was successful as the opinions of the developers showed a 0.92 correlation with the maintainability values produced by our C# maintainability model.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816474","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 : 2012-08-01DOI: 10.14232/ACTACYB.20.3.2012.4
T. Nagy
We present a web mining system that clusters persons sharing the same name and also extracts bibliographical information about them. The input of our system is the result of web search engine queries in English or in Hungarian. For system evaluation in English, our system (RGAI) participated in the third Web People Search Task challenge [1]. The chief characteristics of our approach compared to the others are that we focus on the raw textual parts of the web pages instead of the structured parts, we group similar attribute classes together and we explicitly handle their interdependencies. The RGAI system achieved top results on the person attribute extraction subtask, and average results on the person clustering subtask. Following the shared task annotation principles, we also manually constructed a Hungarian person disambiguation corpus and adapted our system from English to Hungarian. We present experimental results on this as well.
{"title":"Person attribute extraction from the textual parts of web pages","authors":"T. Nagy","doi":"10.14232/ACTACYB.20.3.2012.4","DOIUrl":"https://doi.org/10.14232/ACTACYB.20.3.2012.4","url":null,"abstract":"We present a web mining system that clusters persons sharing the same name and also extracts bibliographical information about them. The input of our system is the result of web search engine queries in English or in Hungarian. For system evaluation in English, our system (RGAI) participated in the third Web People Search Task challenge [1]. The chief characteristics of our approach compared to the others are that we focus on the raw textual parts of the web pages instead of the structured parts, we group similar attribute classes together and we explicitly handle their interdependencies. The RGAI system achieved top results on the person attribute extraction subtask, and average results on the person clustering subtask. Following the shared task annotation principles, we also manually constructed a Hungarian person disambiguation corpus and adapted our system from English to Hungarian. We present experimental results on this as well.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2012-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816431","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 : 2011-01-01DOI: 10.14232/ACTACYB.20.1.2011.11
Rudolf Szendrei, Istvan Elek, Mátyás Márton
Paper-based raster maps are primarily for human consumption, and their interpretation always requires some level of human expertese. Todays computer services in geoinformatics usually require vectorized topographic maps. The usual method of the conversion has been an error-prone, manual process. In this article, the possibilities, methods and difficulties of the conversion are discussed. The results described here are partially implemented in the IRIS project, but further work remains. This emphasizes the tools of digital image processing and knowledge-based approach. The system in development separates the recognition of point-like, line-like and surface-like objects, and the most successful approach appears to be the recognition of these objects in a reversed order with respect to their printing. During the recongition of surfaces, homogeneous and textured surfaces must be distinguished. The most diverse and complicated group constitute the line-like objects. The IRIS project realises a moderate, but significant step towards the automatization of map recognition process, bearing in mind that full automatization is unlikely. It is reasonable to assume that human experts will always be required for high quality interpretation, but it is an exciting challenge to decrease the burden of manual work.
{"title":"A knowledge-based approach to raster-vector conversion of large scale topographic maps","authors":"Rudolf Szendrei, Istvan Elek, Mátyás Márton","doi":"10.14232/ACTACYB.20.1.2011.11","DOIUrl":"https://doi.org/10.14232/ACTACYB.20.1.2011.11","url":null,"abstract":"Paper-based raster maps are primarily for human consumption, and their interpretation always requires some level of human expertese. Todays computer services in geoinformatics usually require vectorized topographic maps. The usual method of the conversion has been an error-prone, manual process. In this article, the possibilities, methods and difficulties of the conversion are discussed. The results described here are partially implemented in the IRIS project, but further work remains. This emphasizes the tools of digital image processing and knowledge-based approach. The system in development separates the recognition of point-like, line-like and surface-like objects, and the most successful approach appears to be the recognition of these objects in a reversed order with respect to their printing. During the recongition of surfaces, homogeneous and textured surfaces must be distinguished. The most diverse and complicated group constitute the line-like objects. The IRIS project realises a moderate, but significant step towards the automatization of map recognition process, bearing in mind that full automatization is unlikely. It is reasonable to assume that human experts will always be required for high quality interpretation, but it is an exciting challenge to decrease the burden of manual work.","PeriodicalId":42512,"journal":{"name":"Acta Cybernetica","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66816416","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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