Knowledge Bases Over Algebraic Models

2012 ◽  
Vol 8 (1) ◽  
pp. 22-39 ◽  
Author(s):  
Marina Knyazhansky ◽  
Tatjana Plotkin
Keyword(s):  
Equivalence Problem ◽  
Knowledge Bases ◽  
Formal Definition ◽  
Mathematical Approach ◽  
Algebraic Models ◽  
Mathematical Methods ◽  
Practical Applications ◽  
Definition Of ◽  
Automorphic Equivalence ◽  
Further Development

This paper discusses the informational equivalence problem for knowledge bases. The authors show that using some mathematical approach it is possible to attack this problem and end up with an implementable algorithm. An essential part of the paper is devoted to the explanation of the mathematical idea which stands behind this algorithm. The authors try to do that in common terms or, at least, in less formal terms. In the second part of the paper mathematical methods are applied to study the properties of automorphic equivalence of knowledge bases (multi-models) and show that this notion is much wider than the total isomorphism (identity) of knowledge bases. In order to make the paper self-contained, the reader is provided with the formal definition of a knowledge base. Further development of the theoretical approach presented in the paper can lead to practical applications. For example, it can be used for preventing duplication of information in knowledge bases and in other tasks of improving knowledge management.

scholarly journals Antecedents and dimensions of supply chain robustness: a systematic literature review

2015 ◽  
Vol 45 (1/2) ◽  
pp. 118-137 ◽  
Author(s):  
Christian F. Durach ◽  
Andreas Wieland ◽  
Jose A.D. Machuca
Keyword(s):  
Supply Chain ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Theoretical Framework ◽  
Formal Definition ◽  
Content Type ◽  
Practical Applications ◽  
Definition Of ◽  
Descriptive Knowledge ◽  
Supply Chain Robustness

Purpose – The purpose of this paper is to provide groundwork for an emerging theory of supply chain robustness – which has been conceptualized as a dimension of supply chain resilience – through reviewing and synthesizing related yet disconnected studies. The paper develops a formal definition of supply chain robustness to build a framework that captures the dimensions, antecedents and moderators of the construct as discussed in the literature. Design/methodology/approach – The authors apply a systematic literature review approach. In order to reduce researcher bias, they involve a team of academics, librarians and managers. Findings – The paper first, provides a formal definition of supply chain robustness; second, builds a theoretical framework of supply chain robustness that augments both causal and descriptive knowledge; third,shows how findings in this review support practice; and fourth,reveals methodological insights on the use of journal rankings in reviews. Research limitations/implications – At this stage, managers may benefit from seeing these relationships as clues derived from the literature. The paper is fundamentally a call for researchers to conduct quantitative testing of such relationships to derive more reliable understanding and practical applications. Practical implications – Rather than presenting empirical findings, this paper reveals to managers that visibility, risk management orientation and reduced network complexity have been the main predictive antecedents of supply chain robustness (as discussed in the academic literature). This provides a potentially important signal as to where to invest resources. Originality/value – The study is the first to develop a formal definition of supply chain robustness and to establish a comprehensive theoretical framework for understanding the construct.

scholarly journals A Petri Net Definition of a System Description Language

1981 ◽  
Vol 8 (96) ◽  
Author(s):  
Kurt Jensen ◽  
Morten Kyng ◽  
Ole Lehrmann Madsen
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Formal Model ◽  
Concurrent Systems ◽  
Formal Definition ◽  
Concurrent System ◽  
Description Language ◽  
System Description ◽  
Definition Of ◽  
Further Development

<p>This paper introduces a language, Epsilon, for the description of systems with concurrency, and presents a formal definition of Epsilon's semantics. The language is based on Delta ‹ the first major attempt to create a language solely aimed at system description without the restrictions placed on languages executable on digital computers. The design of Delta was itself heavily influenced by the experience from the development and use of Simula.</p><p>It is not obvious what kind of semantics a system description language should have. The situation is more complex than with normal algorithmic languages and none of the existing semantic approaches appear to be satisfactory.</p><p>To clarify the situation, we first describe the language Epsilon, which contains only a few basic primitives. Then we define the semantics of Epsilon by means of a formal model based on Petri nets. The model called ''Concurrent systems'' is an extension of Petri nets with a data part and with expressions attached to transitions and to places. The model is a further development of formalisms proposed by R.M. Keller and A. Mazurkiewicz. The expressions attached to places is a novel feature and is used to define continuous transformations on the data part. The semantics of a given system description is defined in terms of firing sequences of the corresponding concurrent system.</p><p>To be presented at the Evian Conference on Semantics of Concurrent Computations, July 1979.</p>

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

Towards the digital land reclamation

2020 ◽  
pp. 5-9
Author(s):  
Sergey Vasil'ev ◽  
Vyacheslav Schedrin ◽  
Aleksandra Slabunova ◽  
Vladimir Slabunov
Keyword(s):  
Retrospective Analysis ◽  
Land Reclamation ◽  
Practical Experience ◽  
Maximum Effect ◽  
Optimal Management ◽  
Scientific Potential ◽  
History Of ◽  
Definition Of ◽  
Further Development ◽  
Full Cooperation

The aim of the research is a retrospective analysis of the history and stages of development of digital land reclamation in Russia, the definition of «Digital land reclamation» and trends in its further development. In the framework of the retrospective analysis the main stages of melioration formation are determined. To achieve the maximum effect of the «digital reclamation» requires full cooperation of practical experience and scientific potential accumulated throughout the history of the reclamation complex, and the latest achievements of science and technology, which is currently possible only through the full digitalization of reclamation activities. The introduction of «digital reclamation» will achieve greater potential and effect in the modernization of the reclamation industry in the «hightech industry», through the use of innovative developments and optimal management decisions.

The methodology of experimental research of the feed components extrusion process in order to improve its energy performance

2020 ◽  
pp. 147-152
Author(s):  
E. M. Ratnikov ◽  
D. O. Milko
Keyword(s):  
Experimental Studies ◽  
Energy Performance ◽  
Extrusion Process ◽  
Mathematical Methods ◽  
Screw Extruder ◽  
Mathematical Planning ◽  
Factors Affecting ◽  
Extrusion Processing ◽  
Definition Of

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.

scholarly journals Students’ Understanding on Formal Definition of Limit

2021 ◽  
Vol 1752 (1) ◽  
pp. 012082
Author(s):  
Nurdin ◽  
S F Assagaf ◽  
F Arwadi
Keyword(s):  
Formal Definition ◽  
Definition Of

Diagnosis Rule Discovery Based on Causality in the Context of Fault Diagnosis in Rotating Machinery

2014 ◽  
Vol 532 ◽  
pp. 113-117
Author(s):  
Zhou Jin ◽  
Ru Jing Wang ◽  
Jie Zhang
Keyword(s):  
Fault Diagnosis ◽  
General Framework ◽  
Complex Structure ◽  
Rotating Machinery ◽  
Massive Data ◽  
Formal Definition ◽  
Rule Discovery ◽  
Rule Based ◽  
Simple Implementation ◽  
Definition Of

The rotating machineries in a factory usually have the characteristics of complex structure and highly automated logic, which generated a large amounts of monitoring data. It is an infeasible task for uses to deal with the massive data and locate fault timely. In this paper, we explore the causality between symptom and fault in the context of fault diagnosis in rotating machinery. We introduce data mining into fault diagnosis and provide a formal definition of causal diagnosis rule based on statistic test. A general framework for diagnosis rule discovery based on causality is provided and a simple implementation is explored with the purpose of providing some enlightenment to the application of causality discovery in fault diagnosis of rotating machinery.

A North American Perspective on Service Life and Durability of Concrete Bridges

2018 ◽  
Author(s):  
Neil A. Cumming
Keyword(s):  
Service Life ◽  
Numerical Modelling ◽  
North American ◽  
Concrete Bridges ◽  
Formal Service ◽  
Historical Materials ◽  
American Perspective ◽  
Definition Of ◽  
Further Development ◽  
Empirical Methodology

This paper describes the author’s views on durability and service life of concrete bridges in North America, considering the past, present and future. Historical materials and practices have resulted in disappointing durability and service life that does not meet modern expectations. In recent years formal service life analysis and prediction has been implemented as part of the design process for major projects, typically involving numerical modelling of time to corrosion, and mitigation or avoidance of other forms of deterioration by empirical methodology. These efforts are, however, hampered by a lack of an accepted service life design standard which is adapted to North American practice and materials. Work is under way to answer this need. In the future, further development is needed to provide a better match between expectations and reality, a more practical definition of “service life”, validation of design features implemented to mitigate or avoid deterioration for which there are no available time-based models, and improved validation of numerical modelling parameters that describe exposure conditions and material resistances.

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