Notion Of Consistency Research Articles

Sufficient conditions for hyperbolicity and consistency of the dynamic equations for fluid-saturated solids

Previous studies showed that the dynamic equations for a porous fluid-saturated solid may lose hyperbolicity and thus render the boundary-value problem ill-posed while the equations for the same but dry solid remain hyperbolic. This paper presents sufficient conditions for hyperbolicity in both dry and saturated states. Fluid-saturated solids are described by two different systems of equations depending on whether the permeability is zero or nonzero (locally undrained and drained conditions, respectively). The paper also introduces a notion of wave speed consistency between the two systems as a necessary condition which must be satisfied in order for the solution in the locally drained case to tend to the undrained solution as the permeability tends to zero. It is shown that the symmetry and positive definiteness of the acoustic tensor of the skeleton guarantee both hyperbolicity and the wave speed consistency of the equations.

Maximum Likelihood Estimation and Graph Matching in Errorfully Observed Networks

Given a pair of graphs with the same number of vertices, the inexact graph matching problem consists in finding a correspondence between the vertices of these graphs that minimizes the total number of induced edge disagreements. We study this problem from a statistical framework in which one of the graphs is an errorfully observed copy of the other. We introduce a corrupting channel model, and show that in this model framework, the solution to the graph matching problem is a maximum likelihood estimator (MLE). Necessary and sufficient conditions for consistency of this MLE are presented, as well as a relaxed notion of consistency in which a negligible fraction of the vertices need not be matched correctly. The results are used to study matchability in several families of random graphs, including edge independent models, random regular graphs, and small-world networks. We also use these results to introduce measures of matching feasibility, and experimentally validate the results on simulated and real-world networks. Supplemental files for this article are available online.

(2007-6020) A consistency-driven approach to construction of Z-number-valued pairwise comparison matrices

The notion of consistency is used to estimate the quality of preference knowledge and its stability for reliable evaluation of decision alternatives. It is well-known that a set of strict consistency conditions are used to keep the rationality of preference intensities between compared elements. These requirements are not achievable in the real situations when decision maker has limited rationality and partially reliable preferences. In this study, we propose an approach to deriving consistency-driven preference degrees for such kind of situations. A preference degree is described by a Z-number to reflect imprecision and partial reliability of preference knowledge. An optimization problem with Z-number valued variables is used to formulate design of consistent preferences. A real-world decision making problem is considered to illustrate application of the proposed method and conduct comparison with an existing technique.

A structured literature review of scientometric research of the knowledge management discipline: a 2021 update

PurposeThe purpose of this study is to conduct a structured literature review of scientometric research of the knowledge management (KM) discipline for the 2012–2019 time period.Design/methodology/approachA total of 175 scientometric studies of the KM discipline were identified and analyzed.FindingsScientometric KM research has entered the maturity stage: its volume has been growing, reaching six publications per month in 2019. Scientometric KM research has become highly specialized, which explains many inconsistent findings, and the interests of scientometric KM researchers and their preferred inquiry methods have changed over time. There is a dangerous trend toward a monopoly of the scholarly publishing market which affects researchers’ behavior. To create a list of keywords for database searches, scientometric KM scholars should rely on the formal KM keyword classification schemes, and KM-centric peer-reviewed journals should continue welcoming manuscripts on scientometric topics.Practical implicationsStakeholders should realize that the KM discipline may successfully exist as a cluster of divergent schools of thought under an overarching KM umbrella and that the notion of intradisciplinary cohesion and consistency should be abandoned. Journal of Knowledge Management is unanimously recognized as a leading KM journal, but KM researchers should not limit their focus to the body of knowledge documented in the KM-centric publication forums. The top six most productive countries are the USA, the UK, Taiwan, Canada, Australia and China. There is a need for knowledge brokers that may deliver the KM academic body of knowledge to practitioners.Originality/valueThis is the most comprehensive, up-to-date analysis of the KM discipline.

May Member States’ courts act as catalysts of normalization of the European Union’s Common Foreign and Security Policy?

This article considers whether national courts may act as catalyst of normalization of Common Foreign and Security Policy, in cases on the merits of which prima facie the Court of Justice of the European Union (CJEU) does not have jurisdiction. First, regardless of the exact scope of the CJEU’s jurisdiction, this contribution surveys arguments in favour (the principle of conferral and of effective judicial protection, expression of the value of the rule of law) and against (the notion of autonomy and consistency of EU law) the jurisdiction of national courts. It concludes in favour of the former option. Second, it considers whether national courts may act as agents of ‘normalization’ of CFSP, where this word means the application of general rules of EU law to this policy even in the absence of express literal provision in the Treaty. It argues that national courts may act as catalyst for the normalization of this policy in so far as they can, through the preliminary ruling procedure, give an opportunity to the CJEU to rule on (at least some) CFSP acts.

The differential of probabilistic entailment

Suppose elements a1,…,ak of a boolean algebra A are assigned probabilities π1,…πk. Boole asked to determine the possible probabilities of some other element a∈A, given the assignment ai↦πi,(i=1,…,k). De Finetti's solution of Boole's problem yields a closed interval Ia⊆[0,1] such that the set of possible probabilities of a coincides with Ia. Ia is nonempty iff the assignment is consistent in de Finetti's sense. Now suppose the probability of ak undergoes a small perturbation πk↦πk+dπk. We study the resulting modification of Ia. For instance, we prove that the one-sided derivatives ∂length(Ia)/∂πk± always have a rational, (generally non-integer) value. In the particular case when each probability πi is rational and A is presented as a Lindenbaum algebra, all these derivatives are Turing computable. Their existence domain is decidable by the Tarski-Seidenberg algorithm for polynomial equations and inequalities in real closed fields. Our results build on de Finetti's consistency notion and his solution of Boole's problem, and extend Hailperin's polyhedral methods for combining bounds on probabilities.

Solving CSPs Using Weak Local Consistency

The characterization of all the constraint satisfaction problems solvable by local consistency checking (also known as CSPs of bounded width) was proposed by Feder and Vardi [SIAM J. Comput., 28 (1998), pp. 57--104]. It was confirmed by two independent proofs by Bulatov [Bounded Relational Width, manuscript, 2009] and Barto and Kozik [L. Barto and M. Kozik, 50th Annual IEEE Symposium on Foundations of Computer Science, 2009, pp. 595--603], [L. Barto and M. Kozik, J. ACM, 61 (2014), 3]. Later Barto [J. Logic Comput., 26 (2014), pp. 923--943] proved a collapse of the hierarchy of local consistency notions by showing that (2,3) minimality solves all the CSPs of bounded width. In this paper we present a new consistency notion, jpq consistency, which also solves all the CSPs of bounded width. Our notion is strictly weaker than (2,3) consistency, (2,3) minimality, path consistency, and singleton arc consistency (SAC). This last fact allows us to answer the question of Chen, Dalmau, and Grußien [J. Logic Comput., 23 (2013), pp. 87--108] by confirming that SAC solves all the CSPs of bounded width. Moreover, as known algorithms work faster for SAC, the result implies that CSPs of bounded width can be, in practice, solved more efficiently. The definition of jpq consistency is closely related to a consistency condition obtained from the rounding of an SDP relaxation of a CSP instance. In fact, the main result of this paper is used by Dalmau et al. [Proceedings of the 28th Annual ACM-SIAM Symposium on Discrete Algorithms, SIAM, Philadelphia, ACM, New York, 2017, pp. 340--357] to show that CSPs with near unanimity polymorphisms admit robust approximation algorithms with polynomial loss. Finally, an algebraic characterization of some term conditions satisfied in algebras associated with templates of bounded width, first proved by Brady, is a direct consequence of our result.

Lyapunov Spectrum Local Assignability of Linear Discrete Time-Varying Systems by Static Output Feedback

We consider a linear discrete time-varying input-output system. Our goal is to study the problem of local assignability of the Lyapunov spectrum by static output feedback control. To this end we introduce the notion of uniform consistency for discrete-time linear systems which is the extension of the notion of uniform complete controllability to input-output systems. The property of uniform consistency is investigated, some necessary and sufficient conditions for this property are obtained. The notion of uniform local attainability is introduced for the closed-loop system. We prove that uniform consistency implies uniform local attainability of the closed-loop system. The property of local Lyapunov reducibility is introduced for the closed-loop system. We prove that uniform local attainability implies local Lyapunov reducibility. We prove that, for a locally Lyapunov reducible system, the Lyapunov spectrum is locally assignable, if the free system is diagonalizable or regular (in the Lyapunov sence) or has the stable Lyapunov spectrum.

Consistency of finite volume approximations to nonlinear hyperbolic balance laws

This paper addresses the three concepts of consistency, stability and convergence in the context of compact finite volume schemes for systems of nonlinear hyperbolic conservation laws. The treatment utilizes the framework of “balance laws”. Such laws express the relevant physical conservation laws in the presence of discontinuities. Finite volume approximations employ this viewpoint, and the present paper can be regarded as being in this category. It is first shown that under very mild conditions a weak solution is indeed a solution to the balance law. The schemes considered here allow the computation of several quantities per mesh cell (e.g., slopes) and the notion of consistency must be extended to this framework. Then a suitable convergence theorem is established, generalizing the classical convergence theorem of Lax and Wendroff. Finally, the limit functions are shown to be entropy solutions by using a notion of “Godunov compatibility”, which serves as a substitute to the entropy condition.

Predictive Inference Based on Markov Chain Monte Carlo Output

SummaryIn Bayesian inference, predictive distributions are typically in the form of samples generated via Markov chain Monte Carlo or related algorithms. In this paper, we conduct a systematic analysis of how to make and evaluate probabilistic forecasts from such simulation output. Based on proper scoring rules, we develop a notion of consistency that allows to assess the adequacy of methods for estimating the stationary distribution underlying the simulation output. We then provide asymptotic results that account for the salient features of Bayesian posterior simulators and derive conditions under which choices from the literature satisfy our notion of consistency. Importantly, these conditions depend on the scoring rule being used, such that the choices of approximation method and scoring rule are intertwined. While the logarithmic rule requires fairly stringent conditions, the continuous ranked probability score yields consistent approximations under minimal assumptions. These results are illustrated in a simulation study and an economic data example. Overall, mixture‐of‐parameters approximations that exploit the parametric structure of Bayesian models perform particularly well. Under the continuous ranked probability score, the empirical distribution function is a simple and appealing alternative option.

Enabling consistency in view-based system development — The Vitruvius approach

During the development of large software-intensive systems, developers use several modeling languages and tools to describe a system from different viewpoints. Model-driven and view-based technologies have made it easier to define domain-specific languages and transformations.Nevertheless, using several languages leads to fragmentation of information, to redundancies in the system description, and eventually to inconsistencies. Inconsistencies have negative impacts on the system’s quality and are costly to fix. Often, there is no support for consistency management across multiple languages. Using a single language is no practicable solution either, as it is overly complex to define, use, and evolve such a language. View-based development is a suitable approach to deal with complex systems, and is widely used in other engineering disciplines. Still, we need to cope with the problems of fragmentation and consistency.In this paper, we present the Vitruvius approach for consistency in view-based modeling. We describe the approach by formalizing the notion of consistency, presenting languages for consistency preservation, and defining a model-driven development process. Furthermore, we show how existing models can be integrated. We have evaluated our approach at two case studies from component-based and embedded automotive software development, using our prototypical implementation based on the Eclipse Modeling Framework.

Privacy-aware data cleaning-as-a-service

Data cleaning is a pervasive problem for organizations as they try to reap value from their data. Recent advances in networking and cloud computing technology have fueled a new computing paradigm called Database-as-a-Service, where data management tasks are outsourced to large service providers. In this paper, we consider a Data Cleaning-as-a-Service model that allows a client to interact with a data cleaning provider who hosts curated, and sensitive data. We present PACAS: a Privacy-Aware data Cleaning-As-a-Service model that facilitates interaction between the parties with client query requests for data, and a service provider using a data pricing scheme that computes prices according to data sensitivity. We propose new extensions to the model to define generalized data repairs that obfuscate sensitive data to allow data sharing between the client and service provider. We present a new semantic distance measure to quantify the utility of such repairs, and we re-define the notion of consistency in the presence of generalized values. The PACAS model uses (X, Y, L)-anonymity that extends existing data publishing techniques to consider the semantics in the data while protecting sensitive values. Our evaluation over real data show that PACAS safeguards semantically related sensitive values, and provides lower repair errors compared to existing privacy-aware cleaning techniques.

Subgame Consistent Cooperative Behavior in an Extensive form Game with Chance Moves

We design a mechanism of the players’ sustainable cooperation in multistage n-person game in the extensive form with chance moves. When the players agreed to cooperate in a dynamic game they have to ensure time consistency of the long-term cooperative agreement. We provide the players’ rank based (PRB) algorithm for choosing a unique cooperative strategy profile and prove that corresponding optimal bundle of cooperative strategies satisfies time consistency, that is, at every subgame along the optimal game evolution a part of each original cooperative trajectory belongs to the subgame optimal bundle. We propose a refinement of the backwards induction procedure based on the players’ attitude vectors to find a unique subgame perfect equilibrium and use this algorithm to calculate a characteristic function. Finally, to ensure the sustainability of the cooperative agreement in a multistage game we employ the imputation distribution procedure (IDP) based approach, that is, we design an appropriate payment schedule to redistribute each player’s optimal payoff along the optimal bundle of cooperative trajectories. We extend the subgame consistency notion to extensive-form games with chance moves and prove that incremental IDP satisfies subgame consistency, subgame efficiency and balance condition. An example of a 3-person multistage game is provided to illustrate the proposed cooperation mechanism.

C⁎-operator systems and crossed products

The purpose of this paper is to introduce a consistent notion of universal and reduced crossed products by actions and coactions of groups on operator systems and operator spaces. In particular we shall put emphasis to reveal the full power of the universal properties of the universal crossed products. It turns out to make things consistent, one has to perform the constructions in some bigger categories which allow the right framework for studying the universal properties and which are stable under the construction of crossed products even for non-discrete groups. In the case of operator systems, this larger category is what we call a C⁎-operator system, i.e., a selfadjoint subspace X of some B(H) which contains a C⁎-algebra A such that AX=X=XA. In the case of operator spaces, the larger category is given by what we call C⁎-operator bimodules. We introduce the notion of crossed products in these categories and show that the classical Imai-Takai and Katayama duality theorems for crossed products by group (co-)actions on C⁎-algebras extend to our notion of crossed products by C⁎-operator systems and C⁎-operator bimodules.

And-like-uninorm-based transitivity and analytic hierarchy process with interval-valued fuzzy preference relations

The framework of interval-valued fuzzy preference relations (IVFPRs) is adequate and effective to model human preference evaluations under indeterminacy. This paper analyzes three recently presented multiplicative transitivity models of IVFPRs and exposes their drawbacks. An and-like-uninorm-based functional transitivity equation is developed to introduce a multiplicative consistency notion for IVFPRs. Based on the transitivity logarithmic equation, a geometric-consistency index is further proposed to compute the inconsistency level of an IVFPR. The paper builds a logarithmic least squares model with row indeterminacy constraints and equivalently transforms it into a quadratic programming model for finding a closed-form solution of the normalized interval-valued fuzzy weights of IVFPRs. A novel method is subsequently presented to check the acceptability of an IVFPR by examining its acceptable consistency and acceptable indeterminacy. An approach including an and-like-uninorm-based maximization model is introduced to aggregate local interval-valued fuzzy weights and an interval fuzzy analytic hierarchy process is designed step-by-step. An illustrative example and a comparison study are utilized to demonstrate the performance and merits of the presented models. Meanwhile, an outstanding undergraduate student selection problem in international exchange is provided to show the application of the proposed decision method.

A Pragmatic Logic for Expressivism

AbstractThis article aims to show that the incompatibility between the application of logic to norms and values and the expressive conception of these notions – basically summed up by the Frege–Geach problem – can be overcome. To this end, a logic is constructed for the expressive conception of norms and values which provides a solution to the Frege–Geach problem and is not affected by the limitations that occur in some previous attempts. More specifically, a pragmatic language LP is introduced which is an extension of the language L of standard propositional logic, obtained by adding two categories of logical‐pragmatic signs to the vocabulary of L: the signs of pragmatic mood (, , , standing for assertion, obligation and approval, respectively) and the pragmatic connectives (∼, ∩, ∪, ⊃, ≡, standing for pragmatic negation, conjunction, disjunction, implication and bi‐implication, respectively). The notions of pragmatic validity, consistency (satisfiability), compatibility, equivalence and inference are then defined, and some criteria of pragmatic validity are given. It is thus possible to carry out in LP inferences on norms and values expressively understood, adequately formalizing Geach's problematic inferences.

On the completeness of interface descriptions and the consistency of blocked forces obtained in situ

Blocked forces can be used to describe, independently, the operational characteristics of a vibratory source. Their use within a computational model avoids the need to represent explicitly the complex mechanisms that lead to vibratory excitation. To obtain and apply an experimental blocked force with confidence it is important that likely sources of error are known, and measures of their severity are available. In this paper we introduce the notions of completeness and consistency, and detail their role in the introduction of systematic errors in a blocked force characterisation. Their mathematical origins are described and criteria to quantify their severity are proposed; the Interface Completeness Criterion (ICC), and the Measurement Consistency Criterion (MCC). These are illustrated through numerical and experimental examples. Completeness is related to the interface description adopted in a source characterisation (i.e. the number of degrees of freedom used). The ICC represents the quality of an interface description and can be quantified from in situ measurements, i.e without having to remove the source from its assembly. Consistency is related to the underlying dynamics shared by active and passive quantities (whether measured or modelled). The issue of consistency is more general, completeness being a special case, and so a single criterion is hard to formulate. When an inconsistency arises between the blocked force of a vibration source and its corresponding free interface frequency response function matrix, the MCC provides a quantitative indication of its severity. Importantly, many of the concepts discussed apply equally in the context of experimental dynamic sub-structuring.

OS CONTORNOS DA SEGURANÇA ALIMENTAR NO ÂMBITO DO SISTEMA JURÍDICO MULTILATERAL DE COMÉRCIO

Apesar do grande esforço da comunidade internacional, a falta de segurança alimentar persiste e piorou nos últimos anos. Entre os múltiplos elementos que podem afetar a segurança alimentar, o comércio na agricultura desempenha um papel significativo em termos positivos e negativos. Considerando a segurança alimentar no sistema multilateral de comércio, uma das questões mais importantes é o próprio conceito de segurança alimentar adotado pelas partes negociadoras. Esse conceito corresponde à definição mais utilizada a nível internacional, ou seja, a definição da FAO? O fórum da Organização Mundial do Comércio apresentou uma noção clara e consistente de segurança alimentar? Este artigo discute o conceito de segurança alimentar proveniente do sistema legal da OMC, examinando as regras do Acordo sobre Agricultura relevante e levando em conta o atual processo de reforma.

Instantaneous reaction-time in dynamic consistency checking of conditional simple temporal networks

Conditional Simple Temporal Networks (CSTNs) is a constraint based graph-formalism for conditional temporal planning. Three notions of consistency arise for CSTNs: weak, strong, and dynamic. Dynamic-Consistency (DC) is the most interesting notion, but it is also the most challenging. In order to address the DC-Checking problem, Comin and Rizzi [12] introduced ε-DC (a refined, more realistic, notion of DC), providing an algorithmic solution to it. Next, given that DC implies ε-DC for some sufficiently small ε>0, and that for every ε>0 it holds that ε-DC implies DC, it was offered a sharp lower bounding analysis on the critical value of the reaction-timeεˆ under which the two notions coincide. This delivered the first (pseudo) singly-exponential time algorithm for the DC-Checking of CSTNs. However, the ε-DC notion is interesting per se, and the ε-DC-Checking algorithm of Comin and Rizzi [12] rests on the assumption that the reaction-time satisfies ε>0; leaving unsolved the question of what happens when ε=0. In this work, we introduce and study π-DC, a sound notion of DC with an instantaneous reaction-time (i.e., one in which the planner can react to any observation at the same instant of time in which the observation is made). Firstly, we demonstrate by a counter-example that π-DC is not equivalent to 0-DC, and that 0-DC is actually inadequate for modeling DC with an instantaneous reaction-time. This shows that the main results obtained in our previous work do not apply directly, as they were formulated, to the case of ε=0. Motivated by this observation, as a second contribution, our previous tools are extended in order to handle π-DC, and the notion of ps-tree is introduced, also pointing out a relationship between π-DC and consistency of Hyper Temporal Networks. Thirdly, a simple reduction from π-DC to (classical) DC is identified. This allows us to design and to analyze the first sound-and-complete π-DC-Checking algorithm. Remarkably, the time complexity of the proposed algorithm remains (pseudo) singly-exponential in the number of propositional letters. Finally, it is observed that the technique can be leveraged to actually reduce from π-DC to 1-DC, this allows us to further improve the exponents in the time complexity.

A consistency theorem for randomized singular value decomposition

The singular value decomposition (SVD) and the principal component analysis are fundamental tools and probably the most popular methods for data dimension reduction. The rapid growth in the size of data matrices has lead to a need for developing efficient large-scale SVD algorithms. Randomized SVD was proposed, and its potential was demonstrated for computing a low-rank SVD (Rokhlin et al., 2009). In this article, we introduce a consistency notion for random projections used in randomized SVD and provide a consistency theorem for it. We also present a numerical example to show how the random projections to low dimension affect the consistency.