Checking EMTLK Properties of Timed Interpreted Systems Via Bounded Model Checking

We investigate a SAT-based bounded model checking (BMC) method for EMTLK (the existential fragment of the metric temporal logic with knowledge) that is interpreted over timed models generated by timed interpreted systems. In particular, we translate the existential model checking problem for EMTLK to the existential model checking problem for a variant of linear temporal logic (called HLTLK), and we provide a SAT-based BMC technique for HLTLK. We evaluated the performance of our BMC by means of a variant of a timed generic pipeline paradigm scenario and a timed train controller system.     

Model checking hybrid logics (with an application to semistructured data)

We investigate the complexity of the model checking problem for hybrid logics. We provide model checking algorithms for various hybrid fragments and we prove PSPACE-completeness for hybrid fragments including binders. We complement and motivate our complexity results with an application of model checking in hybrid logic to the problems of query and constraint evaluation for semistructured data.     

A Sat-Based Approach to Unbounded Model Checking for Alternating-Time Temporal Epistemic Logic

This paper deals with the problem of verification of game-like structures by means of symbolic model checking. Alternating-time Temporal Epistemic Logic (ATEL) is used for expressing properties of multi-agent systems represented by alternating epistemic temporal systems as well as concurrent epistemic game structures. Unbounded model checking (a SAT based technique) is applied for the first time to verification of ATEL. An example is given to show an application of the technique.     

Phenomenological validity of an OCD-memory model and the remember/know distinction

In earlier experiments using interactive computer animation with healthy subjects, it was found that displaying compulsive-like repeated checking behavior affects memory. That is, checking does not alter actual memory accuracy, but it does affect 'meta-memory': as checking continues, recollections are experienced as less vivid and less detailed while confidence in memory is undermined. This procedure provides a model of OCD checking and suggests that checking is a counterproductive strategy to reduce memory distrust. The present experiment was carried out to specify the phenomenological quality of memory distrust after checking and to see if repeated checking produces a shift in the memory source that is used to decide about the outcome of checking: from 'remembering' to 'knowing' (Tulving, 1985). Using the same interactive computer-animation, the earlier findings on vividness, detail and confidence were replicated. In addition, it was found that checking made participants endorse quotations from OCD patients (Reed, 1985) expressing a specific ambivalence about memory: 'It is as though the memory is there, but is isn't definite enough', 'I remember doing it in a way, but it's all fuzzy....' And 'I can remember that I've done it. But the memory isn't clear somehow'. This finding adds to the validity of the experimental model. Furthermore, after checking subjects' beliefs about the outcome of checking became based on (general) knowing instead of (specific) remembering. It is suggested that OCD checkers feel a general and relatively strong need to be certain about the veracity of recollections and that they have high standards for memory performance. This may explain earlier findings that OCD checkers have a general tendency to distrust their episodic memory. A need for certainty and a critical attitude towards memory performance may not be problematic or abnormal. It is suggested that clinical problems arise when the patient tries to fight memory distrust by repeated checking. The latter does not reduce distrust but rather increases distrust and the patient may get trapped in a spiral of mutually reinforcing checking behavior and memory distrust.     

Model Checking Techniqes for the Analysis of Reactive Systems

Model checking is a widely used technique that aids in the designand debugging of reactive systems. This paper gives an overview onthe theory and algorithms used for model checking, with a biastowards automata-theoretic approaches and linear-time temporallogic. We also describe elementary abstraction techniques useful forlarge systems that cannot be directly handled by model checking.     

Detection and veracity analysis of fake news via scrapping and authenticating the web search

Social media has become a part of our day-to-day life and has become one of the significant sources of information. Most of the information available on social media is in the form of images. This has given rise to fake news event distribution, which is misinforming the users. Hence, to tackle this problem, we propose a model which is concerned with the veracity analysis of information on various social media platforms available in the form of images. It involves an algorithm which validates the veracity of image text by exploring it on web and then checking the credibility of the top 15 Google search results by subsequently calculating the reality parameter (Rp), which if exceeds a threshold value, an event is classified as real else fake. In order to test the performance of our proposed approach, we compute the recognition accuracy, and the highest accuracy is compared with similar state-of-the-art models to demonstrate the superior performance of our approach.     

An analytic tableau calculus for a temporalised belief logic

A tableau is a refutation-based decision procedure for a related logic, and is among the most popular proof procedures for modal logics. In this paper, we present a labelled tableau calculus for a temporalised belief logic called TML⁺, which is obtained by adding a linear-time temporal logic onto a belief logic by the temporalisation method of Finger and Gabbay. We first establish the soundness and the completeness of the labelled tableau calculus based on the soundness and completeness results of its constituent logics. We then sketch a resolution-type proof procedure that complements the tableau calculus and also propose a model checking algorithm for TML⁺ based on the recent results for model checking procedures for temporalised logics. TML⁺ is suitable for formalising trust and agent beliefs and reasoning about their evolution for agent-based systems. Based on the logic TML⁺, the proposed labelled tableau calculus could be used for analysis, design and verification of agent-based systems operating in dynamic environments.     

Automated theorem proving for Łukasiewicz logics

This paper is concerned with decision proceedures for the ₀-valued ukasiewicz logics,. It is shown how linear algebra can be used to construct an automated theorem checker. Two decision proceedures are described which depend on a linear programming package. An algorithm is given for the verification of consequence relations in, and a connection is made between theorem checking in two-valued logic and theorem checking in which implies that determing of a -free formula whether it takes the value one is NP-complete problem.     

Automatic verification of multi-agent systems by model checking via ordered binary decision diagrams

We present a methodology for the verification of multi-agent systems, whose properties are specified by means of a modal logic that includes a temporal, an epistemic, and a modal operator to reason about correct behaviour of agents. The verification technique relies on model checking via ordered binary decision diagrams. We present an implementation and report on experimental results for two scenarios: the bit transmission problem with faults and the protocol of the dining cryptographers.     

Semi-sparse PCA

It is well known that the classical exploratory factor analysis (EFA) of data with more observations than variables has several types of indeterminacy. We study the factor indeterminacy and show some new aspects of this problem by considering EFA as a specific data matrix decomposition. We adopt a new approach to the EFA estimation and achieve a new characterization of the factor indeterminacy problem. A new alternative model is proposed, which gives determinate factors and can be seen as a semi-sparse principal component analysis (PCA). An alternating algorithm is developed, where in each step a Procrustes problem is solved. It is demonstrated that the new model/algorithm can act as a specific sparse PCA and as a low-rank-plus-sparse matrix decomposition. Numerical examples with several large data sets illustrate the versatility of the new model, and the performance and behaviour of its algorithmic implementation.

     

Coherence and Computational Complexity of Quantifier-free Dependence Logic Formulas

We study the computational complexity of the model checking problem for quantifier-free dependence logic ${(\mathcal{D})}$ formulas. We characterize three thresholds in the complexity: logarithmic space (LOGSPACE), non-deterministic logarithmic space (NL) and non-deterministic polynomial time (NP).     

A mood-as-input account of perseverative checking: the relationship between stop rules, mood and confidence in having checked successfully

The present paper reports the results of two experiments designed to test predictions from the mood-as-input account of perseverative checking. Using an analogue checking task, both experiments showed that perseveration, as indicted by a range of measures relevant to compulsive checking, was affected by the configuration of the stop rule for the task and mood at the outset of checking. Perseveration was most significant in the condition that most closely resembled the characteristics of obsessive-compulsive checkers (negative mood combined with a stop rule that specifies that the task should be done as thoroughly as possible--namely, an 'as many as can' stop rule). The studies also indicated that confidence at having completed the checking task successfully was (1) significantly related to the use of 'as many as can' stop rules at the outset of checking, (2) mood ratings at the end of checking, and (3) checking perseveration generally. These findings provide support for a mood-as-input explanation of perseverative psychopathologies such as compulsive checking, and begin to cast some light on how anxiety-reduction and 'confidence' models of compulsive checking, might be explained within broader mechanisms of perseveration.     

Three-Mode Component Analysis with Crisp or Fuzzy Partition of Units

A new methodology is proposed for the simultaneous reduction of units, variables, and occasions of a three-mode data set. Units are partitioned into a reduced number of classes, while, simultaneously, components for variables and occasions accounting for the largest common information for the classification are identified. The model is a constrained three-mode factor analysis and it can be seen as a generalization of the REDKM model proposed by De Soete and Carroll for two-mode data. The least squares fitting problem is mathematically formalized as a constrained problem in continuous and discrete variables. An iterative alternating least squares algorithm is proposed to give an efficient solution to this minimization problem in the crisp and fuzzy classification context. The performances of the proposed methodology are investigated by a simulation study comparing our model with other competing methodologies. Different procedures for starting the proposed algorithm have also been tested. A discussion of some interesting differences in the results follows. Finally, an application to real data illustrates the ability of the proposed model to provide substantive insights into the data complexities.     

The influence of social anxiety on the body checking behaviors of female college students

Social anxiety and eating pathology frequently co-occur. However, there is limited research examining the relationship between anxiety and body checking, aside from one study in which social physique anxiety partially mediated the relationship between body checking cognitions and body checking behavior (Haase, Mountford, & Waller, 2007). In an independent sample of 567 college women, we tested the fit of Haase and colleagues’ foundational model but did not find evidence of mediation. Thus we tested the fit of an expanded path model that included eating pathology and clinical impairment. In the best-fitting path model (CFI = .991; RMSEA = .083) eating pathology and social physique anxiety positively predicted body checking, and body checking positively predicted clinical impairment. Therefore, women who endorse social physique anxiety may be more likely to engage in body checking behaviors and experience impaired psychosocial functioning.     

Philosophy and the practice of Bayesian statistics

A substantial school in the philosophy of science identifies Bayesian inference with inductive inference and even rationality as such, and seems to be strengthened by the rise and practical success of Bayesian statistics. We argue that the most successful forms of Bayesian statistics do not actually support that particular philosophy but rather accord much better with sophisticated forms of hypothetico‐deductivism. We examine the actual role played by prior distributions in Bayesian models, and the crucial aspects of model checking and model revision, which fall outside the scope of Bayesian confirmation theory. We draw on the literature on the consistency of Bayesian updating and also on our experience of applied work in social science. Clarity about these matters should benefit not just philosophy of science, but also statistical practice. At best, the inductivist view has encouraged researchers to fit and compare models without checking them; at worst, theorists have actively discouraged practitioners from performing model checking because it does not fit into their framework.     

Attenuating memory distrust in a repeated checking task

Repeated checking has been demonstrated to lead to reductions in memory confidence in several previous studies using student and clinical samples. This process of reduced confidence in memory and detail for memory, are thought to arise from the inhibition of perceptual processing that develops during repeated checking. Our research investigated whether reduced memory confidence from repeated checking could be attenuated through the use of novel stimuli during the repeated checking task. Three groups were generated through random assignment of 65 undergraduate students. As seen in previous research, individuals who repeatedly checked a stimulus (a virtual stovetop) showed reduced memory confidence, vividness, and detail, when compared with individuals who repeatedly checked a different stimulus. A third group in which the colour of the repeatedly-checked stovetop changed every five trials showed no significant decline in memory confidence between the pre-test and post-test. Results suggest that increased memory distrust can be ameliorated through the use of stimuli with characteristics that are novel and distinctive. Findings are discussed in the context of the existing model of repeated checking and memory confidence, and implications for treatment methods are presented.     

Enterprise credit risk evaluation based on neural network algorithm

To explore the enterprise credit risk evaluation, the application effect of several common neural network models in Chinese small and medium-sized enterprise data sets was compared and the optimal parameters for each model were determined. In addition, the classification accuracy and the applicability of the model were compared, and finally the common problem of optimization neural network algorithm based on population was solved: need to determine the dimensions in advance. The experimental results showed that the probabilistic neural network (PNN) had the minimum error rate and second types of errors, while the PNN model had the highest AUC value and was robust. To sum up, the algorithm makes some contributions to solve the financing problem of small and medium-sized enterprises in China.     

A computational analysis of conservation

An approach to modeling cognitive development with a generative connectionist algorithm is described and illustrated with a new model of conservation acquisition. Among the conservation phenomena captured with this model are acquisition, the problem size effect, the length bias effect, and the screening effect. The simulations suggest novel explanations for sudden jumps in conservation performance (based on new representations of conservation transformations) and for the problem size effect (based on an analog representation of number). The simulations support the correlation-learning explanation of length bias (that length correlates with number during number altering transformations). Some conservation phenomena that so far elude computational modeling attempts are also discussed along with their prospects for capture. Suggestions are made for theorizing about cognitive development as well as about conservation acquisition. A variety of classic puzzles about cognitive development are addressed in the light of this model and similar models of other aspects of cognitive development.     

Detection of errors in statistical problem solving

Ten subjects were asked to think aloud while solving two statistical problems. The subjects were instructed after each substep of his/her problem solving, to check in various ways the solution of the previous substep. The subjects detected 25 out of a total of 56 errors when they solved the problems. About half of the detected errors were computational errors. Nine errors were eliminated in response to the checking instructions. The think aloud data indicated that subjects' most common way of detecting their own errors was by noting that computations resulted in extreme values. Subjects also detected errors by (a) "spontaneous discovery"; (b) discontent with other aspects of a solution than the numerical value of the answer; (c) repeating a solution. The last mentioned type of error detection only occurred when subjects responded to the checking instructions. Finally it was found that subjects had a strong tendency to respond to the checking instructions either in a routinized or in a non-elaborated way. It was discussed how the formulation of checking instructions can be improved in order to avoid this effect.