Algebraic semantics for modal logics I

1966 ◽  
Vol 31 (1) ◽  
pp. 46-65 ◽  
Author(s):  
E. J. Lemmon
Keyword(s):  
Modal Logic ◽  
General Framework ◽  
Ad Hoc ◽  
Axiomatic Approach ◽  
Present Series ◽  
Algebraic Methods ◽  
Future Research ◽  
Algebraic Semantics ◽  
Semantic Completeness ◽  
Modal Systems

Modal logic received its modern impetus from the work of Lewis and Langford [10]. In recent years, however, their axiomatic approach, aided by somewhat ad hoc matrices for distinguishing different modal systems, has been supplemented by other techniques. Two of the most profound of these were, first, the algebraic methods employed by McKinsey and Tarski (see [11] and [12]) and, second, the semantic method of Kripke (see [5] and [6]); and there have been others. The aim of the present series of papers is to afford a synthesis of these methods. Thus, though new results are given, the interest lies rather in revealing interconnexions between familiar results and in providing a general framework for future research. In general, we show that semantic completeness results of the Kripke kind can be deduced from the algebraic results by means of one central theorem (Theorem 21).

Algebraic semantics for modal logics II

1966 ◽  
Vol 31 (2) ◽  
pp. 191-218 ◽  
Author(s):  
E. J. Lemmon
Keyword(s):  
Modal Logic ◽  
Modal Logics ◽  
Algebraic Methods ◽  
Model Structure ◽  
Algebraic Semantics ◽  
The Relationship ◽  
Model Structures

This paper is a sequel to [7], and the terminology of [7] is largely presupposed here. In [7], the algebraic methods of McKinsey-Tarski were employed and extended to yield semantic results of a Kripke kind for a class of relatively weak modal logics, the strongest of which was the Feysvon Wright system T. Deontic versions of both T and E2, called T(D) and D2, and even weaker systems, were handled. The main aim of the present paper is to extend these results to stronger systems of modal logic. Thus the Lewis systems S2–S5, the Brouwersche system B of Kripke [4], the systems E3–E5 of [5], and Łukasiewicz's modal logic, as well as certain new systems, are considered.Certain modifications of the method of [7] have proved convenient. Thus in Section I, some further results concerning model structures are proved in order that the relationship between S2 and E2, S3 and E3, can be properly stated; in particular, the notions of a refined and connected model structure play a pervasive role throughout.

Language, procedures, and the non-perceptual origin of natural number concepts

2016 ◽  
Author(s):  
David Barner
Keyword(s):  
General Framework ◽  
Ad Hoc ◽  
Building Blocks ◽  
Number Words ◽  
Linguistic Markers ◽  
Logical Foundations ◽  
Large Numbers ◽  
Perceptual Representations ◽  
Positive Integers ◽  
Perceptual Systems

Perceptual representations – e.g., of objects or approximate magnitudes –are often invoked as building blocks that children combine with linguisticsymbols when they acquire the positive integers. Systems of numericalperception are either assumed to contain the logical foundations ofarithmetic innately, or to supply the basis for their induction. Here Ipropose an alternative to this general framework, and argue that theintegers are not learned from perceptual systems, but instead arise toexplain perception as part of language acquisition. Drawing oncross-linguistic data and developmental data, I show that small numbers(1-4) and large numbers (~5+) arise both historically and in individualchildren via entirely distinct mechanisms, constituting independentlearning problems, neither of which begins with perceptual building blocks.Specifically, I propose that children begin by learning small numbers(i.e., *one, two, three*) using the same logical resources that supportother linguistic markers of number (e.g., singular, plural). Several yearslater, children discover the logic of counting by inferring the logicalrelations between larger number words from their roles in blind countingprocedures, and only incidentally associate number words with perception ofapproximate magnitudes, in an *ad hoc* and highly malleable fashion.Counting provides a form of explanation for perception but is not causallyderived from perceptual systems.

scholarly journals Revisiting the CompCars Dataset for Hierarchical Car Classification: New Annotations, Experiments, and Results

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 596
Author(s):  
Marco Buzzelli ◽  
Luca Segantin
Keyword(s):  
Real World ◽  
High Performance ◽  
Ad Hoc ◽  
Future Research ◽  
Levels Of Detail ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Hierarchical Nature ◽  
Multiple Levels ◽  
Entire Dataset

We address the task of classifying car images at multiple levels of detail, ranging from the top-level car type, down to the specific car make, model, and year. We analyze existing datasets for car classification, and identify the CompCars as an excellent starting point for our task. We show that convolutional neural networks achieve an accuracy above 90% on the finest-level classification task. This high performance, however, is scarcely representative of real-world situations, as it is evaluated on a biased training/test split. In this work, we revisit the CompCars dataset by first defining a new training/test split, which better represents real-world scenarios by setting a more realistic baseline at 61% accuracy on the new test set. We also propagate the existing (but limited) type-level annotation to the entire dataset, and we finally provide a car-tight bounding box for each image, automatically defined through an ad hoc car detector. To evaluate this revisited dataset, we design and implement three different approaches to car classification, two of which exploit the hierarchical nature of car annotations. Our experiments show that higher-level classification in terms of car type positively impacts classification at a finer grain, now reaching 70% accuracy. The achieved performance constitutes a baseline benchmark for future research, and our enriched set of annotations is made available for public download.

On finite and infinite modal systems

1938 ◽  
Vol 3 (2) ◽  
pp. 77-82 ◽  
Author(s):  
C. West Churchman
Keyword(s):  
Modal Logic ◽  
Symbolic Logic ◽  
Modal Operator ◽  
Image Position ◽  
Modal Systems ◽  
Complex Modal

In Oskar Becker's Zur Logik der Modalitäten four systems of modal logic are considered. Two of these are mentioned in Appendix II of Lewis and Langford's Symbolic logic. The first system is based on A1–8 plus the postulate,From A7: ∼◊p⊰∼p we can prove the converse of C11 by writing ∼◊p for p, and hence deriveThe addition of this postulate to A1–8, as Becker points out, allows us to “reduce” all complex modal functions to six, and these six are precisely those which Lewis mentions in his postulates and theorems: p, ∼p, ◊p, ∼◊p, ∼◊∼p, and ◊∼p This reduction is accomplished by showingwhere ◊n means that the modal operator ◊ is repeated n times; e.g., ◊3p = ◊◊◊p. Then it is shown thatBy means of (1), (2), and (3) any complex modal function whatsoever may be reduced to one of the six “simple” modals mentioned above.It might be asked whether this reduction could be carried out still further, i.e., whether two of the six “irreducible” modals could not be equated. But such a reduction would have to be based on the fact that ◊p = p which is inconsistent with the set B1–9 of Lewis and Langford's Symbolic logic and independent of the set A1–8. Hence for neither set would such a reduction be possible.

scholarly journals Adoption of agile methodology for improving IT project performance

2021 ◽  
Vol 16 (2) ◽  
pp. 301-320
Author(s):  
Rajan Roshan ◽  
Ambujakumari Santhosh
Keyword(s):  
Work Performance ◽  
Ad Hoc ◽  
Positive Impact ◽  
Research Work ◽  
Project Performance ◽  
Future Research ◽  
Technological Advancement ◽  
Agile Methodology ◽  
It Project ◽  
It Project Performance

Most of the IT organizations are facing various challenges such as technological advancement, new customer requirements, merger & acquisition, and changing market demands, which should be addressed to survive in the industry. For enhancing more value to the customer in the project, the best option is to choose Agile Methodology for managing the project, which helps to accommodate the ad-hoc business requirement than pre-planned. Though, most of the organization, especially in the IT industry is shifting to Agile methodology practice, which helps to enjoy the benefit of better collaboration and customer experience. The study was conducted among 404 IT professionals from the IT corridors of India to understand the influence of Agile methodology on IT project performance. Most responses received from people who have sound experience in IT project management which assures the quality of results obtained. From study, it has been found that Agile methodology (b= 0.630, p<0.00) has a significant and positive impact on the project performance. Also, the study proves that people who are working in Scrum framework (Agile methodology) improves the project quality as well as business value. Based on Stepwise regression results, Product ownership has higher degree of importance than other independent variable for the individual work performance which solidifies the requirement for software development. Multicollinearity Assessment shows Product Ownership and Development Practice have more impact on project performance than Team considered for the study. Previous studies didn't cover the aspect as well as areas proposed in this study to arrive the conclusion of Scrum framework for project performance, and it opens the pathway for future research work.

scholarly journals Epoxy tooling: Technologies, developments, sustainability and future interest to industry 4.0

2021 ◽  
pp. 096739112110598
Author(s):  
Gorka Díez-Barcenilla ◽  
José L Gómez-Alonso ◽  
Koldo Gondra ◽  
Ester Zuza
Keyword(s):  
Industry 4.0 ◽  
Ad Hoc ◽  
Cost Effective ◽  
Smart Manufacturing ◽  
Future Research ◽  
Cooling Channels ◽  
Waste Reuse ◽  
Tool Performance ◽  
Rapid Manufacture ◽  
The Cost

The technology of epoxy tooling, at present under continuous development, is used for the rapid manufacture of cost-effective tools for small batch production. It is a valid alternative with no need for expensive investment in metallic moulds for the development of new products. Current investigations are focused on improvements to the production system, improved tool performance, the cost reduction of moulds and tool manufacturing sustainability. In this paper, both the advantages and the disadvantages of epoxy tooling in injection moulding, wax injection, metal stamping and hot embossing are compared with conventional techniques. Following a brief introduction of rapid tooling technologies, the latest advances of epoxy tooling and their implementation in different manufacturing processes are all analysed. These developments refer to the production of new ad-hoc epoxy composites, increased productivity using conformal cooling channels, the reduction of the tooling manufacturing costs through waste reuse and the emerging industry 4.0 technologies for smart manufacturing and tooling. The main objective is to identify both the challenges facing epoxy tooling techniques and future research directions.

scholarly journals Aristotle and Boethius: Two Theses and Their Possibilities

2021 ◽  
Author(s):  
Miguel López-Astorga
Keyword(s):  
Modal Logic ◽  
Mental Models ◽  
General Framework ◽  
Cognitive Problem

There is a kind of logical theses that can be a cognitive problem. They are theses that are not tautologies and people tend to accept as absolutely correct. This is the case of theses such as those of Aristotle and Boethius. This paper tries to give an explanation of the reasons why this happens. The explanation is based on the theory of mental models. However, it also resorts to modal logic and the account of the ideas presented by Lenzen. Thus, relating the general framework of the theory of mental models to basic aspects of modal logic and this last account, a possible solution of the problem is proposed.

scholarly journals A Survey on Multihop Ad Hoc Networks for Disaster Response Scenarios

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
D. G. Reina ◽  
M. Askalani ◽  
S. L. Toral ◽  
F. Barrero ◽  
E. Asimakopoulou ◽  
...  
Keyword(s):  
Ad Hoc Networks ◽  
Disaster Response ◽  
Ad Hoc ◽  
Future Research ◽  
Multihop Ad Hoc Networks ◽  
Main Work ◽  
Disaster Relief Operations ◽  
Relief Operations ◽  
Hoc Networks ◽  
Multihop Ad Hoc Network

Disastrous events are one of the most challenging applications of multihop ad hoc networks due to possible damages of existing telecommunication infrastructure. The deployed cellular communication infrastructure might be partially or completely destroyed after a natural disaster. Multihop ad hoc communication is an interesting alternative to deal with the lack of communications in disaster scenarios. They have evolved since their origin, leading to different ad hoc paradigms such as MANETs, VANETs, DTNs, or WSNs. This paper presents a survey on multihop ad hoc network paradigms for disaster scenarios. It highlights their applicability to important tasks in disaster relief operations. More specifically, the paper reviews the main work found in the literature, which employed ad hoc networks in disaster scenarios. In addition, it discusses the open challenges and the future research directions for each different ad hoc paradigm.

scholarly journals Gratitude and Social Media: A Pilot Experiment on the Benefits of Exposure to Others’ Grateful Interactions on Facebook

2021 ◽  
Vol 12 ◽  
Author(s):  
Simona Sciara ◽  
Daniela Villani ◽  
Anna Flavia Di Natale ◽  
Camillo Regalia
Keyword(s):  
Social Media ◽  
Social Networking ◽  
Social Networking Sites ◽  
Ad Hoc ◽  
Satisfaction With Life ◽  
Specific Property ◽  
Well Being ◽  
Future Research ◽  
Subjective Well Being ◽  
Pilot Experiment

Facebook and other social networking sites allow observation of others’ interactions that in normal, offline life would simply be undetectable (e.g., a two-voice conversation viewable on the Facebook wall, from the perspective of a real, silent witness). Drawing on this specific property, the theory of social learning, and the most direct implications of emotional contagion, our pilot experiment (N = 49) aimed to test whether the exposure to others’ grateful interactions on Facebook enhances (a) users’ felt gratitude, (b) expressed gratitude, and (c) their subjective well-being. For the threefold purpose, we created ad hoc Facebook groups in which the exposure to some accomplices’ exchange of grateful messages for 2 weeks was experimentally manipulated and users’ felt/expressed gratitude and well-being were consequently assessed. Results partially supported both hypotheses. Observing others’ exchange of grateful posts/comments on Facebook appeared to enhance participants’ in-person expression of gratitude (i.e., self-reported gratitude expression within face-to-face interactions), but not their direct and subjective experiences of gratitude. Similarly, exposure to others’ grateful messages improved some components of subjective well-being, such as satisfaction with life, but not negative and positive affect. Taken together, however, our preliminary findings suggest for the first time that social networking sites may actually amplify the spreading of gratitude and its benefits. Implications of our results for professionals and future research in the field of health, education, and social media communication are discussed.

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