A Logically Justified Model of Computation I

1981 ◽  
Vol 4 (1) ◽  
pp. 151-172
Author(s):  
Pierangelo Miglioli ◽  
Mario Ornaghi
Keyword(s):  
Computer Science ◽  
Program Synthesis ◽  
Completeness Theorem ◽  
Point Of View ◽  
Program Execution ◽  
Computation Model ◽  
Clear Explanation ◽  
Direct Interpretation ◽  
Adequacy Condition ◽  
General Explanation

The aim of this paper is to provide a general explanation of the “algorithmic content” of proofs, according to a point of view adequate to computer science. Differently from the more usual attitude of program synthesis, where the “algorithmic content” is captured by translating proofs into standard algorithmic languages, here we propose a “direct” interpretation of “proofs as programs”. To do this, a clear explanation is needed of what is to be meant by “proof-execution”, a concept which must generalize the usual “program-execution”. In the first part of the paper we discuss the general conditions to be satisfied by the executions of proofs and consider, as a first example of proof-execution, Prawitz’s normalization. According to our analysis, simple normalization is not fully adequate to the goals of the theory of programs: so, in the second section we present an execution-procedure based on ideas more oriented to computer science than Prawitz’s. We provide a soundness theorem which states that our executions satisfy an appropriate adequacy condition, and discuss the sense according to which our “proof-algorithms” inherently involve parallelism and non determinism. The Properties of our computation model are analyzed and also a completeness theorem involving a notion of “uniform evaluation” of open formulas is stated. Finally, an “algorithmic completeness” theorem is given, which essentially states that every flow-chart program proved to be totally correct can be simulated by an appropriate “purely logical proof”.

Medical Diagnosis from a Clinician’s Point of View

1978 ◽  
Vol 17 (01) ◽  
pp. 28-35
Author(s):  
F. T. De Dombal
Keyword(s):  
Decision Making ◽  
Data Analysis ◽  
Computer Science ◽  
Medical Diagnosis ◽  
Information Science ◽  
Point Of View ◽  
Joint Research ◽  
The World

This paper discusses medical diagnosis from the clinicians point of view. The aim of the paper is to identify areas where computer science and information science may be of help to the practising clinician. Collection of data, analysis, and decision-making are discussed in turn. Finally, some specific recommendations are made for further joint research on the basis of experience around the world to date.

On the validity of hilbert's nullstellensatz, artin's theorem, and related results in grothendieck toposes

1988 ◽  
Vol 53 (4) ◽  
pp. 1177-1187
Author(s):  
W. A. MacCaull
Keyword(s):  
Intuitionistic Logic ◽  
Main Idea ◽  
Rational Functions ◽  
Completeness Theorem ◽  
Point Of View ◽  
Polynomial Rings ◽  
Von Neumann ◽  
Ordered Fields ◽  
Von Neumann Regular ◽  
Theoretic Point

Using formally intuitionistic logic coupled with infinitary logic and the completeness theorem for coherent logic, we establish the validity, in Grothendieck toposes, of a number of well-known, classically valid theorems about fields and ordered fields. Classically, these theorems have proofs by contradiction and most involve higher order notions. Here, the theorems are each given a first-order formulation, and this form of the theorem is then deduced using coherent or formally intuitionistic logic. This immediately implies their validity in arbitrary Grothendieck toposes. The main idea throughout is to use coherent theories and, whenever possible, find coherent formulations of formulas which then allow us to call upon the completeness theorem of coherent logic. In one place, the positive model-completeness of the relevant theory is used to find the necessary coherent formulas.The theorems here deal with polynomials or rational functions (in s indeterminates) over fields. A polynomial over a field can, of course, be represented by a finite string of field elements, and a rational function can be represented by a pair of strings of field elements. We chose the approach whereby results on polynomial rings are reduced to results about the base field, because the theory of polynomial rings in s indeterminates over fields, although coherent, is less desirable from a model-theoretic point of view. Ultimately we are interested in the models.This research was originally motivated by the works of Saracino and Weispfenning [SW], van den Dries [Dr], and Bunge [Bu], each of whom generalized some theorems from algebraic geometry or ordered fields to (commutative, von Neumann) regular rings (with unity).

A web-based language learning environment: general architecture

ReCALL ◽  
1999 ◽  
Vol 11 (S1) ◽  
pp. 31-39
Author(s):  
Pierre-Yves Foucou ◽  
Natalie Kübler
Keyword(s):  
Learning Environment ◽  
Language Learning ◽  
Computer Science ◽  
Subject Area ◽  
Point Of View ◽  
Learning Activities ◽  
Web Based ◽  
Wide Range ◽  
General Architecture ◽  
The Web

In this paper, we present the Web-based CALL environment (or WALL) which is currently being experimented with at the University of Paris 13 in the Computer Science Department of the Institut Universitaire de Technologie. Our environment is being developed to teach computer science (CS) English to CS French-speaking students, and will be extended to other languages for specific purposes such as, for example, English or French for banking, law, economics or medicine, where on-line resources are available.English, and more precisely CS English is, for our students, a necessary tool, and not an object of study. The learning activities must therefore stimulate the students' interest and reflection about language phenomena. Our pedagogical objective, relying on research acquisition (Wokusch 1997) consists in linking various texts together with other documents, such as different types of dictionaries or other types of texts, so that knowledge can be acquired using various appropriate contexts.Language teachers are not supposed to be experts in fields such as computer sciences or economics. We aim at helping them to make use of the authentic documents that are related to the subject area in which they teach English. As shown in Foucou and Kübler (1998) the wide range of resources available on the Web can be processed to obtain corpora, i.e. teaching material. Our Web-based environment therefore provides teachers with a series of tools which enable them to access information about the selected specialist subject, select appropriate specialised texts, produce various types of learning activities and evaluate students' progress.Commonly used textbooks Tor specialised English offer a wide range of learning activities, but they are based on documents that very quickly become obsolete, and that are sometimes widely modified. Moreover, they are not adaptable to the various levels of language of the students. From the students' point of view, working on obsolete texts that are either too easy or too difficult can quickly become demotivating, not to say boring.In the next section, we present the general architecture of the teaching/learning environment; the method of accessing and using it, for teachers as well as for students, is then described. The following section deals with the actual production of exercises and their limits. We conclude and present some possible research directions.

Computational Aspects of Digital Steganography

2011 ◽  
pp. 193-211
Author(s):  
Maciej Liskiewicz ◽  
Ulrich Wölfel
Keyword(s):  
Computational Complexity ◽  
Computer Science ◽  
Formal Analysis ◽  
Point Of View ◽  
Secret Data ◽  
Secure Systems ◽  
Computational Aspects ◽  
Computational Resources ◽  
Modern Cryptography ◽  
Digital Steganography

This chapter provides an overview, based on current research, on theoretical aspects of digital steganography— a relatively new field of computer science that deals with hiding secret data in unsuspicious cover media. We focus on formal analysis of security of steganographic systems from a computational complexity point of view and provide models of secure systems that make realistic assumptions of limited computational resources of involved parties. This allows us to look at steganographic secrecy based on reasonable complexity assumptions similar to ones commonly accepted in modern cryptography. In this chapter we expand the analyses of stego-systems beyond security aspects, which practitioners find difficult to implement (if not impossible to realize), to the question why such systems are so difficult to implement and what makes these systems different from practically used ones.

Ubiquitous Music

2015 ◽  
Vol 17 (4) ◽  
pp. 20-28
Author(s):  
Flávio Luiz Schiavoni ◽  
Leandro Costalonga
Keyword(s):  
Computer Science ◽  
Research Field ◽  
Point Of View ◽  
Computer Scientist ◽  
Social Scientists ◽  
The World ◽  
Computer Scientists

Ubimus is a research field that merges Ubicomp and music and studies the influence of ubiquitous devices and applications in Music. This field has been explored by musicians and social scientists around the world helped by a countless number of computer scientists. Nevertheless, it is not easy to a novice computer scientist understand Ubimus concepts and specially how to take part of this research field. Based on this, the authors present in this paper a point of view of Ubimus associating fields in computer science and hardware and software definitions and suggestions to be explored with Ubimus.

Vaughan R. Pratt. Semantical considerations on Floyd–Hoare logic. 17th Annual Symposium on Foundations of Computer Science, Institute of Electrical and Electronics Engineers, New York1976, pp. 109–121. - Michael J. Fischer and Richard E. Ladner. Propositional dynamic logic of regular programs. Journal of computer and system sciences, vol. 18 (1979), pp. 194–211. - Krister Segerberg. A completeness theorem in the modal logic of programs. Universal algebra and applications. Papers presented at Stefan Banach International Mathematical Center at the semester “Universal algebra and applications” held February 15–June 9, 1978, edited by Tadeuz Traczyk, Banach Center Publications, vol. 9, PWN—Polish Scientific Publishers, Warsaw1982, pp. 31–46. - Rohit Parikh. The completeness of propositional dynamic logic. Mathematical foundations of computer science 1978, Proceedings, 7th symposium, Zakopane, Poland, September 4–8, 1978, edited by J. Winkowski, Lecture notes in computer science, vol. 64, Springer-Verlag, Berlin, Heidelberg, and New York, 1978, pp. 403–415. - Dexter Kozen and Rohit Parikh. An elementary proof of the completeness of PDL. Theoretical computer science, vol. 14(1981), pp. 113–118.

1986 ◽  
Vol 51 (1) ◽  
pp. 225-227 ◽  
Author(s):  
Robert Goldblatt
Keyword(s):  
New York ◽  
Computer Science ◽  
Universal Algebra ◽  
Dynamic Logic ◽  
Completeness Theorem ◽  
Theoretical Computer Science ◽  
Propositional Dynamic Logic ◽  
Theoretical Computer ◽  
Mathematical Foundations ◽  
Scientific Publishers

scholarly journals درجة توافر الكفايات المهنية لدى أعضاء هيئة التدريس بجامعة غزة من وجهة نظر طلبتهم

2020 ◽  
Vol 7 (1) ◽  
pp. 69-108
Keyword(s):  
Computer Science ◽  
Undergraduate Students ◽  
Mass Communication ◽  
Point Of View ◽  
High Rate ◽  
Professional Competencies ◽  
Teaching Staff ◽  
Four Dimensions ◽  
Five Disciplines ◽  
Descriptive Method

هدفت الدراسة إلى تعرف درجة توافر الكفايات المهنية لدى أعضاء هيئة التدريس بجامعة غزة من وجهة نظر طلبتهم، واتبعت الدراسة المنهج الوصفي التحليلي، واعتمدت استبانة مكونة من (58 فقرة) موزعة على أربعة مجالات: الكفايات التدريسية، والكفايات التكنولوجية، والكفايات التقويمية، والكفايات الإنسانية. وللحصول على نتائج الدراسة استهدفت الدراسة طلبة جامعة غزة من الكليات الخمس: علوم الحاسوب وتكنولوجيا المعلومات، وعلوم الاتصال واللغات، والعلوم الإدارية والمالية، والقانون، والتربية. وبلغت عينة الدراسة (97) طالبا وطالبة، وأظهرت استجابات عينة الدراسة أن درجة توافر الكفايات المهنية لدى أعضاء هيئة التدريس بجامعة غزة من وجهة نظر طلبتهم كانت عالية (وزن نسبي=72.56%)، وكانت درجة توافر الكفايات لمجالات الدراسة الأربع على الترتيب: الكفايات الإنسانية (وزن نسبي= 74.37%)، والكفايات التقويمية (وزن نسبي= 74.08%)، والكفايات التدريسية (وزن نسبي= 73.40%)، والكفايات التكنولوجية (وزن نسبي= 68.51%)، وجميعها عالية ؛ وأظهرت الدراسة وجود فروق ذات دلالة إحصائية لاستجابة الطلبة على درجة توافر الكفايات المهنية تُعزى لمتغير الجنس لصالح الطلبة الذكور، ووجود فروق ذات دلالة إحصائية تُعزى لمتغير الكلية لصالح كلية علوم الحاسوب وتكنولوجيا المعلومات، وأوصت الدراسة بزيادة الاهتمام بتطوير الكفايات المهنية لأعضاء هيئة التدريس، والوصول بها إلى درجات متميزة، وتنظيم ورش عمل تدريبية لأعضاء هيئة التدريس في أساليب التدريس والتقويم. The study aimed to identify to which degree the professional competencies are available among the teaching staff of Gaza University from the students’ point of view. The study used the analytical-descriptive method. The study used a questionnaire consisting of 58 items; these items were categorized into four main dimensions: Teaching Competences, Technology Competences, Evaluation Competences and Human Competencies. The study targeted the students of Gaza University in the five disciplines: Computer Science and Information Technology, Mass Communication and Languages, Business and Financial Sciences, Law, and Education. The sample of the study consisted of 97 undergraduate students. Findings of the study showed that: the availability of professional competencies among the teaching staff of Gaza University was rated “high” (rate= 72.56%) depending on the responses of students. Rates were also “high” in each of the four dimensions: Teaching Competences Dimension (rate= 74.37%), Technology Competences Dimension (rate= 74.08%), Evaluation Competences Dimension (rate= 73.40%), and Human Competencies Dimension (rate= 68.51%). Besides, the study reported statistically significant differences among the responses related to Gender (in favor of Males) and significant differences related to faculty (in favor of faculty of Computer Science). The study recommended paying more attention to the development of professional competencies of teaching staff in addition to conducting training workshops in teaching and evaluation methods.

scholarly journals METHODOLOGICAL SYSTEM OF TRAINING FUTURE INFORMATICS TEACHERS ON THE BASICS OF ARTIFICIAL INTELLIGENCE

2020 ◽  
Vol 72 (4) ◽  
pp. 250-254
Author(s):  
G. Salgaraeva ◽  
◽  
U. Zhumabaeva ◽  
Keyword(s):  
Artificial Intelligence ◽  
Expert Systems ◽  
Computer Science ◽  
Science Teachers ◽  
Educational Process ◽  
Point Of View ◽  
Basic Knowledge ◽  
Educational Institutions ◽  
Training Systems ◽  
Interdisciplinary Approaches

The article presents a methodological system for training future Informatics teachers on the basics of artificial intelligence. Currently, artificial intelligence is being used in various fields, from the presentation of knowledge to the development of expert systems, intellectual games and robotics tools. In this case, there is a problem of developing a methodological system for training future Informatics teachers based on elements of artificial intelligence in pedagogical educational institutions. This proposed to solve this problem using the method of problem-based learning and combining theory with practice from the point of view of critical thinking technology. Modern analytical platforms, intelligent training systems, and expert systems are used as training tools. The educational content of the basics of artificial intelligence is built on the basis of systematic, fundamental and interdisciplinary approaches. This made it possible to determine the goals of teaching future computer science teachers the basics of artificial intelligence, reveal the requirements for the formation of concepts in the field of artificial intelligence, identify the basic knowledge system that allows you to teach elements of artificial intelligence in a computer science course. The article describes the results of the implementation of the methodological system for training future computer science teachers on the basics of artificial intelligence in the educational process.

scholarly journals A finite bidimensional wavelet framework for computer graphics

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Francisco José Benavides Murillo ◽  
Edgar Benavides Murillo ◽  
Francisco J. Torres-Rojas
Keyword(s):  
Dimensional Space ◽  
Computer Software ◽  
Point Of View ◽  
Wavelet Theory ◽  
Orthonormal Wavelet ◽  
Infinite Dimensional ◽  
Frequency Criterion ◽  
Direct Interpretation ◽  
Infinite Set ◽  
Finite Linear

A lot of material has been written about wavelet theory. Most of these texts provide an elegant framework from the functional and real analysis point of view. The complete infinite dimensional space (the set of all functions such that ) is generally used to develop the theory, but this cannot be directly applied to computer software, because the concept of a non denumerable infinite set of vectors or functions is practically useless here. We provide foundations for a finite, linear-algebra based toolkit of wavelets that supply a rich set of tools that can be used to manage image processing, equalization and compression. We test a frequency criterion to design orthonormal wavelet generators and a multirresolution analysis. We show that this criterion can be easily interpreted graphically. Despite our approach only constructs orthonormal wavelet basis; we believe that this approach is general enough to explore possibilities in other computer graphic fields and solution of integer-differential equations on simple domains. We strongly believe that this approach simplifies considerably the wavelet analysis. The frequency criterion expands possibilities of testing two dimensional wavelet bases according to specific graphical needs, and can be applied to different problems that involve regular grid reduction. We propose this criterion as a fundamental basis to design bidimensional ortonormal wavelets for matrix equalization. It gives a wider range of possibilities than restricting only to some well known bases and gives a direct interpretation for computer images.

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