Jerzy Tyszkiewicz

University of Warsaw | UW · Institute of Informatics

One of the methods of analysing the manufacturing process of lithic tools is by "reading" the scars of removals visible on the surface of cores or bifaces. The paper aims to review the limitations of this approach, by answering the question as to how much information from the original knapping process is still preserved in the cores and bifaces. To...

Prefix aggregation operation (also called scan), and its particular case, prefix summation, is an important parallel primitive and enjoys a lot of attention in the research literature. It is also used in many algorithms as one of the steps. Aggregation over dominated points in $\mathbb{R}^m$ is a multidimensional generalisation of prefix aggregatio...

It is quite common that the same person uses many different devices, depending on the situation: smartphones and tablets in the field, laptops in the office, switching between operating systems and Web-based applications. A spreadsheet user in this situation needs a multiplatform spreadsheet, one which will work equally well on all types of devices...

There are a number of software tools whose aim is to create and maintain Harris matrix data during fieldwork. They tend to be complicated, and most of those we know of, don't work on mobile devices, especially off-line. Filling this gap, we present a very simple open software tool for recording Harris matrix data. It has all fundamental functionali...

The idea we want to advocate is the rapid prototyping of mobile multi-platform applications in the form of vanilla spreadsheets based on spreadsheet formulas, data validation and conditional formatting for tasks like entering and validating data, computing results and generating reports. Spreadsheet software systems, available on all major desktop...

We investigate the expressive power of spreadsheets. We consider spreadsheets which contain only formulas, and assume that they are small templates, which can be filled to a larger area of the grid to process input data of variable size. Therefore we can compare them to well-known machine models of computation. We consider a number of classes of sp...

Spreadsheets are among the most commonly used applications for data management and analysis. Perhaps they are even among the most widely used computer applications of all kinds. However, the spreadsheet paradigm of computation still lacks sufficient analysis. In this article we demonstrate that a spreadsheet can play the role of a relational databa...

Creating user defined functions (UDFs) is a powerful method to improve the quality of computer applications, in particular spreadsheets. However, the only direct way to use UDFs in spreadsheets is to switch from the functional and declarative style of spreadsheet formulas to the imperative VBA, which creates a high entry barrier even for proficient...

We investigate the computational capabilities of Web browsers, when equipped with a standard finite automaton. We observe that Web browsers are Turing-complete. We introduce the notion of a navigational problem, and investigate the complexity of solving Web queries and navigational problems by Web browsers, where complexity is measured by the numbe...

Taverna workbench is an environment for construction, visualization and execution of bioinformatic workflows that integrates specialized tools available on the Internet. It already supports major bioinformatics services and is constantly gaining popularity. However, its user interface requires considerable effort to learn, and sometimes requires pr...

Spreadsheets are among the most commonly used applica- tions for data management and analysis. Perhaps they are even among the most widely used computer applications of all kinds. However, the spreadsheet paradigm of computa- tion still lacks sufficient analysis. In this paper we demonstrate that a spreadsheet can play the role of a relational data...

This paper contains the English version of my Master's thesis [6] written about 22 years ago under supervision of Jerzy Tiuryn. Its main result is the proof of PTIME-completeness of the type reconstruction problem for simply typed lambda calculus. About the time I had the English paper ready, a much simpler proof [3] by John Mitchell (later publish...

In this paper we propose DFL—a formal, graphical workflow language for dataflows, i.e., workflows where large amounts of complex data are manipulated, and the structure of the manipulated data is reflected in the structure of the workflow. It is a common extension of (1) Petri nets, which are responsible for the organization of the processing tasks...

Dataflow repositories are databases containing dataflows and their different runs. We propose a formal conceptual data model for such repositories. Our model includes careful formalisations of such features as complex data manipulation, external service calls, subdataflows, and the provenance of output values.

This article presents our programme written in view of it being taken advantage of by the literary scholars' milieu, particularly, those dealing with textology and scientific editorship. The programme enables clear presentation of differences between various versions of a text. We try to describe to the reader a general idea of how the program may...

We introduce a new abstract model of database query processing, finite cursor machines, that incorporates certain data streaming aspects. The model describes quite faithfully what happens in so-called “one-pass” and “two-pass query processing”. Technically, the model is described in the framework of abstract state machines. Our main results are upp...

The Pi of the Sky experiment searches for fast optical transients in the sky. Its data is stored in huge databases, which contain mainly astrophysical objects' data and measurement of their brightness over time. This paper describes an application that was designed to make analysis of this data more effective. User requirements and solution based o...

Unlabelled: Taverna workbench is an environment for construction, visualization and execution of bioinformatic workflows that integrate specialized tools available through the internet. It is gaining popularity fast, because of supporting the most important bioinformatic services and its simple, yet robust graphical notation. Here we present XQTav...

Suppose that you are a user of a commercial relational database, accessible over the Internet, whose owner has decided to copy the price lists of the US telephone companies — first order queries are for free just like local calls, because they are local by the theorem of Gaifman These are the rules. Well, what is your strategy, to compute all you w...

In the current paper we first show that the fixpoint theory of equality is decidable. The motivation behind considering this theory is that second-order quantifier elimination techniques based on a theorem given in [A. Nonnengart and A. Szałas, “A fixpoint approach to second-order quantifier elimination with applications to correspondence theory”,...

We present new general method for proving that for certain classes of finite structures the limit law fails for properties expressible in transitive closure logic. In all such cases also all associated asymptotic problems are undecidable.

We develop a Kolmogorov complexity based tool to measure expressive power of query languages over finite structures. It works for sentences (i.e., boolean queries), and gives a meaningful definition of the expressive power of a query language in a single finite model. The notion of Kolmogorov expressive power of a boolean query language L in a fini...

In the paper by Gambin et al. (2002) we introduced the model of contextual alignment of biological sequences. It is an extension of the classical alignment, in which the cost of a substitution depends on the surrounding symbols. Consequently, in this model the cost of transforming one sequence into another depends on the order of editing operations...

In this paper we propose a formal, graphical workflow language for dataflows, i.e., workflows where large amounts of complex data are manipulated and the structure of the manipulated data is reflected in the structure of the workflow. It is a common extension of Petri nets, which are responsible for the organization of the processing tasks, and Nes...

In the 1970s Codd introduced the relational algebra, with operators selection, projection, union, difference and product, and showed that it is equivalent to first-order logic. In this paper, we show that if we replace in Codd’s relational algebra the product operator by the “semijoin” operator, then the resulting “semijoin algebra” is equivalent t...

To represent a bioinformatics workflow in NRC the actual atomic processing steps can be defined as abstract external functions, or ”black boxes”, embedded into NRC. These black boxes can be e.g. execution of software, a script or a call to a web-service. The system also allows the use of internal functions to hierarchically organize the constructio...

We demonstrate and discuss the advantages of bioinformatical workflows which have no side-effects over those which do have them. In particular, we describe a method to give a formal, mathematical semantics to the side-effect-free workflows defined in SCUFL, the workflo w definition language of Taverna. This is achieved by translating them into a na...

The semijoin algebra is the variant of the relational algebra obtained by replacing the join operator by the semijoin operator. We provide an Ehrenfeucht-Fraiss\'{e} game, characterizing the discerning power of the semijoin algebra. This game gives a method for showing that queries are not expressible in the semijoin algebra.

We consider the problem of defining conditional objects (a I b), which would allow one to regard the conditional probability Pr(alb ) as a probability of a well-defined event rather than as a shorthand for Pr(ab)/Pt(b). The next issue is to define boolean combinations of con- ditional objects, and possibly also the operator of further conditioning.

This paper describes an experiment into detecting pollution of water and food samples with ammonia. The novelty of the work is the use of an "electronic nose" to measure the smell of the samples, and application of an algorithmic procedure called "decision trees" to these measure-ments, in order to determine the presence of ammonia in the samples....

We consider the navigation power of Web browsers, such as Netscape Navigator, Internet Explorer or Opera. To this end, we formally introduce the notion of a navigational problem. We investigate various characteristics of such problems which make them hard to visit with small number of clicks.

We introduce and investigate a distributed computation model for querying the Web. Web queries are computed by interacting automata running at different nodes in the Web. The automata which we are concerned with can be viewed as register automata equipped with an additional communication component. We identify conditions necessary and sufficient fo...

We present a model of contextual alignment of biological sequences. It is an extension of the classical alignment, in which we assume that the cost of a substitution depends on the surrounding symbols. In this model the cost of transforming one sequence into another depends on the order of editing operations. We present efficient algorithms for cal...

We present a Maple package for experimenting with conditional event algebras of Schay, Adams-Calabrese, Goodman-Nguyen-Walker and Product Space of Goodman and Nguyen. It includes the implementation of the first polynomial time algorithm for calculating probabilities in the product space conditional event algebra.

A model of querying remote databases was considered to analyze computability by sequences of supported queries. The computation-theoretic issues of reflective machines was also investigated to isolate fine hierarchies. The sequences of the queries was determined at runtime signifying ability of the model to perform reflective programming in query l...

We consider the problem of defining conditional objects (a|b), which would allow one to regard the conditional probability Pr(a|b) as a probability of a well-defined event rather than as a shorthand for Pr(ab)/Pr(b). The next issue is to define boolean combinations of conditional objects, and possibly also the operator of further conditioning. Thes...

In this paper we prove that all the existing conditional event algebras embed into a three-valued extension of temporal logic of discrete past time, which the authors of this paper have proposed in anothe paper as a general model of conditional events. First of all, we discuss the descriptive incompleteness of the cea's. In this direction, we show...

We investigate the mutual definability of connectives in two different three valued propositional logics, considered in the calculi of conditional events.

We present new general method for proving that for certain classes of finite structures the limit law fails for properties expressible in transitive closure logic. In all such cases also all associated asymptotic problems are undecidable. 1 Introduction The problems considered in this paper belong to the research area called random structure theory...

The purpose of the paper is to propose a completely new notion of complexity of logics in finite-model theory. It is the Kolmogorov variant of the Vardi's expression complexity. We define it by considering the value of the Kolmogorov complexity C(L[A]) of the infinite string L[A] of all truth values of sentences of L in A: The higher is this value,...

. We show that for logics that capture DSPACE(log n) over ordered structures, and for recursive probability distributions on the class of finite models of the signature, the 0--1 law and the convergence law hold if and only if certain boundedness conditions are satisfied. As one of the applications, we consider the conjecture of Kolaitis and Vardi,...

We propose a new, general and easy method for proving nonexistence of asymptotic probabilities of monadic second-order sentences in classes of finite structures where first-order extension axioms hold almost surely.

. Suppose that you are a user of a commercial relational database, accessible over the Internet, whose owner has decided to copy the price lists of the US telephone companies --- first order queries are for free just like local calls, because they are local by the theorem of Gaifman [6]. All recursive queries, being potentially non-local, are charg...

We study the query language BQL: the extension of the relational algebra with for-loops. We also study FO(FOR): the extension of first-order logic with a for-loop variant of the partial fixpoint operator. In contrast to the known situation with query languages which include while-loops instead of for-loops, BQL and FO(FOR) are not equivalent. Among...

this paper is to find the limit of that fraction when n !1. The answer to this question is equivalent to finding the "density" of inhabited types in the set of all types, or the so-called asymptotic probability of finding an inhabited type in the set of all types. Under the Curry-Howard isomorphism this means finding the density or asymptotic proba...

We prove a 0-1 law for the fragment of second order logic SO(89) over parametric classes of nite structures which allow only one unary atomic type. This completes the investigation of 0-1 laws for fragments of second order logic deened in terms of rst order quantiier preexes over, e.g., simple graphs and tournaments. We also prove a low oscillation...

We prove a 0-1 law for the fragment of second order logic SO(89 ) over parametric classes of structures which allow only one unary atomic type, confirming partially a conjecture of Lacoste. This completes the investigation of 0-1 laws for fragments of second order logic (with equality) defined in terms of first order quantifier prefixes over, e.g.,...

We address the question “How much of the information stored in a given database can be retrieved by all Boolean queries in a given query language?”.In order to answer it we develop a Kolmogorov complexity based measure of expressive power of Boolean query languages over finite structures. This turns the above informal question into a precisely defi...

We study the query language BQL: the extension of the relational algebra with for-loops. We also study FO(FOR): the extension of first-order logic with a for-loop variant of the partial fixpoint operator. In contrast to the known situation with query languages which include while-loops instead of for-loops, BQL and FO(FOR) are not equivalent. Among...

We define a new Kolmogorov complexity based measure of complexity of logics. Then we use this new tool to prove a sharp estimate of the length of first order sentences defining nonuniformly more complicated Lindström quantifiers in terms of simpler ones.

We consider two kinds of reflective relational machines: the usual ones, which use first order queries, and existential reflective machines, which use only first order existential queries. We compare these two computation models. We build on already existing results for standard relational machines, obtained by Abiteboul, Pa-padimitriou and Vianu [...

We consider two kinds of reflective relational machines: the usual ones, which use first order queries, and existential reflective machines, which use only first order existential queries. We compare these two computation models. We build on already existing results for standard relational machines, obtained by Abiteboul, Papadimitriou and Vianu [1...

. Suppose that you are a user of a commercial relational database,accessible over the Internet, whose owner has decided to copy theprice lists of the US telephone companies --- first order queries are for freejust like local calls, because they are local by the theorem of Gaifman[6]. All recursive queries, being potentially non-local, are charged,...

. We analyze the question of existence of asymptotic cumulative probabilities for monadic second order definable properties of finite algebras. We focus our attention on the directly representable varieties and on the variety of groups. We prove in a very strong way that some recently proven first-order 0--1 laws and limit laws for these varieties...

We settle the question of the behavior of probabilities of sentences of first—order logic about a unary function and a binary relation. We show that there are sentences of this logic without asymptotic probability. This settles the last open case in the problem of establishing the behavior of asymptotic probabilities for classes of labeled structur...

We address the question “How much of the information stored in a given database can be retrieved by all Boolean queries in a given query language?”.In order to answer it we develop a Kolmogorov complexity based measure of expressive power of Boolean query languages over finite structures. This turns the above informal question into a precisely defi...

Let L∞ωω be the infinitary language obtained from the first-order language of graphs by closure under conjunctions and disjunctions of arbitrary sets of formulas, provided only finitely many distinct variables occur among the formulas. Let p(n) be the edge probability of the random graph on n vertices. Previous articles have shown that when p(n) is...

We develop an almost complete theory for existence of asymptotic probabilities of least fixed point and partial fixed pint definable properties, and for the complexity of the associated almost sure theory. Our method works for any randomized class of finite structures. © 1994 John Wiley & Sons, Inc.

The Pi of the Sky experiment searches for fast optical transients in the sky. Its data is stored in huge databases, which contain mainly astrophysical objects' data and measurement of their brightness over time. This paper describes an application that was designed to make analysis of this data more effective. User requirements and solution based o...