Min (A)cyclic Feedback Vertex Sets and Min Ones Monotone 3-SAT

In directed graphs, we investigate the problems of finding: 1) a minimum feedback vertex set (also called the Feedback Vertex Set problem, or MFVS), 2) a feedback vertex set inducing an acyclic graph (also called the Vertex 2-Coloring without Monochromatic Cycles problem, or Acyclic FVS) and 3) a minimum feedback vertex set inducing an acyclic graph (Acyclic MFVS). We show that these problems are strongly related to (variants of) Monotone 3-SAT and Monotone NAE 3-SAT, where monotone means that all literals are in positive form. As a consequence, we deduce several NP-completeness results on restricted versions of these problems. In particular, we define the 2-Choice version of an optimization problem to be its restriction where the optimum value is known to be either D or D+1 for some integer D, and the problem is reduced to decide which of D or D+1 is the optimum value. We show that the 2-Choice versions of MFVS, Acyclic MFVS, Min Ones Monotone 3-SAT and Min Ones Monotone NAE 3-SAT are NP-complete. The two latter problems are the variants of Monotone 3-SAT and respectively Monotone NAE 3-SAT requiring that the truth assignment minimize the number of variables set to true. Finally, we propose two classes of directed graphs for which Acyclic FVS is polynomially solvable, namely flow reducible graphs (for which MFVS is already known to be polynomially solvable) and C1P-digraphs (defined by an adjacency matrix with the Consecutive Ones Property)

The common good

Pojęcie dobra wspólnego jest pojęciem szerszym niż pojęcie interesu publicznego, na którym przez lata skupiała się uwaga doktryny i orzecznictwa. W obecnych czasach kryzysu państwa, którego podstawowe elementy omówiono w opracowaniu, refleksja nad pojęciem dobra wspólnego wydaje się szczególnie ważna dla ochrony podstaw idei oraz realizacji rządów prawa. Zakotwiczone w konstytucji ma także poważne konsekwencje dla oceny działań administracji publicznej, jak wskazuje bowiem doktryna, o ile interes publiczny dotyczy zawsze zbiorowości, o tyle dla dobra wspólnego może być niezbędna np. ochrona jednostki, jej godności, pozycji prawnej. Wskazano także, jak naruszenie zasad działania administracji publicznej w procesie legislacyjnym zagraża dobru wspólnemu. W artykule ukazano możliwe konkretyzacje pojęcia dobra wspólnego w prawie administracyjnym. Dotyczyć to może zarówno zadań administracji, jak i wykonywania kierownictwa w administracji publicznej. Przedstawiono postulaty badawcze w tym zakresie.The concept of the common good is a wider concept than the concept of public interest, which has for years been the focus of interest of the doctrine and judicial decisions. At the time of the current State crisis, the fundamental elements of which are discussed in the paper, a reflexion on the common good seems to be of particular importance for the protection of the fundamentals of the idea and the realisation of the rule of law. Both are anchored in the Constitution but have significant consequences for the evaluation of actions taken by public administration. Furthermore, as the doctrine shows, while public interest concerns a collective action, the common good requires the protection of an individual, their dignity and legal position. It has also been shown that the common good may be put in jeopardy as a result of the infringement of the principles according to which public administration functions. Possible concretisations of the concept of the common good in administrative law and consequently in the sphere of the performance of tasks or management in administration have been proposed and relevant directions of research programmes recommended

Ownership concentration & firm performance: Evidence from an emerging market

The initial view of the advantages of ownership concentration in joint stock companies was determined by the concern about the opportunistic managerial behavior. The growing importance of knowledge and human capital in the operation of firms shifts the focus of concern: excessive ownership concentration may stifle managerial initiative. This may be particularly true, and the results obtained in this paper support this hypothesis, in firms with high share of knowledge related activities. I explore the determinants of ownership concentration and the relationship between ownership structure and firm value in the context of a transition economy, i.e. an economy undergoing important changes in its legal and regulatory framework, in macroeconomic policy and most of all, in its property rights allocation. I focus on all non-financial companies traded on the Warsaw Stock Exchange since its inception in 1991 and up to 2003. We can observe that ownership of companies becomes more dispersed with the number of years of listing. The results reported in this paper suggest that firm adjust their ownership structure to firm specific characteristics and that firms belonging to the sector of high technology tend to have lower ownership concentration. However, the positive impact of ownership concentration on firm value detected in OLS regressions becomes even stronger when we control for the endogeneity of ownership.http://deepblue.lib.umich.edu/bitstream/2027.42/57214/1/wp834 .pd

Ownership concentration & firm performance: Evidence from an emerging market

The initial view of the advantages of ownership concentration in joint stock companies was determined by the concern about the opportunistic managerial behavior. The growing importance of knowledge and human capital in the operation of firms shifts the focus of concern: excessive ownership concentration may stifle managerial initiative. This may be particularly true, and the results obtained in this paper support this hypothesis, in firms with high share of knowledge related activities. I explore the determinants of ownership concentration and the relationship between ownership structure and firm value in the context of a transition economy, i.e. an economy undergoing important changes in its legal and regulatory framework, in macroeconomic policy and most of all, in its property rights allocation. I focus on all non-financial companies traded on the Warsaw Stock Exchange since its inception in 1991 and up to 2003. We can observe that ownership of companies becomes more dispersed with the number of years of listing. The results reported in this paper suggest that firm adjust their ownership structure to firm specific characteristics and that firms belonging to the sector of high technology tend to have lower ownership concentration. However, the positive impact of ownership concentration on firm value detected in OLS regressions becomes even stronger when we control for the endogeneity of ownership.Ownership structure, corporate governance, firm behaviour, uncertainty, knowledge economy

Recession, taxes and economic growth.

The current economic situation forces the governments to find solution how to promote economic growth. Economic theory suggests that differences in taxation may play a role in explaining differences in economic performance. The paper summarizes common features tax related measures used to tackling the economic recession in the European Union and it also points out the effect of taxes on economic activity presented by empirical studies.recession; economic crisis; taxation; corporate income tax; personal income tax; value added tax

Challenges for Monetary Policy in the Enlarged European Monetary Union

The eastward enlargement of the Euro area entails significant implications for the accession candidates in Central and Eastern Europe (CEE), the existing Euro system and the monetary policy of the European Central Bank (ECB). The present analysis assesses the challenges and critical aspects in monetary policy modeling with special emphasis to enlargement. The focus is on the difficulty of implementing a unique currency policy in view or growing heterogeneity within the enlarged monetary union, and secondly the issue of the voting mechanism within the ECB. When analyzing those two issues, it is conclusive that the difficulties for the ECB and the current Euro zone members will increase. For the enlarged Euro zone, which is becoming more divergent, it will be very hard to find adequate recipes to meet the needs and requirements of all. The big question is: whether centralisation of monetary policy is a sustainable and superior solution?European Monetary Union, EU enlargement, Monetary policy, ECB reform

A Process for Engineer Domain Ontology: An Experience in Developing Business Analysis Ontology

During the last years several works have been aimed to improve ontology technological as-pects, like representation language and inference mechanisms. This paper presents a discussion on the process and product of an experience in developing ontology for the public sector whose organization requires a strong knowledge management. This process is applied to engineer and develop ontology for Business analysis domain.Ontology, Ontology Engineering, Methodology, Protégé, Business Analysis

Cognitive Processing of Verbal Quantifiers in the Context of Affirmative and Negative Sentences: a Croatian Study

Studies from English and German have found differences in the processing of affirmative and negative sentences. However, little attention has been given to quantifiers that form negations. A picture-sentence verification task was used to investigate the processing of different types of quantifiers in Croatian: universal quantifiers in affirmative sentences (e.g. all), non-universal quantifiers in compositional negations (e.g. not all), null quantifiers in negative concord (e.g. none) and relative disproportionate quantifiers in both affirmative and negative sentences (e.g. some). The results showed that non-universal and null quantifiers, as well as negations were processed significantly slower compared to affirmative sentences, which is in line with previous findings supporting the two-step model. The results also confirmed that more complex tasks require a longer reaction time. A significant difference in the processing of same-polarity sentences with first-order quantifiers was observed: sentences with null quantifiers were processed faster and more accurately than sentences with disproportional and non-universal quantifiers. A difference in reaction time was also found in affirmatives with different quantifiers: sentences with universal quantifiers were processed significantly faster and more accurately compared to sentences with relative disproportionate quantifiers. These findings indicate that the processing of quantifiers follows after the processing of affirmative information. In the context of the two-step model, the processing of quantifiers occurs in the second step, along with negations