On cascade products of answer set programs

Describing complex objects by elementary ones is a common strategy in mathematics and science in general. In their seminal 1965 paper, Kenneth Krohn and John Rhodes showed that every finite deterministic automaton can be represented (or "emulated") by a cascade product of very simple automata. This led to an elegant algebraic theory of automata based on finite semigroups (Krohn-Rhodes Theory). Surprisingly, by relating logic programs and automata, we can show in this paper that the Krohn-Rhodes Theory is applicable in Answer Set Programming (ASP). More precisely, we recast the concept of a cascade product to ASP, and prove that every program can be represented by a product of very simple programs, the reset and standard programs. Roughly, this implies that the reset and standard programs are the basic building blocks of ASP with respect to the cascade product. In a broader sense, this paper is a first step towards an algebraic theory of products and networks of nonmonotonic reasoning systems based on Krohn-Rhodes Theory, aiming at important open issues in ASP and AI in general.Comment: Appears in Theory and Practice of Logic Programmin

Logic-Based Analogical Reasoning and Learning

Analogy-making is at the core of human intelligence and creativity with applications to such diverse tasks as commonsense reasoning, learning, language acquisition, and story telling. This paper contributes to the foundations of artificial general intelligence by developing an abstract algebraic framework for logic-based analogical reasoning and learning in the setting of logic programming. The main idea is to define analogy in terms of modularity and to derive abstract forms of concrete programs from a `known' source domain which can then be instantiated in an `unknown' target domain to obtain analogous programs. To this end, we introduce algebraic operations for syntactic program composition and concatenation and illustrate, by giving numerous examples, that programs have nice decompositions. Moreover, we show how composition gives rise to a qualitative notion of syntactic program similarity. We then argue that reasoning and learning by analogy is the task of solving analogical proportions between logic programs. Interestingly, our work suggests a close relationship between modularity, generalization, and analogy which we believe should be explored further in the future. In a broader sense, this paper is a first step towards an algebraic and mainly syntactic theory of logic-based analogical reasoning and learning in knowledge representation and reasoning systems, with potential applications to fundamental AI-problems like commonsense reasoning and computational learning and creativity

Spatio-temporal Video Parsing for Abnormality Detection

Abnormality detection in video poses particular challenges due to the infinite size of the class of all irregular objects and behaviors. Thus no (or by far not enough) abnormal training samples are available and we need to find abnormalities in test data without actually knowing what they are. Nevertheless, the prevailing concept of the field is to directly search for individual abnormal local patches or image regions independent of another. To address this problem, we propose a method for joint detection of abnormalities in videos by spatio-temporal video parsing. The goal of video parsing is to find a set of indispensable normal spatio-temporal object hypotheses that jointly explain all the foreground of a video, while, at the same time, being supported by normal training samples. Consequently, we avoid a direct detection of abnormalities and discover them indirectly as those hypotheses which are needed for covering the foreground without finding an explanation for themselves by normal samples. Abnormalities are localized by MAP inference in a graphical model and we solve it efficiently by formulating it as a convex optimization problem. We experimentally evaluate our approach on several challenging benchmark sets, improving over the state-of-the-art on all standard benchmarks both in terms of abnormality classification and localization.Comment: 15 pages, 12 figures, 3 table

Neutron star equations of state with optical potential constraint

Nuclear matter and neutron stars are studied in the framework of an extended relativistic mean-field (RMF) model with higher-order derivative and density dependent couplings of nucleons to the meson fields. The derivative couplings lead to an energy dependence of the scalar and vector self-energies of the nucleons. It can be adjusted to be consistent with experimental results for the optical potential in nuclear matter. Several parametrisations, which give identical predictions for the saturation properties of nuclear matter, are presented for different forms of the derivative coupling functions. The stellar structure of spherical, non-rotating stars is calculated for these new equations of state (EoS). A substantial softening of the EoS and a reduction of the maximum mass of neutron stars is found if the optical potential constraint is satisfied.Comment: 19 pages, 4 figure

Automatsko niveliranje hidrauličke platforme s dizalicom

U okviru ovog diplomskog rada opisan je postupak nadogradnje automatske nivelacije hidrauličke radne platforme na postojeću ručnu nivelaciju. Hidraulička radna platforma (tzv. dizalica) je Wumag WT 225 integrirana na kamion Mercedes-Benz 811 – stroj je u vlasništvu tvrtke ŠI-LA-CO. Pružen je uvid u stanje dizalice prije rada te obrazloženi razlozi uvođenja automatske nivelacije. Ključne modifikacije sustava predstavljaju zamjenu isključivo ručno aktuiranih razvodnika s razvodnicima koji omogućuju ručno i električno upravljanje, ugradnja dvoosnog inklinometra te implementacija upravljačkog računala (tj. PLC-a) i njemu pripadajućeg programa za realizaciju željenog zakona upravljanja. Sve navedene modifikacije adekvatnim ožičenjem potrebno je povezati u svrsishodnu cjelinu

To crimea via Belgrade: Thomas Fonblanque to Lord Raglan 1854-1855

Eleven letters sent to Lord Raglan, Commander-in-Chief of British troops in the Crimea in 1854 and 1855, by Thomas Fonblanque, British Consul General at Belgrade, constitute a little known group of documents that provided useful information for the Allied campaign in the Balkans and the Crimea. The paper, however, pays special attention to the Consul’s "Sanitary Memorandum", as it reflects the scope of interest and range of knowledge of the average British diplomat at the time

Tko je vodio pravedan rat? Walzerova teorija i rat u bivšoj Jugoslaviji

Applying Walzer’s theory, this article analyzes the morality of the war in the former Yugoslavia. The main findings are the following: Serbia fought an unjust war during the entire 1991-99 period. Montenegro participated in the aggression on Croatia. Croatia also fought a just war on its own territory and on the territory of Bosnia and Herzegovina in 1992, 1994 and 1995. However, Croatia fought an unjust war in Bosnia and Herzegovina in 1993. Bosnia and Herzegovina and Kosovo both fought just wars. The international community prosecuted just war crimes (Lat. jus in bello) and did not prosecute the very aggression (Lat. jus ad bellum).Ovaj članak – na osnovi Walzerove teorije o pravednom ratu – analizira etičke aspekte rata na prostoru bivše Jugoslavije. Glavni su zaključci sljedeći: Srbija je tijekom čitavog razdoblja od 1991. do 1999. vodila nepravedan rat. Crna Gora sudjelovala je u agresiji na Hrvatsku. Hrvatska je vodila pravedan rat na teritoriju Hrvatske i u Bosni i Hercegovini 1992., 1994. i 1995. godine. Međutim 1993. godine vodila je nepravedan rat u Bosni i Hercegovini. Bosna i Hercegovina i Kosovo vodili su pravedne ratove braneći se od srpske agresije. Međunarodna zajednica propustila je kazniti zločin agresije (jus ad bellum), procesuirajući samo ratne zločine (jus in bellum)

Procedure for Secession

This article analyzes possible procedures for political secession. After a literature review of theories of secession, the article presents the main arguments against and for secession. Than, on the basis of “no-fault” theory, this article proposes a procedure for secession. Furthermore, this procedure is empirically tested through analyses of secessions from former Yugoslavia. The main hypothesis is that secession is justified in two cases: first, when secession occurs as a result of consensus of all the main actors, including central government, and, second, when at least two-third majority of population supports secession

Neutrality as Independence: Great Britain, Serbia and the Crimean War

Special Editions 95. Institute for Balkan Studies of the Serbian Academy of Sciences and Art