Sizing the length of complex networks

Among all characteristics exhibited by natural and man-made networks the small-world phenomenon is surely the most relevant and popular. But despite its significance, a reliable and comparable quantification of the question `how small is a small-world network and how does it compare to others' has remained a difficult challenge to answer. Here we establish a new synoptic representation that allows for a complete and accurate interpretation of the pathlength (and efficiency) of complex networks. We frame every network individually, based on how its length deviates from the shortest and the longest values it could possibly take. For that, we first had to uncover the upper and the lower limits for the pathlength and efficiency, which indeed depend on the specific number of nodes and links. These limits are given by families of singular configurations that we name as ultra-short and ultra-long networks. The representation here introduced frees network comparison from the need to rely on the choice of reference graph models (e.g., random graphs and ring lattices), a common practice that is prone to yield biased interpretations as we show. Application to empirical examples of three categories (neural, social and transportation) evidences that, while most real networks display a pathlength comparable to that of random graphs, when contrasted against the absolute boundaries, only the cortical connectomes prove to be ultra-short

Comparing rule-based and data-driven approaches to Spanish-to-Basque machine translation

In this paper, we compare the rule-based and data-driven approaches in the context of Spanish-to-Basque Machine Translation. The rule-based system we consider has been developed specifically for Spanish-to-Basque machine translation, and is tuned to this language pair. On the contrary, the data-driven system we use is generic, and has not been specifically designed to deal with Basque. Spanish-to-Basque Machine Translation is a challenge for data-driven approaches for at least two reasons. First, there is lack of bilingual data on which a data-driven MT system can be trained. Second, Basque is a morphologically-rich agglutinative language and translating to Basque requires a huge generation of morphological information, a difficult task for a generic system not specifically tuned to Basque. We present the results of a series of experiments, obtained on two different corpora, one being “in-domain” and the other one “out-of-domain” with respect to the data-driven system. We show that n-gram based automatic evaluation and edit-distance-based human evaluation yield two different sets of results. According to BLEU, the data-driven system outperforms the rule-based system on the in-domain data, while according to the human evaluation, the rule-based approach achieves higher scores for both corpora

Using Scratch to Teach Undergraduate Students' Skills on Artificial Intelligence

This paper presents a educational workshop in Scratch that is proposed for the active participation of undergraduate students in contexts of Artificial Intelligence. The main objective of the activity is to demystify the complexity of Artificial Intelligence and its algorithms. For this purpose, students must realize simple exercises of clustering and two neural networks, in Scratch. The detailed methodology to get that is presented in the article.Comment: 6 pages, 7 figures, workshop presentatio

Hormigón Ligero

Peer Reviewe

Content and end-state-based alteration in the practice of political violence since the end of cold war: the difference between the terrorism of the cold war and the terrorism of al Qaeda: the rise of the "transcendental terrorist"

For more than two generations the world was defined in international political terms by the label, the Cold War. This phrase was shorthand for many phenomena, including the division of the East and West into two blocs and the ideologicallybased definition of said blocs. Whilst we cannot state that the whole of the world was divided in an iron-clad fashion into two separate camps – the neutral and nonaligned nations representing a sizeable constituency – the fact remains that for North America, Western Europe, the USSR and the Soviet controlled satellite nations, the bipolarity of the Cold War geostrategic environment had an overarching impact upon several areas of policy, including national security, foreign affairs, defence and attitudes to the use of force. The influence of the bipolar stand-off had a significant shaping effect with regard to how government was organised on both sides of the Iron Curtain and on the ways in which threat perceptions were managed and influenced national policies concerning security. Fundamentally, the effect can be summarised as follows: Internally: National governments secured the law and order and domestic stability of their state system primarily through the agency of the police (or militia). These authorities were mandated to fight common crime and, in the West, to assist in the fight against terrorism. Additionally a threat was posed by the intelligence agents and subversives of the other bloc. As a result the domestic element of this threat was responded to with counter-intelligence agencies. Externally: The threat of a conventional war (World War III) meant that the armed forces of each bloc had to prepare for a possible bloc on bloc conflict in which classic concepts of territorial defence against an outside aggressor were central. The external threat was dealt with fundamentally by means of intelligence. It was not adequate to simply prepare domestically for a war with the other bloc. To be able to deter and to prepare against the opposition it was necessary to gather pertinent information (intelligence) on the enemy. This intelligence could be either technical and military in nature – for example the nature and capabilities of a new piece of military equipment fielded by the opposing army – or political and economic, such as the inner workings and intentions of the enemy’s political elite, or government and the state given industrial sectors. This distinction led to the fact that each type of information was gathered by a separate authority, the former being military intelligence and the latter being civilian intelligence

The Spanish intonation of speakers of a Basque pitch-accent dialect

In this paper the main aspects of the intonation of broad focus declaratives in Lekeitio Spanish are described and analyzed. In this variety, accents are realized as pitch rises rather than falls, similarly to Standard Peninsular Spanish and unlike in Lekeitio Basque, the other native language of these speakers. Accentual valleys are aligned before the onset of the stressed syllable, except in final position in the utterance. Accentual peaks are aligned before the offset of the accented syllable, with an earlier alignment in accents in the object phrase. At the end of the subject phrase, peaks display later alignment. The number of unstressed syllables intervening between accents seems to affect F0 valley and peak alignment for certain positions. For non-object positions, F0 valleys align earlier as more unstressed syllables intervene between accents, and for the final position in the subject, F0 peaks align later as more unstressed syllables intervene between accents.Aquest article descriu i analitza els principals aspectes de l'entonació de les oracions declaratives de l'espanyol parlat a Lekeitio. En aquesta varietat, els accents tonals es realitzen com a moviments ascendents en lloc de descendents: en això s'apropen a la varietat estàndard d'espanyol peninsular i es distingeixen de l'altra seva llengua nativa, el basc parlat a Biscaia. Les valls s'alineen abans del començament de la síl·laba accentuada, llevat dels accents que es troben en posició final de frase. Els pics s'alineen abans del final de la síl·laba accentuada (fins i tot abans en posició d'objecte directe). Al final dels subjectes, els pics mostren més desplaçament cap a la síl·laba següent. El nombre de síl·labes àtones entre accents tonals també sembla afectar la posició de les valls i dels pics en algunes posicions. En posicions que no són d'objecte, les valls d'F0 s'alineen abans quan hi ha més síl·labes àtones intermèdies, i en posició final de subjecte, els pics se situen més tard quan hi ha més síl·labes àtones