String attractors and combinatorics on words

The notion of string attractor has recently been introduced in [Prezza, 2017] and studied in [Kempa and Prezza, 2018] to provide a unifying framework for known dictionary-based compressors. A string attractor for a word w = w[1]w[2] · · · w[n] is a subset Γ of the positions 1, . . ., n, such that all distinct factors of w have an occurrence crossing at least one of the elements of Γ. While finding the smallest string attractor for a word is a NP-complete problem, it has been proved in [Kempa and Prezza, 2018] that dictionary compressors can be interpreted as algorithms approximating the smallest string attractor for a given word. In this paper we explore the notion of string attractor from a combinatorial point of view, by focusing on several families of finite words. The results presented in the paper suggest that the notion of string attractor can be used to define new tools to investigate combinatorial properties of the words

DERIVING EMPIRICAL DEFINITIONS OF SPATIAL LABOR MARKETS: THE ROLES OF COMPETING VERSUS COMPLEMENTARY GROWTH

Rural communities compete with each other for firms, but their residents often commute large distances to work. Consequently, rural communities can benefit from economic growth occurring as much as 50 miles away. Data on county population growth shows that counties benefit from growth one or two counties away.Labor and Human Capital,

STRATEGI BERTAHAN HIDUP PERAJIN SULING BAMBU KELURAHAN GAYAM KECAMATAN MOJOROTO KOTA KEDIRI

Abstract Bamboo flute is one of  the greatest musical instrument for the handicrafts workers in Gayam village, sub district of Mojoroto, city of Kediri. Bamboo flute is one of traditional art musical instrument inherited by local ancestor in gayam village. Since 1950 until now, bamboo flute handicrafts workers declined significantly from 83 to 5 handicrafts workers. This happened because of rare raw materials and the monetary crisis in 1998. Research was to know handicraft workers’ survival startegy to fulfill their family needs. The subject of study were 9 bamboo flute workers who lived in Gayam village, consisting of 5 informants bamboo flute handicrafts workers, 3 informants who were  former Bamboo flute handicrafts worker, and key informants was a local officials. This study used qualitative research conducted by the use of the basic theories of james c scoot. The result of this research showed that bamboo flute handicrafts workers used 3 survival strategy includin, strategy of adding up the expenditure add up, managing expenditure, and using network. Although handicrafts workers were still  classified as the poor family, but they felt prosperous society in their own personal .When handicrafts workers stop being an bamboo flute handicrafts workers they felt not being prosperous. This feeling happened because they were happy to be a Bamboo flute and could  continue cultural heritage as Bamboo flute in Gayam village, sub district of  Mojoroto, city of Kediri.  Keywords: handicrafts workers, survival strategy, prosperous   Abstrak Suling bambu adalah salah satu alat musik yang menjadi andalan bagi para perajin di Kelurahan Gayam Kecamatan Mojoroto Kota Kediri. Suling bambu yang ada di Kelurahan Gayam adalah salah satu seni tradisional alat musik yang diwariskan turun temurun oleh nenek moyang Kelurahan Gayam setempat. Dari tahun 1950 sampai sekarang suling bambu mengalami penurunan jumlah perajin yang signifikan dari 83 perajin menjadi 5 perajin. Penurunan yang signifikan di karenakan bahan baku yang langka dan krisis moneter tahun 1998. Penelitian dilaksanakan di Kelurahan Gayam Kecamatan Mojoroto Kota Kediri. Penelitian ditarik dari strategi bertahan hidup perajin suling bambu demi kesejahteraan kehidupan keluarga perajin yang menurut Scoot ada 3 strategi yaitu strategi alternative substansi, strategi mengikat sabuk lebih kencang dan strategi jaringan. Subjek penelitian adalah perajin suling bambu yang hidup di Kelurahan Gayam dengan jumlah informan 9 orang, terdiri dari 5 informan perajin suling bambu, 3 informan mantan perajin suling bambu, dan informan kunci lurah setempat. Penelitian diangkat dengan metode penelitian kualitatif. Hasil penelitian ini menggambarkan perajin suling bambu yang masih bertahan di karenakan menggunakan 3 strategi bertahan hidup antara lain strategi menambah pemasukan, mengatur pengeluaran, dan memanfaatkan jaringan. Keadaan ekonomi perajin yang dikategorikan masyarakat miskin, perajin suling bambu adalah masyarakat yang sejahtera secara pribadi mereka sendiri. Ketika perajin berhenti menjadi seorang perajin suling bambu di situlah perajin merasa mereka tidak sejahtera, di karenakan yang diinginkan perajin suling bambu ialah menjadi seorang perajin dan meneruskan warisan budaya suling bambu yang ada didaerah Kelurahan Gayam Kecamatan Mojoroto Kota Kediri. Kata Kunci : Perajin, Strategi Beretahan Hidup, Kesejahteraa

An analysis of police officers decisions about whether to refer cases of child abuse for prosecution

In many jurisdictions, police officers are responsible for deciding whether cases of child abuse are referred for potential prosecution. Such discretion justifies the need to scrutinise these professionals\u27 decisions to determine if they are consistent with the scientific eyewitness memory literature. Prior research has shown that interviewer questioning is one of the most critical factors impacting the reliability of child witness statements. Hence, we asked: \u27To what degree do officers\u27 consider the quality of interviewer questions when making case authorisation decisions?\u27. In order to answer this question, we conducted a thematic analysis to identify issues referred to in a sample of documented police correspondence (n=33) about potential prosecution of child abuse cases. Two key themes emerged: the existence of corroborative evidence and whether the suspect denied the allegations. Questioning technique, however, was not considered. All but one decision that referred to interview process focused on the presentation of the witness, even though the witness interviews (as a whole) did not adhere to recommended best-practice guidelines. The implications of these findings are discussed. <br /

On the Impact of Morphisms on BWT-Runs

Morphisms are widely studied combinatorial objects that can be used for generating infinite families of words. In the context of Information theory, injective morphisms are called (variable length) codes. In Data compression, the morphisms, combined with parsing techniques, have been recently used to define new mechanisms to generate repetitive words. Here, we show that the repetitiveness induced by applying a morphism to a word can be captured by a compression scheme based on the Burrows-Wheeler Transform (BWT). In fact, we prove that, differently from other compression-based repetitiveness measures, the measure r_bwt (which counts the number of equal-letter runs produced by applying BWT to a word) strongly depends on the applied morphism. More in detail, we characterize the binary morphisms that preserve the value of r_bwt(w), when applied to any binary word w containing both letters. They are precisely the Sturmian morphisms, which are well-known objects in Combinatorics on words. Moreover, we prove that it is always possible to find a binary morphism that, when applied to any binary word containing both letters, increases the number of BWT-equal letter runs by a given (even) number. In addition, we derive a method for constructing arbitrarily large families of binary words on which BWT produces a given (even) number of new equal-letter runs. Such results are obtained by using a new class of morphisms that we call Thue-Morse-like. Finally, we show that there exist binary morphisms μ for which it is possible to find words w such that the difference r_bwt(μ(w))-r_bwt(w) is arbitrarily large

Metastability for General Dynamics with Rare Transitions: Escape Time and Critical Configurations

Metastability is a physical phenomenon ubiquitous in first order phase transitions. A fruitful mathematical way to approach this phenomenon is the study of rare transitions Markov chains. For Metropolis chains associated with Statistical Mechanics systems, this phenomenon has been described in an elegant way in terms of the energy landscape associated to the Hamiltonian of the system. In this paper, we provide a similar description in the general rare transitions setup. Beside their theoretical content, we believe that our results are a useful tool to approach metastability for non--Metropolis systems such as Probabilistic Cellular Automata

Expanding the therapeutic potential of Statins by means of nanotechnology enabled drug delivery systems

Statins are effective lipid lowering agents traditionally used for the primary and secondary prevention of cardiovascular disease. Statins also exert a range of pleiotropic effects that make them attractive candidates for use in a wide range of disorders, in particular inflammatory and immune mediated conditions. However, the exploitation of such pleiotropic effects has been greatly hindered by poor bioavailability and adverse effects on muscles and the liver at higher doses. Nanotechnology is often suggested as the solution to this problem, as it enables an increased bioavailability of statins. Moreover, colloidal carriers can offer targeted drug delivery approaches that enable localised biological effects of statins, further reducing their potential for unwanted toxicity and adverse effects. This article reviews the available evidences for the increased potential of statin therapy when administered in nano-formulations such as nanocrystals, nanoparticles, liposomes, micelles and various nano-enabled devices. © 2014 Bentham Science Publishers

The NASA Spitzer Space Telescope

The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991–2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/