Improved bounds for the number of forests and acyclic orientations in the square lattice

In a recent paper Merino and Welsh (1999) studied several counting problems on the square lattice $L_n$. The authors gave the following bounds for the asymptotics of $f(n)$, the number of forests of $L_n$, and $\alpha(n)$, the number of acyclic orientations of $L_n$: $3.209912 \leq \lim_{n\rightarrow\infty} f(n)^{1/n^2} \leq 3.84161$ and $22/7 \leq \lim_{n\rightarrow\infty} \alpha(n) \leq 3.70925$. In this paper we improve these bounds as follows: $3.64497 \leq \lim_{n\rightarrow\infty} f(n)^{1/n^2} \leq 3.74101$ and $3.41358 \leq \lim_{n\rightarrow\infty} \alpha(n) \leq 3.55449$. We obtain this by developing a method for computing the Tutte polynomial of the square lattice and other related graphs based on transfer matrices

Reasoning by analogy in the generation of domain acceptable ontology refinements

Refinements generated for a knowledge base often involve the learning of new knowledge to be added to or replace existing parts of a knowledge base. However, the justifiability of the refinement in the context of the domain (domain acceptability) is often overlooked. The work reported in this paper describes an approach to the generation of domain acceptable refinements for incomplete and incorrect ontology individuals through reasoning by analogy using existing domain knowledge. To illustrate this approach, individuals for refinement are identified during the application of a knowledge-based system, EIRA; when EIRA fails in its task, areas of its domain ontology are identified as requiring refinement. Refinements are subsequently generated by identifying and reasoning with similar individuals from the domain ontology. To evaluate this approach EIRA has been applied to the Intensive Care Unit (ICU) domain. An evaluation (by a domain expert) of the refinements generated by EIRA has indicated that this approach successfully produces domain acceptable refinements

Graph-Embedding Empowered Entity Retrieval

In this research, we improve upon the current state of the art in entity retrieval by re-ranking the result list using graph embeddings. The paper shows that graph embeddings are useful for entity-oriented search tasks. We demonstrate empirically that encoding information from the knowledge graph into (graph) embeddings contributes to a higher increase in effectiveness of entity retrieval results than using plain word embeddings. We analyze the impact of the accuracy of the entity linker on the overall retrieval effectiveness. Our analysis further deploys the cluster hypothesis to explain the observed advantages of graph embeddings over the more widely used word embeddings, for user tasks involving ranking entities

vSPARQL: A View Definition Language for the Semantic Web

Translational medicine applications would like to leverage the biological and biomedical ontologies, vocabularies, and data sets available on the semantic web. We present a general solution for RDF information set reuse inspired by database views. Our view definition language, vSPARQL, allows applications to specify the exact content that they are interested in and how that content should be restructured or modified. Applications can access relevant content by querying against these view definitions. We evaluate the expressivity of our approach by defining views for practical use cases and comparing our view definition language to existing query languages

Victoria County, Texas, records of wells, driller's logs, water analyses, and map showing location of wells

Map of Victoria County, Texas, showing location of water wells. Prepared in cooperation with United States Department of the Interior, Geological SurveyUT Librarie

How Unsplittable-Flow-Covering helps Scheduling with Job-Dependent Cost Functions

Generalizing many well-known and natural scheduling problems, scheduling with job-specific cost functions has gained a lot of attention recently. In this setting, each job incurs a cost depending on its completion time, given by a private cost function, and one seeks to schedule the jobs to minimize the total sum of these costs. The framework captures many important scheduling objectives such as weighted flow time or weighted tardiness. Still, the general case as well as the mentioned special cases are far from being very well understood yet, even for only one machine. Aiming for better general understanding of this problem, in this paper we focus on the case of uniform job release dates on one machine for which the state of the art is a 4-approximation algorithm. This is true even for a special case that is equivalent to the covering version of the well-studied and prominent unsplittable flow on a path problem, which is interesting in its own right. For that covering problem, we present a quasi-polynomial time $(1+\epsilon)$-approximation algorithm that yields an $(e+\epsilon)$-approximation for the above scheduling problem. Moreover, for the latter we devise the best possible resource augmentation result regarding speed: a polynomial time algorithm which computes a solution with \emph{optimal }cost at $1+\epsilon$ speedup. Finally, we present an elegant QPTAS for the special case where the cost functions of the jobs fall into at most $\log n$ many classes. This algorithm allows the jobs even to have up to $\log n$ many distinct release dates.Comment: 2 pages, 1 figur

Utilising semantic technologies for intelligent indexing and retrieval of digital images

The proliferation of digital media has led to a huge interest in classifying and indexing media objects for generic search and usage. In particular, we are witnessing colossal growth in digital image repositories that are difficult to navigate using free-text search mechanisms, which often return inaccurate matches as they in principle rely on statistical analysis of query keyword recurrence in the image annotation or surrounding text. In this paper we present a semantically-enabled image annotation and retrieval engine that is designed to satisfy the requirements of the commercial image collections market in terms of both accuracy and efficiency of the retrieval process. Our search engine relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query. We also show how our well-analysed and designed domain ontology contributes to the implicit expansion of user queries as well as the exploitation of lexical databases for explicit semantic-based query expansion

SPEDEN: Reconstructing single particles from their diffraction patterns

Speden is a computer program that reconstructs the electron density of single particles from their x-ray diffraction patterns, using a single-particle adaptation of the Holographic Method in crystallography. (Szoke, A., Szoke, H., and Somoza, J.R., 1997. Acta Cryst. A53, 291-313.) The method, like its parent, is unique that it does not rely on ``back'' transformation from the diffraction pattern into real space and on interpolation within measured data. It is designed to deal successfully with sparse, irregular, incomplete and noisy data. It is also designed to use prior information for ensuring sensible results and for reliable convergence. This article describes the theoretical basis for the reconstruction algorithm, its implementation and quantitative results of tests on synthetic and experimentally obtained data. The program could be used for determining the structure of radiation tolerant samples and, eventually, of large biological molecular structures without the need for crystallization.Comment: 12 pages, 10 figure

Desarrollo de metodologias de propagación y cultivo de plantas nativas de Córdoba con potencialornamental. Development of propagation and cultivation methodologies of native plants of Córdoba withornamental potential.

El problema: La flora nativa de Córdoba, actualmente amenazada, es rica en especies con potencial ornamental que todavía no se cultivan. El uso de estas plantas está limitado por la escasez de material biológico, la falta de conocimientos de su propagación y su insuficiente valoración pública. Hipótesis: La propagación y el cultivo de una amplia gama de plantas nativas cordobesas con potencial ornamental son técnicamente factibles y tienen potencial productivo y económico. Objetivo: Promover el uso de especies nativas ornamentales en la provincia de Córdoba. Objetivos específicos: 1. Desarrollar metodologías de propagación y cultivo de especies nativas con potencial ornamental; 2. Transferir estas metodologías a viveros privados y públicos; 3. Difundir los conocimientos obtenidos a instituciones educativas. Métodos: 1- Colección: Se realizarán viajes de campo para obtener semillas o esquejes de al menos 6 especies nativas seleccionadas. Las semillas se limpiarán y se conservarán en frío. 2- Propagación: En la primavera se sembrarán 100 semillas por especie, accesión y tratamiento; se registrará porcentaje y tiempo de germinación. Los plantines se trasplantarán a almácigos, se registrará supervivencia y crecimiento. Para la propagación vegetativa, se trasplantarán esquejes de estolones directamente a macetas. 3- Trasplante: En verano, los plantines se trasplantarán a macetas grandes; se registrará supervivencia y crecimiento durante un año. 4- Documentación: Se elaborarán protocolos de las metodologías adecuadas para la propagación de las especies, usos ornamentales y características relevantes. 5- Transferencia: Los protocolos, muestras de semillas y de plantas, se transferirán a dos viveros que se comprometan a continuar con el cultivo de las especies. 6- Difusión: Se realizarán cursos, talleres, charlas y pasantías para dar a conocer la propagación de plantas nativas en instituciones educativas, desde la primaria hasta la universidad. Resultados y productos esperados: 1- Protocolos de propagación de al menos 6 especies nativas ornamentales y su transferencia a viveros, como base de una actividad productiva novedosa. 2- Un aporte a la conservación ex situ y el uso sostenible de la flora nativa. 3- Una mayor valoración de esta en la comunidad educativa. Importancia: 1- Desarrollo de la producción de plantas nativas con valor ornamental, como una alternativa económica. 2- Conservación ex situ y uso sostenible de la flora nativa. 3- Difusión del conocimiento del valor ornamental de las nativas. 4. Información científica de la biología y ecología de especies nativas. Pertinencia: Productos (ver Resultados). El impacto inmediato esperado es un aumento en la propagación, la producción, la demanda, la comercialización y el uso de plantas ornamentales nativas. Se espera también la generación de nuevos conocimientos y el estímulo de líneas de investigación biológicas y agronómicas

Protégé: A Tool for Managing and Using Terminology in Radiology Applications

The development of standard terminologies such as RadLex is becoming important in radiology applications, such as structured reporting, teaching file authoring, report indexing, and text mining. The development and maintenance of these terminologies are challenging, however, because there are few specialized tools to help developers to browse, visualize, and edit large taxonomies. Protégé (http://protege.stanford.edu) is an open-source tool that allows developers to create and to manage terminologies and ontologies. It is more than a terminology-editing tool, as it also provides a platform for developers to use the terminologies in end-user applications. There are more than 70,000 registered users of Protégé who are using the system to manage terminologies and ontologies in many different domains. The RadLex project has recently adopted Protégé for managing its radiology terminology. Protégé provides several features particularly useful to managing radiology terminologies: an intuitive graphical user interface for navigating large taxonomies, visualization components for viewing complex term relationships, and a programming interface so developers can create terminology-driven radiology applications. In addition, Protégé has an extensible plug-in architecture, and its large user community has contributed a rich library of components and extensions that provide much additional useful functionalities. In this report, we describe Protégé’s features and its particular advantages in the radiology domain in the creation, maintenance, and use of radiology terminology