A Unary Semigroup Trace Algebra

The Unifying Theories of Programming (UTP) of Hoare and He promote the unification of semantics catering for different concerns, such as, termination, data modelling, concurrency and time. Process calculi like Circus and CSP can be given semantics in the UTP using reactive designs whose traces can be abstractly specified using a monoid trace algebra. The prefix order over traces is defined in terms of the monoid operator. This order, however, is inadequate to characterise a broader family of timed process algebras whose traces are preordered instead. To accommodate these, we propose a unary semigroup trace algebra that is weaker than the monoid algebra. This structure satisfies some of the axioms of restriction semigroups and is a right P-Ehresmann semigroup. Reactive designs specified using it satisfy core laws that have been mechanised so far in Isabelle/UTP. More importantly, our results improve the support for unifying trace models in the UTP

Coronica [sic] y historia de la fundacion y progresso de la provincia de Castilla de la orden del bienauenturado padre San Francisco

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010El nombre del impresor consta en colofónPort. con esc. xil

Angelic Processes

In the formal modelling of systems, demonic and angelic nondeterminism play fundamental roles as abstraction mechanisms. The angelic nature of a choice pertains to the property of avoiding failure whenever possible. As a concept, angelic choice first appeared in automata theory and Turing machines, where it can be implemented via backtracking. It has traditionally been studied in the refinement calculus, and has proved to be useful in a variety of applications and refinement techniques. Recently it has been studied within relational, multirelational and higher-order models. It has been employed for modelling user interactions, game-like scenarios, theorem proving tactics, constraint satisfaction problems and control systems. When the formal modelling of state-rich reactive systems is considered, it only seems natural that both types of nondeterministic choice should be considered. However, despite several treatments of angelic nondeterminism in the context of process algebras, namely Communicating Sequential Processes, the counterpart to the angelic choice of the refinement calculus has been elusive. In this thesis, we develop a semantics in the relational setting of Hoare and He's Unifying Theories of Programming that enables the characterisation of angelic nondeterminism in CSP. Since CSP processes are given semantics in the UTP via designs, that is, pre and postcondition pairs, we first introduce a theory of angelic designs, and an isomorphic multirelational model, that is suitable for characterising processes. We then develop a theory of reactive angelic designs by enforcing the healthiness conditions of CSP. Finally, by introducing a notion of divergence that can undo the history of events, we obtain a model where angelic choice avoids divergence. This lays the foundation for a process algebra with both nondeterministic constructs, where existing and novel abstract modelling approaches can be considered. The UTP basis of our work makes it applicable in the wider context of reactive systems

Monarquía de España

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Sign.: []2, a-c4, d2, A-Z4, 2A-2Z4, 3A-3E4, 3F2 ; []2, A-Z4, 2A-2Z4, 3A-3I4, 3K2Texto a dos col.Antep

Evaluacion de cinco materiales geneticos de maiz (Zea mays L.) con diferentes poblaciones de plantas en la Granja Agropecuaria del SENA (Santa Marta - Magdalena)

Este estudio se realizó en la Granja Agropecuaria del SENA, ubicada en el corregimiento de Gaira, Municipio de Santa Marta. Geográficamente la zona se encuentra enmarcada dentro de las siguientes coordenadas, 74' 07' y 74' 12' longitud oeste con respecto al meridiano de Greenwich, 11' 11' y 11' y 15' latitud norte con respecto al ecuador. La zona de estudio presenta un relieve plano con una altura de 7 m.s.n.m., una precipitación promedia de EISO mm. anuales, una temperatura media de 32° C y una humedad relativa entre 70-72%, influenciada por vientos que soplan en dirección noreste. El ensayo se llevó a cabo en el segundo semestre del año 1993, el cual consistió en determinar la evaluación de cinco materiales genéticos de maiz: con diferentes poblaciones de plantas. Se utilizó el diseño experimental de parcelas divididas con distribución en bloques al azar, se evaluaron 15 tratamientos con tres repeticiones, correspondiéndole a cada uno de ellos un material genético con tres distancias de siembras entre plantas diferentes. Cada tratamiento estuvo formado por parcelas de 3,6 m de ancho por 4.0 m de largo para un total de 14,4 m2 por parcela, para un área efectiva de 648 m2 y un área total de 1.320 m2 . Los materiales o genotipos sometidos al ensayo fueron los siguientes: Como testigo el ICA V156, y los híbridos SV 902, FUNK'S 65423, HR661 y SV901. Los resultados del presente ensayo con respecto al rendimiento experimental promedio muestran que el material de mejor comportamiento en la zona de estudio fue el HR661, y la densidad poblacional óptima para los materiales ensayados fue de 70.000. plantas/Ha

Isabelle/UTP: Mechanised Theory Engineering for the UTP

Isabelle/UTP is a mechanised theory engineering toolkit based on Hoare and He’s Unifying Theories of Programming (UTP). UTP enables the creation of denotational, algebraic, and operational semantics for different programming languages using an alphabetised relational calculus. We provide a semantic embedding of the alphabetised relational calculus in Isabelle/HOL, including new type definitions, relational constructors, automated proof tactics, and accompanying algebraic laws. Isabelle/UTP can be used to both capture laws of programming for different languages, and put these fundamental theorems to work in the creation of associated verification tools, using calculi like Hoare logics. This document describes the relational core of the UTP in Isabelle/HOL

Angelic Processes for CSP via the UTP

Demonic and angelic nondeterminism play fundamental roles as abstraction mechanisms for formal modelling. In contrast with its demonic counterpart, in an angelic choice failure is avoided whenever possible. Although it has been extensively studied in refinement calculi, in the context of process algebras, and of the Communicating Sequential Processes (CSP) algebra for refinement, in particular, it has been elusive. We show here that a semantics for an extended version of CSP that includes both demonic and angelic choice can be provided using Hoare and He's Unifying Theories of Programming (UTP). Since CSP is given semantics in the UTP via reactive designs (pre and postcondition pairs) we have developed a theory of angelic designs and a conservative extension of the CSP theory using reactive angelic designs. To characterise angelic nondeterminism appropriately in an algebra of processes, however, a notion of divergence that can undo the history of events needs to be considered. Taking this view, we present a model for CSP where angelic choice completely avoids divergence just like in the refinement calculi for sequential programs

Educational and self reflection teacher evaluation: symbiosis and predation?

Se trata de un trabajo que recoge la opinión de profesores chilenos, sobre la autoevaluación que realizan docentes municipales sometidos al programa nacional de evaluación docente. Los resultados de dicho programa revelan que en el quinquenio 2007-2011, existe una marcada diferencia en los promedios nacionales obtenidos en la autoevaluación que se asignan los docentes (3,9 sobre 4), con las ocho dimensiones que evalúa el portafolio, donde su promedio no alcanza el mínimo de aprobación (2,5 sobre 4). Se aplicó una entrevista semiestructurada a 38 profesores pertenecientes a establecimientos particulares subvencionados (los que no tienen obligación alguna de participar del programa nacional de evaluación). La explicación que otorgan en relación a esta discrepancia, es en su mayoría a la falta de reflexión y autocrítica de los docentes con respecto a su desempeño, mientras que un porcentaje no menor, mencionan que los instrumentos de evaluación no se acercan a la realidad nacional y son fácilmente manipulables. Cabe destacar, que existe cierto desconocimiento en relación a las prácticas evaluativas utilizadas por el programa, sin embargo, aun así, se plantea como una forma de abordar el problema, brindar mayor capacitación y supervisión de las prácticas docentes.It’s about a work that piles the opinions of several Chilean professors, on self-assessment made by educators municipal submitted to national teacher evaluation program. The results of this program shows that in the period of 2007-2011, there is a marked difference in the national averages obtained in the self-assessment that teachers are assigned (3,9 over 4) with the 8 dimensions that are evaluated on the briefcase, where the average don’t reach the minimum of approbation (2,5 over 4). A semi structured interview was applied to 38 professors belonging to private subsidized schools (the ones who had no obligations so ever in participate in the national program of evaluation). The explanation they give regarding this discrepancy is mostly a lack of reflection and self-criticism of teachers with regard to their performance, meanwhile a not minor percentage, mentions that the instruments of evaluations are not close to the national reality and are easily manipulable. Remarkably, there is some dark regarding assessment practices used by the program, however, still is seen as a way to address the problem, provide more training and supervision of teaching practice

Origen de las dignidades seglares de Castilla y Leon : con relacion sumaria de los reyes de estos Reynos... de los que las han creado,... de Ricos Homes... : con un resumen al fin de las mercedes que su Magestad ha hecho de Marqueses y Condes desde... 1621 hasta fin del de 1656...

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Sign.: [calderón]\p4\s, A-Z\p8\s, 2A\p6\s, 2B\p2\sTexto a dos colAntep.Resumen de las mercedes de marqueses y condes que su magestad ha hecho desde el año de 1621 hasta el de 1656, el las 3 h. finale

Vida y sucesos prosperos y adversos de Don Fr. Bartolome de Carranza y Miranda, Arzobispo de Toledo ...

Sign.: A-O8ReclamosFriso xil