Formalizing operator task analysis

Human operators are unique in their decision making capability, judgment and nondeterminism. Their sense of judgment, unpredictable decision procedures, susceptibility to environmental elements can cause them to erroneously execute a given task description to operate a computer system. Usually, a computer system is protected against some erroneous human behaviors by having necessary safeguard mechanisms in place. But some erroneous human operator behaviors can lead to severe or even fatal consequences especially in safety critical systems. A generalized methodology that can allow modeling and analyzing the interactions between computer systems and human operators where the operators are allowed to deviate from their prescribed behaviors will provide a formal understanding of the robustness of a computer system against possible aberrant behaviors by its human operators. We provide several methodology for assisting in modeling and analyzing human behaviors exhibited while operating computer systems. Every human operator is usually given a specific recommended set of guidelines for operating a system. We first present process algebraic methodology for modeling and verifying recommended human task execution behavior. We present how one can perform runtime monitoring of a computer system being operated by a human operator for checking violation of temporal safety properties. We consider the concept of a protection envelope giving a wider class of behaviors than those strictly prescribed by a human task that can be tolerated by a system. We then provide a framework for determining whether a computer system can maintain its guarantees if the human operators operate within their protection envelopes. This framework also helps to determine the robustness of the computer system under weakening of the protection envelopes. In this regard, we present a tool called Tutela that assists in implementing the framework. We then examine the ability of a system to remain safe under broad classes of variations of the prescribed human task. We develop a framework for addressing two issues. The first issue is: given a human task specification and a protection envelope, will the protection envelope properties still hold under standard erroneous executions of that task by the human operators? In other words how robust is the protection envelope? The second issue is: in the absence of a protection envelope, can we approximate a protection envelope encompassing those standard erroneous human behaviors that can be safely endured by the system? We present an extension of Tutela that implements this framework. The two frameworks mentioned above use Concurrent Game Structures (CGS) as models for both computer systems and their human operators. However, there are some shortcomings of this formalism for our uses. We add incomplete information concepts in CGSs to achieve better modularity for the players. We introduce nondeterminism in both the transition system and strategies of players and in the modeling of human operators and computer systems. Nondeterministic action strategies for players in \emph{i}ncomplete information \emph{N}ondeterministic CGS (iNCGS) is a more precise formalism for modeling human behaviors exhibited while operating a computer system. We show how we can reason about a human behavior satisfying a guarantee by providing a semantics of Alternating Time Temporal Logic based on iNCGS player strategies. In a nutshell this dissertation provides formal methodology for modeling and analyzing system robustness against both expected and erroneous human operator behaviors.

Contratación logística en Colombia: implementación de un operador logístico integral

Este artículo tiene como objetivo presentar los criterios que se deben tener en cuenta para contratar los servicios de los operadores logísticos. Las evidencias presentadas en este artículo se basan en información obtenida a través de encuestas, entrevistas, estudio de casos, sondeos y revisión de literatura. La principal conclusión muestra que la claridad contractual es clave en el surgimiento de un nuevo modelo de negocio que puede impulsar el desarrollo del país. Las empresas deben ver la contratación logística con una oportunidad estratégica, al igual que pensar en cada posible situación que se pueda presentar para así plasmar un curso de acción en el contrato

Fractional differential equations with dependence on the Caputo-Katugampola derivative

In this paper we present a new type of fractional operator, the Caputo–Katugampola derivative. The Caputo and the Caputo–Hadamard fractional derivatives are special cases of this new operator. An existence and uniqueness theorem for a fractional Cauchy type problem, with dependence on the Caputo–Katugampola derivative, is proven. A decomposition formula for the Caputo–Katugampola derivative is obtained. This formula allows us to provide a simple numerical procedure to solve the fractional differential equation.

Modeling some real phenomena by fractional differential equations

This paper deals with fractional differential equations, with dependence on a Caputo fractional derivative of real order. The goal is to show, based on concrete examples and experimental data from several experiments, that fractional differential equations may model more efficiently certain problems than ordinary differential equations. A numerical optimization approach based on least squares approximation is used to determine the order of the fractional operator that better describes real data, as well as other related parameters.

Solutions of Tikhonov functional equations and applications to multiplication operators on Szegö spaces

We consider a natural representation of solutions for Tikhonov functional equations. This will be done by applying the theory of reproducing kernels to the approximate solutions of general bounded linear operator equations (when defined from reproducing kernel Hilbert spaces into general Hilbert spaces), by using the Hilbert-Schmidt property and tensor product of Hilbert spaces. As a concrete case, we shall consider generalized fractional functions formed by the quotient of Bergman functions by Szegö functions considered from the multiplication operators on the Szegö spaces.

Nivel de satisfacción de la atención integral que brindan las enfermeras/os a las gestantes, en la Clínica Humanitaria “Fundación Pablo Jaramillo C.”, en el periodo noviembre – diciembre 2015

OBJETIVO: evaluar el nivel de satisfacción de la atención que brindan las enfermeras/os, a las gestantes hospitalizadas que cursan su tercer trimestre de embarazo, en la Clínica Humanitaria Fundación Pablo Jaramillo Crespo, periodo Noviembre-Diciembre 2015. METODOLOGÍA: se realizó un estudio cuantitativo, descriptivo con universo y muestra finito, conformado por 34 gestantes hospitalizadas, en el servicio Gineco-Obstetricia en la Clínica Humanitaria en su tercer trimestre de gestación. Se utilizó el instrumento Caring Assessment Instrument (Care-Q) modificado, conformado por 7 categorías y 25 preguntas. En la tabulación y análisis de datos se utilizó el programa Excel y Word. RESULTADOS: de las 34 gestantes encuestadas, el 68% refieren un nivel de satisfacción alto, el 16% señalan un nivel de satisfacción medio y el 16% un nivel de satisfacción bajo con referencia a la atención de enfermería. Los datos socio demográficos que presentaron las gestantes hospitalizadas indican que el grupo etario con mayor afluencia a la Clínica Humanitaria se encuentran entre los 19 – 24 años de edad con el 38,2%, el estado civil que prevalece entre las usuarias es casadas con el 50%, con un nivel de instrucción secundaria del 53% y residen dentro del sector urbano con el 59%. CONCLUSIONES: este estudio, demuestra que el nivel de satisfacción en la atención que brinda el personal de enfermería es alto, para una cantidad considerable de gestantes hospitalizadas, sin embargo existe un nivel de satisfacción medio y bajo, que deberían considerarse medidas, para ofrecer una excelente atención de calidad y calidez a las usuarias

Láser Q-Switched en el manejo de ocronosis exógena: revisión sistemática de la literatura

Antecedentes: La ocronosis Exógena (OE) es una enfermedad subdiagnosticada y de difícil manejo (1). El láser Q-Switched (QS) surge como una alternativa para el tratamiento de esta (2). Objetivo: Describir las características de los pacientes, del láser QS y los desenlaces en el tratamiento de OE. Métodos: Se realizó una búsqueda de la literatura en las bases PubMed, Embase, PMC, Scielo, Elselvier, BMJ Case Reports, Journal of Medical Case Reports, Cases Journal e International Medical Case Reports Journal, desde enero del 2000 a marzo del 2016, pacientes con ocronosis exógena, 18 a 70 años, tratados con láser QS. Los artículos fueron evaluados mediante la herramienta de evaluación de validez y valor educativo de reportes de caso descrito por Pierson (3). Resultados: Se encontraron 256 artículos, 63 fueron seleccionados: 28 repetidos y 31 no cumplieron criterios de inclusión. Se escogieron 4 artículos que reportan 12 casos de pacientes con ocronosis exógena diagnosticada mediante estudio histopatológico y tratada con láser QS. Discusión: Hay poca experiencia con el láser QS en OE. En la práctica clínica se usa para tatuajes y patologías pigmentarias dérmicas con resultados satisfactorios. El pigmento dérmico en OE y la corta duración de pulso de láser QS, podrían ser el pilar de tratamiento para OE. Conclusión: El láser QS puede ser útil para el tratamiento en OE, con nivel de evidencia 3 y grado de recomendación D. Se sugiere realizar estudios clínicos con mayor grado de evidencia.

Aceitabilidade de formulações de baião-de-dois elaboradas a partir de arroz integral e feijão caupi biofortificados.

O objetivo deste trabalho foi analisar sensorialmente formulações de baião-de-dois elaborados a partir de arroz integral e feijão-caupi biofortificados. Foram analisadas amostras de cinco formulações de baião-de-dois: baião padrão (arroz polido comercial + feijão-caupi comercial); baião controle (arroz integral comercial + feijão-caupi comercial); baião 1 (arroz integral Chorinho + feijão-caupi BRS Aracê); baião 2 (arroz integral Chorinho + feijão-caupi BRS Tumucumaque); e baião 3 (arroz integral Chorinho + feijão-caupi BRS Xiquexique).

Perfil de aminoácidos de formulações de baião-de-dois elaboradas a partir de arroz integral e feijão-caupi biofortificados.

O baião-de-dois é um prato tradicional na região Nordeste do Brasil, bastante apreciado pela população, elaborado com arroz e feijão-caupi imaturo. O objetivo deste trabalho foi determinar o perfil de aminoácidos de formulações de baião-de-dois elaborados a partir de arroz integral e feijão-caupi biofortificados.

Concentrações de ferro, zinco e proteínas em formulações de baião-de-dois elaboradas a partir de arroz integral e feijão-caupi biofortificados.

O objetivo deste trabalho foi determinar as concentrações de ferro, zinco e proteína em formulações de baião-de-dois elaborados a partir de arroz integral e feijão-caupi biofortificados.

Detailed analysis of a conservative difference approximation for the time fractional diffusion equation

Diffusion equations that use time fractional derivatives are attractive because they describe a wealth of problems involving non-Markovian Random walks. The time fractional diffusion equation (TFDE) is obtained from the standard diffusion equation by replacing the first-order time derivative with a fractional derivative of order α ∈ (0, 1). Developing numerical methods for solving fractional partial differential equations is a new research field and the theoretical analysis of the numerical methods associated with them is not fully developed. In this paper an explicit conservative difference approximation (ECDA) for TFDE is proposed. We give a detailed analysis for this ECDA and generate discrete models of random walk suitable for simulating random variables whose spatial probability density evolves in time according to this fractional diffusion equation. The stability and convergence of the ECDA for TFDE in a bounded domain are discussed. Finally, some numerical examples are presented to show the application of the present technique.