Principal-agent dynamic interaction in the context of the lifecycle operation of infrastructure systems

A Public-private partnership (PPP) is contract framework designed to carry out public works in the hope that the more advanced knowledge and financial support of private agents may be advantageous to develop better infrastructure projects that serve public needs. This relationship, which is embodied by a principal (e.g., government) and an agent (e.g., independent contractor), is inherently conflictive. Three main factors give rise to such conflict: the interests of the public and private party do not generally coincide, there is information asymmetry between them and their interaction unfolds in environments under uncertainty. Traditionally, the regulations put forth to mitigate the cost overruns caused by moral hazard, low performance levels and litigations are determined by methods which neither take into account a formal mathematical description of the interaction among participants nor the deterioration of physical components and their susceptibility to natural hazards. In this paper we propose an alternative approach that addresses these issues. We describe an agent-based model which represents the infrastructure system as an entity that is affected by the operations of three players: principal, agent and nature. They perform operations on the infrastructure, based on their own strategies and perceived payoffs, but are bound by a contract that constraint their actions. The purpose of the model is to simulate the interaction history among players and compute the resulting outcome in the form of the utility that each player receives. The model can be used within an optimization routine to determine which contractual rules maximize the utility for both players simultaneously

On the subalgebra lattice of a restricted Lie algebra

In this paper we study the lattice of restricted subalgebras of a restricted Lie algebra. In particular, we consider those algebras in which this lattice is dually atomistic, lower or upper semimodular, or in which every restricted subalgebra is a quasi-ideal. The fact that there are one-dimensional subalgebras which are not restricted results in some of these conditions being weaker than for the corresponding conditions in the non-restricted case

Evaluating learnability in a 3D heritage tour

The implementation of 3D virtual reality (VR) environments to represent human culture and heritage has been growing during the last two decades as a result of information and communication technologies (ICT) development. Precisely, regarding virtual heritage development, some weaknesses have been detected such as ‘‘lifeless’’ environments lacking interaction, and research still under development on learning assessment. In this article, a VR environment is presented, through users taking a virtual tour visiting some elements of cultural heritage of the island of San Andrés, Colombia. In the tour, users participate in a 3D VR environment, answering questions and learning about the cultural heritage of the island. Also, the usability of the VR environment is assessed through SUMI (Software Usability Measurement Inventory) standard ISO9241-11 evaluating aspects such as usefulness and learnability. The results demonstrate that with the implementation of a VR environment about heritage, the users achieved optimum performance with an 80% average of correct answers and a high correlation between learning and the usability of the 3D VR environment

Protective astrogenesis from the SVZ niche after injury is controlled by Notch modulator Thbs4.

Postnatal/adult neural stem cells (NSCs) within the rodent subventricular zone (SVZ; also called subependymal zone) generate doublecortin (Dcx)(+) neuroblasts that migrate and integrate into olfactory bulb circuitry. Continuous production of neuroblasts is controlled by the SVZ microenvironmental niche. It is generally thought that enhancing the neurogenic activities of endogenous NSCs may provide needed therapeutic options for disease states and after brain injury. However, SVZ NSCs can also differentiate into astrocytes. It remains unclear whether there are conditions that favour astrogenesis over neurogenesis in the SVZ niche, and whether astrocytes produced there have different properties compared with astrocytes produced elsewhere in the brain. Here we show in mice that SVZ-generated astrocytes express high levels of thrombospondin 4 (Thbs4), a secreted homopentameric glycoprotein, in contrast to cortical astrocytes, which express low levels of Thbs4. We found that localized photothrombotic/ischaemic cortical injury initiates a marked increase in Thbs4(hi) astrocyte production from the postnatal SVZ niche. Tamoxifen-inducible nestin-creER(tm)4 lineage tracing demonstrated that it is these SVZ-generated Thbs4(hi) astrocytes, and not Dcx(+) neuroblasts, that home-in on the injured cortex. This robust post-injury astrogenic response required SVZ Notch activation modulated by Thbs4 via direct Notch1 receptor binding and endocytosis to activate downstream signals, including increased Nfia transcription factor expression important for glia production. Consequently, Thbs4 homozygous knockout mice (Thbs4(KO/KO)) showed severe defects in cortical-injury-induced SVZ astrogenesis, instead producing cells expressing Dcx migrating from SVZ to the injury sites. These alterations in cellular responses resulted in abnormal glial scar formation after injury, and significantly increased microvascular haemorrhage into the brain parenchyma of Thbs4(KO/KO) mice. Taken together, these findings have important implications for post-injury applications of endogenous and transplanted NSCs in the therapeutic setting, as well as disease states where Thbs family members have important roles

Relation analysis of knowledge management, research, and innovation in university research groups

Knowledge is a competitive advantage for companies. Knowledge Management helps to keep this competitiveness. Universities face with challenges in research, innovation and international competitiveness. The purpose of this paper includes studying Knowledge Management Models, and Innovation Models apply to Research Groups of Universities, through an analysis of relation in inter-organizational level. Some researchers and leaders of research groups participated in a survey about knowledge management and innovation. Here we show the relationship between knowledge management, innovation and research, including processes and operations performed by universities around these. We organize the results in three dimensions: Knowledge Management perception, the relationship between Knowledge Management and Innovation, and Strategic Knowledge organization. Too, we identify a generality of good practices, challenges, and limitations on Research Groups for Knowledge Management

Diseño y desarrollo de un malacate eléctrico para extracción de vagonetas en una mina subterránea de carbón

On this paper, the design of an electric winch to be used in an underground coal mine is shown. The design includes as background current mining methods, in order to compare their advantages and disadvantages. The formulation of the solution starts from the free body diagram of a full load wagon at the deepest point of the mine, from there, the forces acting on it are identified, and the tension is calculated in the steel cable. The design also includes the required protection and the control circuit for the motor starter. Under real operation in mine, we check the correct operation and performance of the prototype, fully being satisfied customer's need. In addition, the objectives were met 100\%, fully meeting the proposed schedule.Éste artículo muestra el diseño de un malacate eléctrico para ser utilizado en una mina subterránea de carbón. El diseño contempla como antecedente los métodos actuales de extracción minera, a fin de comparar sus ventajas y desventajas. La formulación de la solución parte del diagrama de cuerpo libre de un vagón a plena carga en el punto más profundo de la mina, a partir de allí se identifican las fuerzas que actúan sobre éste, y se calcula la tensión en el cable de acero. El diseño contempla también las protecciones requeridas y el circuito de control para el arrancador del motor. Bajo operación real en una mina, se comprobó el correcto funcionamiento y desempeño del prototipo, satisfaciéndose completamente la necesidad del cliente

Plan de gestión integral de residuos peligrosos o residuos (pgirespel) enfocado hacia la explotación de carbón en el municipio de Guachetá Cundinamarca en la compañía minera Colombo Americana de carbón S.A.S

En esta pasantía se dejara un informe completo para poder realizar un (PGIRESPEL) paso a paso y así poder realizar un buen manejo de los insumos y residuos peligrosos que se generan, a su vez también identificar las falencias que se generan en los distintos procesos por la utilización de insumos y manejo de residuos peligrosos que produce la compañía, dar soluciones de disminución y mitigación de los distintos impactos ambientales que producen los residuos peligrosos, ya sean por derrames de ellos, mal almacenamiento o utilización de estos. El informe dejara un esquema de cómo realizar el seguimiento de estos residuos, como formatos para registrar la información relacionada con la cuantificación de los RESPEL generados, para así llevar un registro mensual de la generación de RESPEL e identificar el tipo de productor que somos respecto a la clasificación que lleva a cabo por el Decreto 4147 del 2005 que aplica para el cumplimiento y buen manejo de los residuos peligrosos que es la siguiente. Gran generador cantidad igual o mayor a 1000 Kg/mensual, Mediano generador igual o mayor a 100 Kg/mensuales y menor a 1000 Kg/mensuales, Pequeño generador cantidad igual o mayor a 10 Kg/mensuales y menor a 100 Kg/mensuales, considerando los períodos de tiempo de generación del residuo y llevando promedios de los últimos seis (6) meses de las cantidades pesadas, todo esto se lleva a cabo para cumplir el Decreto 4147 del 2005.PregradoTecnólogo en Desarrollo AmbientalTecnología en Desarrollo Ambienta

ANÁLISIS DE JUICIO DE DESALOJO EN LOS CASOS DE INCUMPLIMIENTO DE CONTRATO DE LOCACIÓN

La presente investigación trata de Procedimiento de desalojo en los casos de incumplimiento de contrato de locación, para ello se procedió a exponer los principios normativos que afectan al proceso de desalojo, a describir el criterio en la doctrina referente al derecho de propiedad, la posesión, el ocupante precario y desalojo entre otros aspectos importantes para el tema. Se verificó la legislación vigente respecto del proceso de desalojo en el Paraguay y se analizó el proceso de desalojo que pueda implementarse en el Paraguay. En cuanto a la metodología, trata de un estudio no experimental, de tipo descriptivo, con un enfoque cualitativo, a través del estudio documental de fuentes primarias y secundarias