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Solutions for Concurrency Control in DBMS : A Survey
Solutions for Concurrency Control in DBMS : A Survey
This is my first Survey paper and topic is from DBMS: Concurrency control solutions. I have compared different methods in this paper. As this is my first paper so critical review is highly needed
Faheem Feroz
Schoendoosanamorfosen en speelplaatsanamorfosen
Schoendoosanamorfosen en speelplaatsanamorfosen
Een van de verbanden tussen magie en wiskunde is de anamorfosekunst. Een anamorfosekunstwerk is een vervormde tekening die haar ware aard pas laat zien wanneer ze vanuit een welbepaald standpunt bekeken wordt (de perspectivistische anamorfose) of wanneer ze weerspiegeld wordt in spiegel met een welbepaalde vorm (de spiegelanamorfose). In deze studie gaat het alleen over de perspectivistische anamorfosen. Wiskundig leggen ze een link met centrale projecties en met centraalperspectief.
Van den Broeck Luc
Diseño e Implementación de un Sistema de Control utilizando MATLAB enlazado a un Autómata Programable
Diseño e Implementación de un Sistema de Control utilizando MATLAB enlazado a un Autómata Programable
En la actualidad, el estudio y análisis de los sistemas de control automático representan un campo de aplicación bastante extendido, esto debido a las imperantes necesidades por mejorar los procesos productivos, optimizar los recursos e incluso para predecir comportamientos, desde entornos educativos, investigativos o industriales, hasta entornos económicos, sociales y demás. En efecto, esto ha impulsado a los desarrolladores a buscar herramientas o alternativas que permitan aumentar las capacidades de cómputo al momento de desarrollar un sistema de control automático. Ahora bien, la instrumentación industrial desde hace muchos años viene comandada por los Autómatas Programables (PLC), dispositivos útiles e ideales para ejecutar las tareas de control de una planta, independientemente de la escala. El presente documento presenta el diseño e implementación de un controlador PID en una planta didáctica conformada con equipos industriales, haciendo uso de OPC y algunos conceptos de la teoría de control. Mediante la herramienta computacional MATLAB se realiza la identificación de la planta obteniendo su función de transferencia, y haciendo uso de algunas herramientas disponibles en este software, se determinan los parámetros de sintonía de un controlador tipo PID, para posteriormente sintonizar la estrategia de control implementada en un autómata programable de gama alta.
Armando Uribe
Briefly on Behaviorism and Introspectionism
Briefly on Behaviorism and Introspectionism
A very brief description of the history of introspectionism and behaviorism and some of the characters involved.
Daniel Comstock
SOLAR SALES ON YOUR TRIP TO MARS
SOLAR SALES ON YOUR TRIP TO MARS
We study Logarithmically Spiral Trajectories and, in particular, we look for a solution to minimize the transit time of a Spacecraft propelled by a Solar Sail, while simultaneously minimizing the area of the Solar Sail, which would allow us to carry more payload on board. We start by analyzing the forces that act on the Spacecraft taking into account that its propellant is a Solar Sail; we use the studied forces to deduce the motion equations. We then solve this motion equation with a Runge-Kutta 4 method and transform the problem of minimizing time and area to a Non-linear Optimization problem. When solving the NLP we also try to minimize the relative final speed of th spacecraft with the destination planet in order to guarantee the possibility of a safe landing on its surface. The model improves when an angle parameter α (describing the angle formed by the Solar Sail with the colliding photons) is defined as a piecewise constant function and optimized whose values are optimized in every interval to minimize transit time and Area. Using the developed model to optimize the trajectory to be followed for sending from Earth to Mars a 2000kg-spacecraft propelled by a Solar Sail, subject to the condition that at trajectory start Mars and Earth were at their closest approach, and the Arrival Relative Velocity is less than 9km/s, give us a minimal transit time of 500days and a minimal area for the Solar Sail of 183158m2, meaning that the maximal payload would be 718kg. Compared with different number of partitions of α, the optimum stays stable. This gives a solid optimal trajectory and a great result for the numerical method used. Actually, waiting until the best moment to throw the Spacecraft, id est, Mars is at 1.14 radians respectively to Earth initial position, the minimal sail area 145950 m2 and, therefore, ables to transport until 978 kg of payload with the same transit time. In addition and to conclude we tried the model to optimize the inverse trajectory.
Marco Praderio Bova, Eneko Martin Martinez, & Maria dels Àngels Guinovart Llort
Reporte: Capítulo 2: Razonamiento Científico
Reporte: Capítulo 2: Razonamiento Científico
El inductivismo saca conclusiones generales de algo particular. Este ha sido el método científico más común utilizado y sobre éste surgieron nuevos paradigmas para hacer ciencia. Se analizarán las características y limitantes de este método.
Sandra Juárez Osorio
Introduction to Computers
Introduction to Computers
A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of operations, called programs. These programs enable computers to perform an extremely wide range of tasks. Conventionally, a modern computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices include input devices (keyboards, mice, joystick, etc.), output devices (monitor screens, printers, etc.), and input/output devices that perform both functions (e.g., the 2000s-era touchscreen). Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.(Demo Document )
Ankur Sharma
Lição 07 - Frutificando traz alegria
Lição 07 - Frutificando traz alegria
Lição Célula protótipo
Egmon Pereira
SPARQL Query Optimization for Federated Linked Data
SPARQL Query Optimization for Federated Linked Data
The Web has evolved from a system of internet servers supporting formatted documents into a web of linked data. In the last years, the Web of Data is constantly growing. Consequently, it has developed a large collection of interlinked data sets from multiple domains. To exploit the diversity of all available data, federated queries are needed. However, many problems such as processing power, query response time, high workload or outdated information are hindering the query processing. In this paper, I am aiming to explain various optimization techniques which have the potential to lead a significant improvement on the final query runtime. I will start by briefly introducing recent approaches of federation and show why SPARQL federation endpoints are mostly in my focus. Specifically, I will compare state-of-the-art SPARQL query federation engines and analyze respective optimization approaches. The main federation engines I will analyze in terms of query optimization are FedX, DARQ and SPLENDID. As the result I provide concrete examples and conclude which of the engines has the best performance based on the query execution time as key criterion.
Desared Osmanllari