The value of mobile learning

The value of mobile learning^[13]—Tutors who have used m-learning programs and techniques have made the following value statements in favor of m-learning.

• It is important to bring new technology into the classroom.
• Devices used are more lightweight than books and PCs.
• Mobile learning can be used to diversify the types of learning activities students partake in (or a blended learning approach).
• Mobile learning supports the learning process rather than being integral to it.
• Mobile learning can be a useful add-on tool for students with special needs. However, for SMS and MMS this might be dependent on the students’ specific disabilities or difficulties involved.
• Mobile learning can be used as a ‘hook’ to re-engage disaffected youth.

Benefits ^[2][14][15]

• Relatively inexpensive opportunities, as the cost of mobile devices are significantly less than PCs and laptops
• Multimedia content delivery and creation options
• Continuous and situated learning support
• Decrease in training costs
• Potentially a more rewarding learning experience
• New opportunities for traditional educational institutions
• Readily available a/synchronous learning experience^[16]

Challenges[edit]

Technical challenges include

• Connectivity and battery life
• Screen size and key size^[17]
• Meeting required bandwidth for nonstop/fast streaming
• Number of file/asset formats supported by a specific device
• Content security or copyright issue from authoring group
• Multiple standards, multiple screen sizes, multiple operating systems
• Reworking existing E-Learning materials for mobile platforms
• Limited memory^[18]
• Risk of sudden obsolescence ^[19]
• Security
• Work/Life Balance
• Cost of Investment^[20]

Social and educational challenges include

• Accessibility and cost barriers for end users: Digital divide.
• How to assess learning outside the classroom
• How to support learning across many contexts^[21]
• Content's security or pirating issues
• Frequent changes in device models/technologies/functionality etc.
• Developing an appropriate theory of learning for the mobile age
• Conceptual differences between e-learning and m-learning
• Design of technology to support a lifetime of learning^[22][23]
• Tracking of results and proper use of this information
• No restriction on learning timetable
• Personal and private information and content
• No demographic boundary
• Disruption of students' personal and academic lives^[24]
• Access to and use of the technology in developing countries^[25]
• Risk of distraction ^[2]

Growth[edit]

Over the past ten years mobile learning has grown from a minor research interest to a set of significant projects in schools, workplaces, museums, cities and rural areas around the world. The m-learning community is still fragmented, with different national perspectives, differences between academia and industry, and between the school, higher education and lifelong learning sectors.^[26] Possible future applications for mobile learning include location based learning, augmented reality, wearable learning, learning implants, and ambient intelligence. Advancements in mobile learning will require a change from traditional classroom pedagogical approaches to a digital pedagogical approach that will suit mobile learners.^[27]

Current areas of growth include:

• Testing, surveys, job aids and just-in-time (J.I.T.) learning
• Location-based and contextual learning
• Social-networked mobile learning
• Mobile educational gaming
• Delivering m-Learning to cellular phones using two way SMS messaging and voice-based CellCasting (podcasting to phones with interactive assessments) ^[26]
• Cloud computer file storage ^[14]

Sistemas operativos

Un sistema operativo es el software más importante que se ejecuta en un ordenador. Gestiona la memoria de la computadora, los procesos, y todos sus software y hardware. También le permite comunicarse con el ordenador sin saber hablar el lenguaje de la computadora. Sin un sistema operativo, una computadora es inútil.
El trabajo del sistema operativo

Sistema operativo de su ordenador (OS) gestiona todo el software y hardware en el equipo. La mayor parte del tiempo, hay muchos programas de computadora que se ejecutan al mismo tiempo, y todos ellos tienen que acceder a la unidad central de procesamiento de la computadora (CPU), la memoria y el almacenamiento. El sistema operativo coordina todo esto para asegurarse de que cada programa obtiene lo que necesita.

Tipos de sistemas operativos

Los sistemas operativos generalmente vienen precargados en cualquier ordenador de comprar. La mayoría de la gente utiliza el sistema operativo que viene con su ordenador, pero es posible actualizar o cambiar los sistemas operativos.

Los tres sistemas operativos más comunes para los ordenadores personales son Microsoft Windows, Apple Mac OS X, andLinux.

Los sistemas operativos generalmente vienen precargados en cualquier ordenador de comprar. La mayoría de la gente utiliza el sistema operativo que viene con su ordenador, pero es posible actualizar o cambiar los sistemas operativos.

Los tres sistemas operativos más comunes para los ordenadores personales son Microsoft Windows, Apple Mac OS X,  y Linux.

Los sistemas operativos modernos utilizan una interfaz gráfica de usuario o GUI (pronunciado pegajosa). Una interfaz gráfica de usuario le permite utilizar el ratón para hacer clic iconos, botones y menús, y todo lo que se muestra claramente en la pantalla utilizando un ofgraphics combinación y texto.

GUI de cada sistema operativo tiene un aspecto diferente y se siente, así que si usted cambia a un sistema operativo diferente puede parecer poco familiar al principio. Sin embargo, los sistemas operativos modernos están diseñados para ser fácil de usar, y la mayoría de los principios básicos son los mismos.

Antes de interfaces gráficas de usuario, ordenadores tenido una interfaz de línea de comandos, lo que significaba que los usuarios tenían que escribir cada comando en el equipo y la computadora le mostrar sólo texto.

Ver más: http://www.gcflearnfree.org/computerbasics/2

Operating system

An operating system is the most important software that runs on a computer. It manages the computer's memory, processes, and all of itssoftware and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's language. Without an operating system, a computer is useless.

The operating system's job

Your computer's operating system (OS) manages all of the software and hardware on the computer. Most of the time, there are many different computer programs running at the same time, and they all need to access your computer's central processing unit (CPU), memory, and storage. The operating system coordinates all of this to make sure each program gets what it needs.

Types of operating systems

Operating systems usually come preloaded on any computer you buy. Most people use the operating system that comes with their computer, but it's possible to upgrade or even change operating systems.

The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, andLinux.

Operating systems usually come preloaded on any computer you buy. Most people use the operating system that comes with their computer, but it's possible to upgrade or even change operating systems.

The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, andLinux.

Modern operating systems use a graphical user interface, or GUI (pronounced gooey). A GUI lets you use your mouse to click icons, buttons, and menus, and everything is clearly displayed on the screen using a combination ofgraphics and text.

Each operating system's GUI has a different look and feel, so if you switch to a different operating system it may seem unfamiliar at first. However, modern operating systems are designed to be easy to use, and most of the basic principles are the same.

Before GUIs, computers had a command-line interface, which meant users had to type every single command to the computer and the computer would only display text.

See more:    http://www.gcflearnfree.org/computerbasics/2

CELL PHONE

CELL PHONE:
Telephony system that does not require a fixed link, for example via telephone cable for transmission and reception. Use the radio airwaves by as conventional radio, so the terminal will emit and receive the signals with an antenna to and from the nearest repeater (mobile phone masts) or satellite. The first mobile phone emissions can be traced back to the use of radio transmitters installed in vehicles, military or institutional use; as referred to by the first use by police in Detroit in 1921. The radios themselves were introduced in 1946 in the United States; the following year, the Bell Telephone developed cell technology based on modern systems of mobile phone itself. However, no developments were civilians until 1956, when a car terminal, 40 kg, which was fed by the vehicle battery was installed in Sweden. Japan's first cellular mobile telephone system in 1979 was launched; He was followed by the United Kingdom in 1983
Operating System
The mobile cellular system based on transmission areas, cells, covering areas between 1.5 and 5 km, within which there are one or more repeater stations, which work with a certain frequency, which must be different surrounding cells. The mobile phone sends the signal that is received by the station and sent through the network to the recipient; as the user moves, the recipient cell is also switched, by varying the frequency of the Hertzian wave transmission supports. According systems, it sends the signal or data packet sequentially, either as such or compressed and encrypted.
Digital systems
Currently, most cellular telephone systems employ digital systems have replaced analog first generation (1G); these systems were introduced in Spain in 1990 (MoviLine telephone company). The first European digital system (GSM Global System for Mobile Communication), commonly known as second-generation cellular system (2G) began to implement in 1992, and in 1995 operated for the first time in Spain; with it launched the transmission system short text messages, SMS (Short Messaging Service), and access to Internet through WAP (Wireless Application Protocol). And in 2000 in Europe and 2002 in the United States, they began trading gifted with GPRS (General Packet Radio Service, General packet radio service through information) systems; It is known as 2.5G telephony system, an intermediate technology between systems of second and third generation. Among the new features is the possibility of receiving and sending continuous data sets using the IP (Internet Protocol), which substantially improves navigation through the network and to overcome the limit of 160 characters in SMS, while to send and receive images and multimedia elements.
(3G) third generation systems, exploited commercially in Japan since 2001 by NTT DoCoMo, have suffered repeated postponements by technological and logistical problems worldwide, which has substantially slowed the market. In Europe and parts of Asia it has been chosen in 2000 by the UMTS (Universal Mobile Communication Service, universal mobile communications), and the United States and parts of Asia and America, the so-called CDMA-2000 system; both are part of the IMT-2000 standard of the International Telecommunications Union (ITU) in Geneva, Switzerland. 3G systems are mainly based on two standards, the CDMA-2000 (Code Division Multiple Access 2000) and W-CDMA (W-CDMA) and other owners of certain operators, such as NTT DoCoMo of that before being incompatible each other and differing in the maximum speed of data transmission. CDMA systems are easier to implement and provide up to three times greater transmission capacity; in the transmitter the data is converted to digital format and compressed, the receiver further to receive and decode data packets, does error checking and reconverted to wave format, if, for voice transmissions.
Messaging and multimedia
With the advent of digital systems (telephone second generation 2G), the terminals have the ability to send and receive short text messages (SMS), which operate much like email messages in Internet, although specifying as a destination terminal number and not a user ID. With the advent of 2.5G and 3G systems have been implemented EMS (Enhanced Messaging Service) and MMS (Multimedia Message Service) services, which offer improvements over basic SMS text service; thus allowed unlimited text size, including pictures, animations and melodies and, in the case of MMS, enable sending and receiving all kinds of multimedia elements, including videos. To use EMS and MMS required, respectively, of mobile terminals or other GPRS and UMTS 3G.
The integration of mobile phones with mobile computing has come in two different ways: with the connectivity of mobile phones with PDA using wireless technologies such as infrared or Bluetooth, and physical integration of both devices into a single device, such as is the case of other PocketPC Phone Edition running under Linux or Palm

Read more: http://www.monografias.com/trabajos15/redes-telefonicas/redes-telefonicas.shtml#CELULAR#ixzz3cfnQV1mr

TELEFONÍA CELULAR:

TELEFONÍA CELULAR:

Sistema de telefonía que no requiere de un enlace fijo, por ejemplo vía cable telefónico, para la transmisión y recepción. Utiliza la radiotransmisión mediante ondas hercianas, como la radio convencional, por lo que el terminal emitirá y recibirá las señales con una antena hacia y desde el repetidor más próximo (antenas repetidoras de telefonía móvil) o vía satélite. Las primeras emisiones de telefonía móvil se remontan al uso de radiotransmisores instalados en vehículos, de uso militar o institucional; como referencia se cita la primera utilización por parte de la policía de Detroit en 1921. Los radioteléfonos propiamente dichos se introdujeron en 1946 en Estados Unidos; al siguiente año, la Bell Telephone desarrolló la tecnología celular, base de los modernos sistemas de telefonía móvil propiamente dicha. Con todo, no se vieron desarrollos civiles hasta 1956, cuando se instaló en Suecia un terminal para automóviles, de 40 kg, que se alimentaba de la batería del vehículo. En Japón se puso en marcha el primer sistema de telefonía móvil celular en 1979; le siguió el Reino Unido, en 1983

Funcionamiento del sistema

La telefonía móvil celular se basa en un sistema de áreas de transmisión, células, que abarcan áreas comprendidas entre 1,5 y 5 km, dentro de las cuales existen una o varias estaciones repetidoras, que trabajan con una determinada frecuencia, que debe ser diferente de las células circundantes. El teléfono móvil envía la señal, que es recibida por la estación y remitida a través de la red al destinatario; conforme se desplaza el usuario, también se conmuta la célula receptora, variando la frecuencia de la onda herciana que da soporte a la transmisión. Según los sistemas, la señal enviará datos secuencialmente o por paquetes, bien como tales o comprimidos y encriptados.

Sistemas digitales

En la actualidad, la mayoría de los sistemas de telefonía celular emplean sistemas digitales, que han sustituido a los analógicos de primera generación (1G); estos sistemas fueron introducidos en España en 1990 (MoviLine de la compañía Telefónica). El primer sistema digital europeo (GSM de Global System for Mobile Communication), conocido vulgarmente como sistema celular de segunda generación (2G), se comenzó a implantar en 1992, y en 1995 operó por primera vez en España; con él se puso en marcha el sistema de transmisión de mensajes cortos de texto, SMS (Short Messaging Service), y el acceso a Internet mediante la tecnología WAP (Wireless Application Protocol). Ya en 2000 en Europa y en 2002 en Estados Unidos, comenzaron a comercializarse los sistemas dotados con GPRS (General Packet Radio Service, servicio general de radio mediante paquetes de información); se le conoce como sistema de telefonía 2,5G, una tecnología intermedia entre los sistemas de segunda y tercera generación. Entre sus novedades destaca la posibilidad de recepción y envío continuo de grupos de datos mediante el protocolo IP (Internet Protocol), que mejora sustancialmente la navegación a través de la red y el poder superar el límite de 160 caracteres en los SMS, a la vez que permite enviar y recibir imágenes y elementos multimedia.

Los sistemas de tercera generación (3G), explotados comercialmente en Japón desde 2001 por parte de la NTT DoCoMo, han sufrido repetidos aplazamientos por problemas tecnológicos y logísticos en todo el mundo, lo que ha retrasado sustancialmente su comercialización. En Europa y parte de Asia se ha optado en 2000 por el sistema UMTS (Universal Mobile Communication Service, servicio móvil universal para comunicaciones), y en Estados Unidos y parte de Asia y América, por el denominado sistema CDMA-2000; ambos forman parte del IMT-2000, un estándar de la International Telecommunications Union (ITU), con sede en Ginebra, Suiza. Los sistemas 3G se apoyan fundamentalmente en dos estándares, el CDMA-2000 (Code Division Multiple Access 2000) y W-CDMA (Wideband Code Division Multiple Access), y otros propietarios de ciertos operadores, como el del antes citado NTT DoCoMo, siendo incompatibles entre sí y diferenciándose en la velocidad máxima de transmisión de datos. Los sistemas CDMA son más sencillos de implementar y proporcionan hasta tres veces mayor capacidad de transmisión; en el emisor se convierten los datos a formato digital y se comprimen, el receptor además de recibir los paquetes de datos y decodificarlos, hace una comprobación de errores y los reconvierte a formato de onda, en su caso, para transmisiones de voz.

Mensajería y multimedia

Con la aparición de los sistemas digitales (telefonía de segunda generación, 2G), los terminales disponen de la capacidad de enviar y recibir mensajes cortos de texto (SMS), que operan de manera muy similar a los mensajes de correo electrónico en Internet, aunque especificando como destinatario un número de terminal y no un identificador de usuario. Con la aparición de los sistemas 2,5G y 3G se han implantado los servicios EMS (Enhanced Messaging Service) y MMS (Multimedia Message Service), que ofrecen mejoras en el servicio SMS básico sobre texto; así, admiten texto de dimensiones ilimitadas, inclusión de imágenes, melodías y animaciones y, en el caso del MMS, posibilitan el envío y recepción de todo tipo de elementos multimedia, incluidos vídeos. Para utilizar EMS y MMS se requiere, respectivamente, de terminales de telefonía móvil GPRS y UMTS u otro 3G.

La integración de los teléfonos celulares con la informática móvil ha llegado en dos formas diferentes: con la conectividad de los teléfonos móviles con un PDA mediante tecnologías inalámbricas, como infrarrojos o Bluetooth, y con la integración física de ambos dispositivos en un mismo aparato, como es el caso de los PocketPC Phone Edition y otros que funcionan bajo Linux o Palm

Leer más: http://www.monografias.com/trabajos15/redes-telefonicas/redes-telefonicas.shtml#CELULAR#ixzz3cfnQV1mr

Telephone networks

A telephone network is a telecommunications network used for telephone calls between two or more parties.
There are several different types of telephone networks:
A fixed-line network, where phones must be connected directly to a telephone exchange. This is known as the public switched telephone network PSTN or.
A wireless network that phones are mobile and can be moved anywhere within the coverage area.
A private network, where a closed group of phones are mainly connected to each other and use a gateway to reach the outside world. This is usually used inside companies and call centers and is called private branch exchange (PBX).
Public telephone operators (PTO) own and build networks of the first two types and provide services to the public under license from the national government. The virtual network operators (VNO) rent capacity wholesale PTOs and sell telephone service to the public directly.
Communications Network:
Set of interconnected elements if one or more nodes can receive / transmit information, share resources and service users.
Networks that allow this are advanced and complex equipment. Its effectiveness is based on the confluence of many different components. The design and implementation of a global communications network is one of the great 'technological miracles' of recent decades.
Until recently, most computers had their own interfaces and had its particular structure. A team could communicate with another of the same family, but had great difficulty doing so with a stranger. Only the most privileged have the time, skills and equipment needed to extract different information resources that they needed.
In the 1990s, the level of agreement between different computers reached the point where they could efficiently interconnect, which allows anyone to profit from a remote computer. The main components of this process are client / server systems, object technology and open systems.
In practice the open system concept decoupling results in all components of a similar system used in all other structures. This entails a mixture of standards (which indicate that manufacturers should do) and associations (groups of related entities to help them do it). The final effect is to be able to talk to each other.
Elements of a communications network:
Source
Transmitter
Destination
Receiver
Transmission medium
Message
Interface


Read more: http://www.monografias.com/trabajos15/redes-telefonicas/redes-telefonicas.shtml#RED#ixzz3cUMiDg4F

Digital photography

Digital photography is imaging using a pinhole camera, similar to chemical Photography. However, as in the latter images are recorded on a photosensitive film and subsequently revealed through a chemical process in digital photography the images are captured by an electronic sensor that has multiple photosensitive units, which exploit the photoelectric effect to convert light into an electrical signal, which is digitized and stored in a memory.The advantage of this system over chemical photography is that you have recorded images instantly, without having to bring the film to the lab and reveal the negative to see the images; this advantage in speed of image availability allows the photographer to make changes to the time and make corrections immediately deems appropriate, facilitating achieve the image you want.

In the digital camera can be viewed on a screen the photos you just took. The camera can be connected to a computer or other device capable of displaying photos on a monitor. As they are in digital format, the photos can be sent directly via email, posted on the Web and can be processed with programs of photographic processing in a computer, to increase or restrict, make reframing (a part of the picture), correct colors and brightness, and perform many other possible modifications depending on the program you are using.

Another big advantage of digital photography is that every time the camera takes a picture creates a file Exif metadata (non-visual data) and stored within the image file capture relevant information such as date, time, opening diaphragm, shutter speed, ISO speed. This information is very useful to study the images and understand more about each photo and also facilitates the ordering and management of photographic archives.

Other useful resources existing in digital photography are the brightness histogram, a graph showing the distribution of pixels in the image according to their levels of brightness; and the RGB histogram showing the distribution of pixels in different color channels: in the case of RGB mode, the channels are red (R: red), Green (G: green), and blue (B: blue ). This resource does not exist in chemical photography.




 

Analog photography vs digital Photograph

Analog Photography
DEFINITION
Analog photography, sometimes called chemical photography, is the term that describes the traditional or classic photograph compared to digital photography, more recent appearance. In still cameras, it is usually based on physical-chemical processes for obtaining and processing images. In analog camcorders, analog electronic sensors such as CCD or vidicon used.
Although the concept of "analogue photography" began to be used, especially since the existence of the "digital photography" to distinguish them, and that notion existed before. True, some prefer to call "chemical photography" It is based on physical-chemical processes for obtaining and processing images.
The reason is called ANALOG is because (regardless of the chemical bases of operation) that makes traditional photography is to create an analogon (ie a "like" or "almost identical" to that reality image captured) .
PROCESSES
To obtain photographic images, in black and white in this case, film where the light-sensitive element is the silver halide suspended in very pure gelatin are used. The size and quantity of silver halide crystals determine the sensitivity of the film, commonly called speed, which is normalized and expressed in degrees ISO. When the target for a brief moment opens, light strikes the film and the impression left on her image, which at this point is called a latent image, which will be breaking from that time to be revealed. Light actually begins a physical-chemical process to produce a point of sensitivity in silver halide, thereby obtaining a latent image, which in the end, when the film is immersed in the developer, through a process of oxide reduction will occur in the processing of black metallic silver halide, thus obtaining a visible image. The developing process of black and white film consists of four basic steps: developing, unemployment and washing, fixing and washing. The image thus obtained is negative, that is, light values ​​are inverted with respect to the original.
Once dry, this film or "negative" can make copies of the image on paper or on another film, in which case we will get a positive slide or translucent to allow us to see the photograph projected or transparency. The images obtained by investing the light values ​​again for expansion or contact, give us results in a "positive". This process is called printing.
If we use the camera in a specially treated film, "slide" we obtain positive images directly on to develop the film.

Ref: https://rockoland.wordpress.com/2012/05/13/fotografia-analoga/


https://rockoland.wordpress.com/2012/05/13/fotografia-analoga/

Windows Photo Gallery

Before you begin, check if you installed the scanner to your computer if the scanner is on.
To open Windows Photo Gallery, click the InicioImagen Start button, click All Programs, and then click Windows Photo Gallery.
Click File, then Import from Camera or Scanner.
In the Import Pictures and Videos window, click the scanner you want to use and click Import.
In the New Scan dialog box, click the Profile list, and then click Photo. The default settings are automatically displayed to scan an image.
If you are using a scanner with a document feeder, click the Paper Size list and then click the size of the image placed on the scanner or click the size that is closest to the image size.
Click the Color format list, and then click the color format that you want to submit the scanned file.
Click the File Type list, and then click the file type you want to use to save the scanned image.
Click on the list Resolution (dpi), and then click the resolution, in dots per inch, that you want.
Adjust the brightness and contrast settings or type the values ​​you want to use.
To see what the appearance of the image when it is scanned, click Preview. If necessary, change the scanning settings, and then preview the image. Repeat these steps until you're satisfied with the results of the preview. Some scanners require you to place the picture in the document feeder each time you do a scan.
Click Scan. When the scan is complete, Windows Photo Gallery prompts you to assign a label to the image to make it easier to organize or look in the future.
The list Tag these pictures (optional), type a tag name, and then click Import. Windows Photo Gallery displays the picture so you can see it, correct it or organize

Distance education

Distance education is a form of education in which students are not required to physically attend the place of study. In this system of education students receive the study material (in person, by mail, email or other Internet facilities), allowing the educational act New techniques and strategies student-centered learning itself are used, so it encouraging self-education and self-management, ie, is a flexible and self-directed education, whose main tools are the technologies of communication and information. Learning developed new communication technologies is called e-learning. The most currently used for this type platform is Moodle.

Moodle is a learning management system open source (LMS) used by educational institutions, companies and NGOs to create effective distance education programs. There are already around 75,000 organizations using Moodle in more than 200 countries, offers the study to nearly 60 million students.

Depending from the school, students can physically go for tutoring or classroom tests must be performed. There is distance education for any level of education, but the most usual is being conducted for college.Another feature of distance education is the use of information and communications technology (ICT) to form communities or networks of study where individuals can interact, promoting the educational use of social networks, forums and virtual platforms to discuss various issues and also acquire knowledge and modern tools. It is also essential to have a new vision of the roles of teachers and students in this type of study, the teacher ceases to be the protagonist, becoming a facilitator of the educational process and gives way to the student, which must have a firm commitment to their own learning process.

One of the universities of distance education is the oldest Federal Teacher Training Institute of Mexico, founded in 1945 and considered the world's largest regular school because for historical reasons for country had to train more than 90,000 teachers in education primary service that lacked the title to exert teaching. Then there are the University of South Africa, which has been offering this service since 1946. In the UK, the larger the Open University, which was founded in 1969. In Spain, the National University of Distance Education (UNED) started its activities teachers in 1973 and a year later, in Germany the FernUniversität Hagen was founded. These four universities have over 100,000 students, which is possible thanks to the low cost involved in distance education.

The Open University in Mexico System was driven by Dr. Pablo Gonzalez Casanova, With approved by the University Council on February 25, 1972 Statute and Regulations adopted on 2 December 1997.A since 1997, was established Coordination Open and Distance Education University (CUAED) 

Among the history of distance education are correspondence courses, which were initiated by the need to provide education to students in remote locations, where it was not possible to build a school. Such courses are offered at primary and secondary level, and they often were the parents who supervised the educational progress of students.

Currently, there are several factors that determine the growth of distance education, 3 among them:

- Reducing the cost of computers and telecommunications.

- Greater opportunities for people to access the technology.

- Using friendlier as multimedia interfaces.

-  increased demand for education.

- The creation of new educational institutions, as well as the increase in higher physical facilities (classrooms), is not proportional to population growth.

- High cost of classroom education.

Digital image processing

The digital image processing is the set of techniques applied to digital images in order to improve quality or facilitate the search for information.
Filtering process
It is the set of techniques encompassed within the pre-processing images whose main objective is to obtain, from a source image, one end of which result is more appropriate for a specific application to improve certain features of it that makes it possible to carry out operations of processing on it .
The main objectives to be achieved by the application of filters are:
Soften the image: reduce the amount of intensity variations between neighboring pixels.
Remove Noise: remove those pixels whose intensity level is very different from its neighbors and whose origin can be both in the process of acquiring the image and the transmission.
Enhance edges: to highlight the edges that are located in an image.
Detect edges: detect the pixels where an abrupt change in the intensity function.
Therefore, the filters are considered as transactions that are applied to the pixels of a digital image to be optimized, emphasize certain information or a special effect in it.
The filtering process can be performed on the frequency domain and / or space.
Type


There are basically three different types of filters that can be applied:
Lowpass filter: attenuates high frequencies and low remains unchanged. The result in the spatial domain is equivalent to a smoothing filter, where high frequencies are filtered correspond to strong changes of intensity. Get reduce noise smoothing existing transitions.
Highpass filter: attenuates low frequencies while keeping unchanged the high frequencies. Since high frequencies correspond to the images to sudden changes in density, this type of filter is used because, among other advantages, offers improved edge detection in the spatial domain, as these contain lots of these frequencies. Reinforces the contrasts found in the image.
Bandpass filter: attenuates very high or very low frequencies while maintaining midrange band.
Advantage
Simple and easy to implement method.
Easy concept association with certain frequency characteristics of the image; soft key changes involving low frequencies and high frequencies swings.
It provides flexibility in designing solutions for this search.
Filtering speed when using the convolution theorem.
Disadvantages [edit]
Knowledge is required in various fields to develop an application for image processing.
The noise can not be completely eliminated.
Domain filtering space
Filtering operations are performed directly on the image pixels. In this process relates to each and every one of the points of the image, a set of nearby pixels to the target pixel in order to obtain useful information, dependent on the type of applied filter, which allows to act on the particular pixel in which it is carrying out the filtering process to thereby obtain improvements over the image and / or data that could be used in future actions or work processes on it.
The filters in the spatial domain can be classified into:
Linear filters (or masks based on convolution kernels).
Nonlinear filters.
The concept is understood as a kernel coefficient matrix where the environment of the point (x, y) is considered in the image for g (x, y) is determined by the size and shape of the selected kernel. Although the shape and size of the matrix is ​​variable and is the choice of each user is common to use nxn square kernels. Depending on the implementation, in the image boundaries special treatment is applied (an outer frame or assumed zero values ​​of the edge are repeated) is applied or none. It is for this reason that the type of filtering is set by the content of the kernel used.

Light, image and sound

How electricity is transformed into motion, light, image and sound

The power has several ways to actions prove.

1- In a motor current enters the motor coils and creates a rotating magnetic field which rotates the motor shaft.

2- In a lamp current flows through the coil-shaped filament which provides a high resistance to current flow, and this causes heat by the joule effect and the filament becomes red hot, which emits light.

3- In a computer, cell phone, digital camera or electricity is encoded into binary codes 0-1. And then these codes are arranged in groups and order representing the image.

4- In the same way that the image on a computer, the sounds are stored as binary codes, when reproducing music player and decode the codes represented by electrical impulses that are sent to the speaker, then this current travels horn coil is interacting with a magnet which causes spider vibrate the horn and this pushes the air in front.

Learning across multiple contexts

M-learning or mobile learning is defined as "learning across multiple contexts, through social and content interactions, using personal electronic devices.”^{[1]:page 4}A form of e-learning distance education, m-learners can use mobile device educational technology in many locations at their time convenience.^[2]

M-learning technologies include handheld computers, MP3 players, notebooks, mobile phones and tablets. M-learning focuses on the mobility of the learner, interacting with portable technologies. Using mobile tools for creating learning aids and materials becomes an important part of informal learning.^[3]

M-learning is convenient in that it is accessible from virtually anywhere. Sharing is almost instantaneous among everyone using the same content, which leads to the reception of instant feedback and tips. This highly active process has proven to increase exam scores from the fiftieth to the seventieth percentile, and cut the dropout rate in technical fields by 22 percent.^[4] M-learning also brings strong portability by replacing books and notes with small devices, filled with tailored learning contents.

Background[edit]

Mobile learning is the delivery of learning, education or learning support on mobile phones, PDAs or tablets. E-Learning has provided the ability for traditional learning to break out of the classroom setting and for students to learn at home. Mobile learning has enhanced upon e-learning by taking it a step further and allowing students to learn virtually anywhere a mobile signal is available. This allows students to stay connected to the classroom while traveling, vacationing, during breaks or during any other free time one may have. Mobile learning is in its infancy and as of September 2011, 9.35% of apps from the iTunes App Store were in the education category. ^[5]

New mobile technology, such as hand-held based devices, is playing a large role in redefining how we receive information. The recent advances in mobile technology are changing the primary purpose of mobile devices from making or receiving calls to retrieving the latest information on any subject. "Numerous agencies including the Department of Defense (DoD), Department of Homeland Security (DHS), Intelligence community, and law enforcement are utilizing mobile technology for information management." 

Ref: http://en.wikipedia.org/wiki/M-learning

Redes de Comunicaciones

Una red telefónica es una red de telecomunicaciones utilizada para llamadas telefónicas entre dos o más partes.

Hay varios tipos diferentes de redes de telefonía:

• Una red de líneas fijas, donde los teléfonos deben estar conectados directamente a una central telefónica. Esto se conoce como la red telefónica pública conmutada o PSTN.
• Una red inalámbrica en la que los teléfonos son móviles y puede moverse en cualquier lugar dentro del área de cobertura.
• Una red privada, donde un grupo cerrado de teléfonos están conectados principalmente el uno al otro y usan una puerta de entrada para alcanzar el mundo exterior. Esto se utiliza generalmente en el interior de las empresas y los centros de llamadas y se denomina centralita privada (PBX).

Los operadores de telefonía pública (PTO) poseen y construyen redes de los dos primeros tipos y proporcionan servicios al público bajo licencia del gobierno nacional. Los operadores de redes virtuales (OVN) alquilan capacidad al por mayor de los PTOs y venden el servicio de telefonía al público directamente.

Red de Comunicaciones:

Conjunto de elementos conectados entre si en uno o mas nodos capaz de recibir / transmitir información, compartir recursos y dar servicio a usuarios.

Las redes que permiten todo esto son equipos avanzados y complejos. Su eficacia se basa en la confluencia de muy diversos componentes. El diseño e implantación de una red mundial de comunicaciones es uno de los grandes ‘milagros tecnológicos’ de las últimas décadas.

Hasta hace poco, la mayoría de las computadoras disponían de sus propias interfaces y presentaban su estructura particular. Un equipo podía comunicarse con otro de su misma familia, pero tenía grandes dificultades para hacerlo con un extraño. Sólo los más privilegiados disponían del tiempo, conocimientos y equipos necesarios para extraer de diferentes recursos informáticos aquello que necesitaban.

En la década de 1990, el nivel de concordancia entre las diferentes computadoras alcanzó el punto en que podían interconectarse de forma eficaz, lo que le permite a cualquiera sacar provecho de un equipo remoto. Los principales componentes de este proceso son los sistemas cliente/servidor, la tecnología de objetos y los sistemas abiertos.

En la práctica, el concepto de sistema abierto se traduce en desvincular todos los componentes de un sistema y utilizar estructuras análogas en todos los demás. Esto conlleva una mezcla de normas (que indican a los fabricantes lo que deberían hacer) y de asociaciones (grupos de entidades afines que les ayudan a realizarlo). El efecto final es que sean capaces de hablar entre sí.

Elementos de una red de comunicaciones:

1. Fuente
2. Transmisor
3. Destino
4. Receptor
5. Medio de transmisión
6. Mensaje
7. Interfaz

Leer más: http://www.monografias.com/trabajos15/redes-telefonicas/redes-telefonicas.shtml#RED#ixzz3cUMiDg4F