martes, 1 de diciembre de 2009

Operating Systems



An operating system is a software system, ie, a set of computer programs designed to perform many tasks among which the management of peripheral devices.

When voltage is applied to the processor of an electronic device, it runs a small assembly language code located in a specific address in ROM (address reset) and known as reset code, which in turn executes a routine which initializes accompanying hardware processor. Also in this phase usually initialized controller interrupts. Following this stage runs the boot code (startup code), also code in assembly language, whose most important task is to run the main program (main ()) application software [1].

An operating system can be found in most electronic devices that use microprocessors to operate, because thanks to them we can understand the machine and that it fulfills its functions (cell phones, DVD players, radios, computers, radios, etc. ).


luisa Nuñez c.i:21.146.188

viernes, 27 de noviembre de 2009

SAP R/3




SAP R/3

SAP R / 3 software can be defined as an open, technology-based client / server, designed to handle the information needs of a company. SAP R / 3 is the software of this kind of wider dissemination throughout the world, with over 18,000 installations in over 100 countries. It is the enhanced version of an earlier product (system R / 2) that has enabled SAP AG to become the leading enterprise software, which is basically what is SAP R / 3 . However, not limited to being just a software package, SAP R / 3 goes beyond this is a whole team (staff, programs, communications, partners ...) working 24 hours a day for the company it is installed.

The R / 3 system is a system "On-line real-time and designed to comprehensively cover the needs of corporate management or type information medium / large. It consists of a set of fully integrated modules that cover a wide range of business functions among which include: Economic and Financial Management (General Accounting, Analytical Accounting, Fixed Assets, Financial Module, etc.)., Logistics, Sales and Distribution, Production (Planning, Control, Serial Production Systems, lots, JIT, etc.)., Quality Control, Maintenance, Integrated Projects, Human Resources, Workflow, etc.

In short, one can argue that covers all functional areas of the company. Also, are being developed and where appropriate improve, the so-called Industrial Solutions, which means better aligning the SAP system to the particularities of each business sector: Oil, Automotive, Publishing, Pharmaceutical Laboratories, Retail, Food, Public Sector, Telecommunications etc.


Features of the R / 3:

SAP R / 3 has been so successful because it combines unique features that are ideal when working in business management.

SAP is very flexible. Helps streamline the daily tasks of any business regardless of sector and country you work, its size (although that seems to be directed more to large enterprises) and other factors that may pose a problem with other software.


Another important aspect that is highly integrated: Beat the hierarchical and functional limitations typical of the company. Everything is integrated in one software that coordinates the different structures, processes and events of all departments and functional areas, allowing each employee to have all the necessary information at all times. This will not only updates the information in real time (important feature of SAP is a huge advantage), but also just enter data once, since it is the system is responsible for passing and updating the data in the rest modules or programs.

So the interface between central offices, production facilities, etc. is ensured. Before SAP systems, all operations could be done in each department, office, factory .... with specific programs for each (software for materials management, software to control wages, sales, purchasing, etc.. and each of them working with their own protocols, with your own information, adapted to different hardware without connecting or share information) with what worked twice: the data are repeated in different areas are handled several times (for example, in the warehouse and administration) and, not being interconnected, (although there is an internal network, the programs could work with various formats, data, incompatible machines) is necessary for someone to be devoted to pass information from one to another, wasting time that could be spent on improving the strategy.

Posted by Geraldine Avila

martes, 24 de noviembre de 2009

Free Software


The issue of freedom Free Software


Free software is a matter of the users' freedom to run, copy, distribute, study, change and improve the software. More precisely, it means that users of programs have the four essential freedoms.

-The freedom to run the program, for any purpose (freedom 0).
-The freedom to study how the program works, and change it to do what you want (freedom 1). Access to the source code is a precondition for this.
-The freedom to redistribute copies so you can help your neighbor (freedom 2).
-The freedom to improve the program and publish their improvements, and modified versions in general to the whole community benefits (freedom 3). Access to the source code is a necessary condition.

A program is free software if users have all these freedoms. Then, you should be free to redistribute copies, either with or without modifications, either gratis or charging a fee for distribution, to anyone anywhere. Being free to do these things means, among other things, that does not have to ask permission or pay.

You should also have the freedom to make modifications and use them privately in their own work or play, without even mentioning that they exist. If you publish your changes, should not be obliged to notify someone, or some particular form

The freedom to run the program means the freedom for any person or organizaion to use in any computer system for any type of work and purpose, without being obliged to tell your programmer, or any other specific entity. In this freedom, the purpose of users is what matters, not the purpose of programmers. As a user is free to run a program for their purposes, and if distributed to another person, also free to run for their purposes, but you have no right to impose their own purposes.


Posted by Geraldine Avila

sábado, 21 de noviembre de 2009

Programming Languages




Visual Basic Programming

Programming in Visual Basic is an agile and simple way to create applications for Microsoft Windows.
The programming language in Visual Basic provides all the necessary tools for rapid application development.

We could define programming in Visual Basic as the method used to develop graphical user interface.
With programming in Visual Basic you can develop almost any program you can imagine.

In addition to ActiveX technology, Visual Basic provides a tool for creating unlimited applications in the network.

Programming in Visual Basic allows to quickly build Windows applications. It is not necessary to know other programming languages to program in Visual Basic podersaber.

Programming in Visual Basic is a simple way to create applications besides language offers a number of tools to simplify this work, including projects, templates, forms, objects, custom controls, add-ins and a database manager.

Version 6.0 of Visual Basic programming is specially designed for the Internet. Using executable ActiveX controls operate like Visual Basic application is independent and through which they can access Internet Explorer.

Key features of programming in Visual Basic 6.0:

-The ability to access data from the database, client / server and scalable applications such as Microsoft SQL Server.
-ActiveX Technology
-ActiveX Controls
-Internet programming, web servers, DHTML, etc. ..
-Creating. Exe files, allowing circulated plication with great freedom.





Creado por Geraldine Avila

Database management systems

Database management systems

A database management system (DBMS) consists of software that organizes the storage of data. A DBMS controls the creation, maintenance, and use of the database storage structures of social organizations and of their users. It allows organizations to place control of organization wide database development in the hands of Database Administrators (DBAs) and other specialists. In large systems, a DBMS allows users and other softwares to store and retrieve data in a structured way.

Database management systems are usually categorized according to the database model that they support, such as the network, relational or object model. The model tends to determine the query languages that are available to access the database. One commonly used query language for the relational database is SQL, although SQL syntax and function can vary from one DBMS to another. A common query language for the object database is OQL, although not all vendors of object databases implement this, majority of them do implement this method. A great deal of the internal engineering of a DBMS is independent of the data model, and is concerned with managing factors such as performance, concurrency, integrity, and recovery from hardware failures. In these areas there are large differences between the products.

A relational database management system (RDBMS) implements features of the relational model. In this context, Date's "Information Principle" states: "the entire information content of the database is represented in one and only one way. Namely as explicit values in column positions (attributes) and rows in relations (tuples). Therefore, there are no explicit pointers between related tables." This contrasts with the object database management system (ODBMS), which does store explicit pointers between related types.

STRUCTURED PROGRAMMING


STRUCTURED PROGRAMMING.


Structured Programming: A technique in which the structure of a program the writing of its parts is made as clearly as possible through the use of three logical structures of control:

Sequence; a sequence of two or more simple operations.

Selection: Conditional Split one or more transactions.

Interaction: Repeating an operation while a condition is met.


These three types of logical structures of control can be combined to produce programs that handle all information processing task.

A structured program cosists of segments, which may be constituted by a few instructions or a page or more coding. Each segment has only one entrance ande one exit these segments, assuming you do not have infinite loops and have never run instructions are called programs themselves. When several programs themselves are combined using the three basic control structures mentioned above, the outcome is also own program.

Structured programming is based on the structure theorem, which states that any proper program (a program with one entrance and one exit only) is equivalent to a program that contains only the logical structures mentioned above.

An important feature is a structured program that can be read sequentially, from beginning to end without losing the continuity of the task that the program meets opposite of what occurs with other programming styles.

This is important because it is much easier to understand fully the work they perform a particular funtion, if all instructions that affect is action are physically close and enclosed by a block. The ease of reading, from beginning to end, is a consequence of using only three control structures and to eliminate diversion instruction control flow, except in very special circumstances such as simulation of a logical structure in language control programming that does not possess.


Creado por Geraldine Avila

viernes, 20 de noviembre de 2009

Programming Language(language c + +):

C + + is a programming language designed in the mid-1980s by Bjarne Stroustrup. The intention of its creation was to extend the successful C programming language with mechanisms that allow manipulation of objects.

Any program in C + + should have the main () (unless specified at compile time another entry point, which actually is the function that has the main ())

The main function must have one of the following prototypes:int main ()int main (int argc, char ** argv)The first is the omission of a program that receives no parameters or arguments. The second form takes two arguments: argc, a number that describes the number of arguments the program (including program name itself), and argv, a pointer to an array of pointers to argc elements, where the element argv [i] represents the i-th argument given to the program.The return type of main is int. At the end of the main function, must include the return value (for example, return 0;, although the standard provides only two possible return values: EXIT_SUCCESS and EXIT_ERROR defined in cstddef file), or leave through the exit function . Alternatively you can be left blank, in which case the compiler is responsible for adding the proper output.
luisa nuñez

What is Systems Engineering?

Systems Engineering is the application of mathematical and physical sciences to develop systems that use economically the materials and forces of nature for the benefit of mankind.A particularly full-definition, dating from 1974 - offers us the military standard U.S. Air Force engineering management. Systems Engineering is the application of scientific and engineering efforts to:

(1) transform an operational need into a description of system performance parameters and system configuration through the use of an iterative process of definition, synthesis, analysis, design, testing and evaluation.


(2) integrate related technical parameters to ensure compatibility of all functional and program interfaces in order to optimize the identification and total system design.


(3) integrating factors of reliability, maintainability, safety, survivability, human and others in the total engineering effort to meet cost objectives, planning and technical performance.


luisa nuñez

photos in class


in English class two with the teacher.
Luisa nuñez
20 de noviembre del 2009 a las 09:30pm

viernes, 13 de noviembre de 2009

Redes

The Communication Networks (Las Redes de Comunicacion)


1. Introduction


Communication networks are nothing more than the possibility of a universal sharing of information between groups of computers and their users, a vital component of the information age. Widespread computer or personal computer (PC) and local area network (LAN) during the eighties has led to the ability to access information in remote databases, load applications from overseas points, send messages to other countries and share files, all from a personal computer. The 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 network of computers is a major 'technological miracles' of recent decades.


2. Concept Network



It is a set of physical devices hardware and software "software", by which computers can communicate to share resources (disks, printers, software, etc..) And (time of calculation, data processing, etc.). . Each of the computers connected to the network is called a node. Network is considered local if it only reaches a few kilometers.

3. Types Of Networks



Information networks can be classified by their size and topology. A small network can start to grow with the organization or institution. Below is the different types of networks available:

Extension According to geographical distribution:

Network segment (subnet) :



A network segment is usually defined by the hardware or a specific network address. For example, in the environment "Novell NetWare" on a network segment includes all workstations connected to a network interface card on a server and each segment has its own network address.

Local area network (LAN) :



A LAN is a network segment that is connected workstations and servers or a set of interconnected network segments, usually within the same area. For example a building.

Campus Network



A campus network is extended to other buildings within a campus or industrial area. The various segments or LAN in each building are connected by network cables support. Metropolitan area network (MAN) A MAN network is a network that spreads by towns or cities and are interconnected by various public or private facilities such as telephone system or the suppliers of microwave communication systems or optical media.


Wide Area Network (WAN and global networks)


WANs and global networks extend beyond the borders of cities, towns or nations. The links are made public telecommunications facilities and private, in addition to microwaves and satellites.


4. Topology


The topology or logical form of a network is defined as the way to build the cable to individual workstations, for walls, floors and ceilings of the building. There are a number of factors to consider to determine which topology is most appropriate for a given situation. There are three common topologies:

"Ring"

The stations are linked to each other in a circle through a common wire (Figure 1). The last node of the chain is connected to the first closing the ring. The signals traveling in one direction around the circle, regenerating at each node. With this approach, each node examines the information that is sent through the ring. If information is not directed to the node that the review, go to the next in the ring. The disadvantage of the ring is that if a connection is broken, the entire network goes down.

Figure 1






"Star"


The network joins a single point, usually with a centralized control panel, as a hub for wiring (Figure 2). The blocks of information are routed through central control panel to their destinations. This scheme has an advantage to have a control panel that monitors the traffic and avoid collisions and a broken connection does not affect the rest of the network.


Figure 2



"Bus"

The stations are connected via a single cable segment (Figure 3). Unlike the ring, the bus is passive, there is no regeneration of signals at each node. The nodes in a network of "bus" transmit information and hope it will not collide with other information transmitted by another node. If this happens, each node waits a short amount of time at random, then tries to relay information. Figure 3






  • Hybrid
The linear bus, star and ring sometimes combine to form combinations of hybrid networks (Figure 4).


* Star Ring


This topology is used in order to facilitate network administration. Physically, the network is a central star in a hub, while logical level, the network is a ring.


* "Bus" star


The order is equal to the previous topology. In this case the network is a "bus" to be physically wired as a star through hubs.


* Hierarchical Star


This structure cabling is used in most existing local networks through hubs pair arranged in cascade form a hierarchical network.

Figura 4








5. Network Protocols


A network protocol is like a language for communication of information. Are the rules and procedures used on a network to communicate between nodes that access the cable system. The protocols govern two levels of communication:
The high-level protocols: These define the way applications communicate.
The low level protocols: These define how signals are transmitted by cable.
As usual in the case of computers constantly changing protocols are also constantly changing. Currently, the most commonly used protocols in the networks are Ethernet, Token Ring and ARCNET. Each of these is designed to provide some kind of network topology and have certain standard features.

Ethernet

Currently the protocol is easy and inexpensive. Use the topology of "Bus" linear.

Token Ring

The network protocol is the IBM token ring, which is based on ring topology.

Arnet

It is based on the star or star topology distributed, but has a topology and protocol.

6. Network devices


NIC / MAU (Network Card) "Network Interface Card (network interface card) or" Medium Access Unit (Medium Access Unit). Each computer needs the hardware to transmit and receive information. This is the device that connects other computer network computadorau with the physical environment. The NIC is a type of expansion card from the computer and provides a port on the back of the PC to which it connects the network cable. Today more and more computers with network interface, primarily Ethernet incorporated. It is sometimes also necessary network card, a transceiver. This is a device that connects to the physical environment and the card, either because it is not possible direct connection (10 base 5) or because the medium is different from that to the card.

Hubs (concentrators)

These are computers that allow structured cabling networks. The variety of types and characteristics of these teams is great. At first there were only wiring hubs, but have increasingly greater number of network capacity, remote management, etc. The trend is to incorporate more functions in the hub. There are hubs for all types of physical media.
Repeaters
Teams are physically active. Prolong the length of the network by joining two segments and amplifying the signal, but with it also amplify the noise. The network remains a single, which still apply the limitations on the number of stations that can share the medium.
"Bridges" (Bridges)
Are teams joining two networks operating on low-level protocols at the level of media access control. Only network traffic that is directed to the other through the device. This allows administrators to divide the networks into logical segments, relieving traffic interconnections. Bridges produce signals, thus noise is not transmitted through them.
Routers (Router)
They are networking equipment operating at the level of network protocols. Can use different interconnection systems improve the efficiency of transmission between networks. Its operation is slower than bridges but its capacity is greater. Allow even link two networks based on a protocol by one using a different protocol.
"Gateways"
Teams are to interconnect networks with completely different protocols and architectures at all levels of communication. The translation of the information units greatly reduces the transmission rate through these devices.
Servers
These are computers that allow connection to the network of peripheral equipment for both input and output data for. These devices are offered in the network as shared resources. Thus a terminal connected to one of these devices can establish sessions against several multi-user computers available on the network. Similarly, any system on the network can print to printers connected to a server.
Modems
These are computers that enable computers to communicate with each other over telephone lines, modulation and demodulation of electronic signals that can be processed by computers. Modems can be external (communication device) or internal (internal communication device or circuit board that is inserted into an expansion slot of the computer).

















The development of information technology.

The Information Technology has been conceptualized as the integration and convergence of computing microelectronics, telecommunications and technology for data processing, its main components are: the human factor, the content of information, equipment, physical infrastructure , software and mechanisms for electronic exchange of information, elements of policy and regulations and financial resources.

Is the information between computers, integrated services digital networks, satellite transmission and trans-border data flow global problems of mankind and a serious political issue of unpredictable social and economic conscience?.
If we examine these components we realize that are the major players in software development in a society for their development both as to its implementation also recognizes as information technologies are the core of a multidimensional transformation experienced by the economy and society, hence the importance of the study and mastery of the influences that such a transformation requires humans as social beings, as it tends to change not only their habits and behavior patterns, but even their way of thinking .

The key factors were:

  • The weapons of microelectronics that have allowed a huge advance in computing power and capacity of computers.
  • Advances in telecommunications have led to explosion in the use of networks of local and global scopes.
  • The accelerated development of programs and applications that are generalized moving closer to the "general public" by means of easy communication interfaces, pleasing to the use of multimedia techniques.
These factors make every day are reduced costs and therefore expand the use of these media in other sectors, not only at the military academy or industry, but in business, health, education, leisure and own homes.
It is estimated that this sector will have greater global investments and to current sociological theories exist, with idealistic approach, which they see as the miraculous element, a catalyst to solve social economic problems.
Importantly, the NTIC today act as an important engine of growth because their economic benefits in terms of value added, productivity and employment, add other character related bidirectional interconnecting, which allows the transmission and spread of benefits and experiences different regions and environments.
This new technological revolution not only ignores the barriers of time and space as their services are 24 hours and anywhere in the world, but also affect the people, which inter solutions with different institutions.
The access to large knowledge base in universities and libraries, distance learning, collaboration between research disinterested or use of telemedicine are examples of the infinite universe of possibilities that can provide these technologies and to enlighten the human condition today.
It is contradictory because currently, many satellite service providers have completed their business as profitable channels such as digital television, however, makes no such infrastructure available to cut social services even if a small operation of these technologies could save human lives.

Information Systems


An information system is a set of elements that interact in order to support the activities of a company or business.


The computer equipment: hardware needed for the information system to operate.


The human resource that interacts with the Information System, which consists of people who use the system.


An information system performs four basic activities: input, storage, processing and output of information.


Entry Information: The process whereby the information system takes the data required to process information. Entries can be manual or automatic. The manuals are those that are provided directly by the user, while automatics are coming data or information or are from other systems or modules. The latter is called automatic interfaces.


Typical units for data entry terminals are computers, magnetic tapes, floppy drives, bar codes, scanners, voice, touch screens, keyboard and mouse, among others.


Data storage: Storage is one of the most important activities or capabilities that have a computer, since this property through the system can recall the information stored in the section or previous process. This information is often stored in data structures called files. The typical unit of storage are magnetic disks or hard disks, floppy disks or diskettes and compact discs (CD-ROM).


Information Processing: The ability of the Information System to perform calculations in accordance with a predetermined sequence of operations. These calculations may be made with data recently introduced in the system or data that are stored. This feature allows processing systems source data into information that can be used for decision making, making it possible, inter alia, that a decision maker to generate a financial projection based on data that contains a state performance or a balance sheet of a base year.


Departure Information: Departure is the capacity of an information system to get the information processed or outside input. Typical units of output are printers, terminals, floppy disks, tapes, voice, graphics and plotters, among others. It is important to clarify that the output of an information system can be the gateway to other information system or module. In this case, there is also output interfaces automatically. For example, the Client Management System has an automatic interface with output accounting system, because it creates the accounting policies of procedural motions from customers.

Concept Engineering


Engineering is the art of taking a series of important decisions, given a set of incomplete and inaccurate data in order to get to a certain problem, among the possible solutions that operate more successfully.


""Engineering is the profession in which knowledge of mathematics and natural sciences gained by study, experience and practice, judiciously applied to develop ways that can be used, economically, the materials and the forces of nature for the benefit of the community.


""The engineering practice is any act of planning, design, composition, evaluation, advice, opinion, directive or supervisory or management of the foregoing, requiring the engineering principles and concerning the protection of life , land, property, economic interests, welfare or the environment. "