This document provides statistics on entries and teams for the XXVII Pan-American Championships in Buenos Aires, Argentina from May 16-18, 2013. There were a total of 479 entries across 22 weight categories for kata and kumite competitions in both female and male divisions, with 39 country teams and no regional teams participating. The largest number of entries was in the male kumite open category with 32 entries.
We live in both the real world and a digital world. In the digital world, we construct online personas and identities and can hide behind anonymity. However, our online and real lives are also interconnected. The digital world gives us opportunities to connect with others but may weaken our social skills. It has become difficult to balance time spent in the digital world versus the real world.
Presentacion sobre la relacion terapeuta paciente de miguel villegas22m19l22e
presentación que describe como se desarrolla la relación terapeuta paciente y a su vez cual es la tarea tanto del paciente como del terapeuta para hacer de esa relación un proceso de cambio positivo para la vida del paciente y también para la del terapeuta.
Certain gases in the atmosphere, such as carbon dioxide, methane, nitrous oxide, and CFCs, trap heat in a process similar to a greenhouse, causing global warming. As levels of these greenhouse gases increase due to human activities like burning fossil fuels and deforestation, the average temperature of the Earth is projected to rise 1.5-4.5°C by 2100. This warming could lead to sea level rise, more extreme weather, changes in agricultural patterns, and disruption of natural ecosystems. International agreements like the Kyoto Protocol aim to reduce greenhouse gas emissions and limit global temperature increase through strategies such as transitioning to renewable energy and making industry more energy efficient.
Este documento apresenta o portfólio de uma turma do 1o ano do ensino fundamental. Ele contém informações sobre os objetivos do portfólio, a justificativa, a identificação da professora e da turma, a avaliação diagnóstica inicial dos alunos, amostras de trabalhos realizados e atividades como cantos, contos, vídeos e fotografias. O portfólio tem como objetivo registrar o desenvolvimento integral das crianças ao longo do ano letivo.
This document provides statistics on entries and teams for the XXVII Pan-American Championships in Buenos Aires, Argentina from May 16-18, 2013. There were a total of 479 entries across 22 weight categories for kata and kumite competitions in both female and male divisions, with 39 country teams and no regional teams participating. The largest number of entries was in the male kumite open category with 32 entries.
We live in both the real world and a digital world. In the digital world, we construct online personas and identities and can hide behind anonymity. However, our online and real lives are also interconnected. The digital world gives us opportunities to connect with others but may weaken our social skills. It has become difficult to balance time spent in the digital world versus the real world.
Presentacion sobre la relacion terapeuta paciente de miguel villegas22m19l22e
presentación que describe como se desarrolla la relación terapeuta paciente y a su vez cual es la tarea tanto del paciente como del terapeuta para hacer de esa relación un proceso de cambio positivo para la vida del paciente y también para la del terapeuta.
Certain gases in the atmosphere, such as carbon dioxide, methane, nitrous oxide, and CFCs, trap heat in a process similar to a greenhouse, causing global warming. As levels of these greenhouse gases increase due to human activities like burning fossil fuels and deforestation, the average temperature of the Earth is projected to rise 1.5-4.5°C by 2100. This warming could lead to sea level rise, more extreme weather, changes in agricultural patterns, and disruption of natural ecosystems. International agreements like the Kyoto Protocol aim to reduce greenhouse gas emissions and limit global temperature increase through strategies such as transitioning to renewable energy and making industry more energy efficient.
Este documento apresenta o portfólio de uma turma do 1o ano do ensino fundamental. Ele contém informações sobre os objetivos do portfólio, a justificativa, a identificação da professora e da turma, a avaliação diagnóstica inicial dos alunos, amostras de trabalhos realizados e atividades como cantos, contos, vídeos e fotografias. O portfólio tem como objetivo registrar o desenvolvimento integral das crianças ao longo do ano letivo.
Experiencias 1 a 1 en argentina, chile y uruguayLau Sagardoyburu
Este documento resume los programas de experiencias 1 a 1 implementados en Argentina, Chile y Uruguay. Argentina implementó su programa Conectar Igualdad en la escuela secundaria en 2010, entregando más de 1.7 millones de netbooks. Chile implementó su programa Laboratorios Móviles Computacionales en la escuela primaria en 2009, entregando más de 50,000 netbooks. Uruguay implementó su programa CEIBAL en la escuela primaria y secundaria en 2006, entregando más de 450,000 netbooks. Todos los programas buscan reducir la brecha digital y
Exploring Social Media as a Powerful Tool for Creating Meaningful Change Marryam Khan
Digital activism is more impactful than commonly believed. While some dismiss online activists as "slacktivists", research shows social media activists are twice as likely to volunteer, four times as likely to encourage others to take action, and twice as likely to participate in events or donate. Awareness raised through social platforms can translate to tangible benefits, like the $7 million raised through text donations for Haiti earthquake relief in 2010. When coupled with offline action, digital tools give voice to more people and spread issues rapidly, showing how online and real-world activism can work together powerfully for change.
El documento describe los diferentes tipos de planos fotográficos, desde planos generales que muestran escenas completas hasta planos de detalle que se enfocan en una pequeña porción de la imagen. Explica 10 tipos de planos comunes que van desde planos generales hasta primeros planos, y cómo cada plano afecta la proporción del sujeto dentro del encuadre. También describe brevemente diferentes tipos de cámaras fotográficas.
The document discusses the definition and types of pollution. It defines pollution as an undesirable change in the environment that harms human or ecosystem health. It then summarizes the main sources and types of pollution, including air, water, soil, and waste pollution. The document also discusses waste generation processes and the waste management hierarchy of reduce, reuse, recycle. It provides examples of point and non-point pollution sources. The majority of the document then focuses on defining and describing various forms of water pollution in more detail, including physical, chemical, and biological indicators and impacts.
El primer parque eólico de Colombia, llamado Jepírachi, se encuentra en La Guajira y comenzó a funcionar en 2004. Tiene 15 aerogeneradores con una capacidad total de 19.5 MW que aprovechan los constantes vientos alisios. La energía producida se transmite a través de líneas de alta tensión hasta ser integrada al sistema eléctrico nacional. Además de proveer energía renovable, el parque ha beneficiado la economía local y servido como modelo para futuros proyectos con comunidades indígenas
Open source has not only taken over most fields of computing, its methodology has spread to many other domains too. So are there any big challenges left for the next generation of coders? Edward Snowden's revelations indicate what needs to be done: adding strong crypto to a new generation of free software programs that give us back our freedom.
El documento describe un proyecto de centro cultural para la comunidad de Antuco, Chile. Actualmente, Antuco carece de identidad como pueblo y de puntos de encuentro públicos para la comunidad. El proyecto propone trasladar la plaza principal a un área más céntrica rodeada de comercio y edificios públicos. El centro cultural se ubicaría junto a la nueva plaza para servir como espacio público comunitario y punto de encuentro, fortaleciendo la interacción social y el flujo turístico.
El documento describe las rivalidades imperialistas que llevaron a la Primera Guerra Mundial, incluyendo las disputas comerciales y coloniales entre Inglaterra y Alemania, las disputas territoriales entre Francia y Alemania y entre Austria-Hungría y Serbia, y las alianzas militares que se formaron. También resume algunos eventos clave de la guerra como el asesinato que desató el conflicto, la derrota alemana en la Batalla de Marne y el tratado de paz de Brest-Litovsk.
O documento lista alimentos funcionais e seus benefícios para a saúde. Ele descreve substâncias encontradas em cada alimento, quantidades recomendadas e efeitos no organismo, como redução do colesterol, propriedades antioxidantes e efeitos anti-inflamatórios. O documento também fornece recomendações de consumo de nutrientes e justificativas com base nos benefícios à saúde.
The SCD-2080R is a high resolution IR dome camera that:
1) Can capture clear images in complete darkness up to 20 meters away thanks to its built-in IR LEDs.
2) Automatically adjusts the intensity of its IR LEDs according to the distance of the subject to ensure a balanced image.
3) Provides flexibility for various applications with its 3.6x varifocal lens ranging from 2.8 to 10mm.
El documento es una evaluación para el tercer periodo de un estudiante de primer grado en el Colegio Técnico Agropecuario en La Unión. La evaluación incluye dos actividades: 1) colorear dibujos que representan profesiones y 2) copiar palabras del tablero y decir en qué estado se encuentran.
Formation Les bases de la communication financièreActions-Finance
Actions-Finance propose la formation Les bases de la communication financière
Cette formation en finance permet notamment de:
•Fournir aux stagiaires l’ensemble des connaissances techniques usuelles nécessaires au sein d’une équipe de communication d’un groupe coté.
•Aider les nouveaux entrants au sein d’une équipe à mieux intégrer certains aspects techniques de la communication financière.
Pour plus de renseignements sur la formation Les bases de la communication financière, N’hésitez pas à nous contacter par téléphone au + 33 (0)1 47 20 37 30, ou par email sur contact@actions-finance.com
This study examined how chronic physical restraint stress alters gene expression in mouse spleens. Mice were subjected to restraint stress for 12 hours per day for two days. Microarray analysis found that 48 out of 225 apoptosis- and p53 signaling-related genes showed significant expression changes in stressed mice compared to unstressed controls. Four genes (Fas, FADD, p53, p21) were validated with real-time PCR. The results provide evidence that apoptotic pathways contribute to stress-induced lymphopenia and identify potential stress response biomarkers.
RT2 qPCR Primer Assays are specifically designed gene expression analysis tools that use SYBR Green-based quantitative real-time PCR, with each assay being experimentally verified to ensure amplification of a single correct-sized product with uniform high PCR efficiency (>90%) for accurate comparisons of gene expression levels. The assays have a wide linear dynamic range, high performance equivalent to TaqMan assays, and coverage of every human, mouse and rat gene for easy multiple gene expression profiling. RT2 qPCR Primer Assays deliver reliable results and convenience when used with optimized RT2 qPCR Master Mixes for various real-time PCR instruments.
El documento habla sobre la competencia digital docente en la educación primaria. Explica cómo los maestros pueden compartir presentaciones en SlideShare para enseñar a sus estudiantes y mejorar sus habilidades tecnológicas. Recomienda que los maestros usen herramientas digitales como SlideShare para involucrar a los estudiantes y mantenerlos interesados en el aprendizaje.
Minam lanza campaña “Pon de tu parte” para luchar contra el cambio climáticoPerú 2021
La página web Inforegión.com provee información sobre las regiones de un país, incluyendo datos demográficos, económicos y culturales. Ofrece estadísticas, mapas e historia de cada región para ayudar a los usuarios a conocer mejor la diversidad geográfica dentro de una nación.
This document discusses the relationship between emotions and risk-taking behaviors. It presents the results of two surveys conducted with 91 second-year engineering students measuring their emotions related to financial decisions and perceptions of financial risk. The surveys found that students tend to feel joy after gains but disappointment after losses. They also tend to be moderate risk-takers, with their decisions influenced by emotions in about 35% of cases. A correlation analysis found a weak negative relationship between emotions and risk-taking. The document concludes that risk-taking behaviors are dependent on emotional states.
Project report RAILWAY TICKET RESERVATION SYSTEM SADNitesh Singh
This document provides a project report on developing a railway ticket reservation system. It includes sections that outline the system's requirements and functions for booking and cancelling tickets, checking PNR status and train details. It also includes data flow diagrams, decision tables, a decision tree, sequence diagram, use case diagram, activity diagram, structure chart, and Ishikawa diagram to model and design the system. Key terms used in the system like PNR, DFD, e-ticket, and i-ticket are defined in a glossary.
This document discusses comedy and comedians like Kapil Sharma, Jonny, Kyle Brauch, and the real work that goes into being funny for an audience. It touches on the traveling involved in the comedy business and different levels of comedy performance. The document expresses gratitude at the end.
This document is a project report submitted by four students to their professor for a DBMS project on automating a laundry service. It includes an acknowledgement section thanking the professor and others for their support and guidance. The contents section lists the various parts of the report covering requirements analysis, ERD diagram, normalization, PL/SQL code, and other sections related to implementing the database system for the laundry service. An overview of the proposed automated system and its key functional requirements are provided in the requirements analysis section.
Experiencias 1 a 1 en argentina, chile y uruguayLau Sagardoyburu
Este documento resume los programas de experiencias 1 a 1 implementados en Argentina, Chile y Uruguay. Argentina implementó su programa Conectar Igualdad en la escuela secundaria en 2010, entregando más de 1.7 millones de netbooks. Chile implementó su programa Laboratorios Móviles Computacionales en la escuela primaria en 2009, entregando más de 50,000 netbooks. Uruguay implementó su programa CEIBAL en la escuela primaria y secundaria en 2006, entregando más de 450,000 netbooks. Todos los programas buscan reducir la brecha digital y
Exploring Social Media as a Powerful Tool for Creating Meaningful Change Marryam Khan
Digital activism is more impactful than commonly believed. While some dismiss online activists as "slacktivists", research shows social media activists are twice as likely to volunteer, four times as likely to encourage others to take action, and twice as likely to participate in events or donate. Awareness raised through social platforms can translate to tangible benefits, like the $7 million raised through text donations for Haiti earthquake relief in 2010. When coupled with offline action, digital tools give voice to more people and spread issues rapidly, showing how online and real-world activism can work together powerfully for change.
El documento describe los diferentes tipos de planos fotográficos, desde planos generales que muestran escenas completas hasta planos de detalle que se enfocan en una pequeña porción de la imagen. Explica 10 tipos de planos comunes que van desde planos generales hasta primeros planos, y cómo cada plano afecta la proporción del sujeto dentro del encuadre. También describe brevemente diferentes tipos de cámaras fotográficas.
The document discusses the definition and types of pollution. It defines pollution as an undesirable change in the environment that harms human or ecosystem health. It then summarizes the main sources and types of pollution, including air, water, soil, and waste pollution. The document also discusses waste generation processes and the waste management hierarchy of reduce, reuse, recycle. It provides examples of point and non-point pollution sources. The majority of the document then focuses on defining and describing various forms of water pollution in more detail, including physical, chemical, and biological indicators and impacts.
El primer parque eólico de Colombia, llamado Jepírachi, se encuentra en La Guajira y comenzó a funcionar en 2004. Tiene 15 aerogeneradores con una capacidad total de 19.5 MW que aprovechan los constantes vientos alisios. La energía producida se transmite a través de líneas de alta tensión hasta ser integrada al sistema eléctrico nacional. Además de proveer energía renovable, el parque ha beneficiado la economía local y servido como modelo para futuros proyectos con comunidades indígenas
Open source has not only taken over most fields of computing, its methodology has spread to many other domains too. So are there any big challenges left for the next generation of coders? Edward Snowden's revelations indicate what needs to be done: adding strong crypto to a new generation of free software programs that give us back our freedom.
El documento describe un proyecto de centro cultural para la comunidad de Antuco, Chile. Actualmente, Antuco carece de identidad como pueblo y de puntos de encuentro públicos para la comunidad. El proyecto propone trasladar la plaza principal a un área más céntrica rodeada de comercio y edificios públicos. El centro cultural se ubicaría junto a la nueva plaza para servir como espacio público comunitario y punto de encuentro, fortaleciendo la interacción social y el flujo turístico.
El documento describe las rivalidades imperialistas que llevaron a la Primera Guerra Mundial, incluyendo las disputas comerciales y coloniales entre Inglaterra y Alemania, las disputas territoriales entre Francia y Alemania y entre Austria-Hungría y Serbia, y las alianzas militares que se formaron. También resume algunos eventos clave de la guerra como el asesinato que desató el conflicto, la derrota alemana en la Batalla de Marne y el tratado de paz de Brest-Litovsk.
O documento lista alimentos funcionais e seus benefícios para a saúde. Ele descreve substâncias encontradas em cada alimento, quantidades recomendadas e efeitos no organismo, como redução do colesterol, propriedades antioxidantes e efeitos anti-inflamatórios. O documento também fornece recomendações de consumo de nutrientes e justificativas com base nos benefícios à saúde.
The SCD-2080R is a high resolution IR dome camera that:
1) Can capture clear images in complete darkness up to 20 meters away thanks to its built-in IR LEDs.
2) Automatically adjusts the intensity of its IR LEDs according to the distance of the subject to ensure a balanced image.
3) Provides flexibility for various applications with its 3.6x varifocal lens ranging from 2.8 to 10mm.
El documento es una evaluación para el tercer periodo de un estudiante de primer grado en el Colegio Técnico Agropecuario en La Unión. La evaluación incluye dos actividades: 1) colorear dibujos que representan profesiones y 2) copiar palabras del tablero y decir en qué estado se encuentran.
Formation Les bases de la communication financièreActions-Finance
Actions-Finance propose la formation Les bases de la communication financière
Cette formation en finance permet notamment de:
•Fournir aux stagiaires l’ensemble des connaissances techniques usuelles nécessaires au sein d’une équipe de communication d’un groupe coté.
•Aider les nouveaux entrants au sein d’une équipe à mieux intégrer certains aspects techniques de la communication financière.
Pour plus de renseignements sur la formation Les bases de la communication financière, N’hésitez pas à nous contacter par téléphone au + 33 (0)1 47 20 37 30, ou par email sur contact@actions-finance.com
This study examined how chronic physical restraint stress alters gene expression in mouse spleens. Mice were subjected to restraint stress for 12 hours per day for two days. Microarray analysis found that 48 out of 225 apoptosis- and p53 signaling-related genes showed significant expression changes in stressed mice compared to unstressed controls. Four genes (Fas, FADD, p53, p21) were validated with real-time PCR. The results provide evidence that apoptotic pathways contribute to stress-induced lymphopenia and identify potential stress response biomarkers.
RT2 qPCR Primer Assays are specifically designed gene expression analysis tools that use SYBR Green-based quantitative real-time PCR, with each assay being experimentally verified to ensure amplification of a single correct-sized product with uniform high PCR efficiency (>90%) for accurate comparisons of gene expression levels. The assays have a wide linear dynamic range, high performance equivalent to TaqMan assays, and coverage of every human, mouse and rat gene for easy multiple gene expression profiling. RT2 qPCR Primer Assays deliver reliable results and convenience when used with optimized RT2 qPCR Master Mixes for various real-time PCR instruments.
El documento habla sobre la competencia digital docente en la educación primaria. Explica cómo los maestros pueden compartir presentaciones en SlideShare para enseñar a sus estudiantes y mejorar sus habilidades tecnológicas. Recomienda que los maestros usen herramientas digitales como SlideShare para involucrar a los estudiantes y mantenerlos interesados en el aprendizaje.
Minam lanza campaña “Pon de tu parte” para luchar contra el cambio climáticoPerú 2021
La página web Inforegión.com provee información sobre las regiones de un país, incluyendo datos demográficos, económicos y culturales. Ofrece estadísticas, mapas e historia de cada región para ayudar a los usuarios a conocer mejor la diversidad geográfica dentro de una nación.
This document discusses the relationship between emotions and risk-taking behaviors. It presents the results of two surveys conducted with 91 second-year engineering students measuring their emotions related to financial decisions and perceptions of financial risk. The surveys found that students tend to feel joy after gains but disappointment after losses. They also tend to be moderate risk-takers, with their decisions influenced by emotions in about 35% of cases. A correlation analysis found a weak negative relationship between emotions and risk-taking. The document concludes that risk-taking behaviors are dependent on emotional states.
Project report RAILWAY TICKET RESERVATION SYSTEM SADNitesh Singh
This document provides a project report on developing a railway ticket reservation system. It includes sections that outline the system's requirements and functions for booking and cancelling tickets, checking PNR status and train details. It also includes data flow diagrams, decision tables, a decision tree, sequence diagram, use case diagram, activity diagram, structure chart, and Ishikawa diagram to model and design the system. Key terms used in the system like PNR, DFD, e-ticket, and i-ticket are defined in a glossary.
This document discusses comedy and comedians like Kapil Sharma, Jonny, Kyle Brauch, and the real work that goes into being funny for an audience. It touches on the traveling involved in the comedy business and different levels of comedy performance. The document expresses gratitude at the end.
This document is a project report submitted by four students to their professor for a DBMS project on automating a laundry service. It includes an acknowledgement section thanking the professor and others for their support and guidance. The contents section lists the various parts of the report covering requirements analysis, ERD diagram, normalization, PL/SQL code, and other sections related to implementing the database system for the laundry service. An overview of the proposed automated system and its key functional requirements are provided in the requirements analysis section.
- Big data refers to large amounts of data that are constantly being generated and require advanced techniques and technologies to capture, manage and analyze. Examples include web logs, social media, sensor data, and financial transactions.
- Hadoop is an open-source software framework for distributed storage and processing of large datasets across clusters of commodity servers. It allows for the reliable, scalable and distributed processing of large data sets across clusters of commodity hardware.
- Key components of Hadoop include HDFS for storage, and MapReduce for distributed processing of large datasets in parallel on multiple servers. HDFS stores data across clusters of commodity servers as blocks, providing reliability even if individual servers fail.
There are two main internet protocols: TCP and UDP. TCP is connection-oriented and reliable, ensuring packets are delivered in order. It is slower than UDP but suited for applications like web browsing where reliability is important. UDP is connectionless and faster but packets may arrive out of order or not at all, making it well-suited for real-time applications like games and streaming media. Key differences between the two protocols include their handling of connections, ordering of packets, speed, and reliability of delivery.
This document provides an overview of key concepts in network layer delivery, forwarding, and routing. It discusses delivery and forwarding of packets, including direct vs indirect delivery and next-hop vs route forwarding methods. It also summarizes several unicast routing protocols, including distance vector protocols like RIP and link state protocols like OSPF. Finally, it discusses path vector routing and Border Gateway Protocol (BGP) for interdomain routing.
Routers and switches are networking devices that allow computers and other devices to connect to each other and form networks. While routers connect separate logical networks and operate at the network layer, switches operate at the data link layer and connect devices within a single local area network by forwarding data frames. The functions of routers and switches differ, with routers directing traffic between networks and switches allowing many devices to share a connection and increasing network bandwidth.
The transport layer is responsible for process-to-process delivery of data across network layers. There are three main protocols at the transport layer: UDP, TCP, and SCTP. UDP provides connectionless and unreliable data delivery, while TCP and SCTP provide connection-oriented and reliable delivery. The transport layer requires port numbers along with IP addresses to uniquely identify the sending and receiving processes and allow for multiplexing and demultiplexing of data between different applications and processes.
IPv4 uses datagram switching at the network layer and is connectionless. It includes fields for identification, flags, fragmentation offset, and time to live. IPv6 was developed to address IPv4's inefficient address space, lack of security, and inability to support real-time audio/video. IPv6 features a larger 128-bit address space, better header format, extensions, flow labeling, and more security. A smooth transition involves dual stack, tunneling, or header translation methods.
The document discusses IP addressing and network layer concepts. It provides examples of converting IP addresses between binary and dotted-decimal notation. It also describes classful addressing which divides the address space into classes A, B, C, D and E. The document then gives an example of address allocation and distribution to different customer groups. It introduces Network Address Translation (NAT) which allows internal networks to use a large set of private addresses while presenting a single external address.
A hub is a networking device that connects multiple computers to a single network using Ethernet, Firewire, or USB connections. It operates at the physical layer of the OSI model and broadcasts all incoming data to all ports, which can cause collisions. A switch is a networking device that connects network segments and operates at the data link layer. It stores MAC addresses in a lookup table to route data only to necessary ports, preventing collisions. Switches allow full duplex communication and the implementation of features like VLANs, spanning trees, and more advanced routing capabilities compared to hubs.
File Transfer Protocol (FTP) allows copying files between two hosts over TCP/IP. It establishes two connections - one for control information like commands and responses, and one for transferring files. FTP solves problems like different file naming conventions or data representations between systems. It uses ports 21 for control and 20 for data, and defines attributes like file type, data structure, and transmission mode to handle heterogeneous systems.
Electronic mail systems allow users to compose and send messages to other users. They utilize user agents to create and manage mailboxes, as well as mail transfer agents (MTAs) like SMTP to transmit messages between systems. MIME extensions allow non-ASCII content like images and files to be included in email messages by encoding them. IMAP and POP3 are common protocols for accessing email on a server, with IMAP providing more features for organizing and searching mail than POP3.
The World Wide Web (WWW) is a distributed system that allows clients using browsers to access and view web pages from servers located around the world. Web pages can contain links to other pages within the same site or other sites. A uniform resource locator (URL) specifies the protocol, host computer, port, and path needed to locate and access a specific web page. Web pages can be static, dynamic, or active depending on when their content is determined.
The document discusses different types of transmission media used for communication, including guided (wired) media like twisted pair, coaxial cable, and optical fiber, as well as unguided (wireless) transmission. It provides details on the characteristics of each medium, such as their bandwidth capabilities, applications, advantages and limitations. Overall, the document compares various physical transmission paths and how they enable data transmission over different distances and environments.
This document discusses the key concepts of data communication including the five components, different types of data flow, network topologies, categories of networks, and protocols. It defines data communication as the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols which are sets of rules that govern communication. There are three main types of data flow: simplex, half-duplex, and full-duplex. Different network topologies include mesh, star, bus, ring, and hybrid variations. Networks can be categorized as LANs, MANs, WANs, or internetworks connecting two or more networks using internetworking devices.
This document discusses the key concepts of data communication including the five components, different types of data flow, network topologies, categories of networks, and protocols. It defines data communication as the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols which are sets of rules that govern communication. Different types of data flow include simplex, half-duplex, and full-duplex. Common network topologies include mesh, star, bus, ring, and hybrid combinations of these. Networks can be LANs, MANs, WANs, or internetworks connecting multiple networks. Protocols establish rules for syntax, semantics, and
The TCP/IP model was developed by DARPA in the late 1970s and defines the protocols used for network communication on the internet. It has four layers - the lowest is the host to network layer which connects hosts to different networks using various protocols. Above this is the internet layer which allows data packets to be routed independently to their destination using the Internet Protocol. The transport layer segments messages and uses protocols like TCP and UDP. The highest application layer provides services that applications use for functions like file transfer, email, and web browsing.
There are two types of transmission media: guided (wired) media and unguided (wireless) media. Guided media contains signal energy within a solid medium like twisted pair cables, coaxial cables, and fiber optic cables used for point-to-point communication. Unguided media uses electromagnetic waves to propagate signals through radio waves or infrared light. Twisted pair cables are commonly used for short-distance digital data and telephone communication, using two insulated copper wires twisted together to reduce interference. Coaxial cable has a central wire surrounded by insulating material and outer shield to carry higher bandwidth signals with noise immunity up to 1 km. Fiber optic cable transmits light signals through thin glass or plastic cores over very long distances with