Notes, summaries, assignments, exams, and exercises for Technology for Vocational training

Metallic Twisted Pair Cables and Coaxial Systems

Twisted pair cables use a couple of conductors for both transmission and reception. If they are not shielded, they are very sensitive to interference. A way to overcome this interference is to weave (twist) the pairs so that the electromagnetic disturbances affecting one conductor are nullified by the adjacent conductor.

Types of Twisted Pair Cables

• UTP (Unshielded Twisted Pair): A twisted pair cable without external metallic coating, making it sensitive to interference.
• STP (Shielded Twisted Pair): Similar to UTP, but includes a metallic coating (shielding) to prevent external interference.

Optical Fiber Systems

Optical fiber allows the transmission of light signals. Fiber is usually made of glass...

Item 5: 2nd Part - Basic Services

1. List the functions of email:
1. Box correo
2. Notificación
3. Réplica
4. Attachments
5. Interfaz user-friendly

2. Indicate 4 points to highlight the application of group work, particularly in hierarchical multi-tasking and active environments:
* Provides communication and coordination of work, allowing for cooperative efforts among users.
* These software packages facilitate group sharing of documents and make it easy for users to access data in a common database.
* Workflow software keeps track of who receives specific information, when they receive it, and what they do with it.
* Natural evolution of email.

3. Explain the possible architectures in a client-server environment:
* Information on a single server.
* Information...

Data Flow Diagrams (DFD)

Data flow diagrams (DFD) are used to model system components, including processes, data entities, and the relationships between them.

Elements of a DFD

External Entities

These elements produce and consume system information without belonging to the system itself. They are represented by a rectangle.

Rules for External Entities

• All must be named.
• No relationship between them should appear outside the system.
• All must appear on the first-level DFD (context diagram), but may appear at lower levels for greater readability.

Processes

Processes represent functions or procedures that conduct an information system, transforming information during system performance. They are represented by a circle.

Rules for Processes

• All must have a

Querying Users and Privileges

DESCRIBE MYSQL.USER;

SELECT USER.User
FROM MYSQL.USER;

Creating Users and Granting Privileges

CREATE USER 'profesor'@'localhost';
GRANT ALL PRIVILEGES ON *.* TO 'profesor'@'localhost';

CREATE USER 'maikelnoviene'@'localhost' IDENTIFIED BY 'maikelnofaltes';
GRANT SELECT,INSERT,UPDATE,DELETE ON *.* TO 'maikelnoviene'@'localhost';

Checking User Privileges

SELECT USER.User
FROM MYSQL.USER;

SELECT USER.User, USER.Select_Priv, USER.Insert_Priv, USER.Delete_Priv,
USER.Update_Priv
FROM MYSQL.USER;

SELECT USER.User, USER.Select_Priv, USER.Insert_Priv, USER.Delete_Priv,
USER.Update_Priv
FROM MYSQL.USER
WHERE USER.User LIKE 'maikelnoviene';

Counting Superusers

SELECT COUNT(USER.User) AS 'Número de superusuarios'
FROM MYSQL.USER;...

Definition of Information Systems

An information system can be defined technically as a set of interrelated components that collect, process, store, and distribute information to support decision-making and control in an organization.

Definition of the Internet of Things (IoT)

The Internet of Things (IoT) is a computing concept that describes a future where everyday physical objects are connected to the internet and can communicate with other devices. The IoT is significant because objects that represent themselves digitally become something greater than the object by itself.

Relation Between Cloud Computing and E-business

To run an e-business, the support of cloud computing is essential. Main business processes are collected on the internet, and...

Network Topologies

Star topology connects each computer to a central point, which can be as simple as a junction of physical wires. When a computer sends a frame, it appears at the central device and is forwarded to the appropriate destination(s) by that central point.

Bus topology consists of a single cable that links all network stations. All computers monitor the cable for activity. When a computer transmits a frame, all computers on the bus receive it and check whether they are the intended recipient. If so, the recipient processes the frame; if not, it discards it.

Ring topology connects each computer to two others so that they form a ring. When a computer sends a frame to another, the frame travels through all intermediate stations. Many...

Windows Server 2008 Backup Methods

Windows 2008 allows five types of backups:

• Normal Backup: A normal backup is a full backup of all selected files and directories. This process deletes the modified bit (archive bit) of each file copied.
• Incremental Backup: During an incremental backup, the program examines the modified bit and performs a backup only of files that have changed since the last incremental or normal backup. As with the normal backup, this task clears the bits of each modified file that was copied. This type of backup minimizes the time and space needed to save data by storing only changed files. However, if you need to restore files after a disaster, you must have all previous tapes available up to the first normal copy.
• Differential

Testing Properties of Materials

Conformation

Used to know the degree of suitability of materials to manufacture parts.

Features

Used to know the mechanical characteristics of metal.

Understanding the Mechanical Properties of Materials

Used to find out the mechanical properties of materials.

Defects

Used to verify that there are no defects in the parts.

Mechanical Properties

• Hardness
• Tensile strength
• Yield strength
• and so on

Types of Hardness Measurements

• Scratch
• Penetration
• Rebound

Penetration Methods

• Brinell: A steel ball is used as the indenter, and the measurement is the area that the steel ball leaves.
• Rockwell: A diamond-tipped conical tip is used for hard materials, and a spherical tip is used for soft materials. Hardness is found by measuring the depth

Creating Tables and Constraints

SQL> CREATE TABLE ped (nif NUMBER(9) CONSTRAINT ped_tda_fk REFERENCES tda(nif), art VARCHAR2(20), c_fab NUMBER(3) CONSTRAINT ped_fab_fk REFERENCES fab(c_fab) ON DELETE CASCADE, pes NUMBER(3) CONSTRAINT ped_>0_ch CHECK(peso>0), cat CHAR(7) CONSTRAINT ped_cat_val_ch CHECK(cat='a' OR cat='b'), fec DATE, CONSTRAINT ped_pk PRIMARY KEY(nif, art, c_fab, pes, cat, fec), CONSTRAINT ped_art_fk FOREIGN KEY(art, pes, cat, c_fab) REFERENCES arts(art, pes, cat, c_fab) ON DELETE CASCADE;

Creating Views and Altering Tables

SQL> CREATE TABLE vent AS SELECT * FROM ped;
SQL> ALTER TABLE vent RENAME COLUMN uni TO uni_v;
SQL> ALTER TABLE vent ADD CONSTRAINT vent_>_0 CHECK(peso>0);
SQL> ALTER TABLE vent ADD CONSTRAINT

Glosario de términos de logística y cadena de suministro

A continuación encontrará un glosario de términos de logística en inglés con su traducción y explicación en español, útil para profesionales del transporte, el almacenaje y el comercio internacional.

Términos de la A a la C

• 3PL: third-party logistics (logística de terceros)
• Air waybill (también conocido como consignment note): conocimiento aéreo
• Assembling / assemble: organizar
• Assembly: ensamblaje
• Bendable: flexible
• Break-bulk: carga fraccionada
• Bundling: agrupar
• Cargo customs clearance: pasar la aduana
• Carriage: transporte
• Carrier: transportista
• Collection: recogida
• Collections: recogidas
• Comprehensive: completos, amplios
• Consolidation: agrupamiento de pequeños envíos en un solo contenedor
• Consignee: