Dosers for structured components. Transfusion of blood, its components and preparations: a textbook

A system is a set of interconnected and related external environment elements or parts, the functioning of which is aimed at obtaining a specific useful result.

Question 2: The concept of a system, its properties. IS, Economic and automated information system.

In accordance with this definition, almost every economic object can be considered as a system striving in its operation to achieve a certain goal. As an example, we can name the education system, energy, transport, economic, etc.

The system is characterized by the following main properties:

complexity;

divisibility;

integrity;

the diversity of elements and the difference in their nature;

System complexity depends on the set of components included in it, their structural interaction, as well as the complexity of internal and external relations and dynamism.

Divisibility of the system means that it consists of a number of subsystems or elements identified according to a certain feature that meets specific goals and objectives.

System Integrity means that the functioning of many elements of the system is subject to a single goal.

Variety of elements systems and differences in their nature is associated with their functional specificity and autonomy. For example, in the material system of an object associated with the transformation of material and energy resources, such elements as raw materials, basic and auxiliary materials, fuel, semi-finished products, spare parts, finished products, labor and financial resources can be distinguished.

Structured system determines the presence of established links and relationships between elements within the system, the distribution of system elements by hierarchy levels.

A system that implements control functions is called control system. The most important functions implemented by this system are forecasting, planning, accounting, analysis, control and regulation.

Systems differ significantly from each other both in composition and in main goals.

Example 1 Here are several systems consisting of different elements and aimed at realizing different goals.

In computer science, the concept of "system" is widespread and has many semantic meanings. Most often it is used in relation to a set of hardware and software. The system can be called the hardware part of the computer. A system can also be considered a set of programs for solving specific applied problems, supplemented by procedures for maintaining documentation and managing calculations.

The addition of the word "information" to the concept of "system" reflects the purpose of its creation and functioning. Information systems ensure the collection, storage, processing, search, and issuance of information necessary in the process of making decisions on tasks from any area. They help analyze problems and create new products.

Information system - an interconnected set of means, methods and personnel used for storing, processing and issuing information in the interests of achieving the goal.

The modern understanding of the information system involves the use of a personal computer as the main technical means of processing information. AT large organizations along with personal computers, the technical base of the information system may include a mainframe or supercomputer. In addition, the technical implementation of the information system in itself will mean nothing if the role of the person for whom the produced information is intended and without which it is impossible to receive and present it is not taken into account.

It is necessary to understand the difference between computers and information systems. Computers equipped with specialized software are the technical base and tool for information systems. An information system is unthinkable without personnel interacting with computers and telecommunications.

Information system- a human-computer system for decision support and production of information products, using computer information technology.

Examples of simple groups:

· address (zip code, city, street, house, apartment);

· date (day, month, day);

· person (last name, first name, patronymic);

· goods (name, code, grade, size).

Examples of complex groups:

driver (person, car);

addressee (address, person).

The intermediate components are called groups , and those that consist only of details are called simple, and those that include other components are called complex.

Indicators.

An indicator is a structural unit of information, consisting of one attribute of the basis, reflecting one or another fact in quantification, and a number of attributes-signs characterizing it and connected with it by logical relations (time, place, actors, objects of labor, etc.).

General form indicator can be presented as follows:

P \u003d (P 1, P 2 ... P n, Q),

where P 1 ,P 2 ... P n - attributes-features; and Q is the base prop.

One of the reasons for highlighting indicators as a special kind of structural units of information is that the indicator, in essence, is the minimum composition of the population that preserves the information content, and therefore sufficient to form an independent document.

For an indicator, there is also a name (identifier), structure or form, value.

The structure of an indicator is its requisite composition.

The indicator value is some construction in which each attribute included in the indicator is assigned a specific value from the corresponding definition area.

When classifying indicators, the following aspects are distinguished:

· object, the state of which reflects the indicator;

the state of the objects;

unit of measurement of the base;

stability of the indicator values.

To the most common groupings by "object" the indicators that determine the population, natural resources, social product, structural units (number of enterprises, organizations, territorial entities, etc.) are assigned.

Of particular interest in this group are indicators with a base value equal to one, in which the phenomenon of a veiled base is observed before the processing process.

Such indicators will be called Boolean. A feature of a Boolean indicator is the alternative value of its base, which is reduced to one of two values: one or zero. At the first meaning the indicator, as it were, is subject to registration due to the presence of the observed object and its inherent features. At the second, zero, the value, as it were, establishes the absence of these signs, and, consequently, of the entire unit of observation. With external simplicity, Boolean indicators make it possible to carry out generalization, aggregation, as a result of which aggregated indicators are created.

On the basis of "state" indicators are divided into static, characterizing the displayed object or its properties at a certain point in time (for example, the number of employees, the price of products, the tariff for services, etc.), and dynamic characterizing the processes of activity or a change in the state of the displayed object over a certain period of time (for example, movement labor resources, change natural resources etc. ).

When classifying indicators on the basis of "base units" stand out absolute and relative indicators.

Absolute indicators are called indicators, the bases of which are obtained by direct counting, measurement and weighing, algebraic summation of others absolute indicators, as well as various average absolute indicators.

in number relative includes indicators whose base values ​​are obtained by the ratio of the bases of two other indicators (for example, structure indicators that characterize specific gravity part as a whole, indicators of intensity, namely, capital productivity, material intensity, labor productivity, etc.) and relative averages.

When classifying on the basis of stability distinguish variables and permanent indicators. In the group of constant indicators, there are normative indicators (norms, standards, rates, prices, constant coefficients and interest rates).

Information space of economic objects

The information space of an object is understood as the totality of all information components of this object or a set of objects, regardless of the ways and means of displaying these components.

One of the most important characteristics of the information space is the degree of its structure.

Structuredness is understood as such a property of the information space, in which all the content and features of this space are represented by its components and the relationships between them, expressed explicitly.

Depending on the degree of structure of the information space, the following five types are distinguished.

Unstructured space- this is something for which it is characteristic that the structuredness of its information components is rare.

An example of an unstructured information space is colloquial speech, although some elements of structure may be present in it.

Weakly structured information space one in which only individual components are fully structured.

An example would be a written language that follows the rules of syntax.

Structured information space characterized by a significant predominance of structured components, the information in it is documented, coding is widely used to ensure an unambiguous interpretation of certain concepts. An example is the economic information system.

Formalized structured information space is a space where there are explicit descriptions of information formations, in which not only information structures and connections are defined, but also algorithms for obtaining the values ​​of any data element.

Machine-structured information space is the one that describes everything information formations, including forms of input and output documents. A typical example is a database.

Verification tests for topic 1

1. Props is:

a) Meaning of data

b) Characteristics of the determined property of the object

c) Composite unit of information

d) Set of records

e) Dataset

2. Economic Information classified by management functions into

b) primary and secondary

3. Economic information is classified according to the method of formation on

a) planning, accounting, analytical, management

b) primary and secondary

c) excess, full and insufficient

d) true and false

e) constant, conditionally constant and variable

4. Economic information is classified according to information saturation on

a) planning, accounting, analytical, management

b) primary and secondary

c) excess, full and insufficient

d) true and false

e) constant, conditionally constant and variable

5. Economic information is classified according to the objectivity of reflection on

a) planning, accounting, analytical, management

b) primary and secondary

c) excess, full and insufficient

d) true and false

e) constant, conditionally constant and variable

6. Economic information is classified by stability into

a) planning, accounting, analytical, management

b) primary and secondary

c) excess, full and insufficient

d) true and false

e) constant, conditionally constant and variable

7. Economic information is classified according to the place of origin and use on

a) planning, accounting, analytical, management

b) primary and secondary

c) excess, full and insufficient

d) true and false

e) incoming, outgoing and internal

8. What models of knowledge representation exist?

a) frame models

b) nomenclature models

c) production models

d) models of semantic networks

e) logical models

4.1. Transmission media

4.1.1. Twisted Pair Cables

4.1.1.1. Transmission performance

SCS uses cable components with transmission performance characteristics of the following categories:

6 - unshielded (UTP) and shielded (ScTP, FTP, SFTP) cables based on a twisted pair of conductors with a wave impedance of 100 Ohm and an operating frequency range of up to 250 MHz;

5e - unshielded (UTP) and shielded (ScTP, FTP, SFTP) cables based on a twisted pair of conductors with a characteristic impedance of 100 Ohm and an operating frequency range of up to 100 MHz;

5 - unshielded (UTP) and shielded (ScTP, FTP) multi-pair cables based on a twisted pair of conductors with a wave impedance of 100 Ohm and an operating frequency range of up to 100 MHz;

3 - unshielded (UTP) multi-pair cables based on a twisted pair of conductors with a characteristic impedance of 100 Ohm and an operating frequency range of up to 16 MHz.

Multi-pair twisted-pair cables with Category 3 and Category 5 transmission performance can only be used in SCS backbone subsystems for signaling low-speed applications (eg analog and digital telephony).

An exception to the above rules are multi-pair cables for outdoor installation, the performance of which usually does not go beyond the first and second levels. These cables consist of 19 AWG (0.9 mm), 22 AWG (0.64 mm), 24 AWG (0.5 mm), or 26 AWG (0.4 mm) solid copper conductors in thermoplastic insulation and are designed to transmit voice and low-speed data applications (OSP cables) or voice, high-speed data and video applications (broadband BBOSP cables).

4.1.1.2. Operation of cables in places with high temperatures

Installation of cable segments is possible in spaces (for example, air ducts, shafts (risers), premises not equipped with microclimate control systems (warehouses), industrial premises, etc.), the ambient temperature of which can be above 20 °C.

To meet the insertion loss (IL) requirements of the channel and permanent link models, it is recommended to reduce the length of the cable segments depending on the average ambient temperature at their installation sites, by applying the temperature coefficient of insertion loss.

Table 2 shows the values ​​of possible changes in the length of cable segments depending on the ambient temperature at the place of cable laying and the temperature coefficient of insertion loss (0.4% per 1 degree Celsius).

table 2

Temperature, °C	Increase in insertion loss, %	Cable length, m	Cable length reduction, m

When calculating the data above, 10 m of equipment and patch cords were taken into account in accordance with the channel model.

4.1.1.3. Horizontal subsystem cables

General provisions

The requirements specified in this section apply to cables based on symmetrical twisted pair conductors intended for use in a horizontal cabling subsystem.

The horizontal cable subsystem cables consist of 22 - 24 AWG solid conductors in thermoplastic insulation, formed into four twisted pairs, covered with an overall thermoplastic jacket, with a single foil shield or double foil and wire mesh shield as options.

All cables based on a symmetrical twisted pair of conductors have a characteristic impedance of 100 ohms.

Notes. 1. Multi-pair balanced twisted-pair cables of any transmission performance category are prohibited.

2. Bundled cables are not allowed.

The formation of bundles of cables during installation, subject to the requirements of section 5, does not lead to the formation of a bundled cable and is not considered a prohibited practice.

The color coding of conductors and pairs in 4-pair horizontal subsystem cables follows the scheme shown in Table 3.

Table 3

	Conductor	color code	Abbreviation
		white-blue
		white-orange
		Orange
		white-green
		white-brown
		Brown

Shielded cables

The use of twisted-pair cables to support telecommunications applications sometimes requires the use of a shield. Shielding the cable conductors helps to improve protection against electromagnetic radiation generated by signal carriers and immunity to electromagnetic interference from external sources. The screen's ability to provide specific benefits to a cable system depends on a variety of factors. These factors include the performance of the cabling components, specific installation methods and care, as well as the design features and methods of connecting active equipment.

4.1.1.4. Trunk subsystem cables

General provisions

The requirements given in this section apply to cables based on symmetrical twisted pair conductors intended for use in the backbone cabling subsystem.

The backbone subsystem cables are constructed from 22 - 24 AWG solid conductors in thermoplastic insulation, formed into four twisted pairs, covered with a common thermoplastic sheath, with a single or double foil shield and wire mesh as additional elements.

All cables based on a symmetrical pair of conductors have a characteristic impedance of 100 ohms.

The color coding of conductors and pairs in 4-pair trunk subsystem cables follows the scheme shown in Table 3.

The use of multi-pair cables based on balanced twisted-pair conductors with transmission performance of categories 3 and 5 is permitted in the backbone cable subsystem.

The use of multi-pair cables is limited to the transmission of homogeneous signals for low-speed telecommunication applications (with an operating frequency band of up to 1 MHz).

Note. Outdoor multi-pair cables may be used up to and including levels 1 and 2, provided the cables consist of 19 AWG (0.9 mm), 22 AWG (0.64 mm), 24 solid copper conductors. AWG (0.5 mm) or 26 AWG (0.4 mm) thermoplastic insulated for signaling voice and low speed data applications (OSP type cables) or voice, high speed data and video applications (BBOSP type broadband cables) .

Shielded cables

The use of twisted-pair cables to support telecommunications applications sometimes requires the use of a shield. Shielding the cable conductors helps to improve protection against electromagnetic radiation generated by signal carriers and immunity to electromagnetic interference from external sources. The ability of a shield to provide specific benefits to a cable system depends on a variety of factors such as the performance of the cable system components, specific installation methods and care, and the design and connection of active equipment.

Shielded cables based on a balanced twisted pair of conductors used in the main cabling subsystem must comply with all requirements of the general provisions.

A feature of shielded cables is the addition of a galvanically continuous shield to the structure of the unshielded cable, located around four pairs under a common sheath. Single shield consists of spiral or longitudinal metal or metal-laminated plastic tape, double shield consists of tape and mesh consisting of 26 AWG tinned bare solid copper conductors. A 26 AWG tinned copper drain conductor is added to the shields and is in galvanic contact with the metal surface of the tape.

4.1.2. Fiber optic cables

4.1.2.1. General provisions

Fiber optic cables used in SCS are designed for indoor and outdoor use. The design of fiber optic cables contains from two to several fibers of various types and sizes in a buffer or sheath.

There are the following main types of cables:

Distribution cable consists of two or more fibers bundled together or as separate multi-fiber elements; used when installing extended segments of the cable system and in cases where all fibers are terminated in one place (for example, on one patch panel or in one wall-mounted optical cabinet);

The connecting cable or cord consists of one or two fibers reinforced with stiffeners (aramid fiber); designed for switching applications over short distances. A single-fiber cord is often referred to as "simplex", and a two-fiber cord is often referred to as "duplex". A duplex cord may consist of two simplex cables, the sheaths of which are interconnected, or of two fibers covered with a common sheath. Such cords are used as hardware and patch cords (jumpers);

A composite cable consists of two or more cable modules, which are separate distribution fiber-optic cables covered with a common sheath so that during installation each of these modules can be separated from the common structure and terminated in a separate place.

Cable color coding is presented in 4.1.2.7.

4.1.2.2. Transmission performance

The transmission performance of fiber optic cables used in SCS is shown in Table 4.

Table 4

Optical fiber type	Operating wavelength, nm	Maximum allowable attenuation, dB/km	Minimum allowable bandwidth factor, MHz x km
Multimode 50/125 µm
Multimode 62.5/125 µm
Single mode indoor application
Singlemode external application

4.1.2.3. Characteristics of cables of the internal subsystem

The design of 2- and 4-fiber optical cables intended for use in the horizontal cable subsystem and COA must provide a minimum allowable bending radius of 25 mm under operating conditions in the absence of tensile forces.

The design of optical 2- and 4-fiber cables intended for installation in the routes of a horizontal subsystem by pulling should provide a minimum allowable bending radius of 50 mm at a tension force of 220 N.

The design of all other cables for internal use must provide a minimum allowable bending radius equivalent to 10 external cable diameters in the absence of tensile forces and 15 external cable diameters with a tensile force not exceeding the maximum allowable limits.

4.1.2.4. External Subsystem Cable Specifications

The design of fiber-optic cables for external use must exclude the possibility of moisture penetrating into the interior of the cable.

Fiber optic cables for external use must withstand a tensile force of at least 2670 N.

The design of fiber-optic cables for external use must provide a minimum allowable bending radius equivalent to 10 external cable diameters in the absence of tension forces and 20 external cable diameters - with tension forces not exceeding the maximum allowable limits.

4.1.2.5. Horizontal subsystem cables

The design of fiber optic cables used in the horizontal subsystem must be based on 50/125 or 62.5/125 µm multimode optical fibers, single-mode optical fibers, or any combination of them. Individual fibers or their groups are subject to the color coding rules given in 4.1.2.7.

Note. Single-mode fiber-optic cables are used to a limited extent (at the request of the user).

4.1.2.6. Trunk subsystem cables

The design of fiber optic cables - according to 4.1.2.5.

4.1.2.7. Color coding and fiber numbering

The numbering of fibers of optical cables is carried out in accordance with their color coding, which greatly simplifies the procedure for installing switching equipment and installing connectors, as well as subsequent administration and testing of the cable system.

The numbering of fibers and the corresponding color codes of fiber-optic cables used in SCS can be of two types:

Type 1 - the numbering of the fibers is based on the color of the modules, which have a different color. Usually the cable has two colored modules, one of which is most often red, the rest are colorless. Modules, as a rule, are numbered by the manufacturer: 1 - red, 2 and the following - other colors.

If there is only one fiber in the module, its number is the same as the module number. With two or more fibers, the numbering of the fibers is carried out using the colors of the buffer coatings of the fibers. There is no system in choosing the color of individual fibers, so the numbering is performed individually in each individual case. The lower fiber number in the module is usually assigned to the fiber with an uncolored buffer coating.

In cases where modules of red and other colors are not located next to each other, the numbering principle does not change.

Type 2 - the numbering of the fibers is carried out in accordance with the individual standard color code given in Table 5. Buffer shells of 250 and 900 microns are subject to color coding. In modular multi-fiber cables, the same color coding applies to the modules.

Table 5

Fiber number	Sheath and marking thread color	Abbreviation
	Orange
	Brown
	Violet
	Blue with black thread
	Orange with black thread
	Green with black thread
	Brown with black thread
	Gray with black thread
	White with black thread
	Red with black thread
	Black with yellow thread
	Yellow with black thread
	Purple with black thread
	Pink with black thread
	Blue with black thread
<*>D/ - dotted marker or thread.

In cables with a free buffer, the number of fibers in one tube of which is more than 12, grouping of light guides into bundles fastened with colored threads can be used.

In some cases, to facilitate pair grouping, the fibers are dyed in the same colors with ring marks every 2 - 3 cm on the second light guide of the pair.

The color coding parameters of the outer sheaths of distribution, composite and connecting cables for indoor use are used to identify their classes. In the case of using a standard system, the colors must comply with the requirements of table 5. Some functional types of indoor cables, due to their special design, do not have colored sheath materials.

The outer sheath of indoor cables containing only one type of fiber shall be color coded to identify the fiber class according to the color scheme given in Table 6. The outer sheath of indoor cables containing more than one fiber type shall be black.

Table 6

Color coded according to

from optical fiber class

Where cables contain fibers of more than one type, fibers of the same type in each single or double fiber cord sheath are coded by the sheath color of the element.

4.2. Switching equipment

4.2.1. Switching equipment based on twisted pair conductors

4.2.1.1. General provisions

The rules for installing switching equipment, managing cable flows, terminating transmission media on connectors are set out in section 8.

Switching equipment based on a twisted pair of conductors must be equipped with insulation displacement contacts (IDC type contact), and their use is limited to the following functional elements of the SCS:

Main cross;

Intermediate crosses;

Horizontal crosses;

Consolidation points;

Telecommunication sockets.

The following devices containing passive or active electronic circuits and intended to serve specific applications or provide security measures in the system are not considered switching equipment approved for use in SCS:

Media converters and media adapters;

Wave impedance matching transformers;

ISDN resistors;

Filters;

network cards;

Devices of primary and secondary protection.

Such adapters and protectors are considered to be part of the active electronic equipment and not part of the cabling system.

4.2.1.2. Transmission performance

The SCS uses category 6 and 5e switching equipment with transmission performance according to 4.1.1.1.

4.2.1.3. Design

4.2.1.3.1. The design of cross-connect switching equipment used for terminating cables based on a twisted pair of conductors with a characteristic impedance of 100 Ohm provides:

Switching cable subsystems using patch cords;

Connecting active electronic equipment to the cable system;

Means of identifying circuits for the purpose of their administration;

Means of standard color coding for the purpose of functional identification of switching fields;

Tracing and cable management tools;

Means for connecting testing and diagnostic equipment.

4.2.1.3.2. The design of consolidation points and telecommunication sockets used for terminating cables based on a twisted pair of conductors with a characteristic impedance of 100 Ohm provides:

Termination of cable segments of the horizontal cable subsystem;

Means of identifying cable conductors in order to comply with the requirements for the wiring diagram.

The switching equipment used in the SCS does not have in its design the means for creating shunted taps and reversed pairs. If you need to support specific applications, you should use adapters and specialized hardware cords (for example, crossover cords). Such devices are not considered part of the SCS.

4.2.1.4. Mechanical characteristics

Switching equipment used for terminating cables based on a twisted pair of conductors with a characteristic impedance of 100 Ohm is designed to operate at an ambient temperature from minus 10 °C to plus 60 °C.

The modular jacks of the switching equipment are designed for at least 750 interfaces with modular plugs of the appropriate design (8c8p).

To ensure normal operation, switching equipment must be adequately protected from mechanical damage, moisture and aggressive environments (inside buildings and with special protection).

Switching equipment must provide a high density of installation, allowing to save the installation space of telecommunications premises, while providing convenient means of tracing cables and managing cable flows.

4.2.1.5. Shielded switching equipment

Shielded switching equipment is designed to terminate shielded cables of the ScTP/FTP and S/FTP types based on a twisted pair of conductors with a characteristic impedance of 100 Ohm.

Modular jacks of shielded switching equipment are designed for at least 750 interfaces with appropriately designed modular plugs (8c8p).

To ensure the effectiveness of the shielding of the system, it is required to maintain the continuity of the shield in all components of the cable subsystems in the models of lines and channels, as well as connect the shields to the telecommunications grounding system and equalize the potentials in accordance with the requirements of regulatory documents.

4.2.2. Fiber optic switching equipment

4.2.2.1. General provisions

Fiber-optic switching equipment includes connectors and switching equipment installed in the main, intermediate and horizontal cross-country, at workplaces, as well as interconnections and couplings in COA and as consolidation points.

Rules for the installation of fiber optic switching equipment are set out in Section 8.

SCS uses various types and designs of fiber optic connectors that meet the requirements of this standard.

Duplex connectors and adapters of type SC (568SC) are used in this standard as an example to illustrate mounting rules.

4.2.2.2. Connectors and adapters

Multimode fiber optic connectors and adapters (or the visible part of their housing) must be identified in beige, single-mode fiber optic connectors and adapters (or the visible part of their housing) in blue.

Two positions of duplex fiber optic connectors and corresponding adapters are shown in Figure 10 (positions A and B). The 568SC adapter provides a logical crossover of fiber pairs when mating two connectors.

Figure 10. Configuration of positions A and B

in connector and adapter type 568SC

Positions A and B can be marked both with factory markings and in the field at the stage of installation of the cable system.

Fiber optic connectors must have the following characteristics:

insertion loss - maximum 0.5 dB in the conjugated state;

return loss - at least 20 dB (multimode fiber);

26 dB minimum (single mode fiber);

durability - at least 500 mating cycles;

cable retention force - 50 N with a tensile load applied at an angle of 0° to the connector axis and fixing the stiffeners in the connector; 2.2 N with a tensile load applied at an angle of 0° to the connector axis and no fixation of the stiffeners in the connector; 19.4 N with a tensile load applied at an angle of 90° to the connector axis and fixation of the stiffeners in the connector; 2.2 N with a tensile load applied at an angle of 90° to the connector axis and no fixation of the stiffeners in the connector;

torsional loads - 15 N with a tensile load applied at an angle of 0° to the connector axis, on the cable sheath fixed in the connector; 2.2 N with a tensile load applied at 0° to the connector axis on the buffered fiber.

Fiber optic adapters must have the following characteristics:

insertion loss - maximum 0.5 dB in the conjugated state;

operating temperature - from 0 °C to plus 60 °C;

durability - at least 500 mating cycles.

4.2.2.3. Couplings

The values ​​of insertion loss of welded and mechanical couplings used in SCS should not be more than 0.3 dB per connection.

Return loss values ​​of welded and mechanical couplings used in SCS should not exceed 20 dB for multimode fibers and 26 dB for single-mode fibers per connection. To clarify the values ​​of the parameters determined for the operation of specific telecommunication applications, one should refer to the relevant regulatory documents (for example, to ensure the normal operation of a wideband analog CATV signal transmission application, it is required to ensure that the value of return loss at the connection point of single-mode fibers is not more than 55 dB).

4.2.2.4. Design

Fiber optic switching equipment is designed for mounting on walls or similar surfaces, mounting racks or any other type of mounting frame, and standard mounting equipment (wiring boxes and sockets).

Fiber-optic switching equipment must provide high density installations to save installation space in telecommunications facilities, while providing convenient means of cable routing and cable flow management.

Fiber optic patch panels and cabinets must be designed to meet the following requirements:

Switching cable subsystems using patch cords;

Connecting active electronic equipment to the cable system;

Means of identifying cable system segments for the purpose of their administration;

Means of standard color coding for the purpose of functional identification of switching fields;

Tracing and cable management tools;

Means for connecting testing, control and active equipment;

Means to protect connectors and adapters on the side of the cable system from contact with foreign objects that can temporarily or permanently affect the performance of the system.

The telecommunications outlet box must be able to accommodate at least two optical fibers, protect the fiber optic cable, and maintain a minimum bend radius of 25 mm.

The design of the fiber optic switching equipment used to connect the cables of the horizontal subsystem to the cables of the internal backbone subsystem in the COA configuration must provide:

Connecting the fibers of the cables of the horizontal and backbone subsystems using detachable connections (connectors and adapters) or couplings. It is recommended to stick to any one method in one cable system or in one object. Detachable connections must comply with the provisions of 4.2.2.2, welded or mechanical couplings - 4.2.2.3;

Fiber splicing technology, in which fibers can be spliced ​​individually or in pairs, provided they are organized and managed on a pair basis;

Means of uniquely identifying each connection position;

Ability to disable existing connections of the horizontal cable subsystem and add new ones;

Means of storage and identification of unused fibers of cables of horizontal and backbone subsystems;

Possibility of adding cables of horizontal and trunk subsystems in the future;

Possibility and means of migration from interconnect to sleeve or cross-connect;

Means for connecting to the cable system of testing equipment.

To ensure the above conditions, the rules set out in section 8 must be met.

4.3. Switching and hardware cables

4.3.1. Patch and hardware cables based on twisted pair conductors

4.3.1.1. Transmission performance

Category 6 and 5e hardware and patch cables (cords) with transmission performance in accordance with 4.1.1.1 may be used in the SCS.

4.3.1.2. stranded cable

Multi-core cables used for the manufacture of patch and equipment cords used in SCS must comply with the requirements for single-core cables given in 4.1.1.

The stranded cables are constructed from 24 - 26 AWG thermoplastic insulated stranded conductors, formed into four twisted pairs, sheathed in an overall thermoplastic sheath, with a single foil shield or a double foil and wire mesh shield as an option.

All multi-core cables based on a symmetrical pair of conductors must have a characteristic impedance of 100 ohms.

The insertion loss (IL) values ​​of multi-core cables over the entire operating frequency range shall not be greater than the insertion loss values ​​of single-core cables with similar performance categories, multiplied by the following correction factors:

Category 5e performance cables (1 - 100 MHz):

1.2 - with 24 AWG conductors;

1.5 - with 26 AWG conductors;

1.2 - Category 6 (1 - 250 MHz) performance cables with 22 - 24 AWG conductor gauges.

The color coding of conductors in multicore cables can be performed according to two schemes in Table 7, one of which (option I) is completely identical to the color coding scheme for conductors of single-core 4-pair cables, the second (option II) is considered alternative.

Table 7

Color coding of conductors in 4-pair cables

	Conductor	Color code (option I)	Abbreviation	Color code (option II)	Abbreviation
		white-blue
		white-orange
		Orange
		white-green
				Orange
		white-brown		Brown
		Brown

4.3.1.3. Cords based on unshielded twisted pair conductors

Hardware and patch cables (cords) used in SCS refer to hardware cords at the workplace, in telecommunications, hardware and urban inputs used to connect active equipment to the cable system, as well as patch cords used in telecommunications, hardware and urban inputs for performing cross-connections and passive connections of cable subsystems among themselves.

The performance characteristics of the hardware and patch cords have a significant impact on the overall performance of the channel model.

Field fabrication of cords is permitted with certain types of plugs to provide the assembled assemblies with Category 5e and Category 6 transmission performance.

Stranded cable conductors used for field fabrication of equipment and patch cords shall comply with the requirements of 4.3.1.2.

Plugs used for field fabrication of equipment and patch cords shall comply with the requirements of 4.2.1.

Modular plugs of equipment and patch cords must be designed for a minimum of 750 interfaces with modular jacks.

Note. Do not use single-core cables for field fabrication of equipment and patch cords.

Due to the identical grouping of pairs, cords with T568A and T568B wiring diagrams can be used interchangeably, provided that both ends of one cord are equipped with plugs in accordance with the same wiring diagram.

Note. Do not use unshielded solid and stranded cables, as well as pairs of such cables without an outer sheath, as cross-connect jumpers. Only modular patch cords should be used for such connections.

4.3.1.4. Cords based on shielded twisted pair conductors

Shielded equipment and patch cords must be constructed of 24 AWG or 26 AWG stranded thermoplastic insulated conductors, formed into four twisted pairs, sheathed in a common thermoplastic jacket, with an additional single foil shield or double foil and wire mesh shield.

Note. Manufacturing in the field of equipment and patch cords based on shielded twisted pair conductors is not allowed.

Shielded equipment and patch cords must retain their shielding properties (transfer impedance) for 500 or more bending cycles with an acceptable radius.

Modular plugs of shielded equipment and patch cords must be designed for at least 750 modular jack pairings.

When using shielded cords with 24 AWG stranded conductors, please note that the insertion loss parameters should not exceed the limits specified for the insertion loss of a 24 AWG solid cable, taking into account a correction factor of 1.2 (4.3.1.2).

When using shielded cords with 26 AWG stranded conductors, it should be taken into account that the insertion loss values ​​should not exceed the values ​​determined for the insertion loss of a single-core 24 AWG cable, taking into account a correction factor of 1.5 (4.3.1.3).

Note. It is not allowed to use shielded single-core and multi-core cables, as well as pairs of such cables without an outer sheath as cross-connect jumpers. Only modular patch cords should be used for such connections.

4.3.2. Fiber Optic Patch and Hardware Cables

Fiber-optic cables (cords) used in SCS refer to equipment cords at the workplace, in telecommunications, equipment and urban inputs used to connect active equipment to the cable system, as well as patch cords used in telecommunications, equipment and urban inputs for performing cross-connections and passive connections of cable subsystems among themselves.

Field fabrication of fiber optic cords of any type is not permitted.

Optical fiber cords shall be made from two-fiber indoor patch cords, the performance of which shall correspond to the transmission performance given in 4.1.2.2.

Fiber optic connectors used in optical fiber cords shall comply with the requirements of 4.2.2.

Fiber optic cords, regardless of their purpose (interconnection, cross-connection or connection of active equipment), must have a crossover logical orientation of the connectors at the two ends of the cord - "position A" must be connected to "position B" on one fiber, "position B " with "position A" on another fiber (Figure 11). Each end of the cord must be identified by "position A" and "position B" in the case where the connector can be divided into simplex components.

Figure 11. Fiber optic patch cord

In the case of using simplex connectors, the connector connected to the receiver must be identified as "position A", the connector connected to the transmitter - "position B".

Where active equipment does not have the connector selected for the installed cabling system, hybrid cords should be used to connect it to patch panels and outlets. So, for example, a hybrid patch cord (patch cord) with duplex SC connectors on one side and ST-compatible connectors on the other can solve the problem of connecting active equipment with ST-compatible ports to a patch panel with duplex SC connectors.

When using hybrid optical cables in cases where the active equipment interface is different from duplex SC, the following rules must be observed:

The two simplex connectors are labeled "position A" and "position B";

Duplex connector other than duplex SC (568SC), whose positions are marked as follows:

"position A" - the port of the receiver and "position B" - the port of the transmitter;

The hybrid fiber optic patch cord must be constructed as follows:

"position A" is connected to "position B" on one fiber of the pair of fibers;

"site B" is connected to "site A" on the other fiber of the fiber pair.

The most well-known method for organizing the learning of children with autism

Structured Learning is a learning strategy developed by the TEACCH (Treatment and Education for Children with Autism and Other Communication Disorders) Division of the University of North Carolina. Structured learning is an approach to teaching children with autism. The strategy uses a variety of skills training methods (visual support, PECS - communication system using picture exchange, sensory integration, applied behavioral analysis, musical / rhythmic strategies, Greenspan's play therapy method). Below we provide a detailed rationale for the use of structured learning as one of the approaches in working with autistic children.

Eric Chopler, founder of the TEACCH Chapter in the early 1970s, provided the rationale for structured learning in his Ph.D. thesis (2). It consists in the fact that autistic people process visual information more easily than verbal information processing by ear.

An example of a class organized along the principles of structured learning, including division into different zones and visual support.

What is structured learning (1)

Structured learning is based on an understanding of the unique traits and characteristics of learners related to the nature of autism.

Structured learning is the specific conditions in which the student must learn, and not "where" and "when" he needs to be taught (i.e., rather, teaches how to learn).

Structured learning is a system of organizing learning environments for autistic people, developing the necessary skills, and helping autistic people understand the requirements of the teacher.

Structured learning uses visual cues to help autistic children focus on up-to-date information given that it can be difficult for them to separate important information from irrelevant information.

Structured learning is a constructive approach to the complex behavior of autistic children and the creation of a learning environment that would minimize the stress, anxiety and frustration that are characteristic of these children. Difficult-to-control behavior may be the result of the following traits in autistic people:

Difficulties with understanding the language;
- Difficulties with the use of the language;
- Difficulties with building social contact;
- difficulties associated with impaired processing of the sensory impulse;
- refusal to change;
- preference for habitual patterns of action and routine;
- difficulties in organizing activities;
- difficulty concentrating on a topic that is relevant to this moment;
- distractibility.

Structured learning increases the child's level of independence (completing a task without prompting from an adult), which is an important and versatile skill.

The article discusses the characteristics of this approach. It is important to remember that for its effective use it is necessary to evaluate individual strengths and personal needs of the student.

A joint lesson with the support of tutors in a class organized according to the principles of structured learning.

Main Components of Structured Learning

Structured space

Visual timetable

Components of the learning process

Structured space

These are structures that allow organizing an individual material learning environment. In this regard, it is important how we arrange furniture and learning materials (1) in different areas, such as: classrooms, playground, workshop, bedroom, corridors, changing rooms/storage rooms, etc.

Attention to material structures is important for a number of reasons:

They provide space organization for autistic learners;
- clear physical and individual boundaries help the student to understand that each environmental space has a beginning and an end;
This arrangement minimizes visual and auditory distractions.

The degree of structuring of space depends on the level of self-control of the child, but not on the level of development of his cognitive skills. As students become more independent, the level of structuring of space gradually decreases (5).

Example: A high-functioning autistic person may have a limited capacity for self-control. He needs a more structured learning space than a child with a lower cognitive level but better self-control.

Structured space consists of a number of parts:

Location. Structured space is essential in all areas in which an autistic student spends time, including classrooms, playgrounds, workshops, bedrooms, hallways, locker/storage rooms.

Design. Clear visual and material boundaries: classroom furniture (bookcases, panels, shelves, tables, rugs, dividing walls) should be arranged in such a way as to indicate the presence of several zones with different purposes. To visually mark the boundaries, you can use floor coverings of different colors or colored adhesive tape for the floor. As a rule, children with autism do not segment space intuitively, as neurotypical children do. In large and open spaces, it is difficult for an autistic child to navigate, because. it's hard for him to understand

- what occurs in each specific zone;
- where each of the zones begins and ends;
- how the easiest way to get to the right zone.

If you arrange the furniture in such a way as to designate clear boundaries for zones of different purposes, this will reduce the child's ability to randomly move around the room. Visual boundaries can then be drawn within specific zones.

The plan of the experimental ABA-class in Moscow, taking into account the principles of structured learning. The plan shows a sensory corner for rest breaks and “unloading” students from stress, as well as desks with partitions. The project is supported by the Exit Foundation. A photo: project page on Facebook.

Example: During the group listening to the story, the children are in an area limited by carpeting or colored adhesive tape on the floor. This makes it easier for autistic children to understand that this specific view activity takes place in this zone. Colored duct tape can be used in the gym to mark the area in which a certain type of exercise is performed, such as a warm-up.

Example: During meals, children can be placed in such a way that each child has his own place, indicated by a specific color. Such a designation will visually and physically limit the personal space of each child while eating at a common table.

Visual cues can help kids navigate space better and rely less on adult help.

Minimizing visual and auditory distractions

Visual distractions can be minimized by:

Paint the entire room (walls, ceilings, boards, etc.) with a muted color (eg cream);

Minimize visual "noise" in the form of student artwork hanging on the walls, seasonal decorations, and unfolded teaching materials;

Use bedspreads / curtains to cover or fence off shelves with currently unnecessary materials and other distracting objects (computer, copier, TV / video projector, etc.);

Storage of equipment and materials in another area. Example: In the play area, limit the number of toys that children can use, and then update the composition weekly: lay out “new” ones and remove “old” ones;

Make use of natural light by cutting down on distracting fluorescent lights. Use curtains and blinds if the sunlight is too bright, while still creating a warm and calm environment;

Using student workspaces placed in the corner of the classroom or separated from group work tables will also reduce visual distractions;

Careful seating for an autistic child in a class with neurotypical children.

Example: Tony, a student with autism, is seated at the front of the class in such a way that he cannot see the door, windows, and shelves of study materials, minimizing visual distractions;

Auditory distractions can be reduced by carpeting, lower ceilings in the room, acoustic tiles, headphones or a walkman;

In any structured environment, there should be an instruction area, an independent work area, a recreation and leisure area. In the classroom, these can be the following zones: a small group work zone, an independent work zone, a one-on-one work zone for a teacher with a student, a recreation (games, leisure) zone, a calm zone in case of a tantrum in a child. All these zones should have clear visual boundaries so that a child with autism understands the purpose of this area of ​​space.

We repeat once again that all zones of a specific purpose must have clear visual boundaries. It is important to remember that distractions can be present in each of the zones, and minimize them.

Organization. To effectively apply the method of structured learning, the space must be highly organized. It is important that various teaching materials and learning aids are kept out of sight of students, but at the same time so that the teacher can easily retrieve and apply the material he needs during the lesson. Example: A high-walled storage area directly in the classroom would be a convenient way to organize the space in compliance with the above requirements.

It is important for autistic students to teach order in the workplace, using pictures, colors, numbers, signs, etc. Example: In the play area, you can place pictures of toys that should be on this shelf on the shelves to help students arrange the toys in their places.

Visual Class Schedule

Definition: A visualized class schedule is one of the most important components of a structured learning environment that tells the student with autism which classes will be held and in what order.

Visualized schedules are important for children with autism for the following reasons:

Helps to overcome the difficulties resulting from poor sequential memory and organize the student's time.

Help children with language problems understand the requirements of the teacher.

Reduce the level of anxiety in autistic children and, therefore, the frequency of behavioral problems through a high level of predictability of what is happening for students.

Schedules make it clear what kind of activity is happening in a certain period of time (for example, recess after class), and also prepares students for possible changes.

Helps the student to independently move from one activity to another, from one area to another, telling where he needs to go after finishing a particular job (5). The visualized schedule can be used in all areas (classroom, gym, occupational therapy, speech therapy, home, Sunday school etc.)

The visualized schedule uses a "first-then" strategy, i.e. “first you do ¬¬___, then you do ¬¬___” (but not “if-then”). Such a strategy allows you to modify, if necessary, to change what is expected of the student "at first" (exercise, activity, task). Modifications may be needed in terms of completion of the task, more or less help from the teacher, depending on changes in the student's condition and his ability to perceive information. Then the student can move on to the next activity, which is also visualized in the schedule.

Example: A student finds it too difficult to complete a series of math examples due to anxiety, sensory overload, difficulty generalizing, external and internal distractions, changes, etc. The task can be changed so that he has to complete only 3 examples first, and then he will have a break, as indicated in the visualized schedule.

The schedule may include various types of social interaction (for example: showing completed work to a teacher/parent for reinforcement, which requires appropriate language forms of greeting and addressing the interlocutor).

You can increase the student's motivation to complete less attractive tasks by interspersing them with more attractive activities included in the visualized schedule. Example: By placing "computer" after "math" in the visualized timetable, you motivate the student to complete the math assignment as after completing it, it will go to "computer".

The student with autism needs to be taught how to use the visualized timetable and then it needs to be used consistently. It cannot be considered "crutches", the use of which can be abandoned over time. The visual schedule should be treated as a kind of permanent auxiliary technical means. For a student with autism, the constant use of a visualized timetable is a very important skill, because. it can help him reduce dependence on other people throughout his life - at school, at home, in society.

Visual schedule development

The timetable should be organized in a top-to-bottom or left-to-right format, and should include the ability for the student to mark that an activity has been completed.

Example: cross out or mark a task as completed, move the task card into an envelope or “done” box, draw a line separating completed from not completed, etc.

At any particular moment in time, two points of the schedule should be presented to the student so that he gradually understands that the activities follow each other, and not each one on its own.

Many different formats can be used to visualize the schedule, depending on the individual needs of a particular student.
Example: the schedule can consist of separate objects, it can be sheets of paper with the designation of activities fastened together, a folder with files, a board from which you can erase the completed task, sticky tape around the edge of the desk with cards with activities attached in a certain sequence, etc. .P.

Can be used various systems activity symbols: real objects, photographs, pictures in a realistic style, commercial picture systems.

Individual schedule

For an autistic child, it is necessary to develop an individual timetable in addition to the general class timetable.

A customized timetable will give the student important information in a visual form that they are prepared to understand.

When compiling a visualized schedule for an autistic child, care must be taken with the length of the schedule (number of activities included). The number of items in the schedule can be changed if any of the upcoming activities causes anxiety in the student, if there is an overload of information at a particular point in time.

Example: A student is excited by the prospect of "rest time" in the schedule. If at the very beginning of the day he saw “rest time” in the schedule, his attention is absorbed by this prospect and as a result, throughout the morning he will be impatient, unable to focus on actual activities. In this case, the visualized schedule given to the student should consist of only a few items preceding the rest time. Individual approach is the key to successful work with baby.

Schedule check

Some students may need cue reminders to check their schedule, what activity follows the one they just finished, and where to go to do it.

Example: Such visualized cues might be laminated strips of color with the student's name written on them, sticks or pieces of cardboard with a checkmark drawn on them, etc.

These visual cues help the student, independently of the adult, move from one activity to another while keeping track of the schedule.

A child who relies on adult cues rather than cues in addition to a schedule will not fully understand the importance of a schedule and will not use it successfully.

An example of individual visual timetables for students in a class based on structured learning.

Transitions

Some students need to pick up a card or object indicating the next activity and physically move it to the location where the next activity will take place. This may be necessary due to the fact that the child has increased distractibility during the transition from one working area to another. This feature is not directly related to the cognitive or verbal level of development of the child.

Example: There are non-speaking autistic students whose development corresponds to the cognitive level of a younger age group, however, they are able to hold their attention better and do not need to transfer the card with the next activity indicated on it to a new zone. On the other hand, there are children with a higher level of cognitive development who are easily distracted and need a reference object to move on to the next activity in the zone intended for it.

Components of the learning process:

The components of the learning process include Task presentation system and visual structure.

Task presentation system called a systematic and organized submission of tasks / materials for the purpose of teaching a child independent work without the help of an adult. It is important to note that presentation systems can be used for any type of assignment and any kind of activity (work on academic skills, daily practical skills, leisure activities and entertainment). Each system, regardless of the type of activity, should include answers to the following questions:

- What work needs to be done? What is the task?(for example, sort objects by color, do two-digit addition and subtraction examples, make a sandwich, brush your teeth, etc.)

- What is the scope of work? It is necessary to visually present to the student exactly how much work he has to do. For example, if a student needs to cut out 10 labels for jars of soup, you do not need to give him a whole pack and wait for him to understand that first you need to count, and then cut 10, and then the task will be considered completed. Even if an autistic child is told that only 10 labels need to be cut, he may become frustrated and anxious at the sight of a whole stack of labels because he does not understand exactly how many labels he should cut.

It must be remembered that autistic children primarily process information coming through the visual channel, so it can be unsettling to see a large amount of work, for example, a whole pack of labels to cut out. Offer him only those materials that are strictly necessary for a particular assignment to avoid misunderstanding the exact scope of the work.

- When will I finish this type of work? The student must himself understand when the task is completed. This can be clear from the task itself, or you can use timers or visual cues, for example, put a red dot on the task sheet to indicate the end of the tasks in this lesson.

- What will follow this? The student is motivated to successfully complete the proposed task if reinforcement should follow: direct material reinforcement, some favorite activity, a change, an activity at the request of the student. In some cases, the student is motivated by the very prospect of the lesson being completed.

Experience with structured learning and the use of task presentation systems suggests that overall student productivity is enhanced if the student is able to understand how much work they need to complete and when they need to finish (1). The use of presentation systems helps to organize the independent work of an autistic child through a structured and systematic approach.

Examples of different presentation systems, from simplest to most complex:

The sequence is from left to right, the box/folder for completed work is in the right corner. This is the most concrete embodiment of the presentation system, when tasks are located to the left of the workplace (on a shelf, in a folder, basket, etc.). The student is explained that he needs to take the item with the task on the left, complete the task and put it on the right in the box (folder, box, etc.)

Designations using symbols (color, shape, letters, numbers). Such a presentation system requires mastery of a more complex skill, since the student must complete work tasks in a sequence indicated by symbols.

Example. The student has a strip with a sequence of numbers from 1 to 10 attached to it with Velcro. On the left are tasks, also marked with numbers. First, the student must stick the numbers from the strip onto the tasks. Thus, the student establishes for himself the order in which he will continue to perform these tasks.

Inscriptions. Such a system requires a more advanced skill of self-organization and is a list of tasks in the order of completion.

visual structure. Visual cues should be included in the student's task/activity so that the student does not have to wait for verbal or physical cues from the teacher to understand exactly what they should do (2). The student can use a well-developed visual recognition skill to understand the task/activity content without the help of a teacher. Thus, visual supports create the best opportunities for successful independent work of the child.

Students with autism have difficulty processing sometimes obvious information in environment and at times focus their attention on unimportant details. To help the student focus on the essentials of the assignment, their daily activities/assignments should include the following components:

Visual instruction. The student needs to present the task in such a way that he can complete it sequentially, based on visual instructions. Visual instruction helps the student to take a series of sequential steps to achieve the goal. (2) Visual instructions can take many forms:

The task materials themselves determine the necessary actions (for example, to assemble a pyramid: the rings are in the box on the left, the rod is on the right, i.e. the sequence is again observed from left to right).

Graphic image (for example, the outlines of plates and eating utensils are drawn, on which the student must put real objects).

Drawings of objects (for example, pictures of toys or clothes in the places where the child should put them when teaching the child to keep his things in order).

Written instruction (a step-by-step description of the task or sequential actions, for example, morning routine or the correct spelling of a word).

A sample of a completed task (for example, a picture made by another student).

Visual organization- this is the presentation of educational materials and the organization of space in such a way as to minimize the influence of extraneous sensory stimuli. Visual organization may include the use of containers to organize materials (for example, materials for each activity are placed in a separate box, the letters of the alphabet are not thrown into the box, but are attached to a special tray, etc.), the visual boundaries of the zone included in which or an assignment (for example, using duct tape to limit the area of ​​the floor that the student must vacuum).

visual clarity. The purpose of visual clarity is to highlight important information, main concepts, parts of instructions and key materials. The assignment should be structured in such a way that the construction itself contains a hint to the student on which details to focus on. Such details are distinguished by color, pictures, numbers or letters. Visual clarity encourages the student to work independently without the guidance of an adult (2). At the most concrete level, visual clarity is manifested in the restriction of objects in the student’s workplace to only those materials that he needs to complete a specific task (unnecessary or Additional materials must be removed from his workplace) (2). Other examples of visual clarity: the use of a color code (each child has his own color identifier and by color he finds his own workplace, a chair during group events, as well as a locker for storing your things, work materials, a place at the table during lunch, etc.); use of labels (when sorting items).

Using the method of visual structuring makes it possible to teach a child with autism to perform tasks on his own without prompting and the guiding role of an adult. Students will be able to work independently for various lengths of time in any environment (at home, at school, in the workshop) on the development of any skill, academic, practical, etc.

Conclusion

A structured learning strategy will allow the student with autism to learn to focus on visual cues in a variety of environments and situations and thus increase self-reliance in various types activities. It is important to note that various systems of education and therapy - sensory integration, picture exchange communication system, Greenspan play therapy, ABA - are successfully combined with a structured learning strategy.

Links

1. Division TEACCH. Division TEACCH Training Manual, revised January 1998. Chapel Hill, NC.

2. Division TEACCH. Visually Structured Tasks: Independent Activities for Students with Autism and Other Visual Learners, March 1996. Chapel Hill, NC.

3. Harris, Sandra L. and Jans S. Handleman. Preschool Programs for Children with Autism. Austin, Pro Ed, 1994.

4. Johnson, Kathleen. Autism 101 Training. CESA 6, Oshkosh, WI. March 16-17, 2000.

5. “Structured Teaching”, August 15, 1998. Division TEACHH, Chapel hill, NC http://www.unc.edu/depts/teacch/

6. Trehin, Paul. “Some Basic Information about TEACCH”, Autisme France. March 23, 2000. http://www.unc.edu/depts/teacch/

Lecture 4. Data and knowledge

The relationship between data and knowledge is always of interest, especially the representations (formalization methods) of both, the data and knowledge representation models, since data and knowledge are a form of information representation in a computer (Fig. 1.17).
The information that the computer deals with is divided into procedural and declarative.

Procedural information is embodied in programs that are executed in the process of solving problems, declarative information is embodied in the data with which these programs work (Fig. 1.18).

The standard form of information representation in a computer is a machine word, consisting of a specific for of this type Computer number of binary digits - bits. In some cases, machine words are divided into groups of eight bits, which are called bytes.

The same number of digits in machine words for commands and data allows them to be considered in the computer as the same information units (IU) and to perform operations on commands as on data. The contents of the memory form an information base (Fig. 1.19).

For the convenience of comparing data and knowledge, we can distinguish the main forms (levels) of the existence of knowledge and data. As shown in Table. 1.2, data and knowledge have a lot in common. However, knowledge has a more complex structure, and the transition from data to knowledge is a natural consequence of the development and complication information structures processed on a computer.

Data

In parallel with the development of the structure of the computer, the development of information structures for presenting data took place.

There are ways to describe data in the form of: vectors, matrices, list structures, hierarchical structures, structures created by the programmer (abstract data types).

Currently, high-level programming languages ​​use abstract data types, the structure of which is created by the programmer. The emergence of databases (DB) marked another step towards the organization of work with declarative information.

With the development of research in the field of InS, arose knowledge concept, which combines many features of procedural and declarative information.
Today, the terms "database", "information intelligent system", like many other terms of computer science, have become widely used. The reason for this is the general awareness (social need) of the need for intensive introduction of computers and other means of automated information processing in a wide variety of fields of activity. modern society. The beginning of the last quarter of this century can rightfully be called the beginning of the era of a new information technology - a technology supported by automated information INS.

The relevance of the problems of INS and the databases underlying them is determined not only by social needs, but also by the scientific and technical possibility of solving classes of problems related to meeting the information needs of various categories of users (including both a person and a program-controlled device). This opportunity arose (around the turn of the 70s) due to significant achievements in the field of technical and software computing systems.

The database as a natural science concept is characterized by two main aspects: informational and manipulative. The first aspect reflects such data structuring, which is the most suitable for meeting the information needs that arise in the subject area (SW). Each software is associated with a set of "information objects", relationships between them (for example, "suppliers", "product range", "consumers" - categories of information objects, and "deliveries" - the type of relationship that takes place between these objects), and as well as processing tasks. The manipulation aspect of the database concerns the meaning of those actions on data structures, with the help of which various components are selected from them, new ones are added, obsolete components of data structures are removed and updated, as well as their transformations.
A database management system (DBMS) is a set of tools (language, software, and possibly hardware) that support a particular type of database. The main purpose of the DBMS, from the point of view of users, is to provide them with tools that allow them to operate with data in abstract terms (names and / or characteristics of information objects) that are not related to the methods of storing data in computer memory. It should be noted that, generally speaking, DBMS facilities may not be enough to solve all the problems of a particular software. Therefore, in practice, it is necessary to adapt (supplement, adjust) the DBMS tools to provide the required capabilities. Systems obtained by adapting the DBMS to this software are referred to as InS.

A viable InS, i.e., capable of supporting a database model taking into account the dynamics of software development, should, of necessity, contain a DBMS as its core. The INS design methodology developed to date (from the point of view of the database) includes four main tasks:

1) software system analysis, specification of information objects and relationships between them (as a result, the so-called conceptual, or semantic, software model is developed);

2) building a database model that provides an adequate representation of the software conceptual model;

3) development of a DBMS that supports the selected database model;

4) functional extension (by means of some programming system) of the DBMS in order to provide the possibility of solving the required class of tasks, i.e. data processing tasks specific to this software.

Knowledge

Let's consider the general set of qualitative properties for knowledge (specific features of knowledge) and list a number of features inherent in this form of information representation in a computer and allowing us to characterize the term "knowledge" itself.

First of all, knowledge has a more complex structure than data (metadata). At the same time, knowledge is specified as extensionally (i.e., through a set of specific facts corresponding to this concept and relating to the subject area), and intensionally (i.e. through the properties corresponding to the given concept and the linking scheme between the attributes).

In view of what has been said, we list the properties.

Internal interpretability of knowledge.

Each information unit (IE) must have a unique name by which the IS finds it, and also responds to requests in which this name is mentioned. When data stored in memory was stripped of names, it was impossible for the system to identify it. Only the program could identify the data.
If, for example, in the computer memory it was necessary to record information about university students, presented in Table. 1.10, then without internal interpretation, a set of four machine words corresponding to the lines of this table would be written to the computer memory.
At the same time, the system does not have information about which groups of binary digits in these machine words encoded information about students. They are known only to the programmer.
During the transition to knowledge, information about a certain protostructure of information units is entered into the computer memory. In the example under consideration, it is a special machine word that indicates in which bits information about last names, years of birth, specialties, and course is stored. In this case, special dictionaries must be specified, which list the surnames, years of birth, names of specialties and courses available in the system's memory. All these attributes can play the role of names for those machine words that correspond to the rows in the table. They can search for the information you need. Each row of the table will be an instance of a protostructure. Currently, DBMSs provide the implementation of the internal interpretability of all IEs stored in the database.