Taller Unidades 1 y 2.

A. Categorías lexicales y uso del diccionario.

1. Selecciona un texto relacionado con tu área de interés.

Human Reliability Analysis

The term "human reliability" is usually defined as the probability that a person will correctly performs some system-required activity during a given time period (if time is a limiting factor) without performing any extraneous activity that can degrade the system. The historical background for the development of the set of methods that are commonly referred to as Human Reliability Analysis (HRA) was the need to describe incorrect human actions in the context of Probabilistic Risk Assessment (PRA) or Probabilistic Safety Analysis (PSA). The premises for HRA were, and are, therefore that it must function within the constraints defined by PRA/PSA, and specifically that it can produce the human action probabilities that are needed by the PRA/PSA.

The accident sequence that is analysed by a PRA/PSA is typically represented as an event tree. A node in the sequence of events that may lead to the accident represents a specific function, task, or activity that can have two different outcomes, usually denoted success and failure. A node can either represent the function of a technical system or component, or the interaction between an operator and the process. For example, if the analysis considers the sequence of events that are part of landing an aircraft, the event "timely extraction of flaps", which is an action that must be taken by the pilot, is represented by a node. From the perspective of the PRA/PSA there is a need to know whether it is likely that an event will succeed or fail, and further to determine the probability of failure in order to calculate the combined probability that a specific outcome or end state will occur. If the node represents the function of a mechanical or electronic component, the failure probability can, in principle, be calculated based on engineering knowledge alone. If the node represents the interaction between an operator and the process, engineering knowledge must be supplemented by a way of calculating the probability that the human, as a "component", will fail. Historically, the role of HRA has been to provide the foundation for calculating this probability. The sought for value has traditionally been called a human error probability (HEP), but as the following will show this is both a misunderstood and misleading term.

Human Error probabilities and Performance Shaping Factors

The practice of HRA goes back to the early 1960s, but the majority of HRA methods were developed in the middle of the 1980s – mainly as a consequence of the concern caused by the accident in 1979 at the nuclear power plant at Three Mile Island. Partly due to the conditions under which it was developed, HRA methods from the beginning used procedures similar to those employed in conventional reliability analysis. The main difference was that human task activities were substituted for equipment failures and that modifications were made to account for the greater variability and interdependence of human performance as compared with that of equipment. The traditional approach is first to determine the HEP for a node, either by using established tables, human reliability models, or expert judgement. The characterisation of human failure modes is usually very simple, for instance in terms of "error of omission" and "errors of commission". Since human actions clearly do not take place in a vacuum, a second step is to account for the influence of possible Performance Shaping Factors (PSF) such as task characteristics, aspects of the physical environment, work time characteristics, etc. This influence is expressed as a numerical factor that is used to modify the basic HEP.

2. Identifica 3 palabras que no conoces.. agrega las abreviaciones.

performing: v. Realizando.

extraneous: adj. Extraño.

outcomes: n. Resultados.

3. Idea principal del texto (en español).

El texto trata sobre el análisis de confiabilidad humana, que es la probabilidad que tiene la persona de realizar correctamente su labor sin realizar una extrana actividad. Los antecedentes para el desarrollo del conjunto de métodos que comúnmente se conoce como Análisis de Confiabilidad Humana, que partede la necesidad de describir incorrecta las acciones humanas en el contexto de la evaluación de riesgos probabilísticos o Análisis Probabilístico de Seguridad.

4. Categorias lexicales: (2 ejemplos por categoria).

·         Palabras de contenido: Human, accident.

·         Palabras de Función: it, in.

·         Verbos: performing, can.

·         Adverbio: specifically, typically.

·         Adjetivo: technical, combined.

·         Artículo: a,  the.

·         Preposiciones: in, of.

·         Conjunción: and, that.

·         Cognados verdaderos: Analysis, activity.

·         cognados Falsos:

·         Sufijo: beginning, specifically.

·         Prefijos: misunderstood, interdependence.

B. Estructura de la oración: (2 ejemplos)

Oración 1.

·        HRA methods from the beginning used procedures similar to those employed inconventional reliability analysis.         

Frase nominal: HRA methods from the beginning

Nucleo de la frase nominal:  methods

Pre modificadores: hra

post modificadores:  from the beginning

Frase verbal:used procedures similar to those employed inconventional reliability analysis.     

Nucleo de la frase verbal:used

Tiempo verbal: pasado simple

Oración 2.

·                     The traditional approach is first to determine the HEP for a node, either by using established tables, human reliability models, or expert judgement.

Frase nominal: The traditional approach

Nucleo de la frase nominal: approach

Pre modificadores: The traditional

post modificadores:

Frase verbal: is first to determine the HEP for a node, either by using established tables, human reliability models, or expert judgement.

Nucleo de la frase verbal: is                

Tiempo verbal: Presente Simple.