2 resultados para threshold position control
em Dalarna University College Electronic Archive
Resumo:
A system for weed management on railway embankments that is both adapted to the environment and efficient in terms of resources requires knowledge and understanding about the growing conditions of vegetation so that methods to control its growth can be adapted accordingly. Automated records could complement present-day manual inspections and over time come to replace these. One challenge is to devise a method that will result in a reasonable breakdown of gathered information that can be managed rationally by affected parties and, at the same time, serve as a basis for decisions with sufficient precision. The project examined two automated methods that may be useful for the Swedish Transport Administration in the future: 1) A machine vision method, which makes use of camera sensors as a way of sensing the environment in the visible and near infrared spectrum; and 2) An N-Sensor method, which transmits light within an area that is reflected by the chlorophyll in the plants. The amount of chlorophyll provides a value that can be correlated with the biomass. The choice of technique depends on how the information is to be used. If the purpose is to form a general picture of the growth of vegetation on railway embankments as a way to plan for maintenance measures, then the N-Sensor technique may be the right choice. If the plan is to form a general picture as well as monitor and survey current and exact vegetation status on the surface over time as a way to fight specific vegetation with the correct means, then the machine vision method is the better of the two. Both techniques involve registering data using GPS positioning. In the future, it will be possible to store this information in databases that are directly accessible to stakeholders online during or in conjunction with measures to deal with the vegetation. The two techniques were compared with manual (visual) estimations as to the levels of vegetation growth. The observers (raters) visual estimation of weed coverage (%) differed statistically from person to person. In terms of estimating the frequency (number) of woody plants (trees and bushes) in the test areas, the observers were generally in agreement. The same person is often consistent in his or her estimation: it is the comparison with the estimations of others that can lead to misleading results. The system for using the information about vegetation growth requires development. The threshold for the amount of weeds that can be tolerated in different track types is an important component in such a system. The classification system must be capable of dealing with the demands placed on it so as to ensure the quality of the track and other pre-conditions such as traffic levels, conditions pertaining to track location, and the characteristics of the vegetation. The project recommends that the Swedish Transport Administration: Discusses how threshold values for the growth of vegetation on railway embankments can be determined Carries out registration of the growth of vegetation over longer and a larger number of railway sections using one or more of the methods studied in the project Introduces a system that effectively matches the information about vegetation to its position Includes information about the growth of vegetation in the records that are currently maintained of the track’s technical quality, and link the data material to other maintenance-related databases Establishes a number of representative surfaces in which weed inventories (by measuring) are regularly conducted, as a means of developing an overview of the long-term development that can serve as a basis for more precise prognoses in terms of vegetation growth Ensures that necessary opportunities for education are put in place
Resumo:
In recent years there has been a resurgence of gender inequality in China. Today, women are pressured to get married by the state and their social surroundings, as they told if they remain unmarried and have the "three highs"; high age, education and salary, they will become leftovers on the marriage market. Previous research on the concept of labelling women as "leftover" has 4 shown that labelling women as "leftover" can have several different negative impacts. In this thesis, both the theory of masculine hegemony and the theory of symbolic interaction have been used. The concept creates a hegemonic masculinity as it is a normative practice that promotes the subordination of women. However, as the concept is based on the notion that all Chinese men, or at least those of relevant social standing, would find the "three highs" undesirable, it is relevant to see how Chinese men in fact do position themselves in relation to the hegemonic masculinity on an individual level. In symbolic interaction, the concept of gender is created through social construction when people attach special meanings to the sex of a person, a process which is called "doing gender". Therefore symbolic interaction is used to see what special meaning Chinese men attach to women having the "three highs" and masculine hegemony to put their answers into a larger context. If it could be shown that Chinese men do not comply with the hegemonic masculinity, Chinese women would not have to feel obliged to adjust to the hegemonic masculinity and thereby making it easier for them to pursue higher education, high paying jobs and marrying at a later age. However, as this thesis is a qualitative study, and therefore a limited number of data subjects, the generalizability of the result should not be exaggerated. The interviews that were conducted for this thesis showed that the data subjects were familiar with the concept and that they considered it to be natural for there to be women China labelled as "leftover". Nevertheless, in relation to their own marital choices, the data subjects did not attach the negative meaning as set out by the hegemonic masculinity, a result which to some extent was confirmed by the data subjects’ experiences and other control questions. The result is interesting, and enforces Connell and MesserSchmidt’s theory, that even though a hegemonic masculinity is normative, not everyone has to comply with it. As the cornerstone of the concept is that Chinese men find women with the "three highs" undesirable, the result of the study shows that there is a need for the concept to be further examined and questioned.