4 resultados para mobile environment, peer-to-peer, PeerHood, software security, vulnerabilities

em Dalarna University College Electronic Archive


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this study was to investigate electricity supply solutions for an educationalcenter that is being built in Chonyonyo Tanzania. Off-grid power generation solutions andfurther optimization possibilities were studied for the case.The study was done for Engineers Without Borders in Sweden. Who are working withMavuno Project on the educational center. The school is set to start operating in year 2015with 40 girl students in the beginning. The educational center will help to improve genderequality by offering high quality education in a safe environment for girls in rural area.It is important for the system to be economically and environmentally sustainable. Thearea has great potential for photovoltaic power generation. Thus PV was considered as theprimary power generation and a diesel generator as a reliable backup. The system sizeoptimization was done with HOMER. For the simulations HOMER required componentdata, weather data and load data. Common components were chose with standardproperties, the loads were based on load estimations from year 2011 and the weather datawas acquired from NASA database. The system size optimization result for this base casewas a system with 26 kW PW; 5.5 kW diesel generator, 15 kW converter and 112 T-105batteries. The initial cost of the system was 55 875 €, the total net present cost 92 121 €and the levelized cost of electricity 0.264 €/kWh.In addition three optimization possibilities were studied. First it was studied how thesystem should be designed and how it would affect the system size to have night loads(security lights) use DC and could the system then be extended in blocks. As a result it wasfound out that the system size could be decreased as the inverter losses would be avoided.Also the system extension in blocks was found to be possible. The second study was aboutinverter stacking where multiple inverters can work as one unit. This type of connectionallows only the required number of inverters to run while shutting down the excess ones.This would allow the converter-unit to run with higher efficiency and lower powerconsumption could be achieved. In future with higher loads the system could be easilyextendable by connecting more inverters either in parallel or series depending on what isneeded. Multiple inverters would also offer higher reliability than using one centralizedinverter. The third study examined how the choice of location for a centralized powergeneration affects the cable sizing for the system. As a result it was found that centralizedpower generation should be located close to high loads in order to avoid long runs of thickcables. Future loads should also be considered when choosing the location. For theeducational center the potential locations for centralized power generation were found outto be close to the school buildings and close to the dormitories.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Small-scale enterprises face difficulties in fulfilling the regulations for organising Systematic Work Environment Management. This study compared three groups of small-scale manufacturing enterprises with and without support for implementing the provision. Two implementation methods, supervised and network method, were used. The third group worked according to their own ideas. Twenty-three enterprises participated. The effects of the implementation were evaluated after one year by semi-structured dialogue with the manager and safety representative. Each enterprise was classified on compliance with ten demands concerning the provision. The work environment was estimated by the WEST-method. Impact of the implementation on daily work was also studied. At the follow-up, the enterprises in the supervised method reported slightly more improvements in the fulfilment of the demands in the provision than the enterprises in the network method and the enterprises working on their own did. The effect of the project reached the employees faster in the enterprises with the supervised method. In general, the work environment improved to some extent in all enterprises. Extensive support to small-scale enterprises in terms of advise and networking aimed to fulfil the regulations of Systematic Work Environment Management had limited effect especially considering the cost of applying these methods.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This is an empirical study about factors that motivate pupils to speak English as a foreign language. The aim of this study is to investigate when pupils in the classroom situation, in Grades 4-6 in a school in Sweden, are motivated to speak English as a foreign language, and why they are motivated to speak English in these situations. To implement this study, questionnaires and interviews have been chosen as methods. 51 pupils in Grades 4-6 took part of the study. Since being able to communicate orally in a foreign language is of great advantage for one, and creates opportunities both for work and for study abroad, it is important for pupils to learn how to communicate orally in English. It is important to be able to use the language. In the English curriculum in Swedish schools, speaking English is a skill pupils must possess. Since this is the requirement it is important that teachers in Sweden relate to this. Many pupils do not like to speak in front of the rest of the class and some pupils only like to speak in informal situations. Therefore, teachers must use various strategies to create a willingness to communicate among pupils and various strategies to motivate them to speak English. The results show that pupils are motivated to use the language in class when they have recently been abroad. It also shows that they are motivated when they can decide the topic and speak about something they are interested in.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The physical environment can influence older people’s health and well-being, and is often mentioned as being an important factor for person-centred care. Due to high levels of frail health, many older people spend a majority of their time within care facilities and depend on the physical environment for support in their daily life. However, the quality of the physical environment is rarely evaluated, and knowledge is sparse in terms of how well the environment meets the needs of older people. This is partly due to the lack of valid and reliable instruments that could provide important information on environmental quality. Aim: The aim of this thesis was to study the quality of the physical environment in Swedish care facilities for older people, and how it relates to residents’ activities and well-being. Methods: The thesis comprises four papers where both qualitative and quantitative methods were used. Study I involved the translation and adaptation of the Sheffield Care Environment Assessment Matrix (SCEAM) into a Swedish version (S-SCEAM). Several methods were used including forward and backward translation, test of validity via expert consultation and reliability tests. In Study II, S-SCEAM was used to assess the quality of the environment, and descriptive data were collected from 20 purposively sampled residential care facilities (RCFs). Study III was a comparative case study conducted at two RCFs using observations, interviews and S-SCEAM to examine how the physical environment relates to older people’s activities and interactions. In study IV, multilevel modeling was used to determine the association between the quality of the physical environment and the psychological and social well-being of older people living in RCFs. The data in the thesis were analysed using qualitative content analysis, and descriptive, bivariate and multilevel statistics. Results: A specific result was the production of the Swedish version of SCEAM. The instrument contains 210 items structured into eight domains reflecting the needs of older people. When using S-SCEAM, the results showed a substantial variation in the quality of the physical environment between and within RCFs. In general, private apartments and dining areas had high quality, whereas overall building layout and outdoor areas had lower quality. Also, older people’s safety was supported in the majority of facilities, whereas cognitive support and privacy had lower quality. Further, the results showed that environmental quality in terms of cognitive support was associated with residents’ social well-being. Specific environmental features, such as building design and space size, were also noted, through observation, as influencing residents’ activities, and several barriers were found that seemed to restrict residents’ full use of the environment. Conclusions: This thesis contributes to the growing evidence-based design field. The S-SCEAM can be used in future research on the association between the environment and people’s health and well-being. The instrument could also serve as a guide in the planning and design process of new RCFs.