780 resultados para Assesment of performance effectiveness


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Political drivers such as the Kyoto protocol, the EU Energy Performance of Buildings Directive and the Energy end use and Services Directive have been implemented in response to an identified need for a reduction in human related CO2 emissions. Buildings account for a significant portion of global CO2 emissions, approximately 25-30%, and it is widely acknowledged by industry and research organisations that they operate inefficiently. In parallel, unsatisfactory indoor environmental conditions have proven to negatively impact occupant productivity. Legislative drivers and client education are seen as the key motivating factors for an improvement in the holistic environmental and energy performance of a building. A symbiotic relationship exists between building indoor environmental conditions and building energy consumption. However traditional Building Management Systems and Energy Management Systems treat these separately. Conventional performance analysis compares building energy consumption with a previously recorded value or with the consumption of a similar building and does not recognise the fact that all buildings are unique. Therefore what is required is a new framework which incorporates performance comparison against a theoretical building specific ideal benchmark. Traditionally Energy Managers, who work at the operational level of organisations with respect to building performance, do not have access to ideal performance benchmark information and as a result cannot optimally operate buildings. This thesis systematically defines Holistic Environmental and Energy Management and specifies the Scenario Modelling Technique which in turn uses an ideal performance benchmark. The holistic technique uses quantified expressions of building performance and by doing so enables the profiled Energy Manager to visualise his actions and the downstream consequences of his actions in the context of overall building operation. The Ideal Building Framework facilitates the use of this technique by acting as a Building Life Cycle (BLC) data repository through which ideal building performance benchmarks are systematically structured and stored in parallel with actual performance data. The Ideal Building Framework utilises transformed data in the form of the Ideal Set of Performance Objectives and Metrics which are capable of defining the performance of any building at any stage of the BLC. It is proposed that the union of Scenario Models for an individual building would result in a building specific Combination of Performance Metrics which would in turn be stored in the BLC data repository. The Ideal Data Set underpins the Ideal Set of Performance Objectives and Metrics and is the set of measurements required to monitor the performance of the Ideal Building. A Model View describes the unique building specific data relevant to a particular project stakeholder. The energy management data and information exchange requirements that underlie a Model View implementation are detailed and incorporate traditional and proposed energy management. This thesis also specifies the Model View Methodology which complements the Ideal Building Framework. The developed Model View and Rule Set methodology process utilises stakeholder specific rule sets to define stakeholder pertinent environmental and energy performance data. This generic process further enables each stakeholder to define the resolution of data desired. For example, basic, intermediate or detailed. The Model View methodology is applicable for all project stakeholders, each requiring its own customised rule set. Two rule sets are defined in detail, the Energy Manager rule set and the LEED Accreditor rule set. This particular measurement generation process accompanied by defined View would filter and expedite data access for all stakeholders involved in building performance. Information presentation is critical for effective use of the data provided by the Ideal Building Framework and the Energy Management View definition. The specifications for a customised Information Delivery Tool account for the established profile of Energy Managers and best practice user interface design. Components of the developed tool could also be used by Facility Managers working at the tactical and strategic levels of organisations. Informed decision making is made possible through specified decision assistance processes which incorporate the Scenario Modelling and Benchmarking techniques, the Ideal Building Framework, the Energy Manager Model View, the Information Delivery Tool and the established profile of Energy Managers. The Model View and Rule Set Methodology is effectively demonstrated on an appropriate mixed use existing ‘green’ building, the Environmental Research Institute at University College Cork, using the Energy Management and LEED rule sets. Informed Decision Making is also demonstrated using a prototype scenario for the demonstration building.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The multiquantum barrier (MQB), proposed by Iga et al in 1986, has been shown by several researchers to be an effective structure for improving the operating characteristics of laser diodes. These improvements include a reduction in the laser threshold current and increased characteristic temperatures. The operation of the MQB has been described as providing an increased barrier to electron overflow by reflecting high energy electrons trying to escape from the active region of the laser.This is achieved in a manner analogous to a Bragg reflector in optics. This thesis presents an investigation of the effectiveness of the MQB as an electron reflector. Numerical models have been developed for calculating the electron reflection due to MQB. Novel optical and electrical characterisation techniques have been used to try to measure an increase in barrier height due to the MQB in AlGaInP.It has been shown that the inclusion of MQB structures in bulk double heterostructure visible laser diodes can halve the threshold current above room temperature and the characteristic temperature of these lasers can be increased by up to 20K.These improvements are shown to occur in visible laser diodes even with the inclusion of theoretically ineffective MQB structures, hence the observed improvement in the characteristics of the laser diodes described above cannot be uniquely attributed to an increased barrier height due to enhance electron reflection. It is proposed here that the MQB improves the performance of laser diodes by proventing the diffusion of zinc into the active region of the laser. It is also proposed that the trapped zinc in the MQB region of the laser diode locally increases the p-type doping bringing the quasi-Fermi level for holes closer to the valence band edge thus increasing the barrier to electron overflow in the conduction band.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The baiqi (Buddhist percussive instruments), also known as faqi (dharma instruments), are mentioned in the Chinese Buddhist scriptures under many different terms: jianzhi, jiandi, jianzhui, or jianchi. The original function of baiqi in earlier monastic life was to gather people or to call an assembly. With the completion of monasticism and monastic institutions, baiqi have become multifunctional in monasteries, and many baiqi instruments have been developed for different monastic applications. In contemporary Buddhist monasteries in Taiwan, baiqi are used, on the one hand, to mark the time throughout the day, signal the beginning and end of monastic daily activities, and regulate the monastic order; and on the other hand, baiqi are indispensable to the musical practices of all Buddhist rituals, where they are used to accompany fanbai (Buddhist liturgical chants) and to articulate the whole ritual process. This study investigates multiple facets of Buddhist baiqi in their performance practice, function, application, notation, and transmission, exploring the interaction between baiqi and fanbai, baiqi and the practitioner, baiqi and the monastic space, and baiqi and various Buddhist contexts. I draw upon ideas from performance theory as it concerns different disciplines, but I maintain a sharper focus on the musicological dimension of performance practice when analyzing, interpreting, and explaining the performance and music of baiqi in terms of the monastic lifestyle and its rituals. The study not only uncovers the musical system of baiqi, but also encapsulates various issues of performed identity, social interaction, performer/audience, associated behaviors, the musical construction of space, and transmission.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The performance of the register insertion protocol for mixed voice-data traffic is investigated by simulation. The simulation model incorporates a common insertion buffer for station and ring packets. Bandwidth allocation is achieved by imposing a queue limit at each node. A simple priority scheme is introduced by allowing the queue limit to vary from node to node. This enables voice traffic to be given priority over data. The effect on performance of various operational and design parameters such as ratio of voice to data traffic, queue limit and voice packet size is investigated. Comparisons are made where possible with related work on other protocols proposed for voice-data integration. The main conclusions are: (a) there is a general degradation of performance as the ratio of voice traffic to data traffic increases, (b) substantial improvement in performance can be achieved by restricting the queue length at data nodes and (c) for a given ring utilisation, smaller voice packets result in lower delays for both voice and data traffic.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

There have been few genuine success stories about industrial use of formal methods. Perhaps the best known and most celebrated is the use of Z by IBM (in collaboration with Oxford University's Programming Research Group) during the development of CICS/ESA (version 3.1). This work was rewarded with the prestigious Queen's Award for Technological Achievement in 1992 and is especially notable for two reasons: 1) because it is a commercial, rather than safety- or security-critical, system and 2) because the claims made about the effectiveness of Z are quantitative as well as qualitative. The most widely publicized claims are: less than half the normal number of customer-reported errors and a 9% savings in the total development costs of the release. This paper provides an independent assessment of the effectiveness of using Z on CICS based on the set of public domain documents. Using this evidence, we believe that the case study was important and valuable, but that the quantitative claims have not been substantiated. The intellectual arguments and rationale for formal methods are attractive, but their widespread commercial use is ultimately dependent upon more convincing quantitative demonstrations of effectiveness. Despite the pioneering efforts of IBM and PRG, there is still a need for rigorous, measurement-based case studies to assess when and how the methods are most effective. We describe how future similar case studies could be improved so that the results are more rigorous and conclusive.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Delivering lectures to large groups of students can provoke high levels of anxiety, particularly for new lecturers (Exley and Dennick, 2009). Further, to provide an informative and engaging lecture requires a teacher who is confident, has a sound knowledge and well developed teaching skills (Bentley-Davies, 2010). Thus, new lecturers often need experience and supervision to develop the tacit knowledge and insight into their own style and persona when teaching in order to feel confident when delivering a lecture (Quinn and Hughes, 2007). Considering this model, therefore, may potentially contribute to a lecturers’ development and performance in the classroom. This paper will present the results of the second phase of a two-stage mixed method study that investigated the similarities between lecturing and acting. Twelve in-depth interviews where undertaken with lecturers within one School of Nursing in The United Kingdom. Findings, established a model of ‘persona adoption’ that represents a series of stages that lecturers may go through to both develop and take on a persona when lecturing. This persona is often different from the way they lecturers present themselves in other parts of their working life. The first stage of this model of persona adoption is when the lecturer is subjected to a range of ‘influencing factors’ that provide not only the basic information about a lecture, but also the perceptual stimuli about giving a lecture on a specific subject, to a particular number of students, at a certain academic level. These influencing factors then inter-play with the ‘facets of the individual’, which represent the lecturer’s self-concept, subject knowledge base and philosophy of teaching. This may result in a cognitive dissonance between these ‘facets’ and the ‘influencing factors’, so affecting the lecturers’ perceptions, thoughts and feelings about having to give that particular lecture. This results in the lecturer undertaking specific ‘back stage preparation’ during which they decide on the content and modes of delivery to prepare in light of that discourse. It may result in delivering the information via single or multiple methods, which during the lecture will require various levels of interaction and participation from the students. Just prior to the lecture, the lecturer builds or ‘puts on their persona’ and gets into role, making their initial impact with the group. They use the ‘elements of acting’ as proposed by Tauber and Mester’s (1994) e.g. animated voice and body, space, props humour and suspense and surprise to portray and maintain their persona. This leads the to lecturer demonstrating either positive or negative ‘persona characteristics’ in terms of appearing confident, knowledgeable, fluent in the technical skills of delivering the lecture, being interesting and engendering interaction with the students, or not. These characteristics, may or may not, potentially heighten student interest, attention and attitudes to learning as suggested by Tauber and Mester (1994). This depends on whether the lecturer has successfully used the persona and if the lecturer has been able to engage students in the lecture, in competition with other factors that may be taking the students’ attention. Although the model suggests a linear process, to a great extent, the elements might be more interdependent and interrelated. This might suggest that depending on the lecturer’s perception of their effectiveness during the lecture, that they may decide to continue or adapt their persona and methods to appear more confident. Furthermore, depending on how successful the lecturer perceived the session to be, both their reflections ‘in’ and ‘on’ practice could influence how they teach in the future (Zwozdiak, 2011). Therefore, these reflections become part of the facets of the individual, via the ‘reflective feedback loop’, in the model, which then in turn influences progression through the model in subsequent lectures. This study concluded that these lecturers went through a process whereby they compare the demands of the lecture with their own knowledge base and skill, this resulted in them undertaking specific preparation in terms of content and delivery style, then they adopted their persona immediately prior to entering the lecture, maintain it throughout the lecture via the use of the elements of acting to achieve an informative interactive lecture. The results of which then feedback into their self-concept as a lecturer and consequently may affect the persona they project in future lectures. If lecturers, therefore, can take a step back to consider how they deliver lectures and the way they can deliberately, yet apparently naturally, use their voices, bodies, space and humour in meaningfully, they engage their students in lecture, it will not just result in them being perceived as a good lecturer, but also be a genuine act of education.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The performance of an air-cycle refrigeration unit for road transport, which had been previously reported, was analysed in detail and compared with the original design model and an equivalent Thermo King SL200 vapour-cycle refrigeration unit. Poor heat exchanger performance was found to be the major contributor to low coefficient of performance values. Using state-of-the-art, but achievable performance levels for turbomachinery and heat exchangers, the performance of an optimised air-cycle refrigeration unit for the same application was predicted. The power requirement of the optimised air-cycle unit was 7% greater than the equivalent vapour-cycle unit at full-load operation. However, at part-load operation the air-cycle unit was estimated to absorb 35% less power than the vapour-cycle unit. The analysis demonstrated that the air-cycle system could potentially match the overall fuel consumption of the vapour-cycle transport refrigeration unit, while delivering the benefit of a completely refrigerant free system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The use of recycled aggregates has increased greatly over the last decade owing to enhanced environmental sensitivities. The level of performance required by such materials is dependent upon the applications for which they are used. Many recycled construction wastes have adequate shear strength in relation to various geotechnical applications. However, a possible drawback of these materials is the risk of crushing during repeated loading. The work reported in this paper examined two waste materials: crushed concrete and building debris, both regarded as construction wastes. Tests were also performed on traditionally used crushed rock, in this case basalt. The materials were subjected to repeated loading in a large direct shear apparatus. The amount of crushing was quantified by performing particle size analysis of the tested material. The results have shown that both recycled construction wastes were susceptible to particle crushing. The amount of crushing was influenced by both the vertical pressure and the number of loading cycles. This leads to a marked decrease in peak friction angle

Relevância:

100.00% 100.00%

Publicador:

Resumo:

International evidence confirms that early childhood educators can enter professional practice unprepared for child protection due to inadequate pre-service preparation. This paper makes an original contribution by using the Child Protection Questionnaire for Educators (CPQE) to examine the pre- and post- intervention child maltreatment and protection knowledge of early childhood and primary teaching students. While students’ knowledge increases significantly after participating in a child protection training programme, Pastoral Pathways, as part of their undergraduate study, post-intervention scores vary between groups. The study provides evidence of programme effectiveness and future training needs of pre-service educators. Findings are relevant to teacher educators and child care training providers in relation to programme content development and evidencing knowledge and skills acquisition.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Based on a series of expert interviews, this study explores the involvement of facilities management (FM) specialists in building design. Early FM involvement in design is found to be particularly useful for the improvement of efficiency and effectiveness from a long-term perspective.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose: The Dementia Care Networks' Study examined the effectiveness of four community-based, not-for-profit dementia networks. The study involved assessing the relationship between the types of administrative and service-delivery exchanges that occurred among the networked agencies and the network members' perception of the effectiveness of these exchanges. Design and Methods: With the use of a case-study method, the evolution, structure, and processes of each network were documented. Social network analysis using a standardized questionnaire completed by member agencies identified patterns of administrative and clinical exchanges among networked agencies. Results: Differences were found between the four networks in terms of their perceptions of service-delivery effectiveness; perceptions of administrative effectiveness did not factor significantly. Exchanges between groups of agencies (cliques) within each of the four networks were found to be more critical than those between individual agencies within each network. Implications: Integration-measured by the types of exchanges within as opposed to across networks-differentiated the four networks studied. This research contributes to our understanding of the use of multiple measures to evaluate the inner workings of service delivery and their impact on elder health and elder health care. Copyright 2005 by The Gerontological Society of America.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cooling techniques play a key role in improving efficiency and power output of modern gas turbines. The conjugate technique of film and impingement cooling schemes is considered in this study. The Multi-Stage Cooling Scheme (MSCS) involves coolant passing from inside to outside turbine blade through two stages. The first stage; the coolant passes through first hole to internal gap where the impinging jet cools the external layer of the blade. Finally, the coolant passes through the internal gap to the second hole which has specific designed geometry for external film cooling. The effect of design parameters, such as, offset distance between two-stage holes, gap height, and inclination angle of the first hole, on upstream conjugate heat transfer rate and downstream film cooling effectiveness performance are investigated computationally. An Inconel 617 alloy with variable properties is selected for the solid material. The conjugate heat transfer and film cooling characteristics of MSCS are analyzed across blowing ratios of Br = 1 and 2 for density ratio, 2. This study presents upstream wall temperature distributions due to conjugate heat transfer for different gap design parameters. The maximum film cooling effectiveness with upstream conjugate heat transfer is less than adiabatic film cooling effectiveness by 24–34%. However, the full coverage of cooling effectiveness in spanwise direction can be obtained using internal cooling with conjugate heat transfer, whereas adiabatic film cooling effectiveness has narrow distribution.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Over the last two decades there has been ongoing debate about the impact of environmental practices on operational performance. In recent years, studies have started to move beyond assessing the direct impact of environmental management on different dimensions of performance to consider factors that might moderate or mediate this relationship. This study considers the extent to which environmental integration and environmental capabilities moderate the relationship between pollution prevention and environmental performance outcomes. The mediating influence of environmental performance on the relationship between pollution prevention and cost and flexibility performance is also considered. Data were collected from a sample of UK food manufacturers and analysed using multiple regression analysis. The findings indicate the existence of some moderated and mediated relationships suggesting that there is more to improving performance than implementing environmental practices.