65 resultados para Top-down control


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The post-larvae and fry of Australian native species, including those of species belonging to the family Percichthyidae, are routinely reared to a fingerling size (35-55 mm in length) in fertilised earthen fry rearing ponds. The juveniles of Murray cod (Maccullochella peelii peelii\ trout cod (Maccullochella macquariensis) and Macquarie perch (Macquaria australasicd) (Percichthyidae) are grown in fry rearing ponds at the Marine and Freshwater Resources Institute, Snobs Creek (Vie. Australia) for production of fingerlings for stock enhancement and aquaculture purposes. However, no detailed studies have been undertaken of the productivity of these ponds and factors that influence fish production. An ecologically based study was undertaken to increase the knowledge of pond ecology and dynamics, particularly in relation to the rearing of juvenile Murray cod, trout cod and Macquarie perch in ponds. Over nine consecutive seasons commencing in 1991, water chemistry, plankton, macrobenthos (2 seasons only) and fish were monitored and studied in five ponds located at Snobs Creek. A total of 80 pond fillings were undertaken during the study period. Additional data collected from another 24 pond fillings undertaken at Snobs Creek collected prior to this study were included in some analyses. Water chemistry parameters monitored in the ponds included, temperature, dissolved oxygen pH, ammonia, nitrite, nitrate, orthophosphate and alkalinity. Water chemistry varied spatially (within and between ponds) and temporally (diurnally, daily and seasonally). Liming of ponds increased the total alkalinity to levels that were considered to be suitable for enhancing plankton communities and fish production. Water quality within the ponds for the most part was suitable for the rearing of juvenile Murray cod, trout cod and Macquarie perch, as reflected in overall production (growth, survival and yield) from the ponds. However, at times some parameters reached levels which may have stressed fish and reduced growth and survival, in particular, low dissolved oxygen concentrations (minimum 1.18 mg/L), high temperatures (maximum 34°C), high pH (maximum 10.38) and high unionised ammonia (maximum 0.58 mg/L). Species belonging to 37 phytoplankton, 45 zooplankton and 17 chironomid taxa were identified from the ponds during the study. In addition, an extensive checklist of aquatic flora and fauna, recorded from aquaculture ponds in south-eastern Australia, was compiled. However, plankton and benthos samples were usually numerically dominated by a few species only. Rotifers (especially Filinia, Brachionus, Polyarthra, and Asplanchnd), cladocerans (Moina and Daphnid) and copepods (Mesocyclops and Boeckelld) were most abundant and common in the plankton, while chironomids (Chironomus, Polypedilum, and Prodadius) and oligochaetes were most common and abundant in the benthos. Both abundance and species composition of the plankton and macrobenthos varied spatially (within and between ponds) and temporally (diurnally, daily and seasonally). Chlorophyll a concentrations, which ranged from 1.8 to 184 \ig/L (mean 29.37 ng/L), initially peaked within two weeks of filling and fertilising the ponds. Zooplankton peaked in abundance 2-4 weeks after filling the ponds. The maximum zooplankton density recorded in the ponds was 6,621 ind./L (mean 721 ind./L). Typically, amongst the zooplankton, rotifers were first to develop high densities (2nd-3rd week after filling), followed by cladocerans (2nd-4th week after filling) then copepods (2nd-5th week after filling). Chironomid abundance on average peaked later (during the 5th week after filling). The maximum chironomid density recorded in the ponds was 27,470 ind./m2 (mean 4,379 ind./m2). Length-weight, age-weight and age-length relationships were determined for juvenile Murray cod, trout cod and Macquarie perch reared in ponds. These relationships were most similar for Murray cod and trout cod, which are more closely related phylogenetically and similar morphologically than Macquarie perch. Growth of fish was negatively correlated with both size at stocking and stocking biomass. Stocking density experiments showed that, at higher densities, growth offish was significantly reduced, but survival was not affected. The diets of juvenile Murray cod trout cod and Macquarie perch reared in fry ponds were similar. The cladocerans Moina and Daphnia, adult calanoid and cyclopoid copepods and the chironomids, Chironomus, Polypedilum and Procladius were the most commonly occurring and abundant prey. Selection for rotifers and copepod nauplii was strongly negative for all three species of fish. Size range of prey consumed was positively correlated with fish size for trout cod and Macquarie perch, but not for Murray cod. Diet composition changed as the fish grew. Early after stocking the fish into the ponds, Moina was generally the more common prey consumed, while in latter weeks, copepods and chironomids became more abundant and common in the diet. On a dry weight basis, chironomid larvae were the most important component in the diets of these fish species. Selective feeding by fish on larger planktonic species such as adult copepods and cladocerans, may have influenced the plankton community structure as proposed by the trophic cascade or top -down hypothesis. The proximate composition and energy content of Murray cod, trout cod and Macquarie perch, reared in the ponds did not vary significantly between the species, and few significant changes were observed as the fish grew. These results suggested that the nutrient requirements of these species might not vary over the size range of fish examined. Significant differences in the proximate composition of prey were observed between species, size of species and time of season. The energy content of prey (cladocerans, copepods and chironomids) on a pond basis, was closely related to the abundance of these taxa in the ponds. Data collected from all pond fillings during the present study, along with historical data from pond fillings undertaken prior to this study, were combined in a data matrix and analysed for interactions between pairs of parameters. In particular, interactions between selected water chemistry parameters, zooplankton and chironomid abundance indicators were analysed to identify key factors that influence fish production (growth, survival, condition and yield). Significant correlations were detected between fish production indicators and several water chemistry and biota (zooplankton and chironomids) parameters. However, these were not consistent across all three species of fish. These results indicated that the interactions between water chemistry, biota and fish were complex, and that combinations of these parameters, along with other factors not included in the present study, may influence fish production in these ponds. The present study, showed that more stringent monitoring of fry rearing ponds, especially water quality, zooplankton and benthos communities and fish, combined with an associated increase in understanding of the pond ecosystem, can lead to substantial improvements in pond productivity and associated fish production. In the present study this has resulted in a general increase in fish survival rates, which became less variable or more predictable in nature. The value of such knowledge can provide managers with a more predicative capacity to estimate production of ponds in support of stock enhancement programs and provision of juvenile for aquaculture grow-out.

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The thesis argues that the "top down" approach which has been a recent feature of vocational provision in Australia has largely excluded vocational teachers and students from being involved in curriculum and policy formation. The emphasis of the current system on "training" to meet economic ends has resulted in a demise of "education" in the vocational arena. Such policy fails to recognise the complexities of learning and work in a rapidly changing society.

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Explores how machine learning techniques can be used to build effective student modeling systems with constrained development and operational overheads, by integrating top-down and bottom-up initiatives. Emphasizes feature-based modelling.

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The topic of systems of systems has been one of the most challenging areas in science and engineering due to its multidisciplinary scope and inherent complexity. Despite all attempts carried out so far in both academia and industry, real world applications are far remote. The purpose of this paper is to modify and adopt a recently developed modeling paradigm for system of systems and then employ it to model a generic baggage handling system of an airport complex. In a top-down design approach, we start modeling process by definition of some modeling goals that guide us in selection of some high level attributes. Then functional attributes are defined which act as ties between high level attributes (the first level of abstraction) and low level metrics/measurements. Since the most challenging issues in developing models for system of systems are identification and representation of dependencies amongst constituent entities, a machine learning technique is adopted for addressing these issues.

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Generic skills are increasingly the focus of universities worldwide and are often developed in professional practice courses. This paper presents qualitative findings from students regarding their perceptions of the generic skills they developed during a capstone course in an Information Systems program. The study found that the capstone course improved their collaborative team-work, presentation skills and ability to apply skills/knowledge to new situations. The paper also demonstrates that students’ perceptions of generic skills were more closely tied to the discipline than university-wide generic skills. This lends support for generic skills policy/practice to be driven bottom-up rather than top-down.

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A conceptual knowledge management (KM) framework was developed and tested. The social bond combined with the expertise of a Community of Practice (CoP) constitutes a bottom-up aproach to KM, at the same time influencing top-down KM efforts by managers. A successful feedback loop between CoP and Management assists in establishing a collaborative and integrated top-down/bottom-up KM strategy.

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This paper explores the situated body by briefly surveying the historical studies of effect and of affect which converge in current work on attention. This common approach to the situated body through attention prompted the coining of a more inclusive term, Æffect, to indicate the situated body’s mode of observation. Examples from the work of artist-turned-architects, Arakawa and Gins, will be discussed to show how architectural environments can act as heuristic tools that allow the situated body to research its own conditions. Rather than isolating effect from affect, observer from subject, organism from environment, Arakawa and Gins’ work optimises the use of situated complexity in the study of the site of person. By constructing surrounding in which to observe and learn about the shape of awareness, their procedural architecture suggests ways in which the interaction of top-down conceptual knowledge and bottom-up perceptual learning may construct possibilities in emergent rather than programmatic ways.

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This paper examines the experiences of selected academics pioneering e-learning in Malaysian tertiary institutions. It begins with an overview of the broad factors shaping the Malaysian educational environment and then proceeds to examine the experience of individual teachers and e-learning programs. It takes an in-depth qualitative approach to engaging with this case study material drawing heavily on semi-structured interviews with key actors.
Conversations with several respondents suggested that the social networks of mentor relations found in the Malaysian case studies might be aptly described as ‘bamboo networks’. Bamboo, which happens to be plentiful in the Malaysian peninsula where these case studies are based, spreads from clump to clump through a series of underground connections involving a mature clump of bamboo sending out a subterranean runner, often over very long distances that then emerge into the open as a new bamboo clump.
All of those interviewed reported that they have found it difficult to find a support base in their first years of pioneering online developments. Consequently, they tended to fall back on their peer networks linked to the institutions at which they had studied. Prominent individuals championing e-learning in the institutions where they teach tend to form small groups for information sharing and networking. They do look to their management for tacit ‘permission’ rather than direct encouragement. Consequently, the active promotion of e-learning in Malaysia can be described as being ‘middle-down’ rather than ‘top-down’ in nature. That is to say, it is mid-level teachers that inspire those below them to join in the development of e-learning programs. They are internally driven and strongly motivated. In time, their activity should produce new generations of locally developed e-learning experts but this has yet to take place in a substantial fashion. This study shows that both men and women ‘academic guanxi’, or peer networks, play a key role in the adoption of online technologies. Key early adopters become change-agents by inspiring a small network of their peers and via their guanxi networks. It was also discovered that motivation is not simply an individual matter but is also about groups and peer networks or communities of exchange and encouragement. In the development of e-learning in Malaysia, there is very little activity that is not linked to small clusters of developers who are tied into wider networks through personal contacts.
Like clumping bamboo, whilst the local clusters tend to be easily seen, the longer-range ‘subterranean’ personal connections are generally not nearly so immediately obvious. These connections are often the product of previous mentoring relationships, including the relationships between influential teachers and their former postgraduate students. These relationships tend to work like bamboo runners: they run off in multiple directions, subterranean and unseen and then throw up new clumps that then send out fresh runners of their own.

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Culture and spirit of land is integral to Indigenous community meaning and identity. With colonisation, transmigration and assimilation policies and practices over the last 200 years, many Indigenous communities, like the Minahasa, have witnessed their culture, curatorial responsibilities, and their mythological associations to their lands eroded. Minahasa, meaning 'becoming one united', encompasses some eight ethnic communities who reside in the Minahasa regencies in the North Sulawesi Province on Sulawesi Island in Indonesia. The region was first colonised by the Portuguese in the 16th century, and then by the Dutch VOC (Verenigde Oostindische Compagnie) in the 17th and 18th centuries bringing a strong Christian Protestant faith to the communities that appropriated many of the cultural symbols and mythological narratives of the Minahasa, and now compromises the largest concentration of Christian faith in the Indonesian archipelago being one of the reasons why there was considerable political requests for the region to formally become a province of The Netherlands in the lead up to Indonesian independence in 1945.

North Sulawesi never developed any large empire like on other islands in the archipelago. In 670, the leaders of the different tribes, who all spoke different languages, met by a stone known as Watu Pinawetengan. There they founded a community of independent states, who would form one unit and stay together and would fight any outside enemies if they were attacked, and the Dutch used this cultural ethos to help unite the linguistically diverse Minahasa confederacy under their colonial regime. Integral to the Minahasa is the Watu Pinawetengan and the series of narratives that enjoin the Minahasan communities to this place and around Lake Tondano. With Indonesian governance considerable angst has been launched by the Minahasa about loss of local autonomy, generic Indonesian policies, and a lack of respect of Indigenous culture and non-mainstream religions within this predominantly Moslem nation. This paper reviews the state of knowledge as to the cultural associations and genius loci meanings of the Minahasa, to their landscape and place, cast against contemporary Indonesian 10 year plans and policies that seek to generically manage the collective Indonesian archipelago as one community and landscape. It is a critique about the Minahasan Indigenous land use and planning philosophies, against top-down generic land use and environmental policies and plans written in Jakarta for generic application across the Indonesian archipelago.

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While our awareness towards sustainable society and environment grows, the importance of ‘green’ materials and manufacturing is gaining significant recognition. We have demonstrated that naturally-occurring fibers as renewable raw materials can be converted into nanoparticles and nano fibers using simple top-down methods without introducing hazardous chemicals. This new class of green nanomaterials will have a wide range of environmental and biomedical applications owing to the inherent biocompatible, biodegradable and carbon-neutral nature.

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Poor safety management in construction management may adversely affect cost, schedule and quality of a project. Heavy fines upon safety offence becomes a burden to the budget; losing working hours as a result of safety incident impacts on the schedule, and compromising quality is always an indirect consequence when workers perform duties in an unsafe site environment. Therefore, promotion of safety management becomes the top priority in any construction manager’s agenda. Working safely will benefit construction project and lead to a “real” success. This paper is a case study, based upon “Geller’s 10 principles for achieving a total safety culture”, reviewing how a Hong Kong leading construction company fosters the safety culture and possesses a pleasant safety record over years. Its safety performance is not only well ahead the local industry, but also ranges top within the Asia Pacific region and comparable to those mature Western industries. The review concluded that safety culture is one of the major components in construction management and collaboration is the essence to realize this positive culture within an organization. Safety management is not merely a “top down” approach, but requires the positive “bottom up” actions from the other end. The successful story of this company can demonstrate the contribution of safety management in construction management.

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Kunib-dji live in Maningrida, a remote community in the Northern Territory and speak Ndj-bbana as their preferred language of communication. Kunib-dji are one of many groups of Indigenous Australian languages who speak a minority language. Very little has been documented about the social practices of literacy with speakers of such languages, particularly with the texts that mediate these languages. Knowing about the beliefs and attitudes towards enacted by these speakers towards these texts is useful for understanding the process of learning of minority and majority languages. This paper presents a middle approach to literacy as distinct form top-down and bottom-up approaches, that has emerged from the minority Indigenous Australian language context in Maningrida. The proposed middle approach to literacy incorporates non-indigenous intervention in Indigenous social practices and technological transform of Indigenous texts. The methodological aspects of such intervention and transformation together with the implications of a middle approach to literacy are presented in this paper. Throughout the paper references are made to Kunib-dji children's access to digital Ndj-bbana texts and their engagement with these texts in a home environment.

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Promoting safety management is always the top priority in construction business. Fostering safety culture will be one of the most effective ways. This paper is a case study, based upon the “Geller’s 10 principles for achieving a total safety culture”, to review how a construction companyin Hong Kong effectively promoting safety culture and enjoying pleasant safety records. Zero harmis not a “zero sum game”, but it requires positive “top down” and “bottom up” actions from both employers and employees.

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Canada and Australia are countries with substantial coastal zones which provide significant economic, social and environmental benefits and opportunities. The coastal zones of Canada and Australia also share significant threats such as, pollution, loss of biodiversity, and climate change, while also facing different challenges that are unique to their particular contexts. Effective management of such zones therefore represents a considerable challenge because of the: complexity of biophysical processes; multiple threats faced; uncertainties associated with understandings of such processes and threats, and the multiple jurisdictions and stakeholder viewpoints as to how such environments should be managed. Further, coasts and the sustainability of coastal resources and ecosystems have been argued to represent ‘wicked problems’ such that their governability is called into question. Therefore drawing on recent experiences in coastal policy, planning and governance in Newfoundland, Canada, and Victoria, Australia, this paper assesses the adequacy of current approaches to coastal governance in the two jurisdictions. In doing so we draw on recent policy and governance literature to consider whether coastal policy, planning and governance in Newfoundland and Victoria, reflect a collaborative, neoliberal, or business as usual (ad hoc, top down) approach. Based on such an assessment we consider the prospects for more integrated coastal zone management in each jurisdiction, as well as broader implications for governance and the resilience of coastal systems. It is argued that while both jurisdictions would benefit from a more collaborative approach, the mechanisms for bringing about such an approach would vary and will not come easily in light of institutional and historic barriers.

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A great deal of research has emphasized the strategic management of corporate social responsibility (CSR). However, gaps remain on how CSR can be effectively integrated with existing business processes. One key question remaining is how to design business processes so that they accommodate stakeholder requirements in an integrated manner. The purpose of this paper is to present a framework that can be used to integrate CSR into business processes. The framework highlights the concept of simultaneous ‘top-down integration’ and ‘bottom-up community-related indicators development’ approaches to CSR. These two approaches are elaborated with the help of two cases. The top-down approach focuses on building CSR into existing business initiatives through an integrated management systems (IMS) approach. This paper concludes that an IMS approach provides the infrastructure for the integration of CSR. The bottom-up approach focuses on the development of indicators linked to community initiatives. Examples of best practice for both the top-down and bottom-up approaches are provided in two case studies.