877 resultados para Technical thought
Resumo:
This paper provides an outline of the development of temporal thinking that is underpinned by the idea that temporal cognition shifts from being event dependent to event independent over the preschool period. I distinguish between three different ways in which it may be possible to have a perspective on time: (1) a perspective that is grounded in script-like representations of repeated events; (2) a more sophisticated perspective that brings in an fundamental categorical distinction between events that have already happened and events that are yet to come; and (3) a mature temporal perspective that involves orienting oneself in time using a linear temporal framework, with a grasp of the distinctions between past, present, and future. I propose that, with development, children possess each of these types of perspective in turn, and that only the last of these involves being able to represent time in an event-independent way.
Resumo:
Due to increasing water scarcity, accelerating industrialization and urbanization, efficiency of irrigation water use in Northern China needs urgent improvement. Based on a sample of 347 wheat growers in the Guanzhong Plain, this paper simultaneously estimates a production function, and its corresponding first-order conditions for cost minimization, to analyze efficiency of irrigation water use. The main findings are that average technical, allocative, and overall economic efficiency are 0.35, 0.86 and 0.80, respectively. In a second stage analysis, we find that farmers’ perception of water scarcity, water price and irrigation infrastructure increase irrigation water allocative efficiency, while land fragmentation decreases it. We also show that farmers’ income loss due to higher water prices can be offset by increasing irrigation water use efficiency.
Resumo:
Gas fired generation currently plays an integral support role ensuring security of supply in power systems with high wind power penetrations due to its technical and economic attributes. However, the increase in variable wind power has affected the gas generation output profile and is pushing the boundaries of the design and operating envelope of gas infrastructure. This paper investigates the mutual dependence and interaction between electricity generation and gas systems through the first comprehensive joined-up, multi-vector energy system analysis for Ireland. Key findings reveal the high vulnerability of the Irish power system to outages on the Irish gas system. It has been shown that the economic operation of the power system can be severely impacted by gas infrastructure outages, resulting in an average system marginal price of up to €167/MWh from €67/MWh in the base case. It has also been shown that gas infrastructure outages pose problems for the location of power system reserve provision, with a 150% increase in provision across a power system transmission bottleneck. Wind forecast error was shown to be a significant cause for concern, resulting in large swings in gas demand requiring key gas infrastructure to operate at close to 100% capacity. These findings are thought to increase in prominence as the installation of wind capacity increases towards 2020, placing further stress on both power and gas systems to maintain security of supply.
Resumo:
Turbogenerating is a form of turbocompounding whereby a Turbogenerator is placed in the exhaust stream of an internal combustion engine. The Turbogenerator converts a portion of the expelled energy in the exhaust gas into electricity which can then be used to supplement the crankshaft power. Previous investigations have shown how the addition of a Turbogenerator can increase the system efficiency by up to 9%. However, these investigations pertain to the engine system operating at one fixed engine speed. The purpose of this paper is to investigate how the system and in particular the Turbogenerator operate during engine speed transients. On turbocharged engines, turbocharger lag is an issue. With the addition of a Turbogenerator, these issues can be somewhat alleviated. This is done by altering the speed at which the Turbogenerator operates during the engine’s speed transient. During the transients, the Turbogenerator can be thought to act in a similar manner to a variable geometry turbine where its speed can cause a change in the turbocharger turbine’s pressure ratio. This paper shows that by adding a Turbogenerator to a turbocharged engine the transient performance can be enhanced. This enhancement is shown by comparing the turbogenerated engine to a similar turbocharged engine. When comparing the two engines, it can be seen that the addition of a Turbogenerator can reduce the time taken to reach full power by up to 7% whilst at the same time, improve overall efficiency by 7.1% during the engine speed transient.
Resumo:
This paper describes how urban agriculture differs from conventional agriculture not only in the way it engages with the technologies of growing, but also in the choice of crop and the way these are brought to market. The authors propose a new model for understanding these new relationships, which is analogous to a systems view of information technology, namely Hardware-Software- Interface.
The first component of the system is hardware. This is the technological component of the agricultural system. Technology is often thought of as equipment, but its linguistic roots are in ‘technis’ which means ‘know how’. Urban agriculture has to engage new technologies, ones that deal with the scale of operation and its context which is different than rural agriculture. Often the scale is very small, and soils are polluted. There this technology in agriculture could be technical such as aquaponic systems, or could be soil-based agriculture such as allotments, window-boxes, or permaculture. The choice of method does not necessarily determine the crop produced or its efficiency. This is linked to the biotic that is added to the hardware, which is seen as the ‘software’.
The software of the system are the ecological parts of the system. These produce the crop which may or may not be determined by the technology used. For example, a hydroponic system could produce a range of crops, or even fish or edible flowers. Software choice can be driven by ideological preferences such as permaculture, where companion planting is used to reduce disease and pests, or by economic factors such as the local market at a particular time of the year. The monetary value of the ‘software’ is determined by the market. Obviously small, locally produced crops are unlikely to compete against intensive products produced globally, however the value locally might be measured in different ways, and might be sold on a different market. This leads to the final part of the analogy - interface.
The interface is the link between the system and the consumer. In traditional agriculture, there is a tenuous link between the producer of asparagus in Peru and the consumer in Europe. In fact very little of the money spent by the consumer ever reaches the grower. Most of the money is spent on refrigeration, transport and profit for agents and supermarket chains. Local or hyper-local agriculture needs to bypass or circumvent these systems, and be connected more directly to the consumer. This is the interface. In hyper-localised systems effectiveness is often more important than efficiency, and direct links between producer and consumer create new economies.
Resumo:
In his essay, Anti-Object, Kengo Kuma proposes that architecture cannot and should not be understood as object alone but instead always as series of networks and connections, relationships within space and through form. Some of these relationships are tangible, others are invisible. Stan Allen and James Corner have also called for an architecture that is more performative and operative – ‘less concerned with what buildings look like and more concerned with what they do’ – as means of effecting a more intimate and promiscuous relationship between infrastructure, urbanism and buildings. According to Allen this expanding filed offers a reclamation of some of the areas ceded by architecture following disciplinary specialization:
‘Territory, communication and speed are properly infrastructural problems and architecture as a discipline has developed specific technical means to deal with these variables. Mapping, projection, calculation, notation and visualization are among architecture’s traditional tools for operating at the very large scale’.
The motorway may not look like it – partly because we are no longer accustomed to think about it as such – but it is a site for and of architecture, a territory where architecture can be critical and active. If the limits of the discipline have narrowed, then one of the functions of a school of architecture must be an attempt occupy those areas of the built environment where architecture is no longer, or has yet to reach. If this is a project about reclamation of a landscape, it is also a challenge to some of the boundaries that surround architecture and often confine it, as Kuma suggests, to the appreciation of isolated objects.
M:NI 2014-15
We tend to think of the motorway as a thing or an object, something that has a singular function. Historically this is how it has been seen, with engineers designing bridges and embankments and suchlike with zeal … These objects like the M3 Urban Motorway, Belfast’s own Westway, are beautiful of course, but they have caused considerable damage to the city they were inflicted upon.
Actually, it’s the fact that we have seen the motorway as a solid object that has caused this problem. The motorway actually is a fluid and dynamic thing, and it should be seen as such: in fact it’s not an organ at all but actually tissue – something that connects rather than is. Once we start to see the motorway as tissue, it opens up new propositions about what the motorway is, is used for and does. This new dynamic and connective view unlocks the stasis of the motorway as edifice, and allows adaptation to happen: adaptation to old contexts that were ignored by the planners, and adaptation to new contexts that have arisen because of or in spite of our best efforts.
Motorways as tissue are more than just infrastructures: they are landscapes. These landscapes can be seen as surfaces on which flows take place, not only of cars, buses and lorries, but also of the globalized goods carried and the lifestyles and mobilities enabled. Here the infinite speed of urban change of thought transcends the declared speed limit [70 mph] of the motorway, in that a consignment of bananas can cause soil erosion in Equador, or the delivery of a new iphone can unlock connections and ideas the world over.
So what is this new landscape to be like? It may be a parallax-shifting, cognitive looking glass; a drone scape of energy transformation; a collective farm, or maybe part of a hospital. But what’s for sure, is that it is never fixed nor static: it pulses like a heartbeat through that most bland of landscapes, the countryside. It transmits forces like a Caribbean hurricane creating surf on an Atlantic Storm Beach: alien forces that mutate and re-form these places screaming into new, unclear and unintended futures.
And this future is clear: the future is urban. In this small rural country, motorways as tissue have made the whole of it: countryside, mountain, sea and town, into one singular, homogenous and hyper-connected, generic city.
Goodbye, place. Hello, surface!
Resumo:
In his essay, Anti-Object, Kengo Kuma proposes that architecture cannot and should not be understood as object alone but instead always as series of networks and connections, relationships within space and through form. Some of these relationships are tangible, others are invisible. Stan Allen and James Corner have also called for an architecture that is more performative and operative – ‘less concerned with what buildings look like and more concerned with what they do’ – as means of effecting a more intimate and promiscuous relationship between infrastructure, urbanism and buildings. According to Allen this expanding filed offers a reclamation of some of the areas ceded by architecture following disciplinary specialization:
‘Territory, communication and speed are properly infrastructural problems and architecture as a discipline has developed specific technical means to deal with these variables. Mapping, projection, calculation, notation and visualization are among architecture’s traditional tools for operating at the very large scale’.
The motorway may not look like it – partly because we are no longer accustomed to think about it as such – but it is a site for and of architecture, a territory where architecture can be critical and active. If the limits of the discipline have narrowed, then one of the functions of a school of architecture must be an attempt occupy those areas of the built environment where architecture is no longer, or has yet to reach. If this is a project about reclamation of a landscape, it is also a challenge to some of the boundaries that surround architecture and often confine it, as Kuma suggests, to the appreciation of isolated objects.
M:NI 2014-15
We tend to think of the motorway as a thing or an object, something that has a singular function. Historically this is how it has been seen, with engineers designing bridges and embankments and suchlike with zeal … These objects like the M3 Urban Motorway, Belfast’s own Westway, are beautiful of course, but they have caused considerable damage to the city they were inflicted upon.
Actually, it’s the fact that we have seen the motorway as a solid object that has caused this problem. The motorway actually is a fluid and dynamic thing, and it should be seen as such: in fact it’s not an organ at all but actually tissue – something that connects rather than is. Once we start to see the motorway as tissue, it opens up new propositions about what the motorway is, is used for and does. This new dynamic and connective view unlocks the stasis of the motorway as edifice, and allows adaptation to happen: adaptation to old contexts that were ignored by the planners, and adaptation to new contexts that have arisen because of or in spite of our best efforts.
Motorways as tissue are more than just infrastructures: they are landscapes. These landscapes can be seen as surfaces on which flows take place, not only of cars, buses and lorries, but also of the globalized goods carried and the lifestyles and mobilities enabled. Here the infinite speed of urban change of thought transcends the declared speed limit [70 mph] of the motorway, in that a consignment of bananas can cause soil erosion in Equador, or the delivery of a new iphone can unlock connections and ideas the world over.
So what is this new landscape to be like? It may be a parallax-shifting, cognitive looking glass; a drone scape of energy transformation; a collective farm, or maybe part of a hospital. But what’s for sure, is that it is never fixed nor static: it pulses like a heartbeat through that most bland of landscapes, the countryside. It transmits forces like a Caribbean hurricane creating surf on an Atlantic Storm Beach: alien forces that mutate and re-form these places screaming into new, unclear and unintended futures.
And this future is clear: the future is urban. In this small rural country, motorways as tissue have made the whole of it: countryside, mountain, sea and town, into one singular, homogenous and hyper-connected, generic city.
Goodbye, place. Hello, surface!