The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Alexandre M. Bayen - One of the best experts on this subject based on the ideXlab platform.
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CASE - Cooperative control of air flow for HVAC systems
2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013Co-Authors: Yushen Long, Alexandre M. BayenAbstract:A dynamic pressure and variable air volume (VAV) control strategy is proposed for building heating, ventilation and air-conditioning (HVAC) systems. The strategy consists in two level control, namely, pressure loop control and temperature loop control. The pressure control loop is to make sure that the air pressure at the inlet of each room is equal to a certain value while the temperature control loop is to control the room temperature which is achieved by adjusting the VAV box so that the supply air flow rate can be varied to achieve the room setting temperature. For the pressure control loop, a cooperative control technique is applied. The two control loops are coupled. This paper will analyze the stability of the overall system and give a sufficient condition on the initial values in terms of rooms and the HVAC system parameters.
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Cooperative control of air flow for HVAC systems
2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013Co-Authors: Yushen Long, Alexandre M. BayenAbstract:A dynamic pressure and variable air volume (VAV) control strategy is proposed for building heating, ventilation and air-conditioning (HVAC) systems. The strategy consists in two level control, namely, pressure loop control and temperature loop control. The pressure control loop is to make sure that the air pressure at the inlet of each room is equal to a certain value while the temperature control loop is to control the room temperature which is achieved by adjusting the VAV box so that the supply air flow rate can be varied to achieve the room setting temperature. For the pressure control loop, a cooperative control technique is applied. The two control loops are coupled. This paper will analyze the stability of the overall system and give a sufficient condition on the initial values in terms of rooms and the HVAC system parameters.
Alexandra Witze - One of the best experts on this subject based on the ideXlab platform.
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Dead bees, dusty offices: US scientists face post-shutdown malaise
Nature, 2019Co-Authors: Lauren Morello, Amy Maxmen, Emiliano Rodríguez Mega, Alexandra WitzeAbstract:Science agencies are scrambling to recover from one government closure as another Looms. Science agencies are scrambling to recover from one government closure as another Looms.
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Science and the shutdown: 5 things to watch as US impasse drags on
Nature, 2019Co-Authors: Lauren Morello, Emiliano Rodríguez Mega, Sara Reardon, Jeff Tollefson, Alexandra WitzeAbstract:A second wave of closures Looms as the government funding fight barrels towards a record-breaking fourth week. A second wave of closures Looms as the government funding fight barrels towards a record-breaking fourth week.
Yushen Long - One of the best experts on this subject based on the ideXlab platform.
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CASE - Cooperative control of air flow for HVAC systems
2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013Co-Authors: Yushen Long, Alexandre M. BayenAbstract:A dynamic pressure and variable air volume (VAV) control strategy is proposed for building heating, ventilation and air-conditioning (HVAC) systems. The strategy consists in two level control, namely, pressure loop control and temperature loop control. The pressure control loop is to make sure that the air pressure at the inlet of each room is equal to a certain value while the temperature control loop is to control the room temperature which is achieved by adjusting the VAV box so that the supply air flow rate can be varied to achieve the room setting temperature. For the pressure control loop, a cooperative control technique is applied. The two control loops are coupled. This paper will analyze the stability of the overall system and give a sufficient condition on the initial values in terms of rooms and the HVAC system parameters.
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Cooperative control of air flow for HVAC systems
2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013Co-Authors: Yushen Long, Alexandre M. BayenAbstract:A dynamic pressure and variable air volume (VAV) control strategy is proposed for building heating, ventilation and air-conditioning (HVAC) systems. The strategy consists in two level control, namely, pressure loop control and temperature loop control. The pressure control loop is to make sure that the air pressure at the inlet of each room is equal to a certain value while the temperature control loop is to control the room temperature which is achieved by adjusting the VAV box so that the supply air flow rate can be varied to achieve the room setting temperature. For the pressure control loop, a cooperative control technique is applied. The two control loops are coupled. This paper will analyze the stability of the overall system and give a sufficient condition on the initial values in terms of rooms and the HVAC system parameters.
Robert C. Allen - One of the best experts on this subject based on the ideXlab platform.
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The hand-loom weaver and the power loom: a Schumpeterian perspective
European Review of Economic History, 2018Co-Authors: Robert C. AllenAbstract:The invention of the power loom was a response to the increase in supply of yarn in the 1780s. This led to an expansion of handloom weaving and a rise in earnings in the 1790s, thereby, creating the “golden age†. The high earnings increased the profitability of developing the power loom by raising the value of the labour that it saved. Consequently, less efficient—hence, cheaper to develop—power Looms could be brought into commercial use than would have been the case had the golden age not occurred. The power loom, in turn, devalued the old skills, so poverty accompanied progress.
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The Hand-Loom Weaver and the Power Loom: A Schumpeterian Perspective REVISED
2017Co-Authors: Robert C. AllenAbstract:Schumpeter’s ‘perennial gale of creative destruction’ blew strongly through Britain during the Industrial Revolution, as the factory mode of production displaced the cottage mode in many industries. A famous example is the shift from hand loom weaving to the use of power Looms in mills. As the use of power Looms expanded, the price of cloth fell, and the ‘golden age of the hand loom weaver’ gave way to poverty and unemployment. This paper argues that the fates of the hand and machine processes were even more closely interwoven. With the expansion of factory spinning in the 1780s, the demand for hand loom weavers soared in order to process the newly available cheap yarn. The rise in demand raised the earnings of hand loom weavers, thereby, creating the ‘golden age’. The high earnings also increased the profitability of developing the power loom by raising the value of the labour that it saved. This meant that less efficient–hence, cheaper to develop--power Looms could be brought into commercial use than would have been the case had the golden age not occurred. The counterfactual possibilities are explored with a model of the costs of weaving by hand and by power. The cottage mode of production was an efficient system of producing cloth, but it self-destructed as its expansion after 1780 raised the demand for sector-specific skills, thus providing the incentive for inventors to develop a power technology to replace it. The power loom, in turn, devalued the old skills, so poverty accompanied progress.
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The Hand-Loom Weaver and the Power Loom: A Schumpeterian Perspective
2016Co-Authors: Robert C. AllenAbstract:Abstract: Schumpeter’s ‘perennial gale of creative destruction’ blew strongly through Britain during the Industrial Revolution, as the factory mode of production displaced the cottage mode in many industries. A famous example is the shift from hand loom weaving to the use of power Looms in mills. As the use of power Looms expanded, the price of cloth fell, and the ‘golden age of the hand loom weaver’ gave way to poverty and unemployment. This paper argues that the fates of the hand and machine processes were even more closely interwoven. With the expansion of factory spinning in the 1780s, the demand for hand loom weavers soared in order to process the newly available cheap yarn. The rise in demand raised the earnings of hand loom weavers, thereby, creating the ‘golden age’. The high earnings also increased the profitability of developing the power loom by raising the value of the labour that it saved. This meant that less efficient–hence, cheaper to develop--power Looms could be brought into commercial use than would have been the case had the golden age not occurred. The counterfactual possibilities are explored with a model of the costs of weaving by hand and by power. The cottage mode of production was an efficient system of producing cloth, but it self-destructed as its expansion after 1780 raised the demand for sector-specific skills, thus providing the incentive for inventors to develop a power technology to replace it. The power loom, in turn, devalued the old skills, so poverty accompanied progress.
E.a.s.k. Fernando - One of the best experts on this subject based on the ideXlab platform.
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Modeling of compressed air requirement for different weft yarns on air jet weaving
2017 Moratuwa Engineering Research Conference (MERCon), 2017Co-Authors: D.p.i.u. Gunarathna, E.a.s.k. Fernando, R.k.d.n. Kumari, S.g.a.k. Subawickrama, T.s.s. JayawardanaAbstract:Although air-jet Looms run faster than mechanical weft insertion Looms such as rapier or shuttle Looms, but their production cost can be higher when their air usage is not optimized. The amount of air required for weft insertion varies greatly for each yarn type and also depends on several key factors. One of these factors is the yarn's air friendliness, which is the measure of how easy it is to project yarns across a web with an air column. In practice, the same air pressure is applied to all yarn types since determining the optimum air pressure for each yarn type is laborious and time intensive. Consequently, a considerable amount of air is wasted and the weaving efficiency of the loom is compromised, especially when weaving with air friendly yarns. A scientific approach that predicts the best pressure for main nozzle and sub nozzles for each yarn type can mitigate the waste of compressed air usage. Thus, a mathematical model that can be applied to optimize the compressed air usage is presented.
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Developing a technological process to weave cotton fabrics on water jet loom
2016 Moratuwa Engineering Research Conference (MERCon), 2016Co-Authors: M.a.a.u. Prasanna, S.s. Senanayake, S.a.k.p. Wijesinghe, E.a.s.k. Fernando, S.a.s. PereraAbstract:Water jet Looms are widely used in woven fabric manufacturing especially for synthetic fabric production. Due to massive growth in synthetic fabric production, the significance of the water jet loom becomes dominant Due to its salient features such as high production speed, low energy consumption, low noise emission, and simple maintenance procedures as compared to other loom counterparts. The major drawback of the water jet loom is its inability to produce cellulosic based fabric such as cotton because cotton yarns absorb considerably higher amount of water during weft insertion and as a result it does not properly insert through the warp sheet. Air jet weaving machine is ideal to produce cellulose based fabrics. However, air jet Looms lacks in the above advantages possessed by water jet Looms. For a sustainable development in the weaving industry and a competitive edge in weaving, it is mandatory to have minimum energy consumption when producing cellulose based fabrics. So, it is prudent to explore the possibility of weaving cellulosic based fabrics on a water jet loom. Hence, the authors attempted to develop an appropriate technological process to achieve this. A non-absorbent cotton yarn was developed and a water jet loom was modified in order to successfully produce cotton based fabrics on a water jet loom.
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Mathematical analysis of startup mark in elastic tape on a narrow fabric loom
2015 Moratuwa Engineering Research Conference (MERCon), 2015Co-Authors: H D C T Dayaratne, E.a.s.k. Fernando, Ranishka Premakumara, Thanura Perera, Stephan Prince, T S S JayawardaneAbstract:Start-up marks are considered as one of the major defect in woven fabric, it occurs when the loom is restarted after loom stoppage due to various reasons. This defect is more prominent in high speed weaving Looms especially with elastic warp yarns and is caused to deteriorate the fabric quality. This research paper deals with the mathematical analysis of the startup mark generation in elastic tape on narrow fabric loom. Mathematical analysis was carried out for both continuous operation condition and under stopping condition of the narrow fabric loom. A system simulation was carried out using the model developed and compared with the experimental results to show the accuracy of the model.
