As valuable energy in iron-and steel-making process,by-product gas is widely used in heating and technical processes in steel plant.After being used according to the technical requirements,the surplus by-product gas i...As valuable energy in iron-and steel-making process,by-product gas is widely used in heating and technical processes in steel plant.After being used according to the technical requirements,the surplus by-product gas is usually used for buffer boilers to produce steam.With the rapid development of energy conservation technology and energy consumption level,surplus gas in steel plant continues to get larger.Therefore,it is significant to organize surplus gas among buffer boilers.A dynamic programming model of that issue was established in this work,considering the ramp rate constraint of boilers and the influences of setting gasholders.Then a case study was done.It is shown that dynamic programming dispatch gets more steam generation and less specific gas consumption compared with current proportionate dispatch depending on nominal capacities of boilers.The ignored boiler ramp rate constraint was considered and its contribution to the result validity was pointed out.Finally,the significance of setting gasholders was studied.展开更多
Knowing the level of efficiency of investment applied in ports of Mexico is relevant information for the design of port policies that contribute to its development and thus to greater freight movement. The objective o...Knowing the level of efficiency of investment applied in ports of Mexico is relevant information for the design of port policies that contribute to its development and thus to greater freight movement. The objective of this paper is to analyze the technical efficiency obtained from International Mexican Ports, through the use of the technique of Data Envelopment Analysis （DEA）. It uses data regarding public and private investment in ports applied during the period 2000-2010 and its influence on the number of Twenty-foot Equivalent Unit （TEU）. Because it has been applied the DEA-CCR （the linear programming model） model input oriented, thus not only the efficiency is calculated in ports, but benchmarking is also obtained to determine the efficient ports that serve as reference to those who were found to be inefficient. The results obtained showed that Manzanillo and Progreso were the most efficient ports. On the other hand, the ports that were not efficient for any of the years reviewed were Mazatlan and Lazaro Cardenas. Generally, public investment has been increasing over the period, and public policies are not designed to allow the ports to have an international projection.展开更多
Over the last few decades, a diverse and expanded practice has emerged from the increasingly collaborative work developed among architects, urbanists, artists, and media designers. This collaboration has more and more...Over the last few decades, a diverse and expanded practice has emerged from the increasingly collaborative work developed among architects, urbanists, artists, and media designers. This collaboration has more and more developed a particular landscape of projects which share the same operative principles and modes of operation. The city at large has been the context where these projects have been implemented and developed with the will of bringing these types of experimentation to the people and to the public and social scale. Cities are continuously produced through entropic processes that mediate between complexity and immediacy. Information technology operates as a linkage able to set up new rules for communication between man and matter. In this framework, by looking at spatial interventions in the urban space, the aim of the paper is to dissect the modes in which spatial practitioners operate in the digital city through ＂Urban Machines＂ and how information technology becomes a tool for place-making. The paper looks at integrated systems or machines that have spatial, social, and environmental implication in how we experience the city. Machines imply ＂something that has been constructed＂ and ＂function with a specific purpose＂ while being composed by parts that respond to a ＂functioning whole＂. These interventions start from sharing the same principle： How do we generate through technologically mediated experiences opportunities for new types of production of（social）space？; How such systems shape our urban experience and deploy forms of participation in civic life？.展开更多
基金Project(L2012082)supported by the Science and Technology Research Funds of Liaoning Provincial Education Department,China
文摘As valuable energy in iron-and steel-making process,by-product gas is widely used in heating and technical processes in steel plant.After being used according to the technical requirements,the surplus by-product gas is usually used for buffer boilers to produce steam.With the rapid development of energy conservation technology and energy consumption level,surplus gas in steel plant continues to get larger.Therefore,it is significant to organize surplus gas among buffer boilers.A dynamic programming model of that issue was established in this work,considering the ramp rate constraint of boilers and the influences of setting gasholders.Then a case study was done.It is shown that dynamic programming dispatch gets more steam generation and less specific gas consumption compared with current proportionate dispatch depending on nominal capacities of boilers.The ignored boiler ramp rate constraint was considered and its contribution to the result validity was pointed out.Finally,the significance of setting gasholders was studied.
文摘Knowing the level of efficiency of investment applied in ports of Mexico is relevant information for the design of port policies that contribute to its development and thus to greater freight movement. The objective of this paper is to analyze the technical efficiency obtained from International Mexican Ports, through the use of the technique of Data Envelopment Analysis （DEA）. It uses data regarding public and private investment in ports applied during the period 2000-2010 and its influence on the number of Twenty-foot Equivalent Unit （TEU）. Because it has been applied the DEA-CCR （the linear programming model） model input oriented, thus not only the efficiency is calculated in ports, but benchmarking is also obtained to determine the efficient ports that serve as reference to those who were found to be inefficient. The results obtained showed that Manzanillo and Progreso were the most efficient ports. On the other hand, the ports that were not efficient for any of the years reviewed were Mazatlan and Lazaro Cardenas. Generally, public investment has been increasing over the period, and public policies are not designed to allow the ports to have an international projection.
文摘Over the last few decades, a diverse and expanded practice has emerged from the increasingly collaborative work developed among architects, urbanists, artists, and media designers. This collaboration has more and more developed a particular landscape of projects which share the same operative principles and modes of operation. The city at large has been the context where these projects have been implemented and developed with the will of bringing these types of experimentation to the people and to the public and social scale. Cities are continuously produced through entropic processes that mediate between complexity and immediacy. Information technology operates as a linkage able to set up new rules for communication between man and matter. In this framework, by looking at spatial interventions in the urban space, the aim of the paper is to dissect the modes in which spatial practitioners operate in the digital city through ＂Urban Machines＂ and how information technology becomes a tool for place-making. The paper looks at integrated systems or machines that have spatial, social, and environmental implication in how we experience the city. Machines imply ＂something that has been constructed＂ and ＂function with a specific purpose＂ while being composed by parts that respond to a ＂functioning whole＂. These interventions start from sharing the same principle： How do we generate through technologically mediated experiences opportunities for new types of production of（social）space？; How such systems shape our urban experience and deploy forms of participation in civic life？.
