This paper aims to discuss how the shaping of a city, Juiz de Fora, in Brazil, has resulted from the power of location of some social agents and from their disputes on the production of space. First, it introduces the...This paper aims to discuss how the shaping of a city, Juiz de Fora, in Brazil, has resulted from the power of location of some social agents and from their disputes on the production of space. First, it introduces the concept of social production of space, emphasizing the role of social agents in urban processes. Then, it presents specific aspects of the history of Juiz de Fora＂ its origins and how social agents and forces have played a significant role in shaping the built environment of the city--specially represented by main streets of the city. The paper studies how the social agents, with their different visions and goals, have influenced the process of formation and development of the city. This demonstrates the complexity of the existing relationships between the built environment and the social context that is specific to the city. Different urban forces fight for city spaces, construct and modify its territory so that their needs are fulfilled. Their strength, their experiences and efforts, and their ideas of a city are inscribed in urban landscapes; in similar ways, these are revealed by the city paths we follow here.展开更多
Using GIS, GPS, GPRS and RFID, a dynamic information management system of digital mining in an open pit was designed and developed.A linear programming model was set up in a practical application.By the model, the sys...Using GIS, GPS, GPRS and RFID, a dynamic information management system of digital mining in an open pit was designed and developed.A linear programming model was set up in a practical application.By the model, the system can automatically draw up production plan of ore blending well every day.The system can monitor and dispatch open-pit trucks and shovels well, and can play back their historical paths.It can monitor and control the process of mining production in real time.By RFID, the system can also count the number of trucks'delivery and shovels'loading automatically.Experiments on real scenes show that the performance of this system is stable and can satisfy production standards of mining in open pits.展开更多
One of the surface mining methods is open-pit mining,by which a pit is dug to extract ore or waste downwards from the earth’s surface.In the mining industry,one of the most significant difficulties is long-term produ...One of the surface mining methods is open-pit mining,by which a pit is dug to extract ore or waste downwards from the earth’s surface.In the mining industry,one of the most significant difficulties is long-term production scheduling(LTPS)of the open-pit mines.Deterministic and uncertainty-based approaches are identified as the main strategies,which have been widely used to cope with this problem.Within the last few years,many researchers have highly considered a new computational type,which is less costly,i.e.,meta-heuristic methods,so as to solve the mine design and production scheduling problem.Although the optimality of the final solution cannot be guaranteed,they are able to produce sufficiently good solutions with relatively less computational costs.In the present paper,two hybrid models between augmented Lagrangian relaxation(ALR)and a particle swarm optimization(PSO)and ALR and bat algorithm(BA)are suggested so that the LTPS problem is solved under the condition of grade uncertainty.It is suggested to carry out the ALR method on the LTPS problem to improve its performance and accelerate the convergence.Moreover,the Lagrangian coefficients are updated by using PSO and BA.The presented models have been compared with the outcomes of the ALR-genetic algorithm,the ALR-traditional sub-gradient method,and the conventional method without using the Lagrangian approach.The results indicated that the ALR is considered a more efficient approach which can solve a large-scale problem and make a valid solution.Hence,it is more effectual than the conventional method.Furthermore,the time and cost of computation are diminished by the proposed hybrid strategies.The CPU time using the ALR-BA method is about 7.4%higher than the ALR-PSO approach.展开更多
In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase o...In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.展开更多
文摘This paper aims to discuss how the shaping of a city, Juiz de Fora, in Brazil, has resulted from the power of location of some social agents and from their disputes on the production of space. First, it introduces the concept of social production of space, emphasizing the role of social agents in urban processes. Then, it presents specific aspects of the history of Juiz de Fora＂ its origins and how social agents and forces have played a significant role in shaping the built environment of the city--specially represented by main streets of the city. The paper studies how the social agents, with their different visions and goals, have influenced the process of formation and development of the city. This demonstrates the complexity of the existing relationships between the built environment and the social context that is specific to the city. Different urban forces fight for city spaces, construct and modify its territory so that their needs are fulfilled. Their strength, their experiences and efforts, and their ideas of a city are inscribed in urban landscapes; in similar ways, these are revealed by the city paths we follow here.
基金Supported by Shannxi Leading Academic Discipline ProjectShannxi Science and Technology Project(the Key Industries R&D Programme)(2009K08-25)
文摘Using GIS, GPS, GPRS and RFID, a dynamic information management system of digital mining in an open pit was designed and developed.A linear programming model was set up in a practical application.By the model, the system can automatically draw up production plan of ore blending well every day.The system can monitor and dispatch open-pit trucks and shovels well, and can play back their historical paths.It can monitor and control the process of mining production in real time.By RFID, the system can also count the number of trucks'delivery and shovels'loading automatically.Experiments on real scenes show that the performance of this system is stable and can satisfy production standards of mining in open pits.
文摘One of the surface mining methods is open-pit mining,by which a pit is dug to extract ore or waste downwards from the earth’s surface.In the mining industry,one of the most significant difficulties is long-term production scheduling(LTPS)of the open-pit mines.Deterministic and uncertainty-based approaches are identified as the main strategies,which have been widely used to cope with this problem.Within the last few years,many researchers have highly considered a new computational type,which is less costly,i.e.,meta-heuristic methods,so as to solve the mine design and production scheduling problem.Although the optimality of the final solution cannot be guaranteed,they are able to produce sufficiently good solutions with relatively less computational costs.In the present paper,two hybrid models between augmented Lagrangian relaxation(ALR)and a particle swarm optimization(PSO)and ALR and bat algorithm(BA)are suggested so that the LTPS problem is solved under the condition of grade uncertainty.It is suggested to carry out the ALR method on the LTPS problem to improve its performance and accelerate the convergence.Moreover,the Lagrangian coefficients are updated by using PSO and BA.The presented models have been compared with the outcomes of the ALR-genetic algorithm,the ALR-traditional sub-gradient method,and the conventional method without using the Lagrangian approach.The results indicated that the ALR is considered a more efficient approach which can solve a large-scale problem and make a valid solution.Hence,it is more effectual than the conventional method.Furthermore,the time and cost of computation are diminished by the proposed hybrid strategies.The CPU time using the ALR-BA method is about 7.4%higher than the ALR-PSO approach.
文摘In the prostate cancer treatment, brachytherapy with iodine-125 seeds has been used. lodine-125 seeds are sealed radioactive sources, made by a titanium capsule containing the radioisotope inside. In the final phase of the seeds production, it is necessary to ensure that there is no leakage of the radioactive material. A leakage test is performed, immersing the seeds in water during 24 h and measuring the resulting activity in the water. This measurement is made in a sodium iodide detector. The immersion water is transferred to a plastic tube with a cap. The tube is placed by an automated positioning system, in the detector chamber. This study aims to determine the best positioning of the tube for the detection. It is also important to determine the influence of the positioning variation intrinsic of the automated positioning system during the iodine-125 seeds production. The results obtained will be used as a reference to adjust the equipment and process control system, in the production of the iodine-125 seeds.
