The reliability of electromechanical product is usually determined by the fault number and working time traditionally. The shortcoming of this method is that the product must be in service. To design and enhance the r...The reliability of electromechanical product is usually determined by the fault number and working time traditionally. The shortcoming of this method is that the product must be in service. To design and enhance the reliability of the electromechanical product, the reliability evaluation method must be feasible and correct. Reliability evaluation method and algorithm were proposed. The reliability of product can be calculated by the reliability of subsystems which can be gained by experiment or historical data. The reliability of the machining center was evaluated by the method and algorithm as one example. The calculation result shows that the solution accuracy of mean time between failures is 97.4% calculated by the method proposed in this article compared by the traditional method. The method and algorithm can be used to evaluate the reliability of electromechanical product before it is in service.展开更多
According to the basic requirements of underground mine personnel position systems and the working characteristics of active RFID tags,we studied the cause of concurrent collision of RFID tags and leak reading probabi...According to the basic requirements of underground mine personnel position systems and the working characteristics of active RFID tags,we studied the cause of concurrent collision of RFID tags and leak reading probability,by means of theoretical analysis and computation.The result shows that the probability of wireless collision increases linearly with an increase in the number of tags.The probability of collision and leak reading can be reduced by extending the working period of the duty cycle and using a backoff algorithm.In a practical application,a working schedule for available labels has been designed according to the requirement of the project.展开更多
Micromixing efficiency of viscous media in Y-type micro-channel reactor was studied by using iodide-iodate test reaction as working system.Experiments were carried out in water-glycerin mixtures with 7 different visco...Micromixing efficiency of viscous media in Y-type micro-channel reactor was studied by using iodide-iodate test reaction as working system.Experiments were carried out in water-glycerin mixtures with 7 different viscosities.The experimental results showed that segregation index of the micro-channel reactor increases with the decrease of volumetric flow rate and the increase of solution viscosity.Based on the incorporation model,the micromixing time tm of the micro-channel reactor was estimated in the range of 10-4-10-3s at different viscosities,which indicated that the micro-channel reactor possesses a much better micromixing performance compared to the stirred tank(tm=0.02-0.2s).展开更多
In 2012, an infestation of Asian Longhomed Beetle （ALB） was detected in Winterthur （Canton Zurich, Switzerland）. With more than 140 adult beetles and several hundred eggs and larvae, the infestation was by far the...In 2012, an infestation of Asian Longhomed Beetle （ALB） was detected in Winterthur （Canton Zurich, Switzerland）. With more than 140 adult beetles and several hundred eggs and larvae, the infestation was by far the most extensive in Switzerland. Based on long-term experiences made in Braunau （Austria）, where the first ALB infestation in Europe occured, the beetle was fought with extensive actions： removal of all infested trees, preventive removal of potential host trees and installation of a focus- and a buffer zone. Transport of plant material out of these zones was banned and a close monitoring regime including specialised dogs put in place. As a result of these efforts, there were no adult beetles and only a few living larvae detected 2013. Neither larvae nor beetles were found in 2014. However, costs are high： 700,000 Swiss francs were spent in 2012 alone, not including hundreds of working hours spent by employees of the Canton Zurich. The previewed monitoring programme between 2013 and 2017 is estimated to cost another 2.8 million Swiss francs, if no more living beetles are detected. The experiences from Winterthur thus show that elimination of a relatively small ALB infestation with determined actions is likely possible in short time. However, the high costs demonstrate the need for strong boarder controls or alternative packaging materials for imports from infested regions （China）. In addition, a concept for small communities with limited resources is needed.展开更多
An accounting professional is called a ＂Certified Public Accountant Financial Advisor （CPAFA）＂ in Turkey and the profession has a notable status in the country. Individuals choosing this profession have to complet...An accounting professional is called a ＂Certified Public Accountant Financial Advisor （CPAFA）＂ in Turkey and the profession has a notable status in the country. Individuals choosing this profession have to complete a minimum 3-year internship program before becoming members of this profession. They have to pass an exam both to start and finish the internship program. The profession and the reasons for choosing it are highly significant issues. Therefore, the present study was conducted to investigate the factors directing the professional choices of prospective individuals who wish to be CPAFAs and the significance of such factors. Along with these objectives, a nation-wide study was conducted on candidates who took the CPAFA internship exam in periods of 2012-3, 2013-1, and 2013-2 （three periods）. The factors affecting candidates＇ choices to be an accountant professional were gathered under five groups. The factors ＂influence of immediate surroundings＂, ＂prestigious social status of the profession＂, ＂high life-long income potential＂, ＂flexible working hours＂, and ＂future guarantee of the profession＂ had higher factor loadings than other factors.展开更多
基金Project(2013ZX04013047)supported by the Major Program of National Natural Science Foundation of ChinaProject(51275014)supported by the National Natural Science Foundation of China
文摘The reliability of electromechanical product is usually determined by the fault number and working time traditionally. The shortcoming of this method is that the product must be in service. To design and enhance the reliability of the electromechanical product, the reliability evaluation method must be feasible and correct. Reliability evaluation method and algorithm were proposed. The reliability of product can be calculated by the reliability of subsystems which can be gained by experiment or historical data. The reliability of the machining center was evaluated by the method and algorithm as one example. The calculation result shows that the solution accuracy of mean time between failures is 97.4% calculated by the method proposed in this article compared by the traditional method. The method and algorithm can be used to evaluate the reliability of electromechanical product before it is in service.
基金supported by the Fund of Coal Gas Sensing Technology and Early Warning Systems-Based Theory and Key Technology Research (No.50534050)
文摘According to the basic requirements of underground mine personnel position systems and the working characteristics of active RFID tags,we studied the cause of concurrent collision of RFID tags and leak reading probability,by means of theoretical analysis and computation.The result shows that the probability of wireless collision increases linearly with an increase in the number of tags.The probability of collision and leak reading can be reduced by extending the working period of the duty cycle and using a backoff algorithm.In a practical application,a working schedule for available labels has been designed according to the requirement of the project.
基金Supported by the National-Natural Science Foundation of China （20821004, 20806004） and the National High Technology Research and Development Program of China （2007AA030207, 2006AA030202, 2006AA030203）.
文摘Micromixing efficiency of viscous media in Y-type micro-channel reactor was studied by using iodide-iodate test reaction as working system.Experiments were carried out in water-glycerin mixtures with 7 different viscosities.The experimental results showed that segregation index of the micro-channel reactor increases with the decrease of volumetric flow rate and the increase of solution viscosity.Based on the incorporation model,the micromixing time tm of the micro-channel reactor was estimated in the range of 10-4-10-3s at different viscosities,which indicated that the micro-channel reactor possesses a much better micromixing performance compared to the stirred tank(tm=0.02-0.2s).
文摘In 2012, an infestation of Asian Longhomed Beetle （ALB） was detected in Winterthur （Canton Zurich, Switzerland）. With more than 140 adult beetles and several hundred eggs and larvae, the infestation was by far the most extensive in Switzerland. Based on long-term experiences made in Braunau （Austria）, where the first ALB infestation in Europe occured, the beetle was fought with extensive actions： removal of all infested trees, preventive removal of potential host trees and installation of a focus- and a buffer zone. Transport of plant material out of these zones was banned and a close monitoring regime including specialised dogs put in place. As a result of these efforts, there were no adult beetles and only a few living larvae detected 2013. Neither larvae nor beetles were found in 2014. However, costs are high： 700,000 Swiss francs were spent in 2012 alone, not including hundreds of working hours spent by employees of the Canton Zurich. The previewed monitoring programme between 2013 and 2017 is estimated to cost another 2.8 million Swiss francs, if no more living beetles are detected. The experiences from Winterthur thus show that elimination of a relatively small ALB infestation with determined actions is likely possible in short time. However, the high costs demonstrate the need for strong boarder controls or alternative packaging materials for imports from infested regions （China）. In addition, a concept for small communities with limited resources is needed.
文摘An accounting professional is called a ＂Certified Public Accountant Financial Advisor （CPAFA）＂ in Turkey and the profession has a notable status in the country. Individuals choosing this profession have to complete a minimum 3-year internship program before becoming members of this profession. They have to pass an exam both to start and finish the internship program. The profession and the reasons for choosing it are highly significant issues. Therefore, the present study was conducted to investigate the factors directing the professional choices of prospective individuals who wish to be CPAFAs and the significance of such factors. Along with these objectives, a nation-wide study was conducted on candidates who took the CPAFA internship exam in periods of 2012-3, 2013-1, and 2013-2 （three periods）. The factors affecting candidates＇ choices to be an accountant professional were gathered under five groups. The factors ＂influence of immediate surroundings＂, ＂prestigious social status of the profession＂, ＂high life-long income potential＂, ＂flexible working hours＂, and ＂future guarantee of the profession＂ had higher factor loadings than other factors.
