Cloud computing is one of the fastest growing and popular computer technologies, and there are more and more enterprise services based on the cloud computing. In order to save costs, more and more enterprises and thei...Cloud computing is one of the fastest growing and popular computer technologies, and there are more and more enterprise services based on the cloud computing. In order to save costs, more and more enterprises and their employees have hired the enterprise cloud services, and put much important information in the cloud gradually. Cloud service systems have become the main targets of malicious attacks. However, the cloud computing technologies are still not perfect, and the management and maintenance of enterprise cloud services are more complex compared to traditional network services of cloud computing. So, enterprise cloud services are more likely to encounter some security problems, and the influenced scale of these security problems is broad. But there are few researches on the security of enterprise cloud services. In this paper, we analyze the software as a service（Saa S） enterprise cloud services and introduce the research status of security problems in cloud computing environment. Combining with the analysis of the characteristics and application architecture of Saa S enterprise cloud services, we propose the security problems analysis model, the analysis system architecture and the relational model. Our researches can support further research of the automatic generation of solutions and guide the deployment of security policies of Saa S enterprise cloud services.展开更多
Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplant...Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.展开更多
基金supported by National Natural Science Foundation of China(Nos.61300049,61502197 and 61503044)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120061120059)+2 种基金the China Postdoctoral Science Foundation(No.2011M500612)the Key Program for Science and Technology Development of Jilin Province of China(No.20130206052GX)the Natural Science Research Foundation of Jilin Province of China(Nos.20140520069JH,20150101054JC and 20150520058JH)
文摘Cloud computing is one of the fastest growing and popular computer technologies, and there are more and more enterprise services based on the cloud computing. In order to save costs, more and more enterprises and their employees have hired the enterprise cloud services, and put much important information in the cloud gradually. Cloud service systems have become the main targets of malicious attacks. However, the cloud computing technologies are still not perfect, and the management and maintenance of enterprise cloud services are more complex compared to traditional network services of cloud computing. So, enterprise cloud services are more likely to encounter some security problems, and the influenced scale of these security problems is broad. But there are few researches on the security of enterprise cloud services. In this paper, we analyze the software as a service（Saa S） enterprise cloud services and introduce the research status of security problems in cloud computing environment. Combining with the analysis of the characteristics and application architecture of Saa S enterprise cloud services, we propose the security problems analysis model, the analysis system architecture and the relational model. Our researches can support further research of the automatic generation of solutions and guide the deployment of security policies of Saa S enterprise cloud services.
文摘Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.
