The energizing of large power transformers has long been considered a critical event in the operation of an electric power system. When a transformer is energized by the utility, a typical inrush current could be as h...The energizing of large power transformers has long been considered a critical event in the operation of an electric power system. When a transformer is energized by the utility, a typical inrush current could be as high as ten times its rated current. This could cause many problems from mechanical stress on transformer windings to harmonics injection, and system protection malfunction. There have been numerous researches focusing on calculation and mitigation of the transformer inrush current. With the development of smart grid, distributed generation from independent power producers (IPPs) is growing rapidly. This paper investigates the inrush current due to black start of an IPP system with several parallel transformers, through a simulation model in DIgSILENT Power Factory software. The study demonstrates that a single genset is capable of energizing a group of transformers since the overall inrush current is slightly above the inrush of the transformer directly connected to the generator. In addition, a simple method is proposed to mitigate the inrush current of the transformers using an auxiliary transformer.展开更多
Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access techno...Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access technologies on universal access indicators.The proposed work demonstrates the possibility of inter-working of all existing Radio Access Technologies(RATs),in a limited area presented in the Six Generation Radio Resources Allocation(6 G-A)network.We propose a solution for the Vertical hand Over(VHO)in 6 G-A heterogeneous system,that adopts Media Independent Handover(MIH)protocol to benefit between different used technologies in a direct communication firstly and facilitate,in addition,coordination between congestion controlmechanisms with themobilitymanagement entity.The mathematical model has been developed to deal with locality coverage and broadband needs,based on a methodological approach consisting in integrating parameters linked to access index through radio technologies.This approach has been applied.In practice,it has contributed to highlighting its relative simplicity of implementation,but it is not enough for sixgeneration system radio access networks.The congestion control mechanism is integrated within the vertical handover process,this proposition is used to prevent each presented congestion state.The media independent handover IS equipment,as well as six G-A equipment which are both considered as the whole architecture key equipment,perform and guaranty this related process.Efficient communication is established besides information exchange between various technologies.Achieved evaluation results are performant and prove that proposed mechanisms are efficient.Both simulation and tests results are accomplished.展开更多
Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of whic...Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of which emerge as outbreaks. In such situations, discovery of novel viruses is utmost important for deciding prevention and treatment strategies. Since last century, a number of different virus discovery methods, based on cell culture inoculation, sequence-independent PCR have been used for identification of a variety of viruses. However, the recent emergence and commercial availability of nextgeneration sequencers(NGS) has entirely changed the field of virus discovery. These massively parallel sequencing platforms can sequence a mixture of genetic materials from a very heterogeneous mix, with high sensitivity. Moreover, these platforms work in a sequenceindependent manner, making them ideal tools for virus discovery. However, for their application in clinics, sample preparation or enrichment is necessary to detect low abundance virus populations. A number of techniques have also been developed for enrichment or viral nucleic acids. In this manuscript, we review the evolution of sequencing; NGS technologies available today as well as widely used virus enrichment technologies. We also discuss the challenges associated with their applications in the clinical virus discovery.展开更多
Measurement-device-independent quantum key distribution(MDI-QKD)provides us a powerful approach to resist all attacks at detection side.Besides the unconditional security,people also seek for high key generation rate,...Measurement-device-independent quantum key distribution(MDI-QKD)provides us a powerful approach to resist all attacks at detection side.Besides the unconditional security,people also seek for high key generation rate,but MDI-QKD has relatively low key generation rate.In this paper,we provide an efficient approach to increase the key generation rate of MDI-QKD by adopting multiple degrees of freedom(DOFs)of single photons to generate keys.Compared with other high-dimension MDI-QKD protocols encoding in one DOF,our protocol is more flexible,for our protocol generating keys in independent subsystems and the detection failure or error in a DOF not affecting the information encoding in other DOFs.Based on above features,our MDI-QKD protocol may have potential application in future quantum comniunication field.展开更多
文摘The energizing of large power transformers has long been considered a critical event in the operation of an electric power system. When a transformer is energized by the utility, a typical inrush current could be as high as ten times its rated current. This could cause many problems from mechanical stress on transformer windings to harmonics injection, and system protection malfunction. There have been numerous researches focusing on calculation and mitigation of the transformer inrush current. With the development of smart grid, distributed generation from independent power producers (IPPs) is growing rapidly. This paper investigates the inrush current due to black start of an IPP system with several parallel transformers, through a simulation model in DIgSILENT Power Factory software. The study demonstrates that a single genset is capable of energizing a group of transformers since the overall inrush current is slightly above the inrush of the transformer directly connected to the generator. In addition, a simple method is proposed to mitigate the inrush current of the transformers using an auxiliary transformer.
文摘Several assessing efforts are approved making both communication and information technologies available.In addition to being a part of universal access and service,we aim at assessing the impact of radio access technologies on universal access indicators.The proposed work demonstrates the possibility of inter-working of all existing Radio Access Technologies(RATs),in a limited area presented in the Six Generation Radio Resources Allocation(6 G-A)network.We propose a solution for the Vertical hand Over(VHO)in 6 G-A heterogeneous system,that adopts Media Independent Handover(MIH)protocol to benefit between different used technologies in a direct communication firstly and facilitate,in addition,coordination between congestion controlmechanisms with themobilitymanagement entity.The mathematical model has been developed to deal with locality coverage and broadband needs,based on a methodological approach consisting in integrating parameters linked to access index through radio technologies.This approach has been applied.In practice,it has contributed to highlighting its relative simplicity of implementation,but it is not enough for sixgeneration system radio access networks.The congestion control mechanism is integrated within the vertical handover process,this proposition is used to prevent each presented congestion state.The media independent handover IS equipment,as well as six G-A equipment which are both considered as the whole architecture key equipment,perform and guaranty this related process.Efficient communication is established besides information exchange between various technologies.Achieved evaluation results are performant and prove that proposed mechanisms are efficient.Both simulation and tests results are accomplished.
基金Supported by The author’s laboratory is supported by the Defence Research and Development Organization(DRDO),Ministry of Defence,Government of India
文摘Viruses are a cause of significant health problem world-wide, especially in the developing nations. Due to different anthropological activities, human populations are exposed to different viral pathogens, many of which emerge as outbreaks. In such situations, discovery of novel viruses is utmost important for deciding prevention and treatment strategies. Since last century, a number of different virus discovery methods, based on cell culture inoculation, sequence-independent PCR have been used for identification of a variety of viruses. However, the recent emergence and commercial availability of nextgeneration sequencers(NGS) has entirely changed the field of virus discovery. These massively parallel sequencing platforms can sequence a mixture of genetic materials from a very heterogeneous mix, with high sensitivity. Moreover, these platforms work in a sequenceindependent manner, making them ideal tools for virus discovery. However, for their application in clinics, sample preparation or enrichment is necessary to detect low abundance virus populations. A number of techniques have also been developed for enrichment or viral nucleic acids. In this manuscript, we review the evolution of sequencing; NGS technologies available today as well as widely used virus enrichment technologies. We also discuss the challenges associated with their applications in the clinical virus discovery.
基金supported by the National Natural Science Foundation of China under Grant Nos.11974189,12005106the Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant No.SJCX19-0241a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Measurement-device-independent quantum key distribution(MDI-QKD)provides us a powerful approach to resist all attacks at detection side.Besides the unconditional security,people also seek for high key generation rate,but MDI-QKD has relatively low key generation rate.In this paper,we provide an efficient approach to increase the key generation rate of MDI-QKD by adopting multiple degrees of freedom(DOFs)of single photons to generate keys.Compared with other high-dimension MDI-QKD protocols encoding in one DOF,our protocol is more flexible,for our protocol generating keys in independent subsystems and the detection failure or error in a DOF not affecting the information encoding in other DOFs.Based on above features,our MDI-QKD protocol may have potential application in future quantum comniunication field.
