In this paper we consider data transmission in a decode-and-forward(DF)relay-assisted network in which the relay is energy harvesting(EH) powered while the base station(BS) is power-grid powered.Our purpose is to maxi...In this paper we consider data transmission in a decode-and-forward(DF)relay-assisted network in which the relay is energy harvesting(EH) powered while the base station(BS) is power-grid powered.Our purpose is to maximize the BS's energy efficiency(EE) while making full use of the relay's renewable energy and satisfying the specific average throughput requirements.In contrast to existing literature on energy harvesting system which only considers the radio transmission power,we take the static circuit power into account as well.We formulate the EE optimization problem and prove that the EE of the BS and relay are both quasiconvex in the instantaneous transmission rate.Then we divide the complex optimization problem into two point-to-point link level optimization parts and propose an energyefficient resource allocation(EERA) scheme in which power control and sleep mode management are jointly used.The simulation results demonstrate that EERA may achieve good energy saving effects.We also compare the EE of an energy harvesting relay system with a power-grid powered one and provide more insight into the EE problem of energy harvesting relay system.展开更多
Air-gapped computers are isolated both logically and physically from all kinds of existing common communication channel, such as USB ports, wireless and wired net- works. Although the feasibility of infiltrating an ai...Air-gapped computers are isolated both logically and physically from all kinds of existing common communication channel, such as USB ports, wireless and wired net- works. Although the feasibility of infiltrating an air-gapped computer has been proved in recent years, data exfiltration from such sys- tems is still considered to be a challenging task. In this paper we present Powermittcr, a novel approach that can exfiltrate data through an air-gapped computer via its power adapter. Our method utilizes the switched-mode pow- er supply, which exists in all of the laptops, desktop computers and servers nowadays. We demonstrate that a malware can indirectly con- trol the electromagnetic emission frequency of the power supply by leveraging the CPU utili- zation. Furthermore, we show that the emitted signals can be received and demodulated by a dedicated device. We present the proof of con- cept design of the power covert channel and implement a prototype of Powermitter consist- ing of a transmitter and a receiver. The trans- mitter leaks out data by using a variant binary frequency shift keying modulation, and the emitted signal can be captured and decoded by software based virtual oscilloscope through such covert channel. We tested Powermitter on three different computers. The experiment re-suits show the feasibility of this power covert channel. We show that our method can also be used to leak data from different types of embedded systems which use switching power supply.展开更多
The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, ...The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, magnetic and thermal couplings from the constitutive circuitry. The consideration of these phenomena is very difficult at the design of the power supply. This paper presents two complementary methods based first on a circuitry model for the quantification of heat sources and secondly on finite element model for heat diffusion. This approach can help a designer in the goal of improving the performances and thermal stability of radar tied to the supply circuit subset.展开更多
Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to he...Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to help predict relative humidity （Rtt） and other environmental factors influence on sensitive circuitry in power electronic systems. The resistivity and permittivity of an insulator have been modeled using different water contents i.e. RH, such model also included the mechanical properties of the design. An application example of a high power density, high voltage DC-DC converter is used to verify the results.展开更多
基金supported by National programs for High Technology Research and Development(2012AA011402)National Basic Research Program of China(2012CB316002)National Nature Science Foundation of China(61172088)
文摘In this paper we consider data transmission in a decode-and-forward(DF)relay-assisted network in which the relay is energy harvesting(EH) powered while the base station(BS) is power-grid powered.Our purpose is to maximize the BS's energy efficiency(EE) while making full use of the relay's renewable energy and satisfying the specific average throughput requirements.In contrast to existing literature on energy harvesting system which only considers the radio transmission power,we take the static circuit power into account as well.We formulate the EE optimization problem and prove that the EE of the BS and relay are both quasiconvex in the instantaneous transmission rate.Then we divide the complex optimization problem into two point-to-point link level optimization parts and propose an energyefficient resource allocation(EERA) scheme in which power control and sleep mode management are jointly used.The simulation results demonstrate that EERA may achieve good energy saving effects.We also compare the EE of an energy harvesting relay system with a power-grid powered one and provide more insight into the EE problem of energy harvesting relay system.
基金supported by the National High Technology Research and Development Program of China ("863" Program) (Grant No. 2015AA016002)the National Basic Research Program of China ("973" Program) (Grant No. 2014CB340600)
文摘Air-gapped computers are isolated both logically and physically from all kinds of existing common communication channel, such as USB ports, wireless and wired net- works. Although the feasibility of infiltrating an air-gapped computer has been proved in recent years, data exfiltration from such sys- tems is still considered to be a challenging task. In this paper we present Powermittcr, a novel approach that can exfiltrate data through an air-gapped computer via its power adapter. Our method utilizes the switched-mode pow- er supply, which exists in all of the laptops, desktop computers and servers nowadays. We demonstrate that a malware can indirectly con- trol the electromagnetic emission frequency of the power supply by leveraging the CPU utili- zation. Furthermore, we show that the emitted signals can be received and demodulated by a dedicated device. We present the proof of con- cept design of the power covert channel and implement a prototype of Powermitter consist- ing of a transmitter and a receiver. The trans- mitter leaks out data by using a variant binary frequency shift keying modulation, and the emitted signal can be captured and decoded by software based virtual oscilloscope through such covert channel. We tested Powermitter on three different computers. The experiment re-suits show the feasibility of this power covert channel. We show that our method can also be used to leak data from different types of embedded systems which use switching power supply.
文摘The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, magnetic and thermal couplings from the constitutive circuitry. The consideration of these phenomena is very difficult at the design of the power supply. This paper presents two complementary methods based first on a circuitry model for the quantification of heat sources and secondly on finite element model for heat diffusion. This approach can help a designer in the goal of improving the performances and thermal stability of radar tied to the supply circuit subset.
文摘Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to help predict relative humidity （Rtt） and other environmental factors influence on sensitive circuitry in power electronic systems. The resistivity and permittivity of an insulator have been modeled using different water contents i.e. RH, such model also included the mechanical properties of the design. An application example of a high power density, high voltage DC-DC converter is used to verify the results.
