Several key techniques for a PLL-type frequency synthesizer for WLAN receivers are studied. Its structure is analyzed and the main parameters are proposed. A monolithic LC-tuned voltage controlled oscillator （LCVCO）...Several key techniques for a PLL-type frequency synthesizer for WLAN receivers are studied. Its structure is analyzed and the main parameters are proposed. A monolithic LC-tuned voltage controlled oscillator （LCVCO） with low phase noise is fabricated with TSMC 0.18μm RF （radio frequency） CMOS technology. The measured phase noise is - ll7dBc/Hz at 4MHz off the center frequency of 4. 189GHz. A down-scaling circuit with low power dissipation was fabricated in a TSMC 0.18μm mixed-signal CMOS process. The measured results show that the IC can work well under a 1.8V power supply. Its total power dissipation is only 13mW.展开更多
Objective To investigate the risk factors of symptomatic bradyarrhythrnias in relation to β-blockers use. Methods A hospital-based case-control study [228 patients： 108 with symptomatic bradyarrhythmias （cases） an...Objective To investigate the risk factors of symptomatic bradyarrhythrnias in relation to β-blockers use. Methods A hospital-based case-control study [228 patients： 108 with symptomatic bradyarrhythmias （cases） and 120 controls] was conducted in Sultanah Aminah Hospital, Malaysia between January 2011 and January 2014. Results The mean age was 61.1 ~ 13.3 years with a majority of men （68.9%）. Cases were likely than control to be older, hypertensive, lower body mass index and concomitant use of rate-controlling drugs （such as digoxin, verapamil, diltiazem, ivabradine or amiodarone）. Significantly higher level of serum potassium, urea, creatinine and lower level of estimated glomerular filtration rate （eGFR） were observed among cases as compared to controls. On univariate analysis among patients on β-blockers, older age （crude OR： 1.07; 95% CI： 1.03-1.11, P = 0.000）, hypertension （crude OR： 5.6; 95% CI： 1.51-20.72, P = 0.010）, lower sodium （crude OR： 0.04; 95% CI： 0.81-0.99, P = 0.036）, higher potassium （crude OR： 2.36; 95% CI： 1.31-4.26, P = 0.004） and higher urea （crude OR： 1.23; 95% CI： 1.11-1.38, P = 0.000） were associated with increased risk of symptomatic bradyarrhythmias; eGFR was inversely and significantly associated with symptomatic bradyarrhythmias in both ＇β-blockers＇ （crude OR： 0.97; 95% CI： 0.964）.98, P = 0.000） and ＇non-β-blockers＇ （crude OR： 0.99; 95% CI： 0.97-0.99, P = 0.023） arms. However, eGFR was not significantly associated with symptomatic bradyarrhythmias in the final model of both ＇β-blockers＇ （adjusted OR： 0.98; 95% CI： 0.96-0.98, P = 0.103） and ＇non-p-blockers＇ （adjusted OR： 0.99; 95% CI： 0.97-1.01, P = 0.328） arms. Importantly, older age was a significant predictor of symptomatic bradyarrhythmias in the ＇β-blockers＇ as compared to the ＇non-β-blockers＇ arms （adjusted OR： 1.09; 95% CI： 1.03-1.15, P = 0.003 vs. adjusted OR： 1.03; 95% CI： 0.98-1.09, P = 0.232, respectively）. Conclusion Older age was a significant predictor of symptomatic bradyarrhythmias in patients on β-blockers than those without β-blockers.展开更多
Software Defined Networking(SDN) is a revolutionary networking paradigm towards the future network,experiencing rapid development nowadays.However,its main characteristic,the separation of control plane and data plane...Software Defined Networking(SDN) is a revolutionary networking paradigm towards the future network,experiencing rapid development nowadays.However,its main characteristic,the separation of control plane and data plane,also brings about new security challenges,i.e.,Denial-of-Service(DoS) attacks specific to Open Flow SDN networks to exhaust the control plane bandwidth and overload the buffer memory of Open Flow switch.To mitigate the DoS attacks in the Open Flow networks,we design and implement SGuard,a security application on top of the NOX controller that mainly contains two modules:Access control module and Classification module.We employ novel six-tuple as feature vector to classify traffic flows,meanwhile optimizing classification by feature ranking and selecting algorithms.All the modules will cooperate with each other to complete a series of tasks such as authorization,classification and so on.At the end of this paper,we experimentally use Mininet to evaluate SGuard in a software environment.The results show that SGuard works efficiently and accurately without adding more overhead to the SDN networks.展开更多
In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovi...In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovician is studied according to the well drilling,logging,geophysical data,detailed observations of core and the paleontology.The Lianglitage formation belongs to the sequence Ⅳ of Ordovician.The second member of Lianglitage formation is prograde sedimentation in highstand systems tract,and is favorable for developing reef flat.The development scale and thickness of reef flat are controlled by the variation of secondary sea level.The types and characteristics of karst in the highstand systems tract show that the late highstand systems tract is dissolved and cemented by the meteoric fresh water and mixed water.Penecontemporaneous karstification is developed at the top of parasequence and high place of geomorphology.Atmospheric diagenetic lens is formed.The developing regulations and controlling factors of penecontemporaneous karstification can provide new clues to the prediction and exploration of favorable reservoir in this area.展开更多
Compact, hot-pluggable, and data-agnostic, SFP modules bring up to 4.25 Gbps to a flexible new form factor. The SFP transceiver which is the core device of optical communication is always the research focus in the fie...Compact, hot-pluggable, and data-agnostic, SFP modules bring up to 4.25 Gbps to a flexible new form factor. The SFP transceiver which is the core device of optical communication is always the research focus in the field of optical communication for both telecommunication and data communication applications. The working principles of SFP including the transmitter components, the receiver components and the microcontroller are discussed in detail. The basic theory of high-speed signal and the concept of high - speed circuit, high-speed board design techniques are presented. A new design of high performance, cost effective SFP transceiver and PCB layout are also presented. The performance of the transceiver is analyzed and the characteristics of the sample are coincident with the expected ones. The status of the transceiver can be monitored and controlled by F C bus through the interface in real time. This transceiver can meet the requirement of SFF-8472.展开更多
In this paper, we propose a novel, 3D, like cubic shape, modular self-reconfigurable (MSR) robot named M-Cubes. Its key mechanical components are analyzed in detail. By communicating with the neighboring modules, each...In this paper, we propose a novel, 3D, like cubic shape, modular self-reconfigurable (MSR) robot named M-Cubes. Its key mechanical components are analyzed in detail. By communicating with the neighboring modules, each unit employs its automatic lock device composed of a pin and a hole on each connection plane which can connect or disconnect with neighboring modules. The M-Cubes system consisting of many identical modules cooperates to change their connection, and then the whole structure transforms into arbitrary structure. Furthermore, we describe its locomotion control based on the driving function and the adjacency matrix which is effective for solving the computationally difficult problem and optimizing the system motion path during the self-reconfiguration process. Finally, a simulation experiment using java 3D technology, proved the new method for controlling modular robot is robust and useful.展开更多
Nowadays, in a household PV （photovoltaic） generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wron...Nowadays, in a household PV （photovoltaic） generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wrong MPPT （maximum power point tracking） to all modules and a power decreasing of the whole system. Aiming at this problem, this paper presents the idea which improves the MPPT without changing the conventional power-conditioner, by adding a Buck type DC-DC （direct current） converter behind each module. Simulations of PSIM （power simulation） and experiments are taken to prove this theory. The result shows that, by this idea, the generated power of the conventional PV generation system can be greatly increased under the condition of mismatch.展开更多
Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular...Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular high temperature gas-cooled reactor(MHTGR) is considered as one of the best candidates for SMR-based nuclear power plants. Since its dynamics presents high nonlinearity and parameter uncertainty, it is necessary to develop adaptive power-level control, which is beneficial to safe, stable, and efficient operation of MHTGR and is easy to be implemented. In this paper, based on the physically-based control design approach, an adaptive outputfeedback power-level control is proposed for MHTGRs. This control can guarantee globally bounded closedloop stability and has a simple form. Numerical simulation results show the correctness of the theoretical analysis and satisfactory regulation performance of this control.展开更多
A source apportionment tool,ISAM （Integrated Source Apportionment Method）,coupled with a regional air quality modeling system,RAMS-CMAQ （Regional Atmospheric Modeling System and Community Multiscale Air Quality）,w...A source apportionment tool,ISAM （Integrated Source Apportionment Method）,coupled with a regional air quality modeling system,RAMS-CMAQ （Regional Atmospheric Modeling System and Community Multiscale Air Quality）,was applied to simulate the major aerosol components （sulfate,nitrate,ammonium,black carbon,organic carbon,dust,and sea salt） and investigate the impact of local and regional sources on the PM2.5 （particulate matter with an aerodynamic diameter less than 2.5 μm） mass concentration over the North China Plain （NCP） in July 2016.The simulation results indicated that the high mass burden of PM2.5 mainly appeared in the south part of Hebei and west part of Shandong.The PM2.5 particles emitted from Beijing and Tianjin were just concentrated in the local area,but Hebei and Shandong were the dominant source over the NCP.Focusing on Beijing,the local contribution was just 20%-30% due to the emissions control strategies executed in recent years in Beijing.The pollutants derived from Hebei and Shandong were major contributors,providing more than 25% and 10% to the PM2.5 mass concentration in Beijing,respectively.Moreover,the surrounding regions showed larger contributions against the pollution background.The contribution percentage from Hebei and Shandong increased in both cases when the air quality became worse.Thus,it is suggested that comprehensive control strategies should be implemented based on coordinated control of emissions at the regional scale in Beijing,especially during pollution periods.展开更多
This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical acc...This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical access based on the hand veins has been used with a complete local and remote access control system. A technologically ergonomic way to control the house, as well as some biological signal monitoring has also been developed. This has been done by knowing the physical restrictions of the collective who will live in the house. A set of different sensors will control this operation. In order to control all the home automated systems coordinate the whole platform using the TV remote. This project will implement the OSGI standard. This implementation should ensure the system scalability in terms of including new hardware. In addition, a ZibBee networking system has been developed to enable communication between all the sensors, systems and the central processor.展开更多
文摘Several key techniques for a PLL-type frequency synthesizer for WLAN receivers are studied. Its structure is analyzed and the main parameters are proposed. A monolithic LC-tuned voltage controlled oscillator （LCVCO） with low phase noise is fabricated with TSMC 0.18μm RF （radio frequency） CMOS technology. The measured phase noise is - ll7dBc/Hz at 4MHz off the center frequency of 4. 189GHz. A down-scaling circuit with low power dissipation was fabricated in a TSMC 0.18μm mixed-signal CMOS process. The measured results show that the IC can work well under a 1.8V power supply. Its total power dissipation is only 13mW.
文摘Objective To investigate the risk factors of symptomatic bradyarrhythrnias in relation to β-blockers use. Methods A hospital-based case-control study [228 patients： 108 with symptomatic bradyarrhythmias （cases） and 120 controls] was conducted in Sultanah Aminah Hospital, Malaysia between January 2011 and January 2014. Results The mean age was 61.1 ~ 13.3 years with a majority of men （68.9%）. Cases were likely than control to be older, hypertensive, lower body mass index and concomitant use of rate-controlling drugs （such as digoxin, verapamil, diltiazem, ivabradine or amiodarone）. Significantly higher level of serum potassium, urea, creatinine and lower level of estimated glomerular filtration rate （eGFR） were observed among cases as compared to controls. On univariate analysis among patients on β-blockers, older age （crude OR： 1.07; 95% CI： 1.03-1.11, P = 0.000）, hypertension （crude OR： 5.6; 95% CI： 1.51-20.72, P = 0.010）, lower sodium （crude OR： 0.04; 95% CI： 0.81-0.99, P = 0.036）, higher potassium （crude OR： 2.36; 95% CI： 1.31-4.26, P = 0.004） and higher urea （crude OR： 1.23; 95% CI： 1.11-1.38, P = 0.000） were associated with increased risk of symptomatic bradyarrhythmias; eGFR was inversely and significantly associated with symptomatic bradyarrhythmias in both ＇β-blockers＇ （crude OR： 0.97; 95% CI： 0.964）.98, P = 0.000） and ＇non-β-blockers＇ （crude OR： 0.99; 95% CI： 0.97-0.99, P = 0.023） arms. However, eGFR was not significantly associated with symptomatic bradyarrhythmias in the final model of both ＇β-blockers＇ （adjusted OR： 0.98; 95% CI： 0.96-0.98, P = 0.103） and ＇non-p-blockers＇ （adjusted OR： 0.99; 95% CI： 0.97-1.01, P = 0.328） arms. Importantly, older age was a significant predictor of symptomatic bradyarrhythmias in the ＇β-blockers＇ as compared to the ＇non-β-blockers＇ arms （adjusted OR： 1.09; 95% CI： 1.03-1.15, P = 0.003 vs. adjusted OR： 1.03; 95% CI： 0.98-1.09, P = 0.232, respectively）. Conclusion Older age was a significant predictor of symptomatic bradyarrhythmias in patients on β-blockers than those without β-blockers.
基金supported by the National key Research and Development Program of China(No.2016YFB0800100,2016YFB0800101)the National Natural Science Fund for Creative Research Groups Project(No.61521003)the National Natural Science Fund for Youth Found Project(No.61602509)
文摘Software Defined Networking(SDN) is a revolutionary networking paradigm towards the future network,experiencing rapid development nowadays.However,its main characteristic,the separation of control plane and data plane,also brings about new security challenges,i.e.,Denial-of-Service(DoS) attacks specific to Open Flow SDN networks to exhaust the control plane bandwidth and overload the buffer memory of Open Flow switch.To mitigate the DoS attacks in the Open Flow networks,we design and implement SGuard,a security application on top of the NOX controller that mainly contains two modules:Access control module and Classification module.We employ novel six-tuple as feature vector to classify traffic flows,meanwhile optimizing classification by feature ranking and selecting algorithms.All the modules will cooperate with each other to complete a series of tasks such as authorization,classification and so on.At the end of this paper,we experimentally use Mininet to evaluate SGuard in a software environment.The results show that SGuard works efficiently and accurately without adding more overhead to the SDN networks.
基金Project(2008ZX05004-004)supported by the State Key Scientific Research Programs,ChinaProject(SZD0414)supported by the Sichuan Province Key Discipline Construction Project,ChinaProject(KZCX2-YW-Q05-01)supported by the Chinese Academy of Sciences Innovation Engineering Directional Project
文摘In order to reveal the relationship between the penecontemporaneous karstification and sedimentary microtopography in sequence stratigraphy,the sequence stratigraphic framework of Lianglitage formation in Upper Ordovician is studied according to the well drilling,logging,geophysical data,detailed observations of core and the paleontology.The Lianglitage formation belongs to the sequence Ⅳ of Ordovician.The second member of Lianglitage formation is prograde sedimentation in highstand systems tract,and is favorable for developing reef flat.The development scale and thickness of reef flat are controlled by the variation of secondary sea level.The types and characteristics of karst in the highstand systems tract show that the late highstand systems tract is dissolved and cemented by the meteoric fresh water and mixed water.Penecontemporaneous karstification is developed at the top of parasequence and high place of geomorphology.Atmospheric diagenetic lens is formed.The developing regulations and controlling factors of penecontemporaneous karstification can provide new clues to the prediction and exploration of favorable reservoir in this area.
文摘Compact, hot-pluggable, and data-agnostic, SFP modules bring up to 4.25 Gbps to a flexible new form factor. The SFP transceiver which is the core device of optical communication is always the research focus in the field of optical communication for both telecommunication and data communication applications. The working principles of SFP including the transmitter components, the receiver components and the microcontroller are discussed in detail. The basic theory of high-speed signal and the concept of high - speed circuit, high-speed board design techniques are presented. A new design of high performance, cost effective SFP transceiver and PCB layout are also presented. The performance of the transceiver is analyzed and the characteristics of the sample are coincident with the expected ones. The status of the transceiver can be monitored and controlled by F C bus through the interface in real time. This transceiver can meet the requirement of SFF-8472.
基金Project (No. 50305021) supported by the National Natural ScienceFoundation of China
文摘In this paper, we propose a novel, 3D, like cubic shape, modular self-reconfigurable (MSR) robot named M-Cubes. Its key mechanical components are analyzed in detail. By communicating with the neighboring modules, each unit employs its automatic lock device composed of a pin and a hole on each connection plane which can connect or disconnect with neighboring modules. The M-Cubes system consisting of many identical modules cooperates to change their connection, and then the whole structure transforms into arbitrary structure. Furthermore, we describe its locomotion control based on the driving function and the adjacency matrix which is effective for solving the computationally difficult problem and optimizing the system motion path during the self-reconfiguration process. Finally, a simulation experiment using java 3D technology, proved the new method for controlling modular robot is robust and useful.
文摘Nowadays, in a household PV （photovoltaic） generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wrong MPPT （maximum power point tracking） to all modules and a power decreasing of the whole system. Aiming at this problem, this paper presents the idea which improves the MPPT without changing the conventional power-conditioner, by adding a Buck type DC-DC （direct current） converter behind each module. Simulations of PSIM （power simulation） and experiments are taken to prove this theory. The result shows that, by this idea, the generated power of the conventional PV generation system can be greatly increased under the condition of mismatch.
文摘Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular high temperature gas-cooled reactor(MHTGR) is considered as one of the best candidates for SMR-based nuclear power plants. Since its dynamics presents high nonlinearity and parameter uncertainty, it is necessary to develop adaptive power-level control, which is beneficial to safe, stable, and efficient operation of MHTGR and is easy to be implemented. In this paper, based on the physically-based control design approach, an adaptive outputfeedback power-level control is proposed for MHTGRs. This control can guarantee globally bounded closedloop stability and has a simple form. Numerical simulation results show the correctness of the theoretical analysis and satisfactory regulation performance of this control.
基金supported by the National Basic Research Program of China[grant number 2014CB953802]the National Natural Science Foundation of China[grant number 91544221],[grant number 41475098]the Russian Scientific Fund[grant number 14-47-00049]
文摘A source apportionment tool,ISAM （Integrated Source Apportionment Method）,coupled with a regional air quality modeling system,RAMS-CMAQ （Regional Atmospheric Modeling System and Community Multiscale Air Quality）,was applied to simulate the major aerosol components （sulfate,nitrate,ammonium,black carbon,organic carbon,dust,and sea salt） and investigate the impact of local and regional sources on the PM2.5 （particulate matter with an aerodynamic diameter less than 2.5 μm） mass concentration over the North China Plain （NCP） in July 2016.The simulation results indicated that the high mass burden of PM2.5 mainly appeared in the south part of Hebei and west part of Shandong.The PM2.5 particles emitted from Beijing and Tianjin were just concentrated in the local area,but Hebei and Shandong were the dominant source over the NCP.Focusing on Beijing,the local contribution was just 20%-30% due to the emissions control strategies executed in recent years in Beijing.The pollutants derived from Hebei and Shandong were major contributors,providing more than 25% and 10% to the PM2.5 mass concentration in Beijing,respectively.Moreover,the surrounding regions showed larger contributions against the pollution background.The contribution percentage from Hebei and Shandong increased in both cases when the air quality became worse.Thus,it is suggested that comprehensive control strategies should be implemented based on coordinated control of emissions at the regional scale in Beijing,especially during pollution periods.
文摘This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical access based on the hand veins has been used with a complete local and remote access control system. A technologically ergonomic way to control the house, as well as some biological signal monitoring has also been developed. This has been done by knowing the physical restrictions of the collective who will live in the house. A set of different sensors will control this operation. In order to control all the home automated systems coordinate the whole platform using the TV remote. This project will implement the OSGI standard. This implementation should ensure the system scalability in terms of including new hardware. In addition, a ZibBee networking system has been developed to enable communication between all the sensors, systems and the central processor.
