Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimi...Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimize the outage probability with the harvested energy as constraints.Firstly,the optimal transmit power of the sensor is obtained while considering a single link between an access point(AP) located on the waist and a sensor attached on the wrist over the Rayleigh fading channel.Secondly,an optimization problem is formed to minimize the outage probability.Finally,we convert the non-convex optimization problem into convex solved by the Lagrange multiplier method.Simulations show that the optimization problem is solvable.The outage probability is optimized by performing power allocation at the sensor.And our proposed algorithm achieves minimizing the outage probability when the sensor uses energy harvesting.We also demonstrate that the average outage probability is reduced with the increase of the harvested energy.展开更多
In people’s daily life, the role of weatherforecast is self-evident. However, the accuracy offorecasting is based on the accuracy and reliability ofmeteorological data which depends on the sensitivityof meteorologica...In people’s daily life, the role of weatherforecast is self-evident. However, the accuracy offorecasting is based on the accuracy and reliability ofmeteorological data which depends on the sensitivityof meteorological device. Therefore, an importantduty of the detection institution of meteorologicalmetrical device is to have the effective detectionof meteorological device, so as to ensure a highsensitivity of the device. However, the meteorologicaldevice used by some meteorological bureaus is nottechnologically advanced and the device detectionmode is too old, which cannot meet the new regulationsissued by the China Meteorological Administration.So it is necessary for the meteorological bureau todevelop a set of devices that can easily meet the newmeteorological measurement requirements, which is ofgreat significance to ensure the accurate measurementof meteorological data.展开更多
Wired drill pipe(WDP)technology is one of the most promising data acquisition technologies in today s oil and gas industry.For the first time it allows sensors to be positioned along the drill string which enables c...Wired drill pipe(WDP)technology is one of the most promising data acquisition technologies in today s oil and gas industry.For the first time it allows sensors to be positioned along the drill string which enables collecting and transmitting valuable data not only from the bottom hole assembly(BHA),but also along the entire length of the wellbore to the drill floor.The technology has received industry acceptance as a viable alternative to the typical logging while drilling(LWD)method.Recently more and more WDP applications can be found in the challenging drilling environments around the world,leading to many innovations to the industry.Nevertheless most of the data acquired from WDP can be noisy and in some circumstances of very poor quality.Diverse factors contribute to the poor data quality.Most common sources include mis-calibrated sensors,sensor drifting,errors during data transmission,or some abnormal conditions in the well,etc.The challenge of improving the data quality has attracted more and more focus from many researchers during the past decade.This paper has proposed a promising solution to address such challenge by making corrections of the raw WDP data and estimating unmeasurable parameters to reveal downhole behaviors.An advanced data processing method,data validation and reconciliation(DVR)has been employed,which makes use of the redundant data from multiple WDP sensors to filter/remove the noise from the measurements and ensures the coherence of all sensors and models.Moreover it has the ability to distinguish the accurate measurements from the inaccurate ones.In addition,the data with improved quality can be used for estimating some crucial parameters in the drilling process which are unmeasurable in the first place,hence provide better model calibrations for integrated well planning and realtime operations.展开更多
文摘Wireless Body Area Networks(WBANs) are expected to achieve high reliable communications among a large number of sensors.The outage probability can be used to measure the reliability of the WBAN.In this paper,we optimize the outage probability with the harvested energy as constraints.Firstly,the optimal transmit power of the sensor is obtained while considering a single link between an access point(AP) located on the waist and a sensor attached on the wrist over the Rayleigh fading channel.Secondly,an optimization problem is formed to minimize the outage probability.Finally,we convert the non-convex optimization problem into convex solved by the Lagrange multiplier method.Simulations show that the optimization problem is solvable.The outage probability is optimized by performing power allocation at the sensor.And our proposed algorithm achieves minimizing the outage probability when the sensor uses energy harvesting.We also demonstrate that the average outage probability is reduced with the increase of the harvested energy.
文摘In people’s daily life, the role of weatherforecast is self-evident. However, the accuracy offorecasting is based on the accuracy and reliability ofmeteorological data which depends on the sensitivityof meteorological device. Therefore, an importantduty of the detection institution of meteorologicalmetrical device is to have the effective detectionof meteorological device, so as to ensure a highsensitivity of the device. However, the meteorologicaldevice used by some meteorological bureaus is nottechnologically advanced and the device detectionmode is too old, which cannot meet the new regulationsissued by the China Meteorological Administration.So it is necessary for the meteorological bureau todevelop a set of devices that can easily meet the newmeteorological measurement requirements, which is ofgreat significance to ensure the accurate measurementof meteorological data.
基金supported by University of Stavanger, NorwaySINTEF,the Center for Integrated Operations in the Petroleum Industry and the management of National Oilwell Varco Intelli Serv
文摘Wired drill pipe(WDP)technology is one of the most promising data acquisition technologies in today s oil and gas industry.For the first time it allows sensors to be positioned along the drill string which enables collecting and transmitting valuable data not only from the bottom hole assembly(BHA),but also along the entire length of the wellbore to the drill floor.The technology has received industry acceptance as a viable alternative to the typical logging while drilling(LWD)method.Recently more and more WDP applications can be found in the challenging drilling environments around the world,leading to many innovations to the industry.Nevertheless most of the data acquired from WDP can be noisy and in some circumstances of very poor quality.Diverse factors contribute to the poor data quality.Most common sources include mis-calibrated sensors,sensor drifting,errors during data transmission,or some abnormal conditions in the well,etc.The challenge of improving the data quality has attracted more and more focus from many researchers during the past decade.This paper has proposed a promising solution to address such challenge by making corrections of the raw WDP data and estimating unmeasurable parameters to reveal downhole behaviors.An advanced data processing method,data validation and reconciliation(DVR)has been employed,which makes use of the redundant data from multiple WDP sensors to filter/remove the noise from the measurements and ensures the coherence of all sensors and models.Moreover it has the ability to distinguish the accurate measurements from the inaccurate ones.In addition,the data with improved quality can be used for estimating some crucial parameters in the drilling process which are unmeasurable in the first place,hence provide better model calibrations for integrated well planning and realtime operations.