Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be awar...Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be aware of all fishing vessels and other obstacles in a container vessel＇s radar observation blind zone. This greatly increases the risk of collisions and other accidents. Given such great challenges to safe navigation and safety management with container vessels, their security risks are severe. An effective visual monitoring system can improve the safety of the water area surrounding container vessel by eliminating a vessel＇s observation blind zone, providing an effective safety measure for vessels navigating fishing zones and other troublesome areas. The system has other functions, such as accident recording, ship security, and monitoring of loading and unloading operations, thus ensuring the ship operates safely. Six months＇ trial operation showed that the system facilitates safe navigation of container vessels.展开更多
The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption m...The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption monitoring. The magnetic energy harvesting device consists of an energy harvesting module, Cockcroft-Walton circuit and storage capacitor. First of all, typical magnetic fields around several electrical appliances are investigated. In order to harvest 10 mJ energy, the shape of magnetic flux concentration flange in energy harvesting module and number of steps in Cockcroft-Walton circuit are considered. From experimental results, magnetic energy harvesting of 17 mJ from a refrigerator is successfully demonstrated.展开更多
Fatigue stress measurement has been playing a significant role in the ship structural health monitoring and ship structural safety assessment. The PDF （probability density function） of the measured stress is one of ...Fatigue stress measurement has been playing a significant role in the ship structural health monitoring and ship structural safety assessment. The PDF （probability density function） of the measured stress is one of the essentials for the further studyin this domain. This paper, based on the strain-stress data collected from a container ship, focuses on the spectrum feature of the ship structural fatigue stress. A general analysis procedure for ship hull health estimation was firstly demonstrated. With the guidance of this procedure, the estimation and test of the parameters for the PDF of the stress were conducted, which showed that the stress spectrums fit well with the Weibull distribution. To review the fatigue state, the PDF and distribution function of fatigue damage increment were further developed and examined. The structural healthy assessment of this vessel shown the daily relative fatigue damage increment obeys log-normal or Weibull distribution and the increment of the fatigue damage on steel box girders of the ship hull was very low. Finally, the analyzing results yielded that the girder structure of the ship hull had a very low failure probability, matching well with the actual relative low working load of the ship.展开更多
基金the Shanghai Leading Academic Discipline Project Foundation under Grant No.T0603
文摘Container vessels navigate among the world＇s ports, frequently passing through narrow and congested waters. Due to the many layers of containers on a container vessel＇s decks, it is difficult for the crew to be aware of all fishing vessels and other obstacles in a container vessel＇s radar observation blind zone. This greatly increases the risk of collisions and other accidents. Given such great challenges to safe navigation and safety management with container vessels, their security risks are severe. An effective visual monitoring system can improve the safety of the water area surrounding container vessel by eliminating a vessel＇s observation blind zone, providing an effective safety measure for vessels navigating fishing zones and other troublesome areas. The system has other functions, such as accident recording, ship security, and monitoring of loading and unloading operations, thus ensuring the ship operates safely. Six months＇ trial operation showed that the system facilitates safe navigation of container vessels.
文摘The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption monitoring. The magnetic energy harvesting device consists of an energy harvesting module, Cockcroft-Walton circuit and storage capacitor. First of all, typical magnetic fields around several electrical appliances are investigated. In order to harvest 10 mJ energy, the shape of magnetic flux concentration flange in energy harvesting module and number of steps in Cockcroft-Walton circuit are considered. From experimental results, magnetic energy harvesting of 17 mJ from a refrigerator is successfully demonstrated.
文摘Fatigue stress measurement has been playing a significant role in the ship structural health monitoring and ship structural safety assessment. The PDF （probability density function） of the measured stress is one of the essentials for the further studyin this domain. This paper, based on the strain-stress data collected from a container ship, focuses on the spectrum feature of the ship structural fatigue stress. A general analysis procedure for ship hull health estimation was firstly demonstrated. With the guidance of this procedure, the estimation and test of the parameters for the PDF of the stress were conducted, which showed that the stress spectrums fit well with the Weibull distribution. To review the fatigue state, the PDF and distribution function of fatigue damage increment were further developed and examined. The structural healthy assessment of this vessel shown the daily relative fatigue damage increment obeys log-normal or Weibull distribution and the increment of the fatigue damage on steel box girders of the ship hull was very low. Finally, the analyzing results yielded that the girder structure of the ship hull had a very low failure probability, matching well with the actual relative low working load of the ship.
