Applying the Bisection Search Method to Search the Maximum Environmental Conditions in DPCap Analysis for Marine Vessels

2015 ◽  
Vol 25 (2) ◽  
pp. 104-111 ◽  
Author(s):  
Shengwen Xu ◽  
Xuefeng Wang ◽  
Lei Wang ◽  
Shuai Meng
Keyword(s):  
Environmental Conditions ◽  
Search Method ◽  
Bisection Search ◽  
Marine Vessels

scholarly journals PV Systems Installed in Marine Vessels: Technologies and Specifications

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ioannis Kobougias ◽  
Emmanuel Tatakis ◽  
John Prousalidis
Keyword(s):  
Solar Cell ◽  
Environmental Conditions ◽  
Cell Types ◽  
Pv System ◽  
Electrical Grid ◽  
Pv Systems ◽  
Technical Specifications ◽  
Marine Vessels ◽  
Marine Environmental

Considerations are held about the specificationin whichthe PV plants have to fulfill so that they can be installed on marine vessels. Initially, a brief description of the typical electrical grid of ships is presented, distinguishing the main parts, reporting the typical electrical magnitudes, and choosing the most preferable installation areas. The technical specifications,in whichthe PV plants have to be compatible with, are fully described. They are determined by the special marine environmental conditions, taking into consideration parameters like wind, humidity, shading, corrosion, and limited installation area. The work is carried out with the presentation of the most popular trends in the field of solar cell types and PV system technologies and their ability to keep up with the aforementioned specifications.

Reliability of Switched Model-Based Controller for Vessel Dynamic Positioning With Switching Under Estimated Motion Frequency

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Dong T. Nguyen ◽  
Ser Tong Quek
Keyword(s):  
Failure Probability ◽  
Environmental Conditions ◽  
Response Spectrum ◽  
Estimation Error ◽  
Time Lag ◽  
Peak Frequency ◽  
Dynamic Positioning ◽  
Window Width ◽  
Measured Position ◽  
Marine Vessels

In switched-control methodology, which integrates several controllers handling different environmental conditions for dynamic positioning (DP) systems in marine vessels, the supervisor uses the estimated wave peak frequency (WPF) to classify the existing environmental condition so as to switch to the appropriate controller. The WPF is assumed to be the same as the peak frequency of the vessel’s response spectrum at wave frequency estimated by fast Fourier transform (FFT) of the measured position and heading. Using a short window width leads to error in the WPF estimation whereas a longer width causes a significant time lag in control activation. This paper addresses the effect of uncertainty in the estimation of WPF by FFT on the reliability of the switched-controller based DP vessel. The probability of the supervisor switching to a wrong controller due to WPF estimation error is first evaluated for four different environmental conditions. The failure probabilities of the system with and without WPF uncertainty are then evaluated and compared. Numerical simulation based on a supply vessel shows that the increase in failure probability of the switched-controller DP system due to the uncertainty in the estimated WPF by FFT is not significant compared with the failure probability of a perfect switched-controller DP system.

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

The influence of external conditions on sound pressure in the pistonphone at the infrasound frequency range

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin
Keyword(s):  
Environmental Conditions ◽  
Sound Pressure ◽  
Primary Method ◽  
Frequency Range ◽  
External Conditions ◽  
Numerical Estimations

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.

Disentangling the role of shared ancestry and the environment on leaf stable isotopes

2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1
Keyword(s):  
Stable Isotopes ◽  
Environmental Conditions ◽  
Evolutionary History ◽  
Environmental Control ◽  
Phylogenetic Signal ◽  
Individual Species ◽  
Habitat Types ◽  
Δ13c And Δ15n ◽  
Environmental Controls ◽  
Shared Ancestry

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.

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