检索结果-南通市图书馆

Ship performance and navigation data compression and communication under autoencoder system architecture

Journal of ocean Engineering and Science 2018年第2期3卷 133-143页

作者： Lokukaluge P.Perera B.Mo UiT The Arctic University of Norway TromsoNorway sintef ocean TrondheimNorway

Modern vessels are designed to collect,store and communicate large quantities of ship performance and navigation information through complex onboard data handling processes.That data should be transferred to shore based data centers for further analysis and storage.However,the associated transfer cost in large-scale data sets is a major challenge for the shipping industry,today.The same cost relates to the amount of data that are transferring through various communication networks(i.***.satellites and wireless networks),i.***.between vessels and shore based data centers.Hence,this study proposes to use an autoencoder system architecture(i.e.a deep learning approach)to compress ship performance and navigation parameters(i.***.reduce the number of parameters)and transfer through the respective communication networks as reduced data sets.The data compression is done under the linear version of an autoencoder that consists of principal component analysis(PCA),where the respective principal components(PCs)represent the structure of the data set.The compressed data set is expanded by the same data structure(i.***.an autoencoder system architecture)at the respective data center requiring further analyses and storage.A data set of ship performance and navigation parameters in a selected vessel is analyzed(i.***.data compression and expansion)through an autoencoder system architecture and the results are presented in this study.Furthermore,the respective input and output values of the autoencoder are also compared as statistical distributions and sample number series to evaluate its performance.

关键词： Autoencoder Ship performance and navigation information Ship energy efficiency Data compression Data communication Principal component analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ship speed power performance under relative wind profiles in relation to sensor fault detection

引用

Journal of ocean Engineering and Science 2018年第4期3卷 355-366页

作者： Lokukaluge P.Perera B.Mo UiT The Arctic University of Norway TromsoNorway sintef ocean TrondheimNorway

Statistical data analysis and visualization approaches to identify ship speed power performance under relative wind(i.***.apparent wind)profiles are considered in this study.Ship performance and navigation data of a selected vessel are analyzed,where various data anomalies,i.***.sensor related erroneous data conditions,are identified.Those erroneous data conditions are investigated and several approaches to isolate such situations are also presented by considering appropriate data visualization methods.Then,the cleaned data are used to derive various relationships among ship performance and navigation parameters that have been visualized in this study,appropriately.The results show that the wind profiles along ship routes can be used to evaluate vessel performance and navigation conditions by assuming the respective sea states relate to their wind conditions.Hence,the results are useful to derive appropriate mathematical models that represent ship performance and navigation conditions.Such mathematical models can be used for weather routing type applications(i.***.voyage planning),where the respective weather forecast can be used to derive optimal ship routes to improve vessel performance and reduce fuel consumption.This study presents not only an overview of statistical data analysis of ship performance and navigation data but also the respective challenges in data anomalies(i.***.erroneous data intervals and sensor faults)due to onboard sensors and data handling systems.Furthermore,the respective solutions to such challenges in data quality have also been presented by considering data visualization approaches.

关键词： Speed power performance Data anomaly detection Sensor fault identification Weather routing Statistical data analysis Ship wind profile.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Parameterization Scheme for Wind Wave Modules that Includes the Sea Ice Thickness in the Marginal Ice Zone

引用

Advances in Atmospheric Sciences 2023年第12期40卷 2279-2287页

作者： Dongang LIU Qinghua YANG Andrei TSARAU Yongtao HUANG Xuewei LI Navigation College Dalian Maritime UniversityDalian 116026China School of Atmospheric Sciences Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China sintef ocean Brattørkaia 17C7010 TrondheimNorway Norwegian University of Science and Technology 7491 TrondheimNorway

The global wave model WAVEWATCH III®works well in open water.To simulate the propagation and attenuation of waves through ice-covered water,existing simulations have considered the influence of sea ice by adding the sea ice concentration in the wind wave module;however,they simply suppose that the wind cannot penetrate the ice layer and ignore the possibility of wind forcing waves below the ice cover.To improve the simulation performance of wind wave modules in the marginal ice zone(MIZ),this study proposes a parameterization scheme by directly including the sea ice thickness.Instead of scaling the wind input with the fraction of open water,this new scheme allows partial wind input in ice-covered areas based on the ice thickness.Compared with observations in the Barents Sea in 2016,the new scheme appears to improve the modeled waves in the high-frequency band.Sensitivity experiments with and without wind wave modules show that wind waves can play an important role in areas with low sea ice concentration in the MIZ.

关键词： wind wave IMU wave PSD wave attenuation Barents Sea

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental Study of An Aquaculture Net Cage in Waves and Current

引用

China ocean Engineering 2015年第3期29卷 325-340页

作者： David KRISTIANSEN Pal LADER Фsten JENSEN David FREDRIKSSON sintef Fisheries and Aquaculture United States Naval Academy

Model experiments of a floating fish cage subjected to waves and current have been performed. The objective was to study the dynamic behaviour of the fish cage model in waves and current. The fish cage model was composed of a model net, a flexible floating collar of the circular plastic type and a weight system. It was found that there are many wave periods in which cancellation of the wave-induced forces on the model occur. These cancellation wave periods are within the range of dimensioning wave periods commonly used for testing of fish farm structures and hence are important to be aware of. Large deformations of the net under realistic wave and current conditions were observed, where contact between the net and other parts of the structure were identified. This may cause damages to the net due to abrasion.

关键词： aquaculture structure hydrodynamic loads hydroelasticity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nonstationary fuzzy forecasting of wind and wave climate in very long-term scales

引用

Journal of ocean Engineering and Science 2018年第2期3卷 144-155页

作者： Ch.N.Stefanakos E.Vanem sintef ocean Department of Energy and TransportPostboks 4762 TorgardenTrondheim NO-7465Norway DNV GL Group Technology and ResearchP.O Box 3001322HøvikNorway

Global climate change may have serious impact on human activities in coastal and other areas.Climate change may affect the degree of storminess and,hence,change the wind-driven ocean wave climate.This may affect the risks associated with maritime activities such as shipping and offshore oil and gas.So,there is a recognized need to understand better how climate change will affect such processes.Typically,such understanding comes from future projections of the wind and wave climate from numerical climate models and from the stochastic modelling of such projections.This work investigates the applicability of a recently proposed nonstationary fuzzy modelling to wind and wave climatic simulations.According to this,fuzzy inference models(FIS)are coupled with nonstationary time series modelling,providing us with less biased climatic estimates.Two long-term datasets for an area in the North Atlantic ocean are used in the present study,namely NORA10(57 years)and ExWaCli(30 years in the present and 30 years in the future).Two distinct experiments have been performed to simulate future values of the time series in a climatic scale.The assessment of the simulations by means of the actual values kept for comparison purposes gives very good results.

关键词： Fuzzy time series Wind and wave data Forecasting Nonstationary ocean wind and wave climate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Square mesh codend improves size selectivity and catch pattern for Trichiurus lepturus in bottom trawl used along Northwest coast of India

引用

Aquaculture and Fisheries 2023年第5期8卷 564-571页

作者： Madhu Vettiyattil Bent Herrmann Meenakumari Bharathiamma ICAR-Central Institute of Fisheries Technology MatsyapuriWillingdon IslandCochinKerala682029India sintef ocean Fishing Gear TechnologyWillemoesvej 2Hirtshals9850Denmark University of Tromsø BreivikaTromsø9037Norway DTU Aqua Technical University of DenmarkHirtshals2800Denmark Division of Fisheries Science Krishi Anusandhan Bhawan-IIIndian Council of Agricultural ResearchNew Delhi110012India

The size selectivity and catch pattern of Trichiurus lepturus in 40 mm diamond and square mesh codends were investigated in this study.A 34 m high opening trawl was used,which is a common design used by fishermen operating along the northwest coast of India,and the cover codend method was employed to determine codend selectivity.Along with the changes in the length at 50%retention rate for Trichiurus lepturus with the usage of the square and diamond mesh codends,indicators to understand the exploitation pattern of this species in the fishery were assessed based on the total number of individuals and on total weight of the catch.The mean selection length increased and discard fraction is reduced when 40 mm square mesh codends are used in place of diamond meshes,however,it is observed that individuals at commercial length are also lost.The results demonstrate that mandatory use of legal mesh sizes alone will be insufficient to aid in the sustainable harvest of this species,given its estimated length at first sexual maturity of 61.2 cm.This is the first study to compare the size selection of this species in 40 mm diamond and square mesh codends along Northwest coast of India.Results of the study will help as a baseline for gear-based regulations in the region.

关键词： Size selectivity Trichiurus lepturus Square mesh Codend India

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Drag on Hydroid-Fouled Nets – An Experimental Approach

引用

China ocean Engineering 2015年第3期29卷 369-389页

作者： Pl LADER David W. FREDRIKSSON Jana GUENTHER Zsolt VOLENT Nina BLOCHER David KRISTIANSEN Lars GANSEL Jud DECEW sintef Fisheries and Aquaculture United States Naval Academy University of New Hampshire

The present study investigated the drag increase on aquaculture nets due to biofouling of the colonial hydroid Ectopleura larynx. It had two main parts： firstly the growth characteristics of E. larynx were investigated by use of field tests at a Norwegian aquaculture site; secondly the hydrodynamic drag on the fouled twines was studied in a towing tank by using fabricated models of net twines with artificial hydroid fouling. In the field tests, the growth of the hydroids was first measured after three weeks of immersion and then again after six weeks. During this interval, the density of hydroids and the thickness of the hydroid stem were almost constant（1.4 hydroids/mm and 0.29 mm, respectively）, while the average length of the hydroids increased from 6.4 to 11.2 mm. The hydroid length followed a Rayleigh distribution, while the thickness was normal（Gaussian） distributed. Replicas of twines with three different levels of hydroid growth were made（1.5 hydroids/mm twine, hydroid length 9 mm, 16 mm and 20 mm）, and the drag on these twines was measured at different towing velocities（0.1 to 1.4 m/s） and with different twine configurations. For the twine with the shortest hydroids（9 mm）, the drag was from 1.5 times（Re=4000） to 2.2 times（Re=1000） the drag on a clean twine. For the longest hydroids（21 mm）, the drag was 2 times and 3.8 times, respectively.

关键词： hydroid biofouling aquaculture net hydrodynamic drag

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Proposed New Laboratory Protocol for Dispersant Effectiveness Testing Adapted for Subsea Dispersant Injection

引用

Journal of Environmental Protection 2019年第5期10卷 694-709页

作者： Per Johan Brandvik Per S. Daling Dorien Dunnebier Panagiotis E. Makatounis Frode Leirvik Daniel F. Krause sintef ocean Marine Environmental Technology Trondheim Norway National Technical University of Athens Athens Greece

The main objective of this study is to develop a new protocol for bench-scale dispersant effectiveness testing adapted for subsea dispersants injection (SSDI). The new approach includes turbulence conditions, dispersant injection techniques and quantification of effectiveness, more representative for a SSDI operation. Results from the new system are compared to dispersant effectiveness measured with established laboratory methods, used for screening dispersants for surface application. The most significant result is that the dispersant ranking obtained with the new test relevant for subsea releases was very different compared to the ranking obtained by screening methods used for surface application of dispersants. This strongly indicates that existing standard methods for dispersant effectiveness testing designed for simulating conditions relevant for surface application of dispersants, are less relevant for SSDI effectiveness testing and justify the need for a more relevant method. Such a Dispersant Injection Effectiveness Test (DIET) is suggested and documented in this study.

关键词： Subsea Oil Spill Laboratory Effectiveness Testing Dispersants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pressure Tolerant Power Electronics： IGBT Gate Driver for Operation in High Pressure Hydrostatic Environment

引用

Journal of Energy and Power Engineering 2012年第9期6卷 1500-1508页

作者： Riccardo Pittini Magnar Hernes Kjell Ljokelsoy Electric Power Systems SINTEF Energy Research Trondheim 7465 Norway

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparing the size selectivity of a novel T90 mesh codend to two conventional codends in the northern shrimp(Pandalus borealis)trawl fishery

引用

Aquaculture and Fisheries 2021年第4期6卷 382-392页

作者： Haraldur Arnar Einarsson Zhaohai Cheng Shannon M.Bayse Bent Herrmann Paul DWinger Marine and Freshwater Research Institute Skúlagata 4101ReykjavíkIceland Centre for Sustainable Aquatic Resources Fisheries and Marine InstituteMemorial UniversityP.O.Box 4920St.John’sNLA1C 5R3Canada sintef ocean Fishing Gear TechnologyWillemoesvej 29850HirtshalsDenmark University of Tromsø BreivikaN-9037TromsøNorway

The size selectivity and usability of three codends were quantified and compared for the first time in the inshore Northern shrimp(Pandalus borealis)trawl fishery of Iceland using the covered codend method:a conventional diamond-mesh codend(T0),conventional square-mesh codend(T45),and a 90◦turned mesh codend(T90)constructed of four panels and with shortened lastridge ropes.Fishers,wanting to increase the average-individual size of captured shrimp,had requested the T90 codend to be compared with conventional codends for consideration in the fishery.Results showed that,on average,the T45 and T90 codends had better size selectivity than the T0 codend in terms of releasing individuals smaller than 13 mm carapace length(Minimum References Size;MRS).The T90 codend retained significantly less Northern shrimps between 9 and 19 mm than the T0 codend and between 15 and 19 mm than the T45 codend.No significant difference of size selectivity between T45 and T0 codends was observed.All three codends presented high retention ratios of Northern shrimps above MRS(>63%)for the population encountered.However,the T0 codend was not effective at sorting out small Northern shrimps;at least 86%of Northern shrimps smaller than 13 mm were retained in the T0 codend if encountered.Catches from T45 and T90 codends had a lower proportion of shrimp below MRS.Since discarding of undersized Northern shrimps is prohibited in Iceland and fishers wanted to catch on average larger shrimp,using the novel T90 codend would enable fishers to use their quotas more efficiently.

关键词： Size selectivity Codend usability Pandalus borealis Diamond-mesh T45 T90 Iceland Lastridge rope

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：