UNDERWATER TECHNOLOGY最新文献

{"title":"Oil Spill Risk Management: Modeling Gulf of Mexico Circulation and Oil Dispersal","authors":"P. V. Gastel","doi":"10.3723/UT.32.285","DOIUrl":"https://doi.org/10.3723/UT.32.285","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"1 1","pages":"285-286"},"PeriodicalIF":0.4,"publicationDate":"2015-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82152079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated approach to maximise deepwater asset value with subsea fluid samplings","authors":"N. Abili, F. Kara","doi":"10.3723/UT.32.245","DOIUrl":"https://doi.org/10.3723/UT.32.245","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"70 1","pages":"245-253"},"PeriodicalIF":0.4,"publicationDate":"2015-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74688713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the reliability of the Indian tsunami buoy system","authors":"R. Venkatesan, V. R. Shamji, N. Vedachalam, G. Latha, R. Sundar, Simi Mathew, R. R. Rao, M. Muthiah, P. Prasad, M. Atmanand","doi":"10.3723/UT.32.255","DOIUrl":"https://doi.org/10.3723/UT.32.255","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"82 1","pages":"255-270"},"PeriodicalIF":0.4,"publicationDate":"2015-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89846976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composite model reference adaptive control for an unmanned underwater vehicle","authors":"C. D. Makavita, H. Nguyen, D. Ranmuthugala, S. Jayasinghe","doi":"10.3723/ut.33.081","DOIUrl":"https://doi.org/10.3723/ut.33.081","url":null,"abstract":"The control of unmanned underwater vehicles (UUVs) is challenging due to the non-linear and time-varying nature of the hydrodynamic forces from the surrounding fluid. In addition, the presence of external disturbances makes the control even more difficult. Model reference adaptive control (MRAC) is an adaptive control technique that performs well in such situations, while the improved composite/combined model reference adaptive control (CMRAC) is capable of better transient performance. However, the latter is yet to be used in UUV controls. Thus, this paper tests the suitability of CMRAC in UUV applications using validated simulation models and compares its performance against the standard MRAC. Several test scenarios have been considered including initial operation, external disturbance and thruster failure. Simulation results show that CMRAC offers better tracking, faster disturbance rejection and quick recovery from thruster failure compared to MRAC. In addition, CMRAC is more robust against parameter uncertainties and thus the control signal shows fewer oscillations, which in turn reduces the probability of actuator damage.","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"20 1","pages":"81-93"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73365393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subsea cable tracking by an unmanned surface vehicle","authors":"T. Szyrowski, A. Motwani, Sanjay K. Sharma, R. Sutton, G. Kennedy","doi":"10.3723/UT.32.217","DOIUrl":"https://doi.org/10.3723/UT.32.217","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"83 1","pages":"217-229"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83814535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligent Autonomy for Unmanned Marine Vehicles","authors":"C. Insaurralde","doi":"10.1007/978-3-319-18778-5","DOIUrl":"https://doi.org/10.1007/978-3-319-18778-5","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"37 1","pages":"247-247"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76399825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A note on the variation in shape of linear rogue waves in the ocean","authors":"T. Adcock, S. Draper","doi":"10.3723/UT.33.075","DOIUrl":"https://doi.org/10.3723/UT.33.075","url":null,"abstract":"The average shape of large waves in the open ocean made up of linear waves with random phase is given by ‘NewWave’ defined by the auto-correlation function of the wave spectrum. In this note we confirm this result for realistic directionally spread sea-states but show that there is a considerable variation in shape of rogue waves. Practical implications are discussed.","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"94 1","pages":"75-80"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83910984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified concept for recovering a UUV to a submarine","authors":"M. Renilson","doi":"10.3723/UT.32.193","DOIUrl":"https://doi.org/10.3723/UT.32.193","url":null,"abstract":"The use of unmanned underwater vehicles (UUVs) to enhance the military capabilities of submarines and to reduce their operational risk is being considered by navies around the world. However, a major difficulty with the operations of UUVs is their recovery back to the submarine at the end of the mission. Various schemes have been proposed by a number of organisations working in this field; however, they all have major drawbacks. \u0000 \u0000A simple concept is proposed based on a warp from the submarine to a low aspect ratio wing, similar to an otter board used by fishing trawlers. This approach allows the submarine to recover the UUV by slowly overtaking it. This is done at a sufficiently large transverse distance between the vessels where hydrodynamic interaction between the two is minimal, with the submarine travelling at a speed at which it can be safely controlled.","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"31 1","pages":"193-197"},"PeriodicalIF":0.4,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84720109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Function selection among popular dive computer models: A review and proposed improvements","authors":"A. Schuster, P. Buzzacott, S. Reif, B. Kuch, Amir Gerges, E. Azzopardi, M. Sayer, A. Sieber","doi":"10.3723/UT.32.159","DOIUrl":"https://doi.org/10.3723/UT.32.159","url":null,"abstract":"","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"22 1","pages":"159-165"},"PeriodicalIF":0.4,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85695691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in underwater optical wireless communications","authors":"Laura J. Johnson, F. Jasman, R. Green, M. Leeson","doi":"10.3723/UT.32.167","DOIUrl":"https://doi.org/10.3723/UT.32.167","url":null,"abstract":"Abstract Optical wireless communications (OWC) are being consid-ered for use under water because sea water exhibits a win-dow of reduced absorption in the visible spectrum, particularly between 400–550nm. Recent technology has demonstrated the ability to support mid-range links (<200m) and at high bandwidths (<1Gbps) in clear oceans. The present paper outlines the governing transmission characteristics and reviews current experimental research in underwater OWC, highlighting the importance of the local chlorophyll concen -tration, particulate concentration and the resultant wave-length selection. Ideal wavelengths are found to be from 430nm, which represents a deep blue colour, to beyond 550nm in areas where the chlorophyll concentration is high. Keywords: underwater communications, visible-light com-munications, ocean optics 1. Introduction Acoustic systems have enjoyed great success under water owing to their ability to communicate over many kilometres, despite low bandwidth capacity (Chitre et al., 2008). However, in recent times, some underwater applications such as the new generation of autonomous underwater vehicles (AUVs) have called for a complementary technology, capable of high bandwidths over short- to mid-range distances. Optical wireless communications are being consid-ered as a possible solution to this. The use of visible light was first suggested as a viable technology under water over 30 years ago (Wiener and Karp, 1980) because the electromag-netic absorption of sea water presents a window of reduced attenuation in the visible spectrum, particu -larly within the blue-green region. However, it was not until the recent advances in terrestrial visible-light technology that research into underwater optical wireless communications (OWC) began to gather significant momentum. Applying OWC to the underwater environment is not a trivial matter. Not only does light in sea water undergo higher channel attenuation compared to that in clear air, but also the optical properties of the medium itself vary significantly (Stramski et al., 2001) and there are more sources of link disruption. Natural oceans are rich in dissolved and particulate matter, leading to a wide range of circumstances with which an underwater communication system must cope. However, biochemical and optical prop-erties are linked, which is evident when comparing the colour of open ocean with coastal waters. This implies that optical constants can be deduced from the local seawater composition. The present paper introduces the factors that affect light propagation in the ocean and how they might impact on the configuration of underwater OWC sys-tems. It concludes by reviewing experimental achieve-ments in this subject and discussing how these projects are paving a path towards commercialisation.","PeriodicalId":44271,"journal":{"name":"UNDERWATER TECHNOLOGY","volume":"44 1","pages":"167-175"},"PeriodicalIF":0.4,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84336655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}