OCEANS 2006 - Asia Pacific最新文献

{"title":"Optimized Joint Management of Electric Fields and Corrosion on a Naval Platform","authors":"Y. Pei","doi":"10.1109/OCEANSAP.2006.4393963","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393963","url":null,"abstract":"The electric and corrosion related magnetic signatures generated by ship borne impressed current cathodic protection (ICCP) system might be significant and the threats include underwater weapons and underwater reconnaissance systems for surface ships and submarines. Underwater electric sensors represent an effective means in detection, classification and localization of underwater target, especially in littoral water environment. To achieve an electric signature stealth naval platform, techniques such as computer simulation, design optimization and physical scale modelling are the useful tools in solving the combined optimization problem with complex ship structures. This paper proposes an approach to study the joint problem of minimizing the underwater electric field of a naval platform as well as maintaining health corrosion protection ability. To realize this joint requirement, we propose a specified multi-zone anodes impressed current cathodic protection (ICCP) system. In this paper, we use physical scale modelling and numerical simulation to study the electric fields and corrosion potentials. Approximations to system parameters such as numbers, locations and electric current amplitudes of the anodes, are achieved via an inverse approaches to minimize underwater electric field and to improve corrosion protection potential as well. Simulation and scale model measurement results show the potential of the proposed method in achieving this joint requirement.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123167604","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":"Bathymetric results from a multi-frequency InSAS sea-trial","authors":"P. Barclay, M.H. Hayes, Peter T. Gough","doi":"10.1109/OCEANSAP.2006.4393929","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393929","url":null,"abstract":"In this paper we present results from a multi-frequency interferometric synthetic aperture sonar (InSAS) sea-trial. The height estimate is generated using a maximum likelihood (ML) estimate combining the data from the hydrophones. To decrease the effect of the large variance of the phase difference estimates the broadband signal is divided into smaller subbands and combined to give a height estimate with much improved accuracy, albeit at a reduced resolution due to the reduction in system bandwidth. Results are shown for a three vertical element sonar, and the improvement obtained using multiple frequency bands sub-banded to give a lower variance in the height estimate. Multiple pings are also combined as multiple looks, further reducing the height variance.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114419355","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 Concept for Efficient Signal Excess Calculation for Multistatic Operations Analysis","authors":"S. B. Dasinger, B. I. Incze, T. A. Holz","doi":"10.1109/OCEANSAP.2006.4393977","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393977","url":null,"abstract":"This paper presents a method for reducing the time required to calculate signal excess for multistatic sonar systems in support of operations analysis. Runtime can be improved by a factor of 10 to 50 by reusing modeled components that go into the signal excess equation. The presented method introduces errors into the acoustic calculation that, when managed by the analyst, will have negligible effect on the operations analysis result.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114603974","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 Deepwater Tsunami Surveillance System for Malaysia","authors":"S. E. Aasen, Z. Mustapha, P. Schjølberg, T. Elliott","doi":"10.1109/OCEANSAP.2006.4393971","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393971","url":null,"abstract":"The tragic events of the 26 th December 2004 initiated interest in establishing a tsunami surveillance and early warning system in the Indian Ocean and bordering seas. The paper describes the design and installation of a deep-water tsunami detection system for Malaysia. The first buoy in the system has been in operation since December 2005 and will be complemented by two more buoys to provide national tsunami surveillance coverage by mid -2006. The system builds on the Seawatch network developed by Fugro OCEANOR, as well as on the US DART system developed by PMEL. A bottom mounted high-resolution pressure sensor monitored by a processor and powered from onboard batteries form, together with an acoustic modem/release, the seabed part of the system. The seabed unit, the Seawatch Deep Sea Module (SDSM), features several novel features to make this a reliable and cost effective solution for tsunami detection. A Wavescan buoy forms the surface part of the system featuring data transmission and measurements of other oceanographic and meteorological parameters, making this a true multi-hazard system.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124206795","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":"An Adaptive Neural Network Control System using mnSOM","authors":"S. Nishida, K. Ishii, T. Furukawa","doi":"10.1109/OCEANSAP.2006.4393880","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393880","url":null,"abstract":"Autonomous underwater vehicles (AUVs) are attractive tools to survey Earth science and oceanography, however, there exists a lot of problems to be solved such as motion control, acquisition of sensor data, decision-making, navigation without collision, self-localization and so on. In order to realize useful and practical robots, underwater vehicles should take their action by judging the changing condition from their own sensors and actuators, and are desirable to make their behavior, because of features caused by the working environment. We have been investigated the application of brain-inspired technologies such as neural networks (NNs) and self-organizing map (SOM) into AUVs. A new controller system for AUVs using modular network SOM (mnSOM) proposed by Tokunaga et al. is discussed in this paper. The proposed system is developed using recurrent NN type mnSOM. The efficiency of the system is investigated through the simulations.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115088233","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":"Wavelet De-noising with Independent Component Analysis for Segmentation of Dolphin Whistles in a Noisy Underwater Environment","authors":"S. Seramani, E. Taylor, P. Seekings, K. P. Yeo","doi":"10.1109/OCEANSAP.2006.4393920","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393920","url":null,"abstract":"Bottlenose dolphins (Tursiops truncatus) are the most widely studied species of dolphin and are known to produce a complex mixture of different types of sounds. They are believed to communicate through frequency-modulated pure tones (whistles), and produce broadband clicks or click trains for echolocation while investigating their environment. They also produce a large range of other types of sounds variously described as barks, grunts, groans, etc. To further our aim of 2-way acoustically mediated communication with dolphins to study dolphin cognition, we need to separate Bottlenose dolphin whistles from noisy underwater recordings, which not only consist of whistles, but also broadband echolocation clicks, water splashes and other sources of ambient noise. Independent component analysis (ICA) has been successfully used for the separation of independent sound sources in many applications. In this paper we will discuss the use of ICA to separate dolphin whistles from other underwater sound sources.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115166908","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":"Combining Web Services to Manage Real-Time Navigation Data Distribution","authors":"M.O. Ferguson","doi":"10.1109/OCEANSAP.2006.4393820","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393820","url":null,"abstract":"Like many other disciplines, Positioning Navigation and Timing (PNT) data distribution has various requirements that depend on the use and criticality for its consumers, and satisfying these multiple varying needs from a single common source can be a challenge. In particular, the need to manage the distribution of PNT data on a ship, where some systems require various real-time accuracy and latency, as well as different sets of data, is critical. One example is the US Navy's Navigation Sensor System Interface (NAVSSI) that integrates the various ship sensor data, computes a single accurate PNT solution, and distributes it in real-time to other shipboard users. The problem arises when the number of users continues to grow and change, which has led to the creation of multiple PNT data messages in order to isolate the changes from affecting other users. Once a user implements a particular PNT data structure, there is resistance to change it unless it is for their benefit and someone else pays for it. The ideal solution would be to build a single variable superset of PNT data that can add fields without disrupting existing users. The NAVSSI Standard Navigation Message (SNM) was an attempt to provide such a solution. Each field in the SNM included a corresponding description of it, so that a user can scan the SNM and pick the individual fields of interest. The order of the fields and the length of the message were not guaranteed to be the same, so that a new fully described field can be inserted anywhere into the SNM. Unfortunately, there was no enforcement on the user side to implement the flexibility provided by the SNM, which resulted in multiple fixed messages to accommodate later changes. This paper describes a revisit of this problem in light of more recent technological developments, and offers a better solution using Web Services. Under this new proposed solution, a user connects to a Web server that provides the user with the ability to select the set of PNT data fields from a list and create their own tailored message. The user will also specify the rate at which the PNT messages are to be received, and the IP address to which the message will be sent. For security, a user will first have to present credentials and a need-to-know in order to set up an account with access controls. While the Web service is used to set up the transmission parameters, it does not provide the real-time PNT data distribution via the same Web Service, since the Hyper Text Transfer Protocol (HTTP) is not suitable for real-time communications. Instead, the real-time PNT data distribution is via User Datagram Protocol (UDP) over Internet Protocol (IP). However, a separate Web Service for PNT data can also be configured to support non real-time applications that use a Web Browser for their Graphical User Interface (GUI). This service, similar to the management and setup interface, will translate the PNT data into an extensible Markup Language (XML) formatted message, ","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130287363","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":"Characterization of Multipath Acoustic Channels in very Shallow Waters for Communications","authors":"Tan Bien Aik, Quek Swee Sen, Zou Nan","doi":"10.1109/OCEANSAP.2006.4393959","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393959","url":null,"abstract":"The motivations for studying the channel characteristics of a very shallow water environment are twofold: one, to account for the poor performance of commercial off the shelf (COTS) underwater acoustic modems in warm, very shallow waters and two, to design realistic channel models and communication systems which are able to perform in such an environment. This paper presents an experimental analysis of medium frequency (9-28 kHz) channel measurements in very shallow waters (15-30 m) for transmission distance ranging from 80 m to 4 km in the coastal seas of Singapore. The channel probe signals are mainly binary phase shift keying (BPSK) modulated m-sequences. They provide a large bandwidth-duration signal that is ideal for delay-Doppler measurements, giving adequate delay and Doppler resolution. Our channel measurements and analysis have shown that delay and Doppler spread decreases as the distance increases. This implies that at longer distances (up to 4 km), the channel is able to support higher bit rates. In contrary, COTS modems generally degrade to lower bit rates when the transmission range increases in our local shallow water environment.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121612617","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":"The Two-Stage ROV for Sediment Sampling on Mariana Trench","authors":"H. Yoshida, T. Aoki, H. Osawa, T. Miyazaki, J. Tahara, S. Ishibashi, H. Ochi, Y. Watanabe, M. Mizuno","doi":"10.1109/OCEANSAP.2006.4393893","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393893","url":null,"abstract":"JAMSTEC has been developing the remotely operated vehicle system having a limited role to explore the deepest parts of the oceans since April 2005. This ROV system's main mission is to survey sediments in sea bottoms. This system consists of a launcher and a small vehicle. The launcher carries two types of bottom samplers as well as the vehicle. One launches the small vehicle to make a preliminary survey, launching the sampler to obtain a sample. The samplers can be changed a gravity core sampler for a grabber. The system assembly will be completed by the spring of 2006 and then its sea trials will be started.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115872157","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":"Zero-G Class Underwater Robots and Unrestricted Attitude Control using Control Moment Gyros","authors":"B. Thornton, T. Ura, Y. Nose, S. Turnock","doi":"10.1109/OCEANSAP.2006.4393842","DOIUrl":"https://doi.org/10.1109/OCEANSAP.2006.4393842","url":null,"abstract":"The \"zero-G\" is designated as a new class of underwater robot that is capable of unrestricted attitude control. A novel control scheme based on internal actuation using control moment gyros (CMGs) provides zero-G class autonomous underwater vehicles (AUVs) with this unique freedom in control. A geometric study of the singularities of a CMG pyramid is performed and together with considerations of the inverse kinematics of attitude control forms the basis of a global steering law that exactly achieves the desired torques, whilst guaranteeing real-time singularity avoidance within a constrained workspace. The development of the CMG actuated zero-G class underwater robot \"IKURA\" is described. The robot demonstrates its unique manoeuvring capabilities by performing vertically pitched diving and surfacing in surge. The three-dimensional manoeuvring capabilities allow zero-G class underwater robots to plan and optimise their missions in a fully three-dimensional manner, in a way that has not been possible previously.","PeriodicalId":268341,"journal":{"name":"OCEANS 2006 - Asia Pacific","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125641986","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}