scholarly journals Detection of Small Bottom Objects From Multibeam Echosounder Data

2018 ◽  
Vol 25 (1) ◽  
pp. 219-232
Author(s):  
Dominik Iwen ◽  
Mariusz Wąż
Keyword(s):  
Shallow Water ◽  
Post Processing ◽  
Data Format ◽  
Multibeam Echosounder ◽  
Bathymetric Data ◽  
Detection Of Objects ◽  
Processing Techniques ◽  
Echo Sounder

AbstractMultibeam Echo Sounder Systems (MBES) shallow water surveys provide capability not only acquiring bathymetric data useful for determining isobaths and mapping features on the seafloor which may be a hazard to navigation. They also allow detection of objects smaller or deeper than those required for the safety of seafaring and International Hydrography Organization (IHO) standards. In this article some of issues related to of efficient MBES shallow water surveys are stressed. Additionally a draft of post-processing techniques and result data format together with tools allowing extraction of bottom object from bathymetric data are presented.

scholarly journals Optimization of Data Collection and Refinement of Post-processing Techniques for Maritime Canada's First Shallow Water Topographic-bathymetric Lidar Survey

2016 ◽  
Vol 76 ◽  
pp. 31-43 ◽  
Author(s):  
Timothy Webster ◽  
Kevin McGuigan ◽  
Nathan Crowell ◽  
Kate Collins ◽  
Candace MacDonald
Keyword(s):  
Data Collection ◽  
Shallow Water ◽  
Post Processing ◽  
Processing Techniques

scholarly journals Post-Processing Techniques for the Improvement of Liposome Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1023
Author(s):  
Ji Young Yu ◽  
Piyanan Chuesiang ◽  
Gye Hwa Shin ◽  
Hyun Jin Park
Keyword(s):  
Freeze Drying ◽  
Protective Agent ◽  
Post Processing ◽  
Additional Process ◽  
Spray Freeze Drying ◽  
The Stability ◽  
Processing Techniques ◽  
The Impact ◽  
Self Aggregation ◽  
Liposome Stability

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

Abstract WP55: Through Thick and Thin: Improved Aspects Grading and Dense Vessel Detection Using Simple Ncct Post-processing

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
James W Evans ◽  
Sadanand Dey ◽  
Muneer Eesa ◽  
Prasanna Eswaradass ◽  
Ronda Lun ◽  
...  
Keyword(s):  
Maximum Intensity Projection ◽  
Improve Patient Care ◽  
Weighted Kappa ◽  
Slice Thickness ◽  
Post Processing ◽  
Rater Reliability ◽  
Thin Slice ◽  
Vessel Detection ◽  
Contrast Ct ◽  
Processing Techniques

Introduction: Assessing Alberta Stroke Program Early CT Score (ASPECTS) and identifying hyperdense arteries on non-contrast CT (NCCT) are important components of decision-making in acute stroke. Conventional practice uses 5mm averaged slice thickness NCCT for interpretation of these features. We have systematically evaluated several post processing techniques on NCCT to determine if there is improved reliability in identification of ASPECTS and hyperdense artery. Methodology: We assessed four post-processing techniques on NCCT namely (1) 5mm averaged thickness (2) Minimum Intensity Projection (mIP) - 5mm thickness (3) thin slices (0.625mm) and (4) Maximum Intensity Projection (MIP) - 5mm thickness (Figure 1). Three raters (student, fellow and expert) independently assessed 100 NCCT scans from the PRoveIT database. All scans were read at four different times 10-14 days apart. At each time-point the post processing modality was changed and the patient order randomized. Information on side of suspected infarction was provided. Raters were asked to score ASPECTS and identify presence of hyperdense artery at each reading. Inter-rater reliability was assessed using Intra-cluster correlation (ICC) for ASPECTS and weighted kappa (wKap) for hyperdense artery. Results: The highest inter-rater reliability was found with the MIP technique (ICC 0.42; p<0.001), followed by 5 mm average, mIP and thin slice respectively (ICC 0.33, 0.32, 0.20; all p<0.01). Highest agreement for hyperdense vessel detection was noted with thin slice (wKap 0.30; p<0.001) followed by Average, MIPs and mIPs respectively (wKap 0.25, 0.18, 0.13; all p <0.05). Conclusion: The use of MIP images for ASPECTS grading and thin images for hyperdense vessel detection improves reliability on NCCT. These simple processing steps are easily available on any modern scanner and may help improve patient care.

scholarly journals Post-Processing Techniques to Enhance the Quality of Metallic Parts Produced by Additive Manufacturing

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 77
Author(s):  
Muhammad Arif Mahmood ◽  
Diana Chioibasu ◽  
Asif Ur Rehman ◽  
Sabin Mihai ◽  
Andrei C. Popescu
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Post Processing ◽  
Laser Polishing ◽  
Shock Peening ◽  
Processing Techniques ◽  
Am Processes ◽  
Conventional Machining

Additive manufacturing (AM) processes can produce three-dimensional (3D) near-net-shape parts based on computer-aided design (CAD) models. Compared to traditional manufacturing processes, AM processes can generate parts with intricate geometries, operational flexibility and reduced manufacturing time, thus saving time and money. On the other hand, AM processes face complex issues, including poor surface finish, unwanted microstructure phases, defects, wear tracks, reduced corrosion resistance and reduced fatigue life. These problems prevent AM parts from real-time operational applications. Post-processing techniques, including laser shock peening, laser polishing, conventional machining methods and thermal processes, are usually applied to resolve these issues. These processes have proved their capability to enhance the surface characteristics and physical and mechanical properties. In this study, various post-processing techniques and their implementations have been compiled. The effect of post-processing techniques on additively manufactured parts has been discussed. It was found that laser shock peening (LSP) can cause severe strain rate generation, especially in thinner components. LSP can control the surface regularities and local grain refinement, thus elevating the hardness value. Laser polishing (LP) can reduce surface roughness up to 95% and increase hardness, collectively, compared to the as-built parts. Conventional machining processes enhance surface quality; however, their influence on hardness has not been proved yet. Thermal post-processing techniques are applied to eliminate porosity up to 99.99%, increase corrosion resistance, and finally, the mechanical properties’ elevation. For future perspectives, to prescribe a particular post-processing technique for specific defects, standardization is necessary. This study provides a detailed overview of the post-processing techniques applied to enhance the mechanical and physical properties of AM-ed parts. A particular method can be chosen based on one’s requirements.

scholarly journals A comparison of bathymetry mapped with the Simrad ME70 multibeam echosounder operated in bathymetric and fisheries modes

2010 ◽  
Vol 67 (6) ◽  
pp. 1301-1309 ◽  
Author(s):  
George R. Cutter ◽  
Laurent Berger ◽  
David A. Demer
Keyword(s):  
Software Development ◽  
Data Processing ◽  
Bay Of Biscay ◽  
Marine Science ◽  
Dual Use ◽  
Detection Range ◽  
Multibeam Echosounder ◽  
Acoustic Backscattering ◽  
Bathymetric Data ◽  
Phase Data

Abstract Cutter, G. R. Jr, Berger, L., and Demer, D. A. 2010. A comparison of bathymetry mapped with the Simrad ME70 multibeam echosounder operated in bathymetric and fisheries modes. – ICES Journal of Marine Science, 67: 1301–1309. The Simrad ME70 multibeam echosounder was designed for quantitative fisheries research and is currently installed on Ifremer's fishery survey vessel (FSV) “Thalassa” and each of the new, quiet, NOAA FSVs. The ME70 has configurable beams and transmits in the range 70–120 kHz to provide calibrated, acoustic-backscattering data throughout the detection range (fisheries mode, FM). With optional hardware and software, the ME70 can also collect soundings that potentially meet International Hydrographic Organization's S–44 Order 1 standards (bathymetric mode, BM). Furthermore, with custom algorithms and software, bathymetric data can be obtained from the ME70 operating in FM, and volume backscatter can be sampled from the ME70 operating in BM. This flexibility allows data to be concurrently collected on fish and their seabed habitat. A method is described for processing the echo amplitude and phase data from multiple split-beams formed in FM to estimate seabed range, slope, and roughness. The resulting bathymetry is compared with that collected with the ME70 operating in BM in the same area of the Bay of Biscay. A proposal is made for software development to facilitate dual-use data processing.

Mapping shallow water bubbling reefs – a method comparison between topobathymetric lidar and multibeam echosounder

2021 ◽  
Author(s):  
Mikkel Skovgaard Andersen ◽  
Lars Øbro Hansen ◽  
Zyad Al-Hamdani ◽  
Signe Schilling Hansen ◽  
Manfred Niederwieser ◽  
...  
Keyword(s):  
Shallow Water ◽  
Habitat Type ◽  
High Energy ◽  
Survey Method ◽  
Sidescan Sonar ◽  
Small Scale ◽  
Lidar Data ◽  
Multibeam Echosounder ◽  
Full Coverage ◽  
Spatial Coverage

&lt;p&gt;Bubbling reefs are submarine structures formed by aggregating carbonate resulting from leaking gases. The reef formations can form pillars rising several meters above the sea floor. They support a high diversity of benthic communities, and in the EU Habitat Directive they are specifically mentioned as a natural habitat type that require conservation.&lt;/p&gt;&lt;p&gt;Knowledge about the presence, locations and shape of bubbling reefs are usually obtained by geophysical surveying using multibeam echosounder (MBES), sidescan sonar and/or seismic acquisition systems, combined with ground truth verification. However, this traditional survey method is time consuming, especially for full coverage surveys in shallow water. Full coverage surveys are a requirement to capture the bubbling reefs due to their relatively small spatial extent. Besides, traditional geophysical vessel borne surveys have their limitations in shallow water due to low spatial coverage and vessel draft.&lt;/p&gt;&lt;p&gt;In recent years, airborne topobathymetric (green wavelength) lidar has emerged as a new possible surveying method in shallow water (e.g. Andersen et al., 2017). Compared to vessel borne MBES, full coverage lidar surveys can be conducted within hours instead of days/weeks, while also including full coverage in the shallow water and a seamless transition between land and water. Thus, topobathymetric lidar may be a good choice for carrying out full coverage surveys in large shallow water areas. However, the accuracy and the resolution of the collected dataset are important in these surveys, not least when mapping small scale features such as bubbling reefs.&lt;/p&gt;&lt;p&gt;In this study, we investigated the potential of mapping bubbling reefs in shallow water (&lt;10 m) using topobathymetric lidar. The main objective was to assess the performance of airborne topobathymetric lidar to detect and resolve small scale objects, i.e. bubbling reefs, by comparison to MBES data. Both MBES and lidar data were acquired in spring 2019 in a designated Natura 2000 area close to Hirsholmene in the northern Kattegat region in Denmark. The comparison of the two datasets included a quantification of the accuracy, and an assessment of the performance for mapping bubbling reefs.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Reference:&lt;/p&gt;&lt;p&gt;Andersen M.S., Gergely A., Al-Hamdani Z., Steinbacher F., Larsen L.R., Ernstsen V.B. (2017). Processing and performance of topobathymetric lidar data for geomorphometric and morphological classification in a high-energy tidal environment. Hydrology and Earth System Sciences, 21: 43-63, DOI:&amp;#160;10.5194/hess-21-43-2017.&lt;/p&gt;

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