scholarly journals Analysis of Ship RCS Detected by Multifrequency HFGWR

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Ke Sun ◽  
Biyang Wen ◽  
Ruokun Wang
Keyword(s):  
Probability Of Detection ◽  
Empirical Formulas ◽  
Detection And Tracking ◽  
Automatic Information ◽  
Wave Radar ◽  
Relationship Of ◽  
The Relationship ◽  
Ground Wave ◽  
Automatic Information System ◽  
Key Parameter

One of the important applications of high frequency-ground wave radar (HFGWR) is to detect offshore ships. A proper method should be used to obtain the ship radar cross section (RCS), which is a key parameter of the ship. This paper proposes a method based on an automatic information system (AIS). The relationship of the ship RCS versus bearing for different frequencies is analyzed by processing multifrequency HFGWR data. With this new method, bearing information is taken into consideration, which is not the case in traditional empirical formulas. The results provide prior knowledge for ship detection and tracking; therefore, the probability of detection is significantly improved.

Target detection and tracking with a high frequency ground wave radar

1994 ◽  
Vol 19 (4) ◽  
pp. 540-548 ◽  
Author(s):  
R. Khan ◽  
B. Gamberg ◽  
D. Power ◽  
J. Walsh ◽  
B. Dawe ◽  
...  
Keyword(s):  
Target Detection ◽  
High Frequency ◽  
Detection And Tracking ◽  
Wave Radar ◽  
Ground Wave

Fatigue and Fracture Reliability and Maintainability of TLP Tendons

1993 ◽  
Vol 115 (2) ◽  
pp. 137-141 ◽  
Author(s):  
C. J. Kung ◽  
P. H. Wirsching
Keyword(s):  
System Reliability ◽  
Structural Integrity ◽  
Probability Of Detection ◽  
Structural Performance ◽  
Periodic Inspection ◽  
Maintenance Program ◽  
Fatigue And Fracture ◽  
Relationship Of ◽  
Design Factors ◽  
The Relationship

A tension leg platform (TLP) tendon system experiences oscillatory tensile stresses, and therefore is vulnerable to fatigue and fracture. Because design factors have significant uncertainty, a reliability analysis to quantify structural performance is appropriate. A maintenance program of periodic inspection and repair shows promise for improving system reliability and enhancing structural integrity. The performance of a TLP tendon system was simulated in order to study the relationship of design factors to system reliability. Effects on system reliability and maintenance performance (repair and replacement rates) can be studied as a function of (a) number of joints, J; (b) number of members, M; (c) inspection frequency; (d) inspection sensitivity as defined by the POD (probability of detection) curve; (e) ultimate strength; (f) repair policy; etc. The performance of an initially damaged or flawed tendon system is investigated. The reliability of a system that uses pressurized tendons to detect through-thickness cracks is studied, as is the vulnerability of the tendon system before replacement of broken tendons.

Ultrasonic NDE System Modeling and Reliability – An Overview

2006 ◽  
Vol 110 ◽  
pp. 111-116
Author(s):  
Lester W. Schmerr
Keyword(s):  
Nondestructive Evaluation ◽  
System Modeling ◽  
Probability Of Detection ◽  
Reliability Modeling ◽  
Modeling Technology ◽  
The Past ◽  
Ultrasonic Nde ◽  
Relationship Of ◽  
The Relationship ◽  
Made In

Over the past two and a half decades there has been considerable progress made in the modeling of ultrasonic nondestructive evaluation (NDE) inspections. These models have also been combined with models of the noise and variability present in an inspection to estimate probability of detection (POD) versus flaw size curves. An overview will be given of the past and present accomplishments made in ultrasonic NDE modeling, POD modeling, and the relationship of those advances to reliability modeling that incorporates explicitly the results of inspections. A brief look into the future of this modeling technology will also be given.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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