Service Factor Assessment of a Great Lakes Bulk Carrier Incorporating the Effects of Hydroelasticity

2009 ◽  
Vol 46 (02) ◽  
pp. 116-121
Author(s):  
Spyridon E. Hirdaris ◽  
Norbert Bakkers ◽  
Nigel White ◽  
Pandeli Temarel
Keyword(s):  
Rigid Body ◽  
Great Lakes ◽  
Body Wave ◽  
Three Dimensional ◽  
Bending Moment ◽  
Suez Canal ◽  
Two Dimensional ◽  
Bulk Carrier ◽  
Service Factor

This paper presents a summary of an investigation into the effects of hull flexibility when deriving an equivalent service factor for a single passage of a Great Lakes Bulk Carrier from the Canadian Great Lakes to China. induced bending moment predicted using traditional three-dimensional rigid body hydrodynamic methods is augmented due to the effects of springing and whipping by including allowances based on two-dimensional hydroelasticity predictions across a range of headings and sea states. The analysis results are correlated with full scale measurements that are available for this ship. By combining the long term "rigid body" wave-bending moment with the effects of hydroelasticity, a suitable service factor is derived for a Great Lakes Bulk Carrier traveling from the Canadian Great Lakes to China via the Suez Canal.

scholarly journals Remember like humans

2017 ◽  
Vol 14 (1) ◽  
pp. 172988141769231 ◽  
Author(s):  
Ning An ◽  
Shi-Ying Sun ◽  
Xiao-Guang Zhao ◽  
Zeng-Guang Hou
Keyword(s):  
Short Term Memory ◽  
Three Dimensional ◽  
Sensory Memory ◽  
Long Term Memory ◽  
Observation Model ◽  
Two Dimensional ◽  
Short Term ◽  
Term Memory ◽  
Memory Register

Visual tracking is a challenging computer vision task due to the significant observation changes of the target. By contrast, the tracking task is relatively easy for humans. In this article, we propose a tracker inspired by the cognitive psychological memory mechanism, which decomposes the tracking task into sensory memory register, short-term memory tracker, and long-term memory tracker like humans. The sensory memory register captures information with three-dimensional perception; the short-term memory tracker builds the highly plastic observation model via memory rehearsal; the long-term memory tracker builds the highly stable observation model via memory encoding and retrieval. With the cooperative models, the tracker can easily handle various tracking scenarios. In addition, an appearance-shape learning method is proposed to update the two-dimensional appearance model and three-dimensional shape model appropriately. Extensive experimental results on a large-scale benchmark data set demonstrate that the proposed method outperforms the state-of-the-art two-dimensional and three-dimensional trackers in terms of efficiency, accuracy, and robustness.

Bending of an Infinite Beam on an Elastic Foundation

1937 ◽  
Vol 4 (1) ◽  
pp. A1-A7 ◽  
Author(s):  
M. A. Biot
Keyword(s):  
Elastic Foundation ◽  
Poisson Ratio ◽  
Elementary Theory ◽  
Three Dimensional ◽  
Bending Moment ◽  
Two Dimensional ◽  
Concentrated Load ◽  
Elastic Continuum ◽  
Infinite Beam ◽  
A Value

Abstract The elementary theory of the bending of a beam on an elastic foundation is based on the assumption that the beam is resting on a continuously distributed set of springs the stiffness of which is defined by a “modulus of the foundation” k. Very seldom, however, does it happen that the foundation is actually constituted this way. Generally, the foundation is an elastic continuum characterized by two elastic constants, a modulus of elasticity E, and a Poisson ratio ν. The problem of the bending of a beam resting on such a foundation has been approached already by various authors. The author attempts to give in this paper a more exact solution of one aspect of this problem, i.e., the case of an infinite beam under a concentrated load. A notable difference exists between the results obtained from the assumptions of a two-dimensional foundation and of a three-dimensional foundation. Bending-moment and deflection curves for the two-dimensional case are shown in Figs. 4 and 5. A value of the modulus k is given for both cases by which the elementary theory can be used and leads to results which are fairly acceptable. These values depend on the stiffness of the beam and on the elasticity of the foundation.

scholarly journals INVESTIGATIONS ON MESOPHOTIC CORAL ECOSYSTEMS IN CUBA (1970-1973) AND MEXICO (1983-1984)

2018 ◽  
Vol 33 (2) ◽  
pp. 27
Author(s):  
Vassil Zlatarski
Keyword(s):  
Coral Reefs ◽  
Species Complex ◽  
Three Dimensional ◽  
Published Data ◽  
Two Dimensional ◽  
Mesophotic Coral Ecosystems ◽  
Trends Analysis ◽  
Collaborative Efforts ◽  
Existing Data

After a pioneering study of Jamaican coral reefs, the Cuban archipelago was the second to be surveyed by SCUBA for scleractinian corals and reef life to a depth of 90m, sampling all phenotypes.  Regrettably, the published data on the mesophotic coral ecosystems (MCEs) of Cuba, collected 1970 to 1973, have been ignored.  This is also true for the published data on the MCEs of the Mexican Yucatán Peninsula, collected 1983 to 1984.  These two investigations described immense areas exhibiting a rich continuum of coral life, from shallow reefs into MCEs without scleractinian faunal break, and no depth-specialists species complex.  Instead, a morphological changeover of three-dimensional corallum into two-dimensional corallum was observed and documented.  The existing data on the Cuban and Mexican MCEs (now 45 and 34 years old, respectively) present a unique opportunity for long-term status and ecosystem trends analysis.  MCEs require terminological clarification from collaborative efforts to effectively use the globally available data.Investigaciones sobre ecosistemas coralinos mesofóticos en Cuba (1970-1973) y México (1983-1984)RESUMEN. Después de un estudio pionero en arrecifes de Jamaica sobre corales escleratinios y vida arrecifal, el archipiélago cubano fue el segundo que se estudió mediante buceo SCUBA a profundidades de hasta 90m, incluyendo muestras de todos los fenotipos. Infortunadamente, los datos publicados sobre ecosistemas coralinos mesofóticos (ECM), recabados entre 1970 y 1973 han sido soslayados, al igual que los datos publicados sobre los ECM de la Península de Yucatán, México, recabados entre 1983 y 1984.  Ambas investigaciones describen áreas inmensas que exhiben un rico continuo de vida coralina, desde arrecifes someros hasta ECM sin ruptura en la fauna escleratinia y sin complejos de especies especialistas de profundidad. En vez de esto, se observó y documentó un reemplazamiento de formas tridimensionales de corales por formas bidimensionales.  La información existente sobre ECM cubanos y mexicanos con antigüedades de 45 y 34 años, respectivamente ofrecen una oportunidad única para realizar análisis sobre estatus a largo plazo y tendencias de ecosistema.  Los ECM requieren aclaración terminológica de esfuerzos de colaboración para utilizar efectivamente los datos disponibles globalmente.

scholarly journals Cardiac Surveillance for Early Detection of Late Subclinical Cardiac Dysfunction in Childhood Cancer Survivors After Anthracycline Therapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Rosaria Sofia ◽  
Veronica Melita ◽  
Antonio De Vita ◽  
Antonio Ruggiero ◽  
Alberto Romano ◽  
...  
Keyword(s):  
Cancer Survivors ◽  
Speckle Tracking ◽  
Three Dimensional ◽  
Childhood Cancer Survivors ◽  
Two Dimensional ◽  
Anthracycline Therapy ◽  
Echocardiographic Parameters ◽  
Dimensional Echocardiography

BackgroundIn childhood cancer survivors (CCSs) anthracycline-related cardiotoxicity is an important cause of morbidity and late mortality, but the optimal modality of cardiac surveillance still remains to be defined. The aim of this study was to assess whether non-invasive echocardiography-based functional cardiac measures can detect early subclinical myocardial changes in long-term pediatric cancer survivors who received anthracycline therapy.MethodsTwenty anthracycline-treated long-term CCSs and 20 age, sex, and body surface area matched healthy controls were enrolled in this study. Among cancer survivors, mean age at diagnosis was 6.5 ± 4.4 years, and the mean cumulative anthracycline dose was 234.5 ± 87.4 mg/m2. All subjects underwent a comprehensive functional echocardiographic protocol study including two-dimensional echocardiography (2D Echo), tissue Doppler imaging (TDI), speckle tracking (STE) and three-dimensional echocardiography (3D Echo). Patients were studied at a mean follow-up time of 6.5 ± 2.8 years from the end of therapy.ResultsNo significant differences in two-dimensional left ventricle ejection fraction (LVEF), diastolic parameters and speckle tracking (STE)-derived myocardial strain were observed between patients treated with anthracyclines and controls. Myocardial performance index was significantly prolonged (p = 0.005) and three-dimensional LVEF was significantly reduced (p = 0.002) in CCSs compared to controls, even though most values were within the normal range. There were no significant correlations between 2D, STE, and 3D echocardiographic parameters and age at diagnosis or duration of follow-up. No significant differences in echocardiographic parameters were found when stratifying cancer patients according to established risk factors for anthracycline cardiomyopathy.ConclusionsThis study found significantly reduced three-dimensional LVEF in CCSs compared with controls, despite no significant differences in two-dimensional LVEF and longitudinal strain values. These findings suggest that long-term CCSs who had received anthracycline therapy may be found to have subclinical features of myocardial dysfunction. However, further studies are needed to demonstrate the validity of new imaging techniques, including STE and 3D Echo, to identify patients at risk for cardiomyopathy in the long-term follow-up of CCSs.

Exact, Hierarchical Solutions for Localized Loadings in Isotropic, Laminated, and Sandwich Shells

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
E. Carrera ◽  
G. Giunta
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
Two Dimensional ◽  
Application Area ◽  
Spherical Shells ◽  
Closed Form Solutions ◽  
Simply Supported ◽  
Transverse Pressure ◽  
Shell Models ◽  
Stress And Deformation

This paper presents closed form solutions for simply supported cylindrical and spherical shells subjected to uniform localized distributions of transverse pressure and bending moment. These distributions have been expanded in terms of Fourier’s series for which Navier type “exact” solutions have been found for the governing differential equations of the employed shell theories. Shells made of isotropic materials, composites laminates, and sandwich have been analyzed. Carrera’s unified formulation has been adopted in order to implement a large variety of two-dimensional theories. Classical, refined, zigzag, layerwise, and mixed theories are compared in order to evaluate the stress and deformation variables. Conclusions are drawn with respect to the accuracy of the various theories for the considered loadings and layouts. The importance of the refined shell models in order to describe accurately the three-dimensional stress state in the neighborhood of the localized loading application area is outlined.

scholarly journals Territories in Time: Mapping Palimpsest Horizons

2020 ◽  
Vol 5 (2) ◽  
pp. 94-98 ◽  
Author(s):  
Chiara Cavalieri ◽  
Elena Cogato Lanza
Keyword(s):  
Rapid Evolution ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Data Recording ◽  
New Paradigm ◽  
Dimensional Matrix ◽  
History Of ◽  
Theoretical Question

In the early 80s André Corboz, in describing the territory as being the result of slow and long-term processes involving multiple transformations, implicitly declares the onset of a new paradigm for understanding cities and territories: a new gaze attentive to the chronological dimension of spaces, aware of the long history of places, interested in that ensemble of signs, traces and voids so tangible, and yet ignored by the paradigm of tabula rasa. To describe this complexity, Corboz proposes the metaphor of territory as palimpsest: A palimpsest is a two-dimensional writing board bearing a three-dimensional matrix of signs, which, as a metaphor, allows for a contextual, four-dimensional apprehension of territory, portraying space in its chronological evolution. This text re-contextualizes the notion of palimpsest—both as a methodological and a theoretical question—in the light of two main conceptual ‘shifts’: the ‘territorial turn,’ which increased interest among different disciplines, projects, and policies for the dimension of cities as territory, and the ‘digital turn,’ namely the rapid evolution of data recording, archiving, and mapping technologies.

scholarly journals Shear Stress at the Base of a Rigidly Rotating Cirque Glacier

1971 ◽  
Vol 10 (58) ◽  
pp. 31-37 ◽  
Author(s):  
J. Weertman
Keyword(s):  
Shear Stress ◽  
Rigid Body ◽  
Three Dimensional ◽  
Spherical Shape ◽  
Ice Thickness ◽  
Shear Stresses ◽  
Two Dimensional ◽  
Body Rotation ◽  
Recent Compilation ◽  
Basal Shear

AbstractThe value of the basal shear stress is derived for two-dimensional and three-dimensional cirque glaciers. It is assumed that a cirque glacier moves primarily by a rigid-body rotation over a bed of cylindrical or spherical shape. In the region of maximum ice thickness the new value of the basal shear stress is only about one half that derived from equations in common use in the literature. The new expression for the basal shear stress of a cirque glacier is used to correct a data point in Paterson’s recent compilation of measured sliding velocities and basal shear stresses of glaciers.

Reform Based on "No Paper-Drawing" Mechanical Drawing Course System

2011 ◽  
Vol 271-273 ◽  
pp. 1519-1523 ◽  
Author(s):  
Wei Hu ◽  
Chang Chun Li ◽  
Guo Hong Dai
Keyword(s):  
Manufacturing Industry ◽  
Teaching Practice ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Important Process ◽  
Production Chain ◽  
Recognition Ability ◽  
Design And Manufacturing ◽  
Modern Manufacturing

"No paper-drawing" is the important process of informatization of manufacturing industry, which has greatly impacted the teaching of traditional mechanical drawing. In order to adapt to the demand of development of current manufacturing industry for drawing recognition ability of the talents, the structure of mechanical drawing course must correspond to this demand and perform fundamental reform; through long-term teaching practice, put drafting teaching into the whole production chain of product design and manufacturing so as to form the course form mainly based on three-dimensional expression and supported with two-dimensional expression, thus enabling the structure of mechanical drawing course to fit the development of modern manufacturing industry. The students cultivated under this mode can meet the requirements of manufacturing industry for drawing recognition ability.

scholarly journals Shear Stress at the Base of a Rigidly Rotating Cirque Glacier

1971 ◽  
Vol 10 (58) ◽  
pp. 31-37 ◽  
Author(s):  
J. Weertman
Keyword(s):  
Shear Stress ◽  
Rigid Body ◽  
Three Dimensional ◽  
Spherical Shape ◽  
Ice Thickness ◽  
Shear Stresses ◽  
Two Dimensional ◽  
Body Rotation ◽  
Recent Compilation ◽  
Basal Shear

The value of the basal shear stress is derived for two-dimensional and three-dimensional cirque glaciers. It is assumed that a cirque glacier moves primarily by a rigid-body rotation over a bed of cylindrical or spherical shape. In the region of maximum ice thickness the new value of the basal shear stress is only about one half that derived from equations in common use in the literature. The new expression for the basal shear stress of a cirque glacier is used to correct a data point in Paterson’s recent compilation of measured sliding velocities and basal shear stresses of glaciers.

An Interferometer Based Experimental Technique to Evaluate Large Strains and Springback on Sheet Metal

2013 ◽  
Author(s):  
Luis Rafael Sanchez ◽  
Shannon Peterson ◽  
Carl G. Simonsen ◽  
Abrar Satar
Keyword(s):  
Sheet Metal ◽  
Three Dimensional ◽  
Bending Moment ◽  
Large Strains ◽  
Two Dimensional ◽  
Strain Gages ◽  
Additional Information ◽  
Software Algorithms ◽  
Dimensional Measurements ◽  
Vertical Scanning Interferometry

A technique was successfully developed to measure large tensile, compressive strains, springback and strain reversal effects on sheet metal bent to small radii. Vertical Scanning Interferometry (VSI) was used to measure three dimensional data from surfaces with sides varying from 160 nm to 2 mm. Software algorithms were utilized to determine surface topography maps from three-dimensional curved locations and to represent them in a two dimensional plane. Fine reference marks were engraved on both sides of sample. The sample was bent /unbent to small radii under a pure bending moment. Outer strains were calculated from VSI two-dimensional measurements of the original and final lengths between the reference marks. Strain gages, applied at locations close to the reference marks, gave additional information at the elasto-plastic range. Experimental data collected included bending moment as a function of strain, 3-D curvature profiles, springback and reverse bending effects. The technique was proved useful for the experimental evaluation and theoretical validation of bending and springback properties of sheet metal. Experimental results for aluminum and steel alloys are presented.

Sign in / Sign up

Export Citation Format

Share Document