A Novel Fatigue Stress Model of Power Phases and Coated Tubes in Deep-Water Power Cables, Umbilicals, and Power Umbilicals

2016 ◽  
Author(s):  
Magnus Komperød
Keyword(s):  
Real Life ◽  
Power Cable ◽  
The Novel ◽  
Power Cables ◽  
Insulation System ◽  
Fatigue Stress ◽  
Water Power ◽  
Significant Challenge ◽  
Deep Waters ◽  
Novel Model

Short fatigue life is a significant challenge for power cables, umbilicals, and power umbilicals to be installed in ultra-deep and hyper-deep waters. This paper presents a novel model for calculating fatigue stresses in conductors of power phases and in tubes with coating. The novelty is that the axial displacement of the conductor within the electric insulation system, or the tube within the sheath, is taken into consideration. For a real-life power cable designed for 2 300 m water depth, the novel model gives a reduction in fatigue stress of 69% compared to the traditional resultant-based approach for oscillations smaller than the slip curvature. This corresponds to a reduction in fatigue damage of more than 99%.

A Frequency-Domain Model of Bitumen-Coated Armor Wires in Subsea Power Cables, Umbilicals, and Power Umbilicals

2016 ◽  
Author(s):  
Magnus Komperød
Keyword(s):  
Viscoelastic Behavior ◽  
Bending Moment ◽  
Bending Stiffness ◽  
Domain Model ◽  
The Novel ◽  
Power Cables ◽  
Simple Analytical Model ◽  
Temperature Dependent ◽  
Anticorrosion Protection ◽  
Novel Model

Bitumen is commonly used as anticorrosion protection for armor wires in subsea power cables, umbilicals, and power umbilicals. Bitumen’s viscoelastic behavior influences the cable’s mechanical properties. The present paper derives a simple, analytical model of bitumen-coated armor wires. The model calculates the axial stresses of the armor wires and the armor wires’ contribution to the cable’s bending stiffness. The model shows that there is a phase shift between the sinusoidal curvature oscillations and the corresponding armor wire stresses and cable bending moment. Two examples show that the armor wire stresses and the cable’s bending stiffness are strongly temperature-dependent. The purpose of the novel model is to calculate bending stiffness, fatigue stresses, and capacity (allowed combinations of axial cable tension and cable bending curvature) more accurately and to study these variables’ sensitivity to temperature and frequency. The model may also be included in calculations of bitumen’s influence on VIV damping.

scholarly journals Rough Atanassov’s Intuitionistic Fuzzy Sets Model over Two Universes and Its Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shuqun Luo ◽  
Weihua Xu
Keyword(s):  
Fuzzy Sets ◽  
Rough Set ◽  
Real Life ◽  
Intuitionistic Fuzzy Sets ◽  
Point Of View ◽  
The Novel ◽  
Intuitionistic Fuzzy ◽  
Two Universes ◽  
Novel Model ◽  
Atanassov’S Intuitionistic Fuzzy Sets

Recently, much attention has been given to the rough set models based on two universes. And many rough set models based on two universes have been developed from different points of view. In this paper, a novel model, that is, rough Atanassov’s intuitionistic fuzzy sets model over two different universes, is firstly proposed from Atanassov’s intuitionistic point of view. We study some important properties of approximation operators and investigate the rough degree in the novel model. Furthermore, an illustrated example is employed to demonstrate the conceptual arguments of the model. Finally, rough Atanassov’s intuitionistic fuzzy sets approach to decision is presented in the generalized approximation space over two universes by considering the problem about how to arrange patients to see the doctor reasonably, from which it can be found that the method is valuable and useful in real life.

A multi-objective sparse evolutionary framework for large-scale weapon target assignment based on a reward strategy

2021 ◽  
Vol 40 (5) ◽  
pp. 10043-10061
Author(s):  
Xiaoping Shi ◽  
Shiqi Zou ◽  
Shenmin Song ◽  
Rui Guo
Keyword(s):  
Large Scale ◽  
The Novel ◽  
Genetic Operators ◽  
Multi Objective ◽  
Target Assignment ◽  
Solution Selection ◽  
Battlefield Environment ◽  
Sparse Problems ◽  
Novel Model ◽  
Error Parameter

 The asset-based weapon target assignment (ABWTA) problem is one of the important branches of the weapon target assignment (WTA) problem. Due to the current large-scale battlefield environment, the ABWTA problem is a multi-objective optimization problem (MOP) with strong constraints, large-scale and sparse properties. The novel model of the ABWTA problem with the operation error parameter is established. An evolutionary algorithm for large-scale sparse problems (SparseEA) is introduced as the main framework for solving large-scale sparse ABWTA problem. The proposed framework (SparseEA-ABWTA) mainly addresses the issue that problem-specific initialization method and genetic operators with a reward strategy can generate solutions efficiently considering the sparsity of variables and an improved non-dominated solution selection method is presented to handle the constraints. Under the premise of constructing large-scale cases by the specific case generator, two numerical experiments on four outstanding multi-objective evolutionary algorithms (MOEAs) show Runtime of SparseEA-ABWTA is faster nearly 50% than others under the same convergence and the gap between MOEAs improved by the mechanism of SparseEA-ABWTA and SparseEA-ABWTA is reduced to nearly 20% in the convergence and distribution.

scholarly journals Polyethylene Nanocomposites for Power Cable Insulations

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Ilona Pleşa ◽  
Petru Noţingher ◽  
Cristina Stancu ◽  
Frank Wiesbrock ◽  
Sandra Schlögl
Keyword(s):  
Electrical Performance ◽  
Power Cable ◽  
Power Cables ◽  
Structure Property ◽  
Thermoplastic Polymers ◽  
Water Tree ◽  
Tree Resistance ◽  
Structure Property Relationships ◽  
Aging Mechanisms ◽  
Comprehensive Study

This review represents a comprehensive study of nanocomposites for power cables insulations based on thermoplastic polymers such as polyethylene congeners like LDPE, HDPE and XLPE, which is complemented by original results. Particular focus lies on the structure-property relationships of nanocomposites and the materials’ design with the corresponding electrical properties. The critical factors, which contribute to the degradation or improvement of the electrical performance of such cable insulations, are discussed in detail; in particular, properties such as electrical conductivity, relative permittivity, dielectric losses, partial discharges, space charge, electrical and water tree resistance behavior and electric breakdown of such nanocomposites based on thermoplastic polymers are described and referred to the composites’ structures. This review is motivated by the fact that the development of polymer nanocomposites for power cables insulation is based on understanding more closely the aging mechanisms and the behavior of nanocomposites under operating stresses.

Mechanical Qualification of Dynamic Deep Water Power Cable

2011 ◽  
Author(s):  
Roger Slora ◽  
Stian Karlsen ◽  
Per Arne Osborg
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Failure Modes ◽  
Electrical Power ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Power Cable ◽  
Water Power ◽  
System Integrity ◽  
Water Depths

There is an increasing demand for subsea electrical power transmission in the oil- and gas industry. Electrical power is mainly required for subsea pumps, compressors and for direct electrical heating of pipelines. The majority of subsea processing equipment is installed at water depths less than 1000 meters. However, projects located offshore Africa, Brazil and in the Gulf of Mexico are reported to be in water depths down to 3000 meters. Hence, Nexans initiated a development programme to qualify a dynamic deep water power cable. The qualification programme was based on DNV-RP-A203. An overall project plan, consisting of feasibility study, concept selection and pre-engineering was outlined as defined in DNV-OSS-401. An armoured three-phase power cable concept assumed suspended from a semi-submersible vessel at 3000 m water depth was selected as qualification basis. As proven cable technology was selected, the overall qualification scope is classified as class 2 according to DNV-RP-A203. Presumed high conductor stress at 3000 m water depth made basis for the identified failure modes. An optimised prototype cable, with the aim of reducing the failure mode risks, was designed based on extensive testing and analyses of various test cables. Analyses confirmed that the prototype cable will withstand the extreme loads and fatigue damage during a service life of 30 years with good margins. The system integrity, consisting of prototype cable and end terminations, was verified by means of tension tests. The electrical integrity was intact after tensioning to 2040 kN, which corresponds to 13 000 m static water depth. A full scale flex test of the prototype cable verified the extreme and fatigue analyses. Hence, the prototype cable is qualified for 3000 m water depth.

A novel fractional discrete grey model with an adaptive structure and its application in electricity consumption prediction

Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yitong Liu ◽  
Yang Yang ◽  
Dingyu Xue ◽  
Feng Pan
Keyword(s):  
Fractional Order ◽  
Electricity Consumption ◽  
Grey Model ◽  
The Novel ◽  
Raw Data ◽  
Content Type ◽  
Power Load ◽  
Grey Models ◽  
Novel Model ◽  
Consumption Prediction

PurposeElectricity consumption prediction has been an important topic for its significant impact on electric policies. Due to various uncertain factors, the growth trends of electricity consumption in different cases are variable. However, the traditional grey model is based on a fixed structure which sometimes cannot match the trend of raw data. Consequently, the predictive accuracy is variable as cases change. To improve the model's adaptability and forecasting ability, a novel fractional discrete grey model with variable structure is proposed in this paper.Design/methodology/approachThe novel model can be regarded as a homogenous or non-homogenous exponent predicting model by changing the structure. And it selects the appropriate structure depending on the characteristics of raw data. The introduction of fractional accumulation enhances the predicting ability of the novel model. And the relative fractional order r is calculated by the numerical iterative algorithm which is simple but effective.FindingsTwo cases of power load and electricity consumption in Jiangsu and Fujian are applied to assess the predicting accuracy of the novel grey model. Four widely-used grey models, three classical statistical models and the multi-layer artificial neural network model are taken into comparison. The results demonstrate that the novel grey model performs well in all cases, and is superior to the comparative eight models.Originality/valueA fractional-order discrete grey model with an adaptable structure is proposed to solve the conflict between traditional grey models' fixed structures and variable development trends of raw data. In applications, the novel model has satisfied adaptability and predicting accuracy.

Assessing Bypassed Hydrocarbons

2021 ◽  
Author(s):  
Stanley Oifoghe ◽  
Nora Alarcon ◽  
Lucrecia Grigoletto
Keyword(s):  
Continental Shelf ◽  
Reservoir Characterization ◽  
Gamma Ray ◽  
West African ◽  
The Novel ◽  
The West ◽  
Present Case Study ◽  
Novel Model

Abstract Hydrocarbons are bypassed in known fields. This is due to reservoir heterogeneities, complex lithology, and limitations of existing technology. This paper seeks to identify the scenarios of bypassed hydrocarbons, and to highlight how advances in reservoir characterization techniques have improved assessment of bypassed hydrocarbons. The present case study is an evaluation well drilled on the continental shelf, off the West African Coastline. The targeted thin-bedded reservoir sands are of Cenomanian age. Some technologies for assessing bypassed hydrocarbon include Gamma Ray Spectralog and Thin Bed Analysis. NMR is important for accurate reservoir characterization of thinly bedded reservoirs. The measured NMR porosity was 15pu, which is 42% of the actual porosity. Using the measured values gave a permeability of 5.3mD as against the actual permeability of 234mD. The novel model presented in this paper increased the porosity by 58% and the permeability by 4315%.

scholarly journals Woman’s Suppression in Azab dan Sengsara: A Feminist Perspective

2017 ◽  
Vol 4 (1) ◽  
pp. 37-51
Author(s):  
Siti Hafsah
Keyword(s):  
Qualitative Method ◽  
Real Life ◽  
Feminist Perspective ◽  
Material Object ◽  
The Novel ◽  
Literary Sociology ◽  
A Company

Azab dan Sengsara is an Indonesian novel written by Merari Siregar (1921), one of the famous roman novelists in Indonesia in Balai Pustaka era. The novel is a material object of the present study. The study aims at revealing oppression, violence, exploitation of woman and all varieties of injustice to woman, revealing social symptoms ideological forms containing in the novel as a manifestation of a company condition in old era. This research uses a qualitative method and approaches of literary feminist and literary sociology as its support. This research succeeds in answering the problems of woman life, as manifestation of real life which reflects kinds of woman’s life in society of Indonesian, for example: marriage, custom, violence, etc. for the hero “Mariamin” (a woman). She is the manifestation of the authority life, besides talking on oppression of woman images of its community lives. The author succeeded offering solutions with various contradictions, conflicts, handling down the novel as manifestation in real life.

scholarly journals Tilsynekomstens politik. Om virkelighedsmodellering i Joseph Conrads Nostromo

2011 ◽  
Vol 39 (111) ◽  
pp. 7-26
Author(s):  
Jonas Kjærgård Laursen
Keyword(s):  
Real Life ◽  
The Novel ◽  
Human Consciousness ◽  
Politics And Literature ◽  
Ideological Criticism ◽  
Jacques Ranciere ◽  
Politics Of Literature ◽  
Material Interests ◽  
Political Problem ◽  
Novelistic Form

POLITICS OF APPEARANCE. ON REALITY MODELLING IN JOSEPH CONRAD’S NOSTROMOArtistically Nostromo is arguably the most ambitious of Joseph Conrad’s novels. It is also without a doubt the most explicitly political in that it openly engages with the question of how capitalism, imperialism, and revolution affect the human consciousness. There is however no agreement as to how this political problem is to be understood or, more precisely, what kind of understanding of the interrelationship between politics and literature is necessary when engaging this artwork. As a necessary supplement to both a 60’s Marxist reading and readings from the 70’s and 80’s dealing with ideological criticism, this article suggests a reading focusing on how the text creates a model of society by reconfiguring certain real life elements. By developing a specific artistic idiom Nostromo attempts to show the very limited view of the whole of society caused by, in the wording of the novel, the material interests of imperial capitalism. Under the inspiration of both Jurij Lotman and Jacques Rancière the analysis presented here is able to address some key political insights that appear as a consequence of the novelistic form when understood as a relatively autonomous model of society. And that is what is meant by the expression politics of appearance: the politics of literature is to be analysed as something generated by the specific gestalt of the text, as something that comes into sight with – and only with – the text.

scholarly journals Filmed Monologue Vignettes: a novel method for investigating how clinicians document consultations in electronic health records

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Simon Glew ◽  
Elizabeth M Ford ◽  
Helen Elizabeth Smith
Keyword(s):  
Real Life ◽  
Correct Selection ◽  
Free Text ◽  
The Novel ◽  
Face To Face ◽  
Full Compliance ◽  
Electronic Healthcare Record ◽  
Novel Method ◽  
Quality Rating ◽  
Selection Of Descriptors

Introduction and Objectives The accuracy of conclusions based on Electronic Healthcare Record (EHR) research is highly dependent on the correct selection of descriptors (codes) by users. We aimed to evaluate the feasibility and acceptability of filmed vignette monologues as a resource-light method of assessing and comparing how different EHR users record the same clinical scenario. Methods Six short monologues of actors portraying patients presenting allergic conditions to their General Practitioners were filmed head-on then electronically distributed for the study; no researcher was present during data collection. The method was assessed by participant uptake, reported ease of completion by participants, compliance with instructions, the receipt of interpretable data by researchers, and participant perceptions of vignette quality, realism and information content. Results 22 participants completed the study, reporting only minor difficulties. 132 screen prints were returned electronically, enabling analysis of codes, free text and EHR features. Participants assigned a quality rating of 7.7/10 (range 2-10) to the vignettes and rated the extent to which vignettes reflected real-life (86-100%). Between 1 and 2 hours were required to complete the task. Full compliance with instructions varied between participants but was largely successful. Conclusions Filmed monologues are a reproducible, standardized method which require few resources, yet allow clear assessment of clinicians’ and EHRs systems’ impact on documentation. The novel nature of this method necessitates clear instructions so participants can fully complete the study without face to face researcher oversight.

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