The Impact of the Second Order Vessel Motion on the Fatigue Life of Steel Catenary Risers

2004 ◽  
Author(s):  
Ghiath Mansour
Keyword(s):  
Fatigue Life ◽  
Early Stage ◽  
Second Order ◽  
Wind Loading ◽  
Coupled Analysis ◽  
Steel Catenary Riser ◽  
Simplified Approach ◽  
First Order ◽  
Vessel Motion ◽  
The Impact

Fatigue is a primary factor in assessing the feasibility of a steel catenary riser solution for production and export of offshore hydrocarbons from floating production systems. The first and second order vessel motion due to wave and wind loading is a major source of fatigue. While the first order motion fatigue can be readily estimated through the vessel response amplitude operators, assessing the impact of the second order motion is time and effort consuming especially in generating the vessel motion time traces, more so for coupled analysis. However, inclusion of the second order motion at early stages of the riser feasibility assessment, when the mooring system design is far from final, is essential in predicting the riser fatigue life. In this article, a simplified approach for estimating the impact of the second order motion at an early stage in the design is presented based on the first order motion analysis and the vessel mean static offsets as obtained from frequency domain analysis.

Optimal Capacitors Placement of Distribution Systems Using 2nd Order Power Loss Sensitivity Analysis and Hierarchical Clustering

2014 ◽  
Vol 986-987 ◽  
pp. 377-382 ◽  
Author(s):  
Hui Min Gao ◽  
Jian Min Zhang ◽  
Chen Xi Wu
Keyword(s):  
Sensitivity Analysis ◽  
Hierarchical Clustering ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Digital Simulation ◽  
Second Order ◽  
First Order ◽  
The Impact

Heuristic methods by first order sensitivity analysis are often used to determine location of capacitors of distribution power system. The selected nodes by first order sensitivity analysis often have virtual high by first order sensitivities, which could not obtain the optimal results. This paper presents an effective method to optimally determine the location and capacities of capacitors of distribution systems, based on an innovative approach by the second order sensitivity analysis and hierarchical clustering. The approach determines the location by the second order sensitivity analysis. Comparing with the traditional method, the new method considers the nonlinear factor of power flow equation and the impact of the latter selected compensation nodes on the previously selected compensation location. This method is tested on a 28-bus distribution system. Digital simulation results show that the reactive power optimization plan with the proposed method is more economic while maintaining the same level of effectiveness.

Argumentation and Reflection in Plato’s Gigantomachia (Sophist 245e6–249d5)

2018 ◽  
Vol 100 (3) ◽  
pp. 241-285
Author(s):  
Daniel Vázquez
Keyword(s):  
Necessary Conditions ◽  
Second Order ◽  
Complex Activity ◽  
Causal Relations ◽  
First Order ◽  
Theoretical Assumptions ◽  
Argumentative Strategies ◽  
New Interpretation ◽  
Argumentative Structure ◽  
The Impact

Abstract This paper argues that Plato’s gigantomachia is simultaneously concerned with first-order arguments about metaphysics and epistemology and with second-order arguments that reflect on the impact of ethical components, argumentative strategies and theoretical assumptions in the conversation. This complex argumentative structure reveals, I suggest, an organic and systematic conception of philosophy where all the elements are interdependent. This interpretation has four consequences, two at the second-order level, and two concerning the first-order arguments. First, it shows that there are methodological and ethical requirements without which philosophy is impossible. Second, it shows that the text does not refute materialism but tries to reflect the necessary conditions to consider possible the existence of incorporeal beings. Third, it argues that the text assumes a conception of knowledge where knowing something is a complex activity composed of two causal relations. Finally, it offers a new interpretation of the overall conclusion of the passage.

Fracture Mechanics Based Mooring Fatigue Analysis for a Semi-Submersible Subjected to Triple Narrow-Band Loading Processes

2019 ◽  
Author(s):  
Xutian Xue ◽  
Nian-Zhong Chen ◽  
Yongchang Pu
Keyword(s):  
Fatigue Life ◽  
Fracture Mechanics ◽  
Fatigue Analysis ◽  
Second Order ◽  
Combination Method ◽  
Mooring System ◽  
Initial Surface ◽  
Loop Current ◽  
Mooring Lines ◽  
First Order

Abstract In the general offshore operating locations, mooring systems are normally considered to be primarily affected by environmental loadings induced by waves, wind and current. WF motion induced by first-order waves, LF motion induced by second-order waves and wind would make the most contribution to the fatigue damage of mooring lines. However, it was reported recently that in the Gulf of Mexico (GoM), the fatigue life of mooring lines can be significantly affected by the vortex induced motion (VIM) induced by loop current. The aim of this presented paper is to address the influence of VIM on fatigue life of the mooring system operating at the central of the GoM through performing a fracture mechanics (FM) based fatigue analysis for an offshore mooring system. A frequency-domain mooring analysis for the semi-submersible is conducted where WF motion induced by first-order waves, LF motion induced by second-order waves and wind, and VIM induced by loop current are taken into account. WF motion, LF motion and VIM are treated as three independent loading processes. A wide-band loading combination method is then used for predicting the loading processes acting on the mooring system combining WF motion, LF motion and VIM. A fracture mechanics based analysis is performed to examine the fatigue life of mooring system, in which initial surface cracks in previous existence are assumed to grow from the surfaces of mooring chain links connecting to the fairleads. The stress intensity factor ranges to estimate the crack growth in the FM based analysis are obtained from a finite element (FE) analysis.

scholarly journals SERVICE DISTRIBUTION AND SATISFACTION TOWARD CUSTOMER LOYALTY

2021 ◽  
Vol 5 (1) ◽  
pp. 113-135
Author(s):  
R. Agoes Kamaroellah ◽  
Anis Eliyana ◽  
Reza Mubarak
Keyword(s):  
Customer Loyalty ◽  
Goodness Of Fit ◽  
Positive Impact ◽  
Second Order ◽  
Service Satisfaction ◽  
Primary Data ◽  
First Order ◽  
Service Distribution ◽  
First Order Phase ◽  
The Impact

Automated Teller Machines (ATMs) are a medium for financial transactions. This study investigates the impact of service distribution and service satisfaction on customer loyalty on ATM usage of the BRI Syariah Sub-Branch Office (KCP) Pamekasan. Data obtained from primary data in ATM user respondents' Form, the data analyzed by SEM with PLS approach. The calculation is carried out in two phases, the first-order phase, and the second-order phase. A validity and reliability test revealed that all three variables were valid and reliable in the first-order phase. At the same time, the second-order phase was used, CFA, and Construct Reliability. Subsequently, an Inner Model test uncovered that the Service Distribution has no significant effect on Customer Loyalty. Contrastively, Service Satisfaction has a significant positive impact on customer loyalty. The goodness of Fit based on R-Square reveals that Service Distribution and Service Satisfaction can explain Service Loyalty at BRI Syariah KCP Pamekasan ATM very well.

Second-Order Flocking Control with Communication Noise

2014 ◽  
Vol 511-512 ◽  
pp. 1077-1080
Author(s):  
Huan Xin Peng ◽  
Bin Liu ◽  
Wen Kai Wang
Keyword(s):  
Second Order ◽  
Consensus Algorithm ◽  
Distributed Consensus ◽  
First Order ◽  
Convergence Performance ◽  
The Impact ◽  
Better Than

In the paper, we analyze the distributed flocking algorithms with communication noise. Under the Boid model, flocking algorithm with communication noise is easy to diverge. In order to improve the convergence performance of flocking algorithms with communication noise, and overcome the impact brought by communication noise on flocking algorithm, in the paper, a distributed flocking algorithm based on SO-DCT distributed consensus algorithm is proposed. The second-order flocking algorithm under the Boid model is analyzed, and simulations are done. Results show that the second-order distributed flocking algorithm can reach cohesion, and its convergence performance is better than that of the first-order distributed flocking algorithm, moreover, the impact of communication noise on the second-order flocking algorithm is smaller.

scholarly journals Teasing Apart Overclaiming, Overconfidence, and Socially Desirable Responding

Assessment ◽  
2017 ◽  
Vol 26 (3) ◽  
pp. 351-363 ◽  
Author(s):  
Doreen Bensch ◽  
Delroy L. Paulhus ◽  
Lazar Stankov ◽  
Matthias Ziegler
Keyword(s):  
Cognitive Ability ◽  
Potential Problem ◽  
Second Order ◽  
Factor Analyses ◽  
Grandiose Narcissism ◽  
Positivity Bias ◽  
First Order ◽  
Potential Indicator ◽  
Exploratory Factor Analyses ◽  
The Impact

Contamination with positivity bias is a potential problem in virtually all areas of psychological assessment. To determine the impact of positivity bias, one common approach is to embed special indicators within one’s assessment battery. Such tools range from social desirability scales to overconfidence measures to the so-called overclaiming technique. Despite the large literature on these different approaches and underlying theoretical notions, little is known about the overall nomological network—in particular, the degree to which these constructs overlap. To this end, a broad spectrum of positivity bias detection tools was administered in low-stakes settings ( N = 798) along with measures of the Big Five, grandiose narcissism, and cognitive ability. Exploratory factor analyses revealed six first-order and two second-order factors. Overclaiming was not loaded by any of the six first-order factors and overconfidence was not explained by either of the two second-order factors. All other measures were confounded with personality and/or cognitive ability. Based on our findings, overclaiming is the most distinct potential indicator of positivity bias and independent of known personality measures.

scholarly journals The Impact of Second-Order FPSO Motions on the Fatigue Performance of Large Diameter SCRs

2019 ◽  
Author(s):  
Rasoul Hejazi ◽  
Andrew Grime ◽  
Mark Randolph ◽  
Mike Efthymiou
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Deep Water ◽  
Large Diameter ◽  
Ocean Waves ◽  
Second Order ◽  
Hydrodynamic Characteristics ◽  
Accurate Estimation ◽  
Gas Field ◽  
The Impact

Abstract Large diameter steel catenary risers (SCRs) are considered a cost efficient export riser solution for gas field developments at deep-water sites. However, SCRs are prone to fatigue damage at their interface with the seabed (the touchdown zone, TDZ) and hence accurate estimation of their fatigue life is crucial. The major source of TDZ fatigue damage is the motions of the host vessel subjected to irregular ocean waves. The first-order interaction between the host vessel and the ocean causes oscillations in all degrees of freedom at the same frequencies as the incident waves. The second-order interactions result in a mean-drift offset from the static equilibrium position in the horizontal plane and slowly-varying cyclic motions about that offset position. This paper investigates the effects of second order motions on the fatigue life of a 26” SCR connected to a representative Floating Production Storage and Offload vessel (FPSO), using realistic environmental conditions relevant for a deep-water site on the Australian Northwest Shelf. A diffraction analysis was performed to obtain the hydrodynamic characteristics of the ship-shaped vessel which was subsequently used as the input into a fully coupled response model consisting of the floater, mooring lines and the SCR. A realistic fatigue wave scatter diagram was adopted, consisting of 100 sea-states combining irregular seas, swell, current and winds. This was combined with dynamic time-domain motion analysis and a rainflow cycle counting algorithm in order to determine the fatigue damage within the SCR TDZ due to the host FPSO motions. The results shows that for this representative system the second-order cyclic low frequency (LF) motions have beneficial impacts on fatigue life of the large diameter SCR. Similarly, mean-offsets of the FPSO have a beneficial effect due to changes in the fatigue hotspot location along the SCR within the TDZ for each sea-state. Finally, a simplified method is presented to capture these beneficial effects at the early design stages.

Coupled Analysis of SCR and Flowline Under High Pressure and High Temperature

2014 ◽  
Author(s):  
C. H. Luk ◽  
Xinhai Qi ◽  
Jianxia Zhong
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermal Stresses ◽  
Dynamic Responses ◽  
Coupled Analysis ◽  
Finite Element Program ◽  
Steel Catenary Riser ◽  
Element Program ◽  
Lateral Displacements ◽  
Vessel Motion

This paper presents a coupled design analysis for a Pipe-in-Pipe (PIP) Steel Catenary Riser (SCR) and Flowline (FL) system in 5000ft of water under high pressure and high temperature (HP/HT) conditions in the Gulf of Mexico (GOM). The finite element program ABAQUS is used to model the inner and outer pipes of the PIP system, the centralizer, the SCR hangoff, the flowline lateral and end supports, and pipe-soil interactions on the seabed. Thermal stresses and stress ranges caused by repeated temperature transients, axial and lateral displacements of SCR and flowline, as well as by the dynamic responses of the coupled riser and flowline system, are presented. Comparisons are also made with results by ABAQUS models with beam and pipe elements, and results obtained by coupled and de-coupled analysis. The sample vessel motion was obtained for an example Spar platform in GOM.

Exploring post-pandemic struggles and recoveries in the rural tourism based on Chinese situation: a perspective from the IAD framework

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haiying Pan ◽  
Meihong Chen ◽  
Wen-Lung Shiau
Keyword(s):  
Collective Action ◽  
Service Providers ◽  
Tourism Industry ◽  
Second Order ◽  
Rural Tourism ◽  
Environmental Resources ◽  
Content Type ◽  
First Order ◽  
The Impact ◽  
Iad Framework

Purpose The public health emergency of COVID-19 (Corona-virus disease) pandemic has greatly impacted tourism industry, especially in the rural tourism. This paper aims to study how rural tourism practitioners can get out of the mire of the pandemic. By analyzing the behaviors of various stakeholders and the logic of the impact of the pandemic, the behaviors of participants and future development were sorted out. The key elements that promote the recovery of rural tourism were discovered. Design/methodology/approach Based on the framework of institute analysis and development (IAD), this research selected six rural tourist communities in China as subjects for the studies. Based on the seven basic principles of hermeneutics and the inductive research method, following the analysis method of “first-order coding, second-order coding, aggregated dimensions,” the texts obtained through in-depth interview and work reports were analyzed and concepts were extracted. Findings The paper extracted 44 first-order concepts and 14 second-order concepts, and obtained 7 aggregation dimensions, including policy formulation and implementation, improvement of integrated marketing capabilities, improvement of tourism product quality, restrictions on rural tourism development, protection and optimization of environmental resources, industrial integration strategies and improvement of managerial and coordinating capabilities. During the pandemic, the government, enterprises and associations, as the service providers of rural tourism, can optimize the environmental resources and industrial resources of rural tourism by formulating policies, refining products and strengthening marketing in the action arena, to promote the industrial integration of rural tourism and provide better products and services for tourists. Originality/value This paper uses the IAD framework to study how rural tourism communities can successfully recover from the impact of the pandemic. It is found that the rapid recovery of rural tourism is the result of collective action. The core of establishing the collective action mechanism of rural tourism is consensus mechanism, co-construction mechanism and sharing mechanism. By studying the path and possibility of collective action of rural tourism communities, this paper explores the approach of multi-center governance of rural tourism communities to promote the imminent recovery of rural tourism.

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