scholarly journals Optimization of LNG terminal parameters for a wide range of gas tanker sizes: the case of the port of Świnoujście

2019 ◽  
Vol 50 (2) ◽  
pp. 91-100
Author(s):  
Stanisław Gucma ◽  
Maciej Gucma
Keyword(s):  
Traffic Engineering ◽  
Investment Project ◽  
Simulation Method ◽  
Research Problem ◽  
Optimization Criterion ◽  
Cargo Handling ◽  
Narrow Scope ◽  
Wide Range ◽  
Cargo Capacity ◽  
Ship Movement

LNG terminals are built to handle tankers of specific size, with cargo capacities within a narrow scope. This is related to the differences in cargo, fender and mooring systems used for LNG tanker handling of various sizes. The research problem solved in the article is the development of the method for optimal design of a universal LNG cargo handling facility that enables safe operations of LNG tankers in a wide range of cargo capacity that covers almost entire spectrum of global fleet tanker sizes. The article presents a methodology of optimizing the parameters of LNG cargo terminals to accommodate both small bunker ships with cargo capacity of 500 m3 (50 metres in length) to Q-flex type tankers capable of carrying up to 220 000 m3 (320 m in length). The authors have determined conditions for the safe operation of these tankers in sea LNG terminals and described differences in the construction of cargo, fendering and mooring systems. The optimization of both location and terminal parameters for a wide range of gas tanker sizes as well as approach channels leading to the LNG berths was performed using a specially designed two-stage simulation method of optimization. In the first stage the best location of a universal LNG terminal and its berths in the existing port basin is determined. The second stage defines optimal parameters of approach waterways to the berths of a universal LNG terminal. The optimization criterion at both stages was the minimization of the costs to build and to operate a universal LNG terminal. The developed optimization methodology was actually used in the design of the universal LNG terminal in the outer port of Świnoujście. The tests made use of real time simulation (RTS) and non-autonomous models of ships, in which ship movement is controlled by a human (pilot, captain). Simulation tests were performed on a multi-bridge ship handling Polaris simulator with a 3D projection, from Kongsberg Maritime AS. This full-mission bridge simulator (FMBS) is located at the Marine Traffic Engineering Centre, Maritime University of Szczecin. Two simulation ship movement models were built and verified for testing the manoeuvres of port entry and berthing. These are: Q-flex type tanker (length: 320 m) and an LNG bunker ship, 6,000 m3 capacity, 104 m in length. The test results were used in the design of the universal LNG terminal in the outer port of Świnoujście and approach waterways leading to the berths (now this investment project is in progress).

scholarly journals Study on Friction in Automotive Shock Absorbers Part 1: Friction Simulation Using a Dynamic Friction Model in the Contact Zone of an FEM Model

Vehicles ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 212-232
Author(s):  
Ludwig Herzog ◽  
Klaus Augsburg
Keyword(s):  
Ride Comfort ◽  
Viscous Friction ◽  
Simulation Method ◽  
Friction Model ◽  
Model Parameters ◽  
Dynamic Friction ◽  
Friction Modeling ◽  
Shock Absorbers ◽  
Operation Conditions ◽  
Wide Range

The important change in the transition from partial to high automation is that a vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorber with two friction types: The intended viscous friction dissipates the chassis vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In this article, a simulation approach is introduced to model damper friction based on the most friction-relevant parameters. Since damper friction is highly dependent on geometry, which can vary widely, three-dimensional (3D) structural FEM is used to determine the deformations of the damper parts resulting from mounting and varying operation conditions. In the respective contact zones, a dynamic friction model is applied and parameterized based on the single friction point measurements. Subsequent to the parameterization of the overall friction model with geometry data, operation conditions, material properties and friction model parameters, single friction point simulations are performed, analyzed and validated against single friction point measurements. It is shown that this simulation method allows for friction prediction with high accuracy. Consequently, its application enables a wide range of parameters relevant to damper friction to be investigated with significantly increased development efficiency.

نماذج المحاكاة- محاكاة مونتي كارلو- كأسلوب كمي من أساليب النمذجة واتخاذ القرارات - مقاربة نظرية وتطبيقية

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
محمد الأمين ◽  
بن حامد عبد الغني ◽  
مراس محمد
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Quantitative Methods ◽  
Practical Importance ◽  
Investment Project ◽  
Simulation Method ◽  
Period Analysis ◽  
Investment Projects ◽  
Monte Carlo Simulation Model

Our research aims to try to present the modeling mechanisms in the field of simulation and quantitative methods. The research is a presentation of the role of quantitative methods in making investment project evaluation decisions, more than that and is the use of the Monte Carlo simulation model in evaluation and multi-period analysis of investment projects under conditions Risk and uncertainty. And highlighting the theoretical, scientific and practical importance of the Monte Carlo simulation method in particular, and the importance of using quantitative methods in helping to make decisions in general

Uncertainty in Collapse Strength Prediction of Sandwich Pipelines

2021 ◽  
Author(s):  
U. Bhardwaj ◽  
A. P. Teixeira ◽  
C. Guedes Soares
Keyword(s):  
Probabilistic Models ◽  
Uncertainty Propagation ◽  
Simulation Method ◽  
External Pressure ◽  
Design Parameters ◽  
Collapse Strength ◽  
Parameters Uncertainty ◽  
Wide Range ◽  
Model Predictions ◽  
Strength Models

Abstract This paper assesses the uncertainty in the collapse strength of sandwich pipelines under external pressure predicted by various strength models in three categories based on interlayer adhesion conditions. First, the validity of the strength models is verified by comparing their predictions with sandwich pipeline collapse test data and the corresponding model uncertainty factors are derived. Then, a parametric analysis of deterministic collapse strength predictions by models is conducted, illustrating insights of models’ behaviour for a wide range of design configurations. Furthermore, the uncertainty among different model predictions is perceived at different configurations of outer and inner pipes and core thicknesses. A case study of a realistic sandwich pipeline is developed, and probabilistic models are defined to basic design parameters. Uncertainty propagation of models’ predictions is assessed by the Monte Carlo simulation method. Finally, the strength model predictions of sandwich pipelines are compared to that of an equivalent single walled pipe.

scholarly journals A Content Analysis of Blog Posts on Angry Library Patrons

2021 ◽  
Author(s):  
◽  
Iris Marigold Operario
Keyword(s):  
Content Analysis ◽  
Exploratory Study ◽  
Qualitative Content Analysis ◽  
Research Problem ◽  
Staff Members ◽  
Wide Range ◽  
Problem Library ◽  
Library Staff ◽  
Insight Into ◽  
Blog Posts

<p>Research Problem: This exploratory study looks into what is written in blogs regarding angry library patrons. It aims to provide insight on angry library patrons by identifying the themes/issues in the blog posts, the reasons for anger of the library patrons, and to describe the characteristics of the blog post authors. Methodology: A qualitative content analysis was used to analyse the blog posts. The blog search engine Google Blogs was used to search for the relevant blog posts. A sample of 92 individual and organisational blog posts were read and analysed. Results: Three main themes emerged in the analysis of the blog posts: 1) the causes of anger which can either be library-related or due to other patrons; 2) how anger was displayed; and 3) the sentiments of the library staff members towards angry patrons. The blog authors mostly come from North America and have a library background. Implications: Analysing these blog posts provides further insight into angry library patrons which might not otherwise be found in existing anger studies in a library setting and problem library patron research. Uncovering what is said in the blogosphere about angry library patrons will give a picture of a wide range of anger issues which may be relevant for library staff members as they try to better understand angry library patrons. While this study was not able to retrieve as much blog posts from an angry library patron’s perspective as originally planned, a study noting the key difference of opinions between angry library patrons and library staff members could be investigated in the future</p>

Automatic tool selection for milling operations Part 1: Cutting data generation

2000 ◽  
Vol 214 (4) ◽  
pp. 271-282 ◽  
Author(s):  
I D Carpenter ◽  
P G Maropoulos
Keyword(s):  
Tool Life ◽  
Chip Thickness ◽  
Minimum Cost ◽  
Optimization Criterion ◽  
Cnc Machining ◽  
Data Generation ◽  
Tool Selection ◽  
Workpiece Material ◽  
Milling Operations ◽  
Wide Range

The selection of tools and cutting data is a central activity in process planning and is often liable to an element of subjectivity. It is further complicated by the wide range of choice presented by the various operation types and the huge portfolio of cutters and inserts available from many different tool manufacturers. This paper describes a procedure to select consistently and efficiently tools for rough and finish milling operations performed on a computer numerical controlled (CNC) machining centre. A wide range of milling operations is considered, including faces, square shoulders, slots, T-slots, pockets, holes and profiles. An initial set of feasible tools is generated that satisfy the constraints of the tool type, the operation geometry, the insert geometry and carbide grade, the workpiece material and the machine tool capacity. Each tool consists of a holder and one or more indexable carbide inserts. Aggressive cutting data are generated for each feasible tool using a rapid search procedure in the permissible depth/width/feed space for good chip control. The cutting data are further refined by a set of technological constraints, which include tool life, surface finish, machine power and available spindle speeds and feeds. The overall cutting data optimization criterion is selected by the user from minimum cost, maximum production rate or predefined tool life. A new optimization criterion, called ‘harshness’, allows the user to influence the chip thickness that is achieved for any given cutter. Any feasible tools that fail to satisfy all the constraints and optimization criteria are discarded.

Parcel Chemical Carriers: Characteristics and Operation

1981 ◽  
Vol 18 (02) ◽  
pp. 109-126
Author(s):  
R. S. Symon
Keyword(s):  
Configuration Design ◽  
Regulatory Requirements ◽  
Trade Routes ◽  
Cargo Handling ◽  
Wide Range

Parcel chemical carriers are a type of tank ship purpose-built to carry a variety of bulk liquids requiring specialized cargo handling and cargo containments. The ships are designed and built to provide exceptional flexibility of cargo tank use and cargo stowage over a wide range of liquid cargo characteristics. The paper describes the salient and more unique characteristics of this ship type. The manner in which cargo tank configuration design is dependent upon trade routes, regulatory requirements for dangerous cargo, and other special requirements are described. Cargo handling flexibility is reviewed. Operational points particular to this ship type are discussed.

scholarly journals Holographic Interferometer for the Study of Phase Media, Which Has Four Output Channels of Different Sensitivity

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yusupzhan Kh. Ismanov ◽  
Nasipbek K. Dzhamankyzov
Keyword(s):  
Computer Simulation ◽  
Simulation Method ◽  
Talbot Effect ◽  
Complex Phase ◽  
Computer Simulation Method ◽  
Holographic Interferometer ◽  
Wide Range ◽  
Talbot Interferometer ◽  
Spatial Filtration

Computer simulation of the interferometer combining properties of low-sensitive Talbot interferometer and high-sensitive holographic interferometer is considered. The interferometer has four output channels having different sensitivity. Channel sensibility can be varied by means of spatial filtration. The base of the interferometer is the holographic Talbot effect. The efficiency of this interferometer was verified by computer simulation method. Some results of the computer simulation are presented in the article. These results were compared with results obtained in optical experiments under the same conditions. A wide range of sensitivity of the interferometer makes it possible to use the interferometer to study complex phase objects, primarily dynamic media.

Bounds of the Thermal Conductivity in Discontinuously Reinforced Metal-Matrix Composites

2005 ◽  
Vol 475-479 ◽  
pp. 3335-3338
Author(s):  
F. Alhama ◽  
Diego Alcaraz ◽  
S. Gómez-Lopera
Keyword(s):  
Thermal Conductivity ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Computing Time ◽  
Simulation Method ◽  
Matrix Composites ◽  
Limit Values ◽  
Wide Range ◽  
Particulate Reinforced ◽  
Network Simulation Method

A simple model based on the network simulation method is proposed to estimate numerically the thermal conductivity of particulate reinforced metal-matrix composites. The estimation is carried out running the model in the standard Pspice code, the computing time being negligible. The 3-D solid is discretized in 1000 cubic volume elements which represent an acceptable approximation of the shape of the particles. For each reinforcement percentage and each combination of matrix and reinforcement more than 200 tests were carried out, so that the results may be considered close to the exact values. The limit values are scarcely influenced by the effect of the 3-D geometry and basically depend on the amount of the reinforcement. Applications to aluminum and titanium matrix composites reinforced with different types of particles are presented covering a wide range of reinforcement percentages.

Assessing basis risk in index-based longevity swap transactions

2018 ◽  
Vol 13 (1) ◽  
pp. 166-197 ◽  
Author(s):  
Jackie Li ◽  
Johnny Siu-Hang Li ◽  
Chong It Tan ◽  
Leonie Tickle
Keyword(s):  
Risk Reduction ◽  
Structural Changes ◽  
Simulation Method ◽  
Age Effect ◽  
Pension Plans ◽  
Basis Risk ◽  
Wide Range ◽  
Fitting Procedures ◽  
Longevity Swap ◽  
Portfolio Size

AbstractIn this paper, we carry out an investigation on modelling basis risk and measuring risk reduction in a longevity hedge constructed by index-based longevity swaps. We derive the fitting procedures of the M7-M5 and common age effect+Cohorts models and define the level of longevity risk reduction. Based on a wide range of hedging scenarios of pension plans, we find that the risk reduction levels are often around 50%–80% for a large plan, while the risk reduction estimates are usually smaller than 50% for a small plan. Moreover, index-based hedging looks more effective under a more precise hedging scheme. We also perform a detailed sensitivity analysis on the hedging results. The most important modelling features are the behaviour of simulated future variability, portfolio size, speed of reaching coherence, data size and characteristics, simulation method, and mortality structural changes.

scholarly journals Optimization of processes in railways based on the cost management model

2018 ◽  
Vol 216 ◽  
pp. 02009 ◽  
Author(s):  
Valery Vorobyov ◽  
Aleksey Manakov ◽  
Anatoly Reger ◽  
Iuliia Tanaino
Keyword(s):  
Cost Management ◽  
Cost Minimization ◽  
Optimization Criterion ◽  
Railway Network ◽  
Cargo Handling ◽  
Business Operations ◽  
Reconstruction Methods ◽  
Local Functions ◽  
The Cost ◽  
Current Stage

The main aim of activities of the branches of vertically integrated Russian Railways JSC is enhancing of manageability and efficiency of business operations. At the current stage, the issue of optimization of costs for product transportation and facilities maintenance in the system of production and technological processes of the railway network has gained relevance. The purpose of this study is development of a mathematical model for the logistic system of transportation, storage, cargo-handling operations, facilities maintenance and reconstruction. Methods of spatial and dynamic modeling in the structure of end-to-end planning of operations were used in the study. Optimization criterion is aggregate cost minimization. Cost function is proposed in the form of local functions of multiple sections along the railway network. The modeling result consists in determining the plans of transportation and supply with minimum costs.

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