scholarly journals Safety or Efficiency? An ECSO Framework of Traffic Organization Optimization for LNG Carriers Entering and Leaving Port

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fan Zhang ◽  
Hang Yu ◽  
Haoran Li ◽  
Liqun Peng ◽  
Tuqiang Zhou
Keyword(s):  
Comparative Analysis ◽  
Service Level ◽  
Liquefied Natural Gas ◽  
Public Concern ◽  
Safety Zone ◽  
Safe Operation ◽  
Or Efficiency ◽  
Marine Industry ◽  
Traffic Organization ◽  
Influence Degree

Liquefied Natural Gas (LNG) is a clean, efficient, and economic energy, which is mainly transported by LNG carriers in the marine industry. Massive storage of LNG has led to public concern about the possible hazards of LNG carriers for people and facilities. This paper aims to determine the appropriate level of a safety zone and to develop an optimized traffic organization scheme. An innovative ECSO framework is proposed to deal with these two tasks. The results of the comparative analysis show that the influence degree of the optimized scheme is 21%, which is distinctly lower than the previous scheme (33%). To some content, the proposed framework can provide meaningful enlightenments for stakeholders to improve port service level and ensure the safe operation of LNG carriers.

scholarly journals Comparative Study of the Identification Methods of the Management System of the Day-Ahead Market of Polish Energy Market S.A.

2021 ◽  
Author(s):  
Radosław Marlęga
Keyword(s):  
Time Series ◽  
Comparative Analysis ◽  
Management System ◽  
System Modeling ◽  
Model Fitting ◽  
Point Of View ◽  
Parametric Models ◽  
Or Efficiency ◽  
Modeling Methods ◽  
Electricity Price Forecasting

Nowadays, identification and neural methods are used more and more often in modeling IT forecasting systems in addition to analytical methods. Six characteristic models used to forecast the Day-Ahead Market system functioning as a transaction management system at the Polish Power Exchange (POLPX) and the Nord Pool Spot market have been selected for comparative analysis. The research was preceded by a detailed discussion of modern criteria used to assess the quality of model fitting to the system, namely: effectiveness, efficiency, and robustness. In the literature, there are two main groups of system modeling methods, namely time series modeling methods and identification modeling methods, including neural modeling methods. Modeling usually results in such models as parametric models and artificial neural networks learned neural models of the Day-Ahead Market, as well as time series models, among others. In the comparative analysis, special attention was paid to the accuracy of the obtained models concerning the system. It has been pointed out that the studied solutions used to measure the accuracy of modeling criteria such as accuracy of fit or efficiency, and did not use the modeling efficiency, which is very important in IT forecasting systems for such large markets as the Day-Ahead Market of POLPX. The search for the best market models, including identification models of the Day-Ahead Market operation that can be used in electricity price forecasting is a very important issue both from the point of view of algorithmic solutions and economical solutions.

The Potential for the Use of Natural Gas and Propane As Alternative Fuels in the Marine Industry

2013 ◽  
Author(s):  
Par Neiburger
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Alternative Fuels ◽  
Alternative Fuel ◽  
Liquefied Natural Gas ◽  
Road Vehicles ◽  
Compressed Natural Gas ◽  
Gaseous Fuels ◽  
Diesel Vehicles ◽  
Marine Industry

Liberator Engine Company, LLC designs, develops and produces alternative fuel engines for vehicles around the globe. The Company’s 6.0 Liter Liberator™ gaseous fuels engine will have the ability to operate on Compressed Natural Gas, Liquefied Natural Gas or Liquid Propane Gas: clean, domestic, economical fuels. The Liberator engine will target OEM on road vehicles, as well as off road applications. The Liberator engine is also an excellent choice for the repower of existing diesel vehicles. The 6.0L Liberator™ engine will serve as a replacement engine for vehicle currently operating on a Cummins 5.9L diesel engine or Mercedes diesel 6.0L engine. Paper published with permission.

scholarly journals Possibility of Applying Business Process Management Methodology in Logistic Processes Optimization

2014 ◽  
Vol 26 (6) ◽  
pp. 507-516 ◽  
Author(s):  
Diana Božić ◽  
Ratko Stanković ◽  
Kristijan Rogić
Keyword(s):  
Comparative Analysis ◽  
Business Process ◽  
Business Process Management ◽  
Process Management ◽  
Service Level ◽  
Synergic Effect ◽  
Workload Distribution ◽  
Managerial Level ◽  
Accurate Quantification

Raising the service level and developing new logistic services require better understanding of logistic processes and possibilities of optimization. Different methodologies have been used for that purpose, while the application of Business Process Management (BPM) methodology is outlined in this paper. Identifying parts of logistic processes that could be optimized is facilitated by applying BPM methodology. It also enables more accurate quantification of impacts of the changes introduced in a particular process or activity on the processes as a whole and to other interacting processes. The application of BPM methodology is demonstrated in the case study, where a solution for logistic processes optimization is suggested and the prospective outcomes are simulated. The results of the logistic process comparative analysis have indicated a synergic effect of different improvements in sub-process on the effectiveness of the process as a whole, both on the operative and managerial level. The respective changes in workload distribution among interacting logistic processes have been quantified according to the same methodology.

scholarly journals Comparative analysis of natural gas imports by pipelines and FSRU terminals

Pomorstvo ◽  
2019 ◽  
Vol 33 (1) ◽  
pp. 110-116
Author(s):  
Filip Jovanović ◽  
Igor Rudan ◽  
Srđan Žuškin ◽  
Matthew Sumner
Keyword(s):  
Comparative Analysis ◽  
Natural Gas ◽  
Energy Supply ◽  
Sustainable Energy ◽  
Liquefied Natural Gas ◽  
Energy Sources ◽  
Energy Market ◽  
Gaseous State ◽  
Feasible Option ◽  
Market Outlook

Natural gas is one of the most sought-after trade commodities in the energy market, mainly due to exploitation of cleaner and sustainable energy sources. The most common transportation method for natural gas imports is either through designated pipelines in its gaseous state or carried in its liquefied state as Liquefied Natural Gas (LNG) by specialized tankers. The analysis and comparison of natural gas import by pipelines and FSRU (Floating Storage and Regasification Unit) terminals is presented in this paper. Pipeline import is currently the cheapest and most feasible option, but it requires significant infrastructural investments, which can affect imports in countries where production is far from the delivery, so alternatively vessels and import terminals are necessary to ensure natural gas imports and energy supply stability. This paper analyses the technology and current market outlook of both natural gas import methods.

scholarly journals Maneuvering qualities of vessels with a wheeled propulsion and steering

2021 ◽  
pp. 154-159
Author(s):  
Л.С. Грошева ◽  
В.И. Мерзляков ◽  
В.И. Плющаев
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Comparative Analysis ◽  
Steering System ◽  
Safe Operation ◽  
Different Types

На судах используются различные типы рулевых устройств – традиционные рули, активные рули, выдвижные колонки, азимутальные подруливающие устройства и пр. В России начали строить колесные суда без традиционного руля. Маневрирование осуществляется путем изменения соотношения частот вращения гребных колес, расположенных по бортам в корме судна - суда с колесным движительно-рулевым комплексом (КДРК). В статье на основе математической модели судна с КДРК проводится сравнительный анализ маневровых характеристик судов с различными видами рулевого устройства – с традиционным рулем, азимутальным подруливающим устройством и КДРК. Было выполнено математическое моделирование стандартных маневров, используемых при испытаниях судов, а именно маневр зигзаг, маневр циркуляция, активное и пассивное торможение. Полученные результаты позволяют утверждать, что суда с КДРК (без традиционного руля) обладают маневровыми характеристиками, обеспечивающими их эффективную и безопасную эксплуатацию. Various types of rudders are used on ships - traditional rudders, active rudders, retractable thrusters, azimuth thrusters, etc. In Russia, they began to build wheeled ships without a traditional rudder. Maneuvering is carried out by changing the ratio of the rotation frequencies of the paddle wheels located along the sides in the stern of the vessel-a vessel with a wheeled propulsion and steering system (WPSS). In the article, on the basis of a mathematical model of a vessel with a WPSS, a comparative analysis of the maneuvering characteristics of vessels with different types of steering gear (a traditional rudder, an azimuth thruster and a WPSS) is carried out. Mathematical modeling of standard maneuvres used in the test of the vessels was performed: the zigzag maneuver, the circulation maneuver, active and passive braking. The results allow us to state that vessels with a WPSS (without a traditional rudder) have maneuvering characteristics that ensure their efficient and safe operation.

scholarly journals Optimal Process Design of Small Scale SMR Process for LNG Vessel

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3677
Author(s):  
Chulmin Hwang ◽  
Taejong Yu ◽  
Youngsub Lim
Keyword(s):  
Comparative Analysis ◽  
Power Consumption ◽  
Process Design ◽  
Liquefied Natural Gas ◽  
Specific Power ◽  
Small Scale ◽  
Fuel Saving ◽  
Specific Power Consumption ◽  
Optimal Process ◽  
Liquefaction Process

Recently, due to regulations on emissions of vessels, fuel is changing to liquefied natural gas (LNG). When using LNG as fuel, it is advantageous in terms of fuel saving and boil-off gas control if a small-scale liquefaction process is installed on the ship. However, due to the limited space, the small-scale liquefaction process for ships has to consider not only efficiency but also simplicity and compactness. In this respect, it is different from the process in onshore liquefaction plants, and research on this is insufficient. Therefore, this paper performs a comparative analysis in terms of efficiency by simplifying the composition of the mixed refrigerant in the liquefaction process. Additionally, a single mixed refrigerant process is used to pursue the compactness of the process. For comparative analysis, the liquefaction process is designed and simulated, and the specific power consumption calculated as the power required to liquefy the unit LNG is used as the objective function to optimize. As a result, it is confirmed that when the number of refrigerants is reduced from 5 to 4, the efficiency is only about a 1% difference, but when it is reduced to 3, the efficiency decreases by 23%, resulting in a decrease in performance.

scholarly journals Comparative Analysis of Variants of Token Bucket Traffic Meter Algorithms for QoS Router using UDP as Traffic Agent

2018 ◽  
pp. 91-104
Author(s):  
Oyetunji M.O. ◽  
Emuoyinbofarhe O.J. ◽  
Oladosu J.B ◽  
Oladeji F.O.
Keyword(s):  
Comparative Analysis ◽  
Loss Rate ◽  
Service Level Agreement ◽  
Network Models ◽  
Packet Delay ◽  
Service Level ◽  
Internet Service ◽  
Anova Model ◽  
Token Bucket ◽  
Traffic Agents

Traffic meter algorithms serve as a means of examining traffic stream’s conformance with service level agreement between customers (traffic sources) and Internet Service provider at the edge router of a differentiated service domain for proper quality of service admission control. This paper presented comparative analysis of variants of token bucket meter algorithms for QoS router using user datagram protocol (UDP) as traffic agents and exponential ON/OFF as traffic generator. The research adopted simulation technique to carry out the design of network models or topologies using the same parameter setting to implement the algorithm of token bucket variants of traffic meter. The following metrics were used for the evaluation: throughput, fairness rate, loss rate and one-way packet delay. The evaluated results were ranked and further subjected to 2-way analysis of variance (ANOVA) model to indicate the significant differences among the traffic meter algorithms. Based on ranking system, TRTCM was ranked first in terms of throughput (with 67117) and fairness rate (with 0.2586) and TBM was ranked first in terms of loss rate (with 74.003) and one-way packet delay (with 0.09304). The 2-way ANOVA model showed the significant differences among the traffic meter algorithms considered for the simulation.

Research on Physical Vulnerability Assessment Method of Grid Infrastructures - Taking Substation as an Example

2014 ◽  
Vol 1044-1045 ◽  
pp. 503-506
Author(s):  
Yong Sheng Men ◽  
Long Zhe Jin ◽  
Xi Yuan Xu
Keyword(s):  
Power System ◽  
Natural Disasters ◽  
Vulnerability Assessment ◽  
Assessment Method ◽  
Grid Infrastructure ◽  
Physical Vulnerability ◽  
Safe Operation ◽  
Factors Affecting ◽  
Grid Infrastructures ◽  
Influence Degree

Grid infrastructure is vulnerable to damage or breakdown by various of natural disasters and man-made disasters to cause a loss of all or parts of the function of power system. In this paper, through the analysis of various factors affecting the hub substation physical vulnerability of hub substation such as human factors, natural disasters and equipment factors, calculate and classifiy the influence degree of each factor on the physical vulnerability. Put forward a series of suitable vulnerability assessment method for China's national hub substation. What’s more, take a specific hub substation for example to verify the assessment methods that provided a basis for safe operation of power facilities and disasters prevention.

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