scholarly journals The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes

2021 ◽  
Vol 28 (1) ◽  
pp. 116-126
Author(s):  
Jerzy Girtler ◽  
Jacek Rudnicki
Keyword(s):  
Decision Making ◽  
Power Plant ◽  
Transition Process ◽  
Expected Profit ◽  
State Transitions ◽  
Dynamic Programming Method ◽  
Time Interval ◽  
Operation Process ◽  
Operating Decisions ◽  
Device Operation

Abstract The article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device (ek, k = 1, 2, 3, 4), and the transition process of its technical states (sl, l = 1, 2, 3). The operational states ek (k = 1, 2, 3, 4) have the following interpretation: e1 – active operation state resulting from the task performed by the device, e2 – state of ready-to-operate stop of the device, e3 – state of planned preventive service of the device, e4 – state of unplanned service of the device, forced by its damage. Whereas the interpretation of the technical states sl (l = 1, 2, 3) is as follows: s1 – state of full serviceability of the device, s2 – state of partial serviceability of the device, and s3 – state of unserviceability of the device. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed which justifies the use of this model to examine real state transitions in marine power plant device operation processes. The article shows the possibility to make operating decisions ensuring a rational course of the device operation process when the proposed model of this process and the dynamic programming method based on the Bellman’s principle of optimality are applied. The optimisation criterion adopted when making operating decisions is the expected profit to be gained as a result of functioning of the device in the time interval [τ0, τm], being the sum of the expected profit gained in interval [τ0, τ1] and to be gained in interval [τ1, τm].

scholarly journals Limiting Distribution of the Three-State Semi-Markov Model of Technical State Transitions of Ship Power Plant Machines and its Applicability in Operational Decision-Making

2020 ◽  
Vol 27 (2) ◽  
pp. 136-144
Author(s):  
Jerzy Girtler
Keyword(s):  
Decision Making ◽  
Statistical Theory ◽  
Power Plant ◽  
Markov Model ◽  
Power Plants ◽  
Preventive Service ◽  
State Transitions ◽  
Gamma Distributions ◽  
Operational Decision Making ◽  
Transition Times

AbstractThe article presents the three-state semi-Markov model of the process {W(t): t ≥ 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application of this model to examine models of real state transitions of ship power plant machines. Empirical data concerning ME were used for calculating limiting probabilities for the process {W(t): t ≥ 0}. The applicability of these probabilities in decision making with the assistance of the Bayesian statistical theory is demonstrated. The probabilities were calculated using a procedure included in the computational software MATHEMATICA, taking into consideration the fact that the random variables representing state transition times of the process {W(t): t ≥ 0} have gamma distributions. The usefulness of the Bayesian statistical theory in operational decision-making concerning ship power plants is shown using a decision dendrite which maps ME states and consequences of particular decisions, thus making it possible to choose between the following two decisions: d1 – first perform a relevant preventive service of the engine to restore its state and then perform the commissioned task within the time limit determined by the customer, and d2 – omit the preventive service and start performing the commissioned task.

scholarly journals Evaluation of Optimal Occasional Tilt on Photovoltaic Power Plant Energy Efficiency and Land Use Requirements, Iran

2021 ◽  
Vol 13 (18) ◽  
pp. 10213
Author(s):  
Amirhossein Fathi ◽  
Masoomeh Bararzadeh Ledari ◽  
Yadollah Saboohi
Keyword(s):  
Power Plant ◽  
Solar Radiation ◽  
Solar Energy ◽  
Orientation Angle ◽  
Optimum Operating ◽  
Time Interval ◽  
Time Intervals ◽  
Optimum Time ◽  
Equal Time ◽  
Geographical Regions

The paper studies the optimum panel horizontal orientation angle toward the Sun and the optimum time interval of the panel’s movement. The optimum time intervals or panel movement can change the rate of input energy to the panel surface in Iran. For this purpose, a neural network has been trained to estimate the intensity of solar radiation in Iran. After model validation, the intensity of solar radiation has been estimated by selecting adequate geographical regions. Based on the intensity of sunlight, Iran has been divided into ten regions. In these regions, 40 cities have been randomly selected to study the effect of the panel’s angle variations within appropriate time intervals, as well as equal time intervals. The results show that the choice of the mounting system with the possibility of five angles’ implementation can increase the amount of solar energy between 3.9% and 7.4%. Compared to this number of angles at the equal time intervals, the amount of incoming solar energy has increased by 3% to 7%. In the first and second cases, the area of the power plant increases by about 12% to 24% compared to the yearly optimum tilt angle. Moreover, the amount of radiation incoming to the panel with the optimum operating angle is in alignment with the results of PVsyst software.

scholarly journals Capacity Allocation and Compensation in a Dual-Channel Supply Chain under Uncertain Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Jiaquan Yang ◽  
Xumei Zhang ◽  
Yating Huang ◽  
Jiafu Su ◽  
Sang-Bing Tsai ◽  
...  
Keyword(s):  
Decision Making ◽  
Supply Chain ◽  
Expected Profit ◽  
Decision Making Process ◽  
Direct Selling ◽  
Channel Conflict ◽  
Dual Channel ◽  
Decentralized Decision Making ◽  
Capacity Uncertainty ◽  
Dual Channel Supply Chain

The dual-channel supply chain is widely adopted by main manufacturers, potentially incurring channel conflicts between the traditional retail channel which is owned by the independent retailer and the online channel which is directly managed by the manufacturer. The purpose of this paper is to deal with the scenario where channel conflicts may arise under production capacity uncertainty, when the manufacturer tends to privilege the direct selling channel over the retail selling channel. To achieve the goal, this paper establishes a Stackelberg game model consisting of a manufacturer and a retailer, studies the scenario where the manufacturer satisfies the direct selling channel first in the presence of capacity uncertainty, employs the decision optimization and the backward induction method to find the optimal inventory decision in the direct selling channel and the optimal order quantity decision making in the retail selling channel, and designs a compensation mechanism aiming to coordinate the channel conflict in the decentralized decision-making process. Results show that the optimal decisions aiming to maximize the expected profit of each supply chain member are not able to maximize the expected profit of entire dual-channel supply chain. However, when the manufacturer compensates the retailer’s profit loss based on the unsatisfied order and, in the meantime, adjusts the wholesale price to prevent the retailer which obtains the compensation from increasing order significantly, the compensation mechanism can coordinate the decision of each supply chain member, mitigate the channel conflict, maximize the expected profit of entire dual-channel supply chain, and achieve the Pareto improvement of supply chain members’ expected profit in the decentralized decision-making process.

scholarly journals Risk analysis with the usage of IT system TURAWA

2018 ◽  
Vol 210 ◽  
pp. 04008
Author(s):  
Marta Woch ◽  
Justyna Tomaszewska ◽  
Jarosław Wójcik ◽  
Mariusz Zieja
Keyword(s):  
Decision Making ◽  
Risk Analysis ◽  
Human Factor ◽  
Air Transportation ◽  
Absolute Number ◽  
Operation Process ◽  
The World ◽  
Failure Event ◽  
Potential Failure ◽  
Different Parts

In the time of globalization and the continuous travelling of people between different parts of the world, air transportation is becoming one of the most important modes of transport. Nevertheless, it is crucial to continuously improve the level of safety and reduce the absolute number of accidents and their victims. The risk analysis with the usage of IT system TURAWA, which was developed to collect the aircraft’s accidents informations, has been discussed in the presented article. Calculation of risk is based on the data sample collected in the operation process. The implementation of the risk of potential failure event in TURAWA is presented and compared with the prediction of such situation by the decision trees. It has been concluded that models should be developed, which cause in the elimination of the human factor from the decision making chain.

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