عدم قطعیت

Open Access Article

1 - An Uncertain Distributed Method for Reasoning in Ontologies
F. Anoosha B. Tork Ladani M. A. Nematbakhsh

20.1001.1.16823745.1392.11.2.4.7

Semantic web has been one of the most important research areas of computer science in recent years. The concept of ontology as one of the most elements of semantic web is used to formally describe the domain knowledge and to enable the reasoning capability. Semantic web More

Semantic web has been one of the most important research areas of computer science in recent years. The concept of ontology as one of the most elements of semantic web is used to formally describe the domain knowledge and to enable the reasoning capability. Semantic web is a distributed system and ontologies may be developed on many different nodes, so centralized reasoning is very hard or even impossible in many cases. On the other hand, since the majority of information in semantic web is uncertain, considering the notion of uncertainty in ontological reasoning is crucial. In this paper a method for distributed reasoning in uncertain ontologies is proposed. For this purpose the distributed description logic (DDL) framework and the certainty theory are considered for distributed reasoning and modeling the uncertainty respectively. To evaluate the functionality and performance of the algorithm, we developed a case study on application of the proposed method in purifying the mappings between ontologies. The results show that our algorithm makes the mappings more precise than other similar methods. Manuscript profile

Open Access Article

2 - Placement of AVRs and Reconfiguration of Distribution Networks Simultaneously and Robust Considering Load Uncertainty
M. R. Shakarami Y. Mohammadi Pour

20.1001.1.16823745.1396.15.4.1.6

: In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive More

: In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive power losses, reliability, voltage profile, voltage stability, and load capacity of lines (MVA). Various load levels were incorporated into the objective function to make sure that switch status in reconfiguration and AVR taps and locations would be robust against load variations. This paper also introduced a new method for calculating the load levels with respect to load uncertainty. It also considered all loads based on a voltage-dependent model. Several scenarios are defined to thoroughly assess the proposed approach. Integer particle swarm optimization algorithm (IPSO) was used to solve the mentioned optimization problem. The results obtained by the simulation of 33-bus and 69-bus standard IEEE .radial power distribution networks demonstrated the effectiveness of the proposed approach Manuscript profile

Open Access Article

3 - Cautious Classification of Hyper Rectangular, Hyper Circular, and Hyper Oval with a Maximum Symmetric Margin Relative to the Data Edge
Yahya Forghani M. Hejazi H. Sadoghi Yazdi

20.1001.1.16823745.1398.17.3.9.6

A robust classification model is a non-standard model for classifying learning based on an uncertain data set. An incautious model is said to have any meaningless answer to any classification model in its possible set of possible solutions. The optimal answer for a caut More

A robust classification model is a non-standard model for classifying learning based on an uncertain data set. An incautious model is said to have any meaningless answer to any classification model in its possible set of possible solutions. The optimal answer for a cautious robust classification model for a training data set may not be the hyper-page, in which case it will not be possible to classify the data at the test stage. In this paper, incautious robust classification models are introduced and their problems are investigated and then by changing the loss function of a robust classifier, a cautious robust classification model is presented to prevent incautious. The proposed cautious model is standardized and solutions are provided to reduce the training time and test time. In the experiments, the proposed model was compared with some incautious robust models to classification incomplete training data set, and complete definitive training data set. The results showed that in the incomplete data set, the proposed model had less training time and error rate than incautious models. Also, in the complete definitive data set, the proposed model training time and test time were less than incautious models. The results approved that adding caution to a robust classifier is efficient. Manuscript profile

Open Access Article

4 - Optimal Placement of Energy Storage Systems Taking into Account the Uncertainties of Renewable Energy Generation, Load and Electricity Prices
NAVID TAGHIZADEGAN KALANTARI Yousef Fonooni Morteza Ahangari Hassas

20.1001.1.16823745.1400.19.3.11.2

One of the main goals of distribution network operators is to reduce the cost of operating the network and improve profit. In this paper, the problem of siting and determining the size of energy storage batteries are studied. The constituent components of the objective More

One of the main goals of distribution network operators is to reduce the cost of operating the network and improve profit. In this paper, the problem of siting and determining the size of energy storage batteries are studied. The constituent components of the objective function of the placement problem include the profit from the operation of the distributed generation unit, the profit from the reduction of grid power losses, the cost of installing an energy storage system, and the profit from the reduction of energy purchased from the upstream network. The model used for positioning is based on the probabilistic behavior of solar radiation, energy consumers, and electricity market operators. To model the stochastic nature of the output power of solar power plants, the probability density function has been used, and to model the load and price of electricity, the scenario method has been used. The simulations were performed using MATLAB software. The proposed method can manage the generation of solar power plants using the siting and management of charge and discharge of batteries. Manuscript profile

Open Access Article

5 - Optimal Robust Controller Design for the Electrical Vehicle Charging Process in the Presence of Uncertainty
mahsa karami roohollah barzamini reza sharifi

20.1001.1.16823745.1400.19.4.4.7

Wireless power transmission technology with titles such as contactless power transmission, magnetic coupling power transfer, etc.are known and in fact, this method safely and reliably transmits power in such a way that does not require a mechanical connection between th More

Wireless power transmission technology with titles such as contactless power transmission, magnetic coupling power transfer, etc.are known and in fact, this method safely and reliably transmits power in such a way that does not require a mechanical connection between the source and the load. In this method, power transmission is done wirelessly using resonance induction coupling. By operating the transducer in the resonant mode, it will be possible to transfer a significant amount of power over an air distance of a few tens of centimeters, while the system efficiency is high and the voltage and current stress of the transducer are reasonable. In this paper, by presenting a method based on robust control and meta-heuristic algorithms, we improve the charging process of electric vehicles by considering uncertainty conditions. The simulation results show the better performance of the proposed controller compared to other controllers. Also, in this paper, the effect of connecting the charging station of electric vehicles to the distribution network is investigated by considering the optimal charging and discharging scheduling systems to maximize the economic profit of the vehicles and the charging station. In the proposed method, the best program for charging and discharging cars in order to maximize their profit is extracted based on genetic algorithm. According to the simulation results, optimal charging and discharging planning has reduced the value of losses to the total network energy to load the station in some trains, so that network targets such as losses and voltage deviation index are minimized and voltage stability index is maximized. In this study, minimization of losses, voltage deviation as well as maximization of voltage stability index have been investigated and the optimal location of the station has been obtained by considering these goals along with the profit of the station and vehicles. Finally, according to the results, with the planning of charging and discharging cars, in addition to providing the required charge, the profit of the station and cars has also increased. Manuscript profile

Open Access Article

6 - Robust Planning of False Data Injection Attack on Electricity Markets in Smart Grids
Hamed Badrsimaei R. Hooshmand Soghra Nobakhtian

20.1001.1.16823745.1402.21.2.1.4

False data injection attack (FDIA) is a destructive cyber threat to the economic performance of electricity markets in smart grids. A cyber attacker can make a huge financial profit by implementing an FDIA through penetrating the virtual transactions of the electricity More

False data injection attack (FDIA) is a destructive cyber threat to the economic performance of electricity markets in smart grids. A cyber attacker can make a huge financial profit by implementing an FDIA through penetrating the virtual transactions of the electricity markets and manipulating electricity prices. In this paper, a new approach to planning an absolutely stealthily FDIA is presented with the aim of achieving maximum financial profit from the perspective of a cyber attacker participating in virtual transactions from two markets of day-ahead (DA) and real-time (RT). A common hypothesis in studies of FDIAs against electricity markets is that the attacker has complete information about the smart grid. But the fact is that the attacker has limited resources and can hardly access all the network information. This paper proposes a robust approach in designing an attack strategy under incomplete network information conditions. In particular, it is assumed that the attacker has uncertainties about the network modeling matrices. The validity of the proposed method is evaluated based on the IEEE 14-bus standard system using the Matpower tool. Numerical results confirm the relative success of the proposed attack in cases of varying degrees of incomplete information. Manuscript profile

Open Access Article

7 - Probabilistic Evaluation of Multi-Chamber Arresters Protection Performance for Reduction of Lighting Failures in Overhead Distribution Lines
Ramezan Ali Naghizadeh

20.1001.1.16823745.1401.20.2.13.9

A sophisticated and accurate probabilistic computational procedure for the calculation of lightning failures and evaluation of MCA performance for reduction of failures is implemented in this paper. Calculation of induced overvoltage caused by indirect lightning is impl More

A sophisticated and accurate probabilistic computational procedure for the calculation of lightning failures and evaluation of MCA performance for reduction of failures is implemented in this paper. Calculation of induced overvoltage caused by indirect lightning is implemented based on the Agarwal method with consideration of lossy ground. The Monte Carlo method with backward scenario reduction is implemented to take into account the uncertainty of lightning flash parameters including peak current and front time with the distance of the striking point from the distribution line with applying a proper model for simulation of MCA in ATP-EMTP software. A link is developed between MATLAB and ATP-EMTP software to simulate the numerous generated scenarios and analyze the output results. Different conditions including the insulation strength of the line, the earth conductivity, and the shielding factor of the adjacent objects to the line are also taken into account in calculations. The results are presented in a proper way to make them useful for the determination of lightning-related failure rates and also accurate evaluation of the effectiveness of MCA installation in different conditions of distribution feeders. Manuscript profile

Open Access Article

8 - Reactive Power management in Distribution Network Considering uncertainties in the Presence of Discrete and Continuous Reactive Power Compensator Equipment
mahboobeh etemadizadeh maryam Ramezani H. Falaghi

20.1001.1.16823745.1402.21.2.5.8

The increasing rate of distributed generation resources expansion into power systems and the random nature of these resources have altered the operation and design of these networks, and reactive power management in distribution networks belongs to this category. The us More

The increasing rate of distributed generation resources expansion into power systems and the random nature of these resources have altered the operation and design of these networks, and reactive power management in distribution networks belongs to this category. The use of these resources in distribution networks is not without challenges and the lack of optimal management of reactive power may not bring economic efficiency for the network. Energy storage systems have the potential to solve this problem. Therefore, in this article, reactive power management in a microgrid connected to the main grid, taking into account distributed generation sources, energy storage systems and discrete reactive power compensating equipment, including capacitor banks, taking into account uncertainty in network load and Wind and solar power generation has been done. Finally, the efficiency of the method is demonstrated by numerical examinations on the distribution networks of 33 and 69 IEEE buses and in the GAMS optimization software. Manuscript profile

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