مجله علوم و فناوری های پدافند نوین
سال یازدهم شماره 3 (پیاپی 41، پاییز 1399)

‎The military decision-making process is very complex and involves uncertainty in the information. Decision makers and players, environmental factors, objectives, strategies and criteria are the important cases for choosing the optimal decision. In this paper, a methodology for military decision-making in different battle situations is described. The modeling of decision-making problems in the conflict between two red and blue forces is expressed in the frameworks of the bi-matrix games. The insider and opponent's strategies are examined and the output of the analysis is placed in two game matrices, separately. Fuzzy theory is used to model the uncertainty resulting from strategies analysis. Using the nearest interval approximation of the fuzzy numbers, the payoffs are written as interval. Then, to compute equilibrium points, two quadratic programming problems are introduced. Finally, model of battle scenario is expressed as a fuzzy bi-matrix game and it's solution is described using the proposed method.

In this paper, a distributed pilot-based power control algorithm is proposed that controls the transmitted power of each user in the uplink direction base on pilot’s measurement in the downlink direction to address the SINR balancing and antennas selection in a multi-user massive MIMO system. In the proposed algorithm, each user chooses a set of antennas of all BSs as their home group antennas and based on their received pilot power, adjust their transmitting power by solving a polynomial equation. The algorithm is performed recursively and after several repetitions, the SINR values of all users converge to the same value in their home group antennas. The simulation results illustrate the improvement in energy efficiency by choosing proper antennas selection and power adjustment.

Cross-Eye jamming is a type of electronic attack techniques. Cross-Eye jamming is analyzed based on Glint's physical phenomenon. This technique generates an angular error in monopulse tracking radars that are resistant to other electronic attack methods. A multiloop retrodirective implementation method has been proposed to obtain the angular permutation error and the appropriate ratio of the JSR in the jammer. In this type of implementation, the length difference of the jammer loop can cause the phase difference of the signal that is sent to the victim radar. The signal phase difference will increase the probability of beacon operation. Beacon operation is a destructive function in cross-eye jamming. In the previous work, the phase difference in the range of -180 to +180 degrees was calculated and analyzed. This analysis increases the computational complexity of the system without the need to impose it. According to this analysis, there is a need for tradeoff between the cross-eye gain and the probability of beacon operation. In this paper, phase difference is considered as a function of baseline length and jammer angle with radar. This analysis is based on the relationships governing the phase difference, path length, and frequency of transmission. This type of analysis has less computational complexity and makes the results more practical. The simulation results by MATLAB show that if dc2≤15m, there will be no chance of beacon operation. On this basis, other jammer parameters can be calculated without the probability of beacon operation to increase cross-eye gain.

In this paper, a simplified model for dual helix cold characteristics (phase velocity and interaction impedance) analysis is presented. The model comprises a conventional circular helix with the center being at a distance of its radius from the envelope center. The cold characteristics of the proposed model are calculated using the sheath field analysis approach. Since the centers of the shifted helix and theenvelope of the proposed model are not coincident, the addition theorem is used for electromagnetic equations. Compared to simulation results of the dual helix in the frequency range of 1-6 GHz, the calculated results of the proposed model show the accuracy ranges of more than %94 and %87 for the phase velocity and interaction impedance, respectively.

This paper proposes a novel plasmonic sensor for biological applications such as single-stranded DNA detection that it is simulated and analyzed using the FDTD method. The sensor detects the adsorption of DNA molecules in the sensing solution (PBS) by changes in the reflectance of the structure. The mechanism of this sensor is based on the variation of refractive index with the absorption of different concentrations of molecules. The proposed structure consists of metal (gold/silver)-indium tin oxide (ITO)-graphene and an assay medium. The results showed that the ITO metal oxide layer plays an important role in the sensor parameters. By optimizing the thicknesses of metals (gold and silver), the metal oxide, and graphene, we obtained the maximum sensitivity of 75 deg/RIU for the gold-graphene-analyte structure and the maximum detection limit of 58.33 for the silver-ITO-analyte structure. The structures proposed in this paper outperform those presented in previous works. Thus, the proposed biosensor is able to open a new window for biomolecule detection.

Coverage problem is one of the location/allocation problems that is used to minimize service point and provide more facilities. The solution for complete coverage is using short-range radio or electromagnetic transducers to improve coverage in areas where topography does not allow long-range transmitter coverage. The most important innovation of this research is the development of a three-dimensional spatial model to optimize the coverage of short-range transmitters in areas out of the coverage of long-range transmitters. The case study is full coverage of a UAV's route to disconnect its communication to the control center. In this model, by identifying the effective parameters of the UAV’s routing and the effective parameters of the transmitter function, a spatial model is developed to optimize the number of transmitters to achieve the highest coverage with the lowest number of transmitters. By using the proposed model, the UAV navigation system is disconnected and the result shows that the number of transmitters with a 90% efficiency decreased by about 30% compared to the conventional models.

The most important parts of any country’s national security, are water and food security. The purpose of this study was to produce and design a toxicological system of water using fish, to protect the drinking water resources and to determine its sensitivity against three types of toxins. In this system, always a sample of water is biologically monitored. The calculations were done by trial and error iterations on two different fish species (tiger barb and tetravirus). As a result, tiger barb fish was introduced as the most appropriate type of fish for using in this system. Also two laser plates were used as transmitter and receiver for electronic parts of the system. The results showed that after entering the toxin into the system, with using tiger barb fish, the alert time of system for concentration of Cyanide (5 ppm) 5 minute and for tree different concentrations of 2,4-D+MCPA herbicide (17.4, 23.2, 34.8 g/l) would be 520, 280, 100 seconds and also for tree different concentrations of Deltamethrin herbicide (0.46, 0.93, 1.99 g/l) would be 220, 160, 60 seconds respectively. These results demonstrate the effectiveness of the system. The performance of the system and its results shows that the use of this system can helps so much in passive defense, maintaining the health of the country’s water supplies and preventing terrorism attacks.

In this paper a novel approach is proposed to predict transient angle stability status without using post-fault data. Since this algorithm uses data measured before the fault clearance, it has the ability to quickly predict the stability status and hence, it provides proper opportunity for system operators and/or special protection systems to implement timely corrective actions to prevent instability and confront malicious attacks. In this method, those measurements provided by Phasor Measurement Units (PMUs) are applied as input to the algorithm to calculate the proposed feature set and apply them to a classifier (Decision Tree or Support Vector Machine) in order to predict the stability status. The results of simulations performed in IEEE 14-bus, IEEE 39-bus, and 16-Machine (68-bus) test systems and comparison of them with previous ones reveal that although the proposed method requires less PMUs, it can predict the stability status more accurately and is an appropriate tool to assess the system security.

Recent advances in the field of information and communication technology (ICT) have led power system's operators to seek assistance from communication network for the continuity of normal operation of this critical infrastructure. However, connecting the communication network to the power system facilitated its operation, but nevertheless caused issues that were not previously apparent. One of these issues is the infection of damage from one infrastructure to another. Sometimes this damage goes so far as not to leave any connection between the infrastructures. In this paper, percolation theory has been used to find the threshold of disconnection of interconnected infrastructures. Two critical infrastructures are modeled as an interconnected network and then it is decomposed into three distinct graphs. By using the adjacency matrices of these three graphs, without actually simulating of any percolation process, the phase change diagram of interconnected network is drawn. Also, the most vital connections between the two infrastructures and the most vulnerable nodes of each infrastructure are identified from the consequences of the present model analysis. These results can be used in code regulation for connection of communication network to the power system.

In this paper, a multidisciplinary Security-Constrained Unit Commitment on a linear AC power flow model using Transmission Switching and Dynamic Line Rating (DLR). Today SCUC is one of the most important issues in the optimal and safe operation of modern electricity markets. This paper presents an improved linear AC power flow model using Transmission Switches (TS) and considering it as a network security constraint with a multi-objective framework for simultaneously applying two objective functions, including minimizing the total operating cost and Minimizing emission of pollutants is provided. Dynamics Thermal Line Rating (DTLR) (with climatic conditions) into the Security-Constrained Unit Commitment using Transmission Switching system, in addition to reducing the Switching and extending the life of the circuit-breaker reduces the cost of operation significantly. In this way, the cost of operating in the DTLR mode is significantly reduced compared to the SLR mode. In order to demonstrate the performance of this model, the proposed method is implemented on the 6- IEEE Bus system using the Gams software.