Blind Classification of Space-Time Codes Using Machine Learning
Mehdi
Teimouri
دانشگاه تهران
author
Masoud
Rezaei
دانشگاه تهران
author
text
article
2019
per
For eavesdropping of modern telecommunications systems, which employ multiple transmit and receive antennas, the first step is to recognize the space-time code. In this paper, we propose a method to classify within broad categories of space-time codes. The method is based on machine learning and pattern recognition. Compared to the previous published researches, the novelty of this paper is including quasi-orthogonal space-time codes and also single antenna transmitter in identification set. Moreover, the method described in this paper outperforms the current classification methods. It is shown that the decision tree classifier based on several features extracted from correlation matrices, has practical advantages over the current classification methods, especially when data is very noisy.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
1
10
https://adst.ihu.ac.ir/article_204283_f646976a77ace001a7f624fae26d622e.pdf
A Low-power Wideband Receiver Front-end Employing Active and Passive N-path Filters
Jalil
Mazloum
نیروی هوایی
author
text
article
2019
per
Control, inspection, detection, and transmitting or receiving data in modern defence principles, essentially requires the low-power radio frequency systems with the ability of operating at various communication standards. In this paper, employing the modern method of active and passive N-path filters, a receiver front-end with the ability of tunablity at various standards and frequencies is proposed. In addition to the analysis of conventional and advanced N-path filters, the prior similar structures are discussed in details. Applying some modifications in the previous structure, not only the NF has been improved but also the power consumption has been considerably decreased, while the stability has been guaranteed. To verify the correctness of the proposed receiver front-end, the cadence IC design tool has been used to simulate the system. According to the simulation results, using CMOS90nm transistors, the amount of power consumption has been remarkably decreased with respect to the previous similar structures. The NF and S11 values in the whole of frequency range, DC to 1.85GHz, are less than 3.6dB and -10dB, respectively. The power consumption is less than 15mW including the power consumption of the recombiners. The out of band IIP3 is +8dBm.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
11
18
https://adst.ihu.ac.ir/article_204284_f3a0a02f17b24f6352e1cc7d895ae5e3.pdf
Providing a New Method for Improving Fault Tolerance in Command and Control Networks Using Software Defined Networks
Mohammad Reza
Parsaei
دانشگاه صنعتی شیراز
author
Reza
Javidan
دانشگاه صنعتی شیراز
author
Reza
Sepahvand
دانشگاه صنعتی شیراز
author
text
article
2019
per
It is an imperative necessity to take care of the country's space and air traffic. Usually radar systems will be used to control and discover possible targets. The received information from a radar system in a specific region must be sent online to the higher levels of command and control centers in order to detect possible threats and make appropriate decisions. This exchange of information requires a reliable communication backbone. However, having an online and secure transceiver communication backbone is still a demanding process. Moreover, errors in the current communication networks will cause an increasing percentage of packet loss and delay which affect the Quality of Service (QoS). In this paper, in order to handle these problems and increase the fault tolerance in command and control networks, a backup path is provided that uses the backup path in case of occurring faults in the main path. In addition, Software Defined networks (SDN) as a new architecture have been used in communication networks to provide desirable QoS. In the proposed method, the fault tolerance problem is modeled as a linear programming problem, which is solved through a combinational method of Genetic Algorithm and Fuzzy System. This solution creates an optimal response to dynamic changes and uncertainty accomplished in the communication network. The results of the performance evaluation showed that the proposed method achieves better fault tolerance compared to existing methods.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
19
31
https://adst.ihu.ac.ir/article_204285_e01c327a92265fbc2d7b969ae7b3d14e.pdf
A Novel Method for Improving the Efficiency of a Reflex Triode Tube in a Dominant Mode
S. Mohammd javad
Razavi
دانشگاه صنعتی مالک اشتر
author
Nader
Shafieikhah
دانشگاه صنعتی مالک اشتر
author
text
article
2019
per
Reflex triode tube is one of the varieties of high-power microwave family models. One of the factors that reduces the efficiency of these lamps is the power distribution in non-dominant modes (the dominant mode is TE11), the other important issue is the relative power of the main frequency component, in this paper we first show that by placing two metal plates At the beginning and the end of the anode axis and the cathode, we can simultaneously improve the relative power of the dominant mode and the main frequency. The results indicate an increase in power distribution of about 12% in the dominant mode and 26% in the main frequency.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
33
37
https://adst.ihu.ac.ir/article_204286_6ffff720712179b3f657aa3b5a5975d1.pdf
A Novel Probabilistic Method for Generating Scheduling of Multi-Zone Virtual Power Plants
Saeid
Molaei
دانشگاه سمنان
author
Zahra
Moravej
دانشگاه سمنان
author
text
article
2019
per
Microgrids are practical samples of the concept of decentralized power production. In this regard, after determination of appropriate technologies and the capacity of power generation and storage units for defensive objectives, the optimal scheduling of units in microgrids is of the crical importance. Thus, scheduling of distributed generations and energy storages in form of virtual power plant have gained significant attentions of both owner of these units and the operators of distributions aiming at increasing the system efficiency. This paper proposes a model for the optimal day-ahead scheduling of electrical and thermal units in a large scale virtual power plant. This plant includes a number of combined heat and power units, distribution consumers, a parking for plug-in hybrid electric vehicles with the ability to follow a smart charging pattern, boilers, renewable energy based generators and storage units. The presence of large number of storages, especially electrical vehicles, in these types of microgrids enhances the resiliency of the grids when encountering malicious attacks. Uncertaintie associated with electrical and thermal loads is modeled using a probabilistic programing while Monte-Carlo simulation has been utilized to model uncertainty in the behavior of electrical vehicles. Simulations have accomplished in two scenarios: 1) normal and 2) islanding operation after a deliberate attack. MATLAB software and cuckoo optimization algorithm are used for optimization task in this paper.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
39
53
https://adst.ihu.ac.ir/article_204287_883e4fb9741e19603e04e1e19d2eb254.pdf
Underground Structures Detection with An-Euler and Blakely Methods Based on Gravity Data
tohid
Abdolrazag Zad
دانشگاه تهران
author
mohammad reza
Seif
دانشگاه امام حسین (ع)
author
text
article
2019
per
Determining the position, edges and dimensions of underground tunnels has always been the challenging issues in protecting underground structures. In this paper, the gravity method is used to identify buried cavities and structures. After introducing the method, the gravity data is modeled directly using the horizontal derivatives filter and the Blakely algorithm. After determining the boundaries and corners of the fabricated models, the depth of the anomalies is estimated using the Analytic Signal-Euler (An-Euler) method. A multi-cube model is simulated in multistructure with different depths to evaluate the ability of the gravity method in exploration of structures at different depths. Then, to explore airborne capability, a multi-cube model is simulated at different altitudes. Finally, by exploring the results of this simulation, appropriate solutions have been proposed to reduce the probability of exploration and increase the probability of camouflage of buried structures.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
55
66
https://adst.ihu.ac.ir/article_204288_684c0e04ff2054af5c1e5febe0c63573.pdf
Fabrication of Qualitative Uranium Indicator and Quantitative Evaluation of the Results by Image Processing Method using MATLAB Software
Alireza
Khajeh-Amiri
سازمان تحقیقات و جهادخودکفایی نزاجا
author
text
article
2019
per
In the present study, the uranium qualitative detector package containing Arsenazo and Bromo-PADAP indicators was designed; and also, the metalic ion detector package using Dithizone Indicator was built for detection and determination of some ionic interference via Uranium colorimetric method. The obtained results indicated that the detection limits of Uranium ions were equal to 50 ppm and 20 ppm respectively using detectors containing Arsenazo and Bromo-PADAP indicators. In the acidic media (pH=5), the uranium detectors had good detection performance. The metalic ion detector detected ions such as cobalt (II), copper (II), nickel (II), zinc (II), cadmium and silver until the detection limit 50 ppm. Arsenazo detector was superior to Bromo-PADAP detector for detection of Uranium since it prevented any ionic interference even in very high concentrations which with absorbtion of a solution containing Uranium ion, Arsenazo and Bromo-PADAP detectors in the presence masking agents in buffer solution produced miry green and purple colors respectively. While the operation time for Uranium ion detection in the presence of Arsenazo and Bromo-PADAP detectors was3 minutes and 1 minute respectively. Also, the quantitative evaluations based on image processing methods using MATLAB software show that the experimental results are consistent with the evaluation results.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
67
78
https://adst.ihu.ac.ir/article_204289_56199328d731b47f0c74f681e0c15bed.pdf
Numerical Investigation of Damages on Concrete Canvas Shell under Near-Field Blast
mohammad
fayyaz
دانشگاه جامع امام حسین (ع)
author
Askar
Ghorban nejad
دانشگاه جامع امام حسین (ع)
author
Ferydoon
Khosravi
دانشگاه جامع امام حسین (ع)
author
text
article
2019
per
Concrete Canvas is a flexible concrete impregnated fabric that hardens on hydration to form a thin, durable water proof and fire-resistant concrete layer. Strength properties of Canvas signify that it could be a blast resistant shell. In this paper, to investigate the concrete canvas shell behavior under blast loads, the blast behavior of reinforced concrete slabs are compared with prior experimental abservations using coupled analysis. Then the dynamic behavior of two-way concrete canvas shell under near-field blest load is modeled using finite element method. Analysis resultes illustrates failure development, distribution of diagonal and radial cracks on surface and central deflection of concrete canvas shall. Resultes shows that using concrete canvas shell with proper thickness is more resistant under blast loads than conventional slabs.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
79
87
https://adst.ihu.ac.ir/article_204290_8fa290405b010eb55bbca689e5fb01a9.pdf
Investigating the Effect of Opening on Loaded Explosion
safa
peyman
دانشگاه جامع امام حسین (ع)
author
amin
lotfi
دانشگاه جامع امام حسین (ع)
author
text
article
2019
per
Various structures are subject to explosion for terrorist and non-terrorist reasons. The study of effective factors in reducing the damage caused by the explosion is one of the most important issues of passive defense. One of these factors is the presence of openings in the structure under confined explosion. In this study, the effect of opening on the loading caused by the explosion has been examined in terms of pressure-time and impulse-time graphs. In this regard, using the UFC 3-340-02 regulations and numerical simulation of the AUTODYN hydrocode, the confined explosion of a TNT explosive with different masses in a cubic chamber, with different openings in terms of size and location, has been investigated. The investigation results of the effect of each of the opening position factors specify the number of pop-ups with openings and the size of the opening on the loading exerted on the inner surface of the structure due to the confined explosion. Finally, in addition to determining the parametric optimal optimization, the results of the confined explosion resulting from numerical simulation are compared and examined with the UFC 3-340-02 regulations.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
89
100
https://adst.ihu.ac.ir/article_204291_ead7df8739e1bc23d787f0e97737c315.pdf
Investigating the Effect of Soil Moisture on the Safety of the Underground Shelters against the Waves Caused by Surface Explosion
Vahid
Hosseinitoudeshki
دانشگاه آزاد اسلامی، واحد زنجان
author
Parham
Mehdipour Ghazvini1
دانشگاه آزاد اسلامی، واحد زنجان
author
text
article
2019
per
Underground structures such as sanctuaries and tunnels are considered as important and strategic structures. The response of an underground structure to loading from a surface explosion is a major issue in passive defence. So far, many studies have been carried out on various parameters such as ground response, structure response, field experiments, etc. However, there are still many unknown and vague aspects of the explosion and its impact on the soil and structure environment. In this study, the effect of soil moisture on the safety of an underground shelter has been investigated for the different amount of stress and displacement. Autodine software has been used to model the underground shelter, and two Lagrangian and Eulerian environments have been considered. The chosen explosive charge in this study is 52.16 kg of TNT, and the data is recorded using the gauges enclosed in the model. The results show that increase in the degree of saturation of the soil layer has increased the excessive pressure from the soil, and as a result, the von Mises stress in the concrete and steel system has increased and led to the deterioration of the situation.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
101
111
https://adst.ihu.ac.ir/article_204292_66145a42ca76b45b1dd807f2f7638bbc.pdf
Evaluation of Tunnel Burial Depth and Section Geometry on Decreasing Destructive Effects of Surface Blast
Haddi
Hosseini Nassab
دانشگاه آزاد اسلامی، نیشابور- علوم و تحقیقات خراسان رضوی
author
Seyyed Mojtaba
Movahedifar
دانشگاه آزاد اسلامی واحد نیشابور
author
text
article
2019
per
Underground structures, especially tunnels, are among the most strategic structures for all countries, and they are a potential target of enemy weapons. Therefore, the safety of these structures and the related studies are of the great importance. In the present study, the explosion phenomenon at the surface of the ground and the effect of its wave on the tunnels which are the most important buried structures is investigated by using nonlinear dynamic analysis by ANSYS-AUTODYN software. The effect of the blast wave propagation in soil was simulated with a full geometry in a 3D environment and after ensuring the accuracy of the results, the effect of the tunnel burial depth and the geometry of the cross section in reducing the destructive effects of the explosion on the tunnel were evaluated in a 2D environment. The results indicate that increasing the depth of the buried tunnel and also using sections such as circle, horseshoe, vertical ellipse and egg shape are effective in reducing the destructive effects of the explosion on buried tunnels.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
10
v.
1
no.
2019
113
121
https://adst.ihu.ac.ir/article_204293_adbaf3c84d8edceb31043e679de66506.pdf