A New Adaptive Steganographic Method with Scalable Capacity and High Vision Quality
Rahman
Soleimani
دانشگاه آزاد
author
Sara
Haghbin
دانشگاه آزاد مشهد
author
masood
Niazi
دانشگاه آزاد مشد
author
text
article
2013
per
In the present paper, a new adaptive steganographic method has been proposed to embed secret data in an image. Proposed method allows the user to set algorithm parameters in a way that reducing the distortion resulted from stegnanography in the image in spite of embedding secret data in all pixels of image, considering size of secret data required for sending to destination. These parameters can be also used as a secret steganographic key. In this method, considering the human vision system, more secrete data bits are embedded in edged areas of image than in its smooth ones. In the proposed method, blocks are classified into different groups based on the extent of local complexity of pixels, and the capacity of each group is determined by total size of secret data. This method is also resistant to statistical and histogram steganalysis attack.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
1
14
https://adst.ihu.ac.ir/article_204083_eba138a734d8701d3f478eba474fa5c0.pdf
Increasing Spectrum Sensing Accuracy by Improved Energy Detector in Cognitive Radio Communication Networks
Yasoub
Eghbali
دانشگاه صنعتی خواجه نصیر
author
text
article
2013
per
Energy detector is a simple detector for spectrum sensing in cognitive radio networks, and is used widely in wireless communication systems. In this paper, an improved energy detector for spectrum sensing is investigated. Improved energy detector makes decisions about spectrum, based on calculation of the optimal norm of received signal’s samples. In order to reduce the interference and improve the spectrum reuse, an optimum threshold for the improved energy detector is obtained. Throughput is an important factor in cognitive radio networks, which shows the effectiveness of a network. Numerical results show the throughput increases by using improved energy detector compared to the traditional energy detector.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
15
21
https://adst.ihu.ac.ir/article_204084_9d5701911a79f88ff7594457528c3f25.pdf
The Effect of the Broadband Jammer on a Distributed Beamforming Performance in a Relay Network
Mehdi
cheraghi
دانشگاه امام حسین
author
sajjad
imani
دانشگاه امام حسین
author
text
article
2013
per
In this paper, the effect of the broadband jammer is considered in two relay communications networks for various positions of the jammer. The first and second network has one and r relays, respectively. In both networks, each relay has one antenna and use Amplify and Forward (AF) protocol to transmit messages. Each of the source and the destination uses one antenna to send and receive messages, respectively. In the first network, the source transmits its signal in two relay-link and direct-link path stoward the destination. In the second network, each relay transmits its received signal after adjusting its power toward the destination. Simulation results show for the first network that when a jammer is close to the source, the jamming effect increases, and in the second network, if the jammer is near to relays, quality of service decrease.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
23
30
https://adst.ihu.ac.ir/article_204085_0bd26b28856a4ddee0d92ff24be83132.pdf
Thermodynamic Study of Carboxy Terminal of Botulinum Neurotoxin Type E by Circular Dichroism Spectroscopy
M.
Rostamian
دانشگاه جامع امام حسین (ع)
author
S. J.
Mousavy
دانشگاه جامع امام حسین (ع)
author
F.
Ebrahimi
دانشگاه جامع امام حسین (ع)
author
text
article
2013
per
Nowadays for prevention of botulism syndrome, researchers have tended to use recombinant vaccines. One of these vaccines is a recombinant protein containing 93 amino acids of C-terminal of botulinum neurotoxin type E (rBoNT/E-HCC). In this study, after expression and purification of rBoNT/E-HCC, the effect of different pH on the protein was carried out by Circular dichroism (CD) spectrometry and followed by thermodynamics studies. The main goal was, to find the optimum purification condition for this protein and also to evaluate the possibility of using this protein as an oral vaccine. For this purpose, thermal danaturation of rBoNT/E-HCC was studied at four different pH (2, 5, 7.4, and 9) by CD. Our results indicated that Tm and ∆G° of rBoNT/E-HCC are higher in alkaline pH in comparison with acidic pH. Finally, our results suggest that neutral or alkaline pH as the optimum pH for rBoNT/E-HCC purification.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
31
38
https://adst.ihu.ac.ir/article_204086_efb9b7ecb4fc78f54a3441871e8eb8b2.pdf
Assessment of Grouting Effect on Resistance of Underground Spaces Against Blast Loading
hamed
hoseinpour
دانشگاه علم و صنعت
author
hosein
mirzeinaly
دانشگاه مالک اشتر
author
text
article
2013
per
Shelters and underground spaces are among the options to come out from the crisis situation in natural and military disasters. In recent years, from the passive defense viewpoint, buried structures have been considered as safe structures against the air and missile attacks. From this perspective, these structures are a part of the main facilities in peacetime and are important factors to save lives in the event of a natural disaster and during the wars. In this study, the effects of grouting around a tunnel to reduce the impact of blast loads on the tunnel structure is evaluated by the numerical modeling software FLAC 2D, in a part of line 7 of the Tehran subway. Intended specifications for the soil around the tunnel, are the results of uniaxial compression tests conducted on some soil samples made from the Tehran alluvial type C. Finally by carrying out an interpolation in the MATLAB software, two equations have been derived to predict displacement and stresses of the tunnel lining (due to the various parameters of the soil, tunnel and bomb) in order to use in the initial stages of tunnel designing for this purpose.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
39
49
https://adst.ihu.ac.ir/article_204087_cc1486293d1602378a6f06459a41e5cb.pdf
A Data Mining Model for Anomaly Detection of Satellite Launch Vehicle
Sina
Dami
دانشگاه صنعتی مالک اشتر
author
Hossein
Shirazi
دانشگاه صنعتی مالک اشتر
author
Mojtaba
Hoseini
دانشگاه صنعتی مالک اشتر
author
text
article
2013
per
Anomaly detection refers to the problem of finding patterns in data that do not conform to expected behavior. Development of advanced anomaly detection and failure diagnosis technologies for satellite launch vehicle (SLV) is a quite significant issue in the aerospace industry, because the space environment is harsh, distant and uncertain.Current SLV health monitoring and fault diagnosis practices involve around-the-clock limit-checking or simple trend analysis using text or graphical displays on large amount of telemetry data. This procedure, which requires large numbers of human experts, is of course cumbersome and time-consuming. Furthermore, humans are not always able to recognize anomalous situations. In this paper, a systematic and transparent diagnostic methodology will be proposed and developed within intelligent anomaly detectioon framework for SLV health monitoring. Experimental results show that the proposed method is capable of characterizing and monitoring interactions between multiple spacecraft parameters and can provide additional insight and valuable decision support for controllers and engineers.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
51
63
https://adst.ihu.ac.ir/article_204088_b7e97675d1ca38a903f3ddd0f876e110.pdf
Investigating the Phase Behavior of Medetomidine Hydrochloride, Ketamine Hydrochloride and Sevoflurane in the Presence of Ethanol and Propellant
mohammad saleh
Abazari
author
text
article
2013
per
In this paper, the phase behavior of mixture of sevoflurane (Sev), medetomidine hydrochloride (Med), ketamine hydrochloride (Ket) in the presence of ethanol and propellants (Propane or HFC134a) is investigated and optimal formulations consisting of drug, solvent (ethanol), propane or HFC134a were achieved. For this purpose, firstly, the phase behavior of various components of the formulation was examined in different temperatures. According to the results, the optimized drug formulation with highest possible concentration of drugs (in w/w%) having single phase behavior was determined. Thus, optimized formulation of Med 5% in propane, Med 10% in HFC134a and Ket 1.5% in propane and HFC134a have been obtained. Addition of Sev to the formulation afforded optimized formulation of Med 4% - Sev 54% in propane, Med 3% - Sev 35% in HFC134a and Ket 2% - Sev 19% in propane and HFC134a.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
65
70
https://adst.ihu.ac.ir/article_204089_c3307de414429c4abb5fb94b6f007afe.pdf
Simulation and Analysis of Species in Electric Discharge Region and Calculation of Singlet Oxygen (O2 (A 1Îg)) Yield for an Electric Discharge Oxygen - Iodine Laser
Javad
Khalilzadeh
دانشگاه امام حسین(ع)
author
Jabbar
Saydi
دانشگاه امام حسین(ع)
author
text
article
2013
per
In this paper, the effect of discharge region temperature on the yield of singlet oxygen (O2 (a 1∆g)) in an electric discharge oxygen iodine laser is theoretically studied to analyze optimum discharge conditions. This study, was done by considering the saturation of O2 (a 1∆g) due to super-elastic electron collisions and O2 (a 1∆g) dissociation by electron impact. Rate equations were solved using two terms approximation of Boltzmann equation. The results show that when the electron temperature was in the Te= 1.9-2.1 eV range, it causes removing the main part of the atomic oxygen O (3P) from the discharge region, and the maximum yield of O2 (a 1∆g) was obtained to be about 45%.
Journal of Advanced Defense Science & Technology
Imam Hussein University
2676-2935
4
v.
1
no.
2013
71
76
https://adst.ihu.ac.ir/article_204090_e50c0406b6ef7df9fb6edc6eaa378b25.pdf