A GPS spoofing attack attempts to deceive a GPS receiver by broadcasting counterfeit GPS signals. Structured to resemble a set of normal GPS signals, but it is a little stronger. In the recent years, there have been presented many different solutions for detection and reduction of spoofing attack. Neural Networks (NNs) are the modern computational method for learning machine and then imposing the acquired knowledge for predicting the output response of complicated systems. This paper presents a main approach to GPS spoofing detection based on intelligent systems. Signals are classified using auto-correlation features. Indices of early-late phase, delta and total signal level as inputs of multi-layer NN in order to detect spoofing signal in GPS receiver tracking loop. Authentic and spoof signals have different statistical pattern in named parameter and NN can detected it. Since NN is able to exploit multiple features from different methods, it classifies signals with error less than the conventional techniques. Finally, the least precision obtained from simulation of NN based GPS software receiver is 98. 78% in correct detection of spoofing signal from valid signal. Moreover, the detection time is less than the existing methods.

Introduction: Usually osseointegration takes between three to six months after implant placement but patients are interested to have early loading. There are no definitive criteria for measuring bone mineral density (BMD), insertion torque (IT) (final torque force) and resonance Frequency analysis (RFA) (primary implant stability) to determine exact loading time based on the relationship between the above-mentioned parameters. The aim of this study was to determine the relationship between IT, RFA and BMD in screw-type implants.Materials and Methods: This clinical trial was conducted on 18 patients who were candidates for ITI implant placement. Written consent was taken and jaw bone density was determined via a digital radiography technique before surgery. After implant placement, RFA and IT were measured. Fifty-five ITI implants of the total 62 implants placed were evaluated; the implants were 12 mm long with a diameter of 4.1 mm. Data was analyzed with Pearson’s test using SPSS.15 software (a=0.05).Results: There was a significant relationship between IT, RFA and BMD. Pearson’s test showed a correlation coefficient of 0.872 to 0.789 between the three parameters, indicating a strong relationship between them. The mean bone density was 1.468±0.042 g/cm2; the mean RFA was 66.01±2.2 ISQ and the mean IT was 34.62±3.33 N/cm2.Conclusion: Based on the results of the present study there is a significant relationship between, IT, RFA and BMD (p value=0.001).

In this paper we propose a new space diversity scheme for broadband PLC systems using orthogonal space-time block coding (OSTBC) transmission combined with Single-carrier Frequency-domain equalization (SC-FDE). To apply this diversity technique to PLC channels, we first propose a new technique for combining SC-FDE with OSTBCs applicable to all dispersive multipath channels impaired by impulsive noise. The proposed technique is then applied to indoor and outdoor PLC channels under different channel scenarios in the presence of background and impulsive noises. We perform the simulations for SISO, MISO and MIMO configurations and show that a significant SNR gain is achieved when SC-FDE is combined with diversity techniques. We also compare our proposed technique with OFDM using Alamouti code for broadband PLC and show the superiority of our technique.

The sonochemical activity of an oxygen bubble formed in an aqueous medium and oscillating under a dual-Frequency excitation is studied in this paper. Several couples of frequencies are formed amongst 35, 140, 300, and 515 kHz, with a maximum acoustic amplitude of 1. 5 atm. The molar yields of the emerging oxidants are analyzed in accordance with the combined frequencies and compared to the cases of mono-Frequency excitations of similar maximum amplitude, i. e., 1. 5 atm. Qualitatively, passing from a mono to a dual-Frequency excitation demonstrated to be with no effect on the predominant species which remain 𝐻 𝑂 • , 𝐻 𝑂 2• , 𝑂 and 𝑂 3. However, the results exhibited a very selective quantitative evolution depending on the combined frequencies. Some couples proved to induce a negative effect and reduce the production at the Single bubble level, particularly with basic frequencies of 140 and 300 kHz, while some others demonstrated a noticeable enhancement such as the couples (35, 140 kHz) and (515, 35 kHz), as compared to mono-Frequency fields.

In this paper we present the problem of designing a three level hub center Network. In our Network, the top level consists of a complete Network where a direct link is between all central hubs. The second and third levels consist of star Networks that connect the hubs to central hubs and the demand nodes to hubs and thus to central hubs, respectively. We model this problem in an incomplete Network environment. In this case, the top level is an incomplete Network where the direct link between all central hubs is not necessary and may lead to lower transportation costs. We propose mixed integer programming model for these problems and conduct a computational study for these two developed models by using the CAB data.