Denoising Method Based on Spectral Subtraction in Time-Frequency Domain

In view of the key problem that a large amount of noise in seismic data can easily induce false anomalies and interpretation errors in seismic exploration, the time-frequency spectrum subtraction (TF-SS) method is adopted into data processing to reduce random noise in seismic data. On this basis, the main frequency information of seismic data is calculated and used to optimize the filtering coefficients. According to the characteristics of effective signal duration between seismic data and voice data, the time-frequency spectrum selection method and filtering coefficient are modified. In addition, simulation tests were conducted by using different S/R, which indicates the effectiveness of the TF-SS in removing the random noise.

An Optimized K-Edge Signal Extraction Method for K-Edge Decomposition Imaging Using a Photon Counting Detector

In K-edge decomposition imaging for the multienergy system with the photon counting detectors (PCDs), the energy bins significantly affect the intensity of the extracted K-edge signal. Optimized energy bins can provide a better K-edge signal to improve the quality of the decomposition images and have the potential to reduce the amount of contrast agents. In this article, we present the Gaussian spectrum selection method (GSSM) for the multienergy K-edge decomposition imaging which can extract an optimized K-edge signal by optimizing energy bins compared with the conventional theoretical attenuation selection method (TASM). GSSM decides the width and locations of the energy bins using a simple but effective model of the imaging system, which takes the degraded energy resolution of the detector and the continuous x-ray spectrum into consideration. Besides, we establish the objective function, difference of attenuation to relative standard deviation ratio (DAR), to determine the optimal energy bins which maximize the K-edge signal. The results show that GSSM gets a better K-edge signal than TASM especially at the lower concentration level of contrast agents. The new method has the potential to improve the contrast and reduce the amount of contrast agents.

Performance Evaluation of Cognitive Internet on Things Under Routing Attacks

Background & Objective:: In past few years, Cognitive Radio (CR) paradigm has emerged as a promising and revolutionary solution to avoid problems of spectrum paucity and inefficiency in spectrum usage. Efficiently utilization of the spectrum offers high network performance. CRs are proficient to identify and adopt the unused spectrum in order to allow secondary users to occupy it without interfering the primary user’s activity. Cognitive Internet on Things (CIoT) is an integration of several technologies and communication solutions which can be effectively realized as Cognitive Radio Adhoc Networks (CRAHN). In CRANH, on-demand routing protocols are the best suitable protocols due to their dynamic feature of available un-utilized channel/spectrum selection. Methods: Here, firstly, Ad-Hoc On-Demand Distance Vector (AODV) routing protocol has been modified and further evaluated to address route selection challenges in CIoT framework. Secondly, the effects on network performance under network layer routing attacks (i.e. blackhole attack, byzantine attack and flooding attacks) are evaluated. Conclusion: The simulations results demonstrate network performance increase with more channels and degrade differently under attacks.

Seed pre-Activation Study by Means of LED Radiation

To study the possibilities of pre-sowing seed activation, irradiation with LEDs emitting in the visible, violet, and near-ultraviolet ranges with a maximum of 405 nm was carried out. As a result of the growing experience, it was found that the height of wheat plants grown from the treated seeds significantly exceeds the control indicators except for the period of 45-55 days. To implement the flow, technology of seed activation with LEDs optoelectronic irradiation unit was developed. The advantages of the given installation are the energy efficiency and of seed treatment efficiency, due to of the optimal radiation spectrum selection and treatment doses.