Background and Aim: It has been several decades since the technology of FREQUENCY lowering (FL) has been proposed. However, primary research has revealed no benefits regarding the use of this technique. Currently, new methods for FL and improvement of perception of speech and fricative sounds have led to the application of these methods by numerous companies to produce hearing aids. In this study, through reviewing the findings of recent studies we introduced several FL techniques used in various companies.Recent Findings: Results of studies conducted since the year 2000 on FL technology suggested that this technology could be used to improve speech perception in cases of high FREQUENCY hearing loss. Today, the majority of hearing aid manufacturers use different FL methods.Conclusion: While the setting principles of FL methods are still vague, improved hearing of fricative sounds has been associated with increased use of this technique by researchers. FL technique has its own benefits and setbacks, understanding of which would facilitate the use of FL techniques and adjustment of hearing aids for hearing-impaired individuals.

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, a distributed generation including diesel generators, wind turbines, and microturbines are introduced, and their mathematical model is described using the Taylor expansion method. With the goal of computational complexity eliminating, the reduced order model (ROM) of microgrid components is considered. The results of the studies indicate that the microgrid FREQUENCY is unstable. The main purpose of this paper is stabilizing the FREQUENCY of the microgrid by design modified LINEAR controller. It is shown that the using proposed LINEAR controller increases the dynamic response of the diesel generator and therefore can be constituted stable microgrid. The results show that the diesel generator can control the FREQUENCY of the microgrid in unwanted islanding and load change conditions. To verify the validity and feasibility of the proposed controller, several simulations results have been presented on MATLAB/Simulink software. The simulation results show the appropriate performance of the proposed controller for example in islanding mode, FREQUENCY restoration time is less than 1 (s) by using the proposed controller, as a result, the microgrid can be exploited in island mode.

In this paper, a LINEAR two-stage adaptive filter is designed in which single-FREQUENCY signal interference (Jammer single FREQUENCY) from messages in throughput wideband signals is removed. As a result, in the proposed system which includes the Doppler Effect, unknown FREQUENCY interference is automatically earned at the entrance and is removed. The proposed system is implemented using two Normalized least mean square (NLMS) LINEAR adaptive filter. The specific innovation of the proposed filter is that even if the jammer with a reference signal FREQUENCY is different, at first it calculates the difference between them. Then the second filter is detected the interference that discover by the first filter which is considered as a reference signal. So, when there is Doppler Effect, the proposed system by combination two filters is accurately detect and easily removed jammer. The simulation results for the proposed interference cancellation system for the broadband QPSK signal which is impregnated with the strong interaction, is achieved. Results show that for the QPSK signal jammer with single-FREQUENCY wideband message is effected on them as a strong interference. The proposed system shows up to 80 dB improvement in the Signal-to-Jammer ratio (SJR). In other words, the proposed system can be effectively used for the defense systems which are installed in front of jammers on a variety of birds.

Background and aim: According to the importance of avoiding injuries to the neurovascular bundles in certain surgical procedures (e.g. placement of implants), an accurate location of the mandibular is neccessary. The aim of the present study was to evaluate and compare between the accuracy of the panoramic spiral tomography in location of the mandibular canal.Methods and materials: In this study, by means of the odonto Rama 2000 (Traphy, French), panoramic radiographies were taken and by means of Cranex tome multifunctional unit (orion corporation Sordex, finland), tomographic slices were taken at 3 different location in each posterior mandible segments (distal to the mental foramen). Then the dry mandibles were sectiond at these 3 sites with specialized desiged drill. The fallowing 2 measurments were performed both on the panoramic radiographies (A, B), tomograms (A’, B’) and the bone sections (A’’, B”) at the 3 sites.Findings: The research was on 6 dry mandibles (36 sites). We found an average mean difference of 3.9 mm with a standard deviation of 1.57 in panoramic radiography and an average mean differences of 0.21mm with a standard deviation of 0.21 in spiral tomography. The report of data showed that 16.4% of cases are in+_0.5mm and 41.4% of cases are in+_1mm (overstimate and underestimate) in panoramic radiography and 94.6% of cases are in+_0.5mm and 97.3% of cases are in+_1mm in spiral tomography. ICC in panoramic radiography was 0.6932 and in spiral tomography was 0.9982 (P<0.001) Conclusion and recommendation: Spiral tomography using the Cranex tome multifunctional x-ray unit provides accurate information and sufficient detailes or preoperative planning of implant in the posterior mandible and this method is recommended for surgures, periodontists and prosthodontists.

Natural disasters threatening and endangering human communities has resulted in the study and research of such disasters through the related sciences and present methods of forecasting their behavior with time and place and also from a qualification and quantity viewpoint. To this end, numerous methods for the determination of the maximum flood in various return periods has been made available which can be refered to as flood FREQUENCY analysis methods. One of these methods is the regional flood FREQUENCY analysis in which instead of using the data from a single station, it considers the data and characteristics of a group of similar stations. In the case under the research this method uses L-Moments and Index Flood in North, Razavi and South Khorasan water basins and MATLAB software. Maximum annual flood statistics were used from 68 Hydrometric stations with minimum and maximum statistical periods of 6 and 39 years. Using Cluster analysis the region under study was divided to 7 partitions. Discordance test has conducted and only one station in region C was found as discordance station. Because of knowing the homogeneity of the regions, the parameter of Kappa distribution were estimated and with using the simulation method of Monte Carlo with 500 times, the homogeneity measure was tested in 7 regions. Using homogeneity test all regions was found homogen. Using goodness-of-fit measure z and Kolmogrove-Smirnov the Log normal 3 parameters distribution were selected for two regions of A and B, GEV for C, Generalized Pareto for D and E, Generalized logistic for F and Pearson III for G. Besides, GEV distribution was found appropriate for all of the regions, only their parameters are different in any regions. For estimating of index flood a logarithmic model has found for each region with 4 variables of area, height, average slop and form factor. Using of these models, the index flood can be estimated in each region and it can be used for standardize the statistics of maximum flood values.

In this research, ground motion analysis and site effect ground motion and site effect analyses were conducted in the south of Yazd city by using geotechnical data, down hole seismic profiles, strong ground motion and accelerograms with regard to changes in FREQUENCY. To estimate the soil non-elastic response and equivalent LINEAR behavior of soil, an iterative loop was utilized. Non-LINEAR behavior of stress-strain means shear modulus change in different ways. The maximum of acceleration records of ground motion in bedrock for a 475 years return period are used for this research work is 0.219 g. Taking the above mentioned return period into consideration, for this borehole the values of resonance FREQUENCY and alluvium resonance ratio were measured as 3.4 and 1.4, respectively. On the basis of average resonance ratios and frequencies obtained from all the models, the amplification of shear waves are intensified in frequencies 3 to 4 Hz with a an amplification ratio 1.6 Vs 30, mean is 360 m/s.

In this work we investigate the n-type single halo implantation in channel of lightly doped drain and source CNTFET (SH-LDDS-CNTFET) and propose the n-type double LINEAR halo implantation in the channel of LDDS-CNTFET. These transistors are simulated with a non-equilibrium Green’s function method. We demonstrate that in the proposed structure the ¦T at the VGS ranges of 0–0.25 V and more than 0.42 V is much higher compared to the LDDS-CNTFET and SH-LDDS-CNTFET and the SH-LDDS-CNTFET, respectively. Finally, simulations demonstrate that the ¦T of the proposed transistor is more than the LDDS-CNTFET at a wide range of VGS, whereas the ¦T of SH-LDDS-CNTFET is more than the LDDSCNTFET for narrow ranges of VGS.