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Performance Comparison of 802.11 and 802.16 Technologies for Video Transmission in NS2-EvalVid

Sueruecue, Dilek | Sueruecue, Murat | Oeztuerk, Ertan

Conference Object | 2008 | 2008 IEEE 16TH SIGNAL PROCESSING, COMMUNICATION AND APPLICATIONS CONFERENCE, VOLS 1 AND 2 , pp.412 - 415

In this study, the video transmission performances of 802.11 and 802.16 technologies are compared by using simulations. The integration of NS2 and EvalVid defined in literature is the simulation tool used in this work 802.16 and EvalVid packets are patched in to NS2. A real video file is converted into MP4 format with preprocessing, then its transmission is simulated over NS2-EvalVid tool for both technologies. The PSNR values obtained by conducting post processing are compared.

Geometric evaluation, automated DEM and orthoimage generation from along-track stereo ASTER images

Marangoz, AM | Buyuksalih, G | Buyuksalih, I | Sefercik, UG | Akcin, H

Conference Object | 2005 | RAST 2005: Proceedings of the 2nd International Conference on Recent Advances in Space Technologies , pp.505 - 510

A cloud-free ASTER scene combination covering 61.5km x 63km Zonguldak testfield in the north-west Turkey has been analysed. It comprises the nadir and backward views with a base-to-height ratio of 0.6. The pixel size on the ground is 15m. The bundle orientation was executed with the related module of PCI Geomatica V9.1.4 software package and resulted the 3D geo-positioning to an accuracy of about 14m in planimetry and 13m in height. This level of accuracy can be provided using the number of GCPs up to 14 which are distributed over the scene uniformly. Based on the scene orientation, a DEM of the area has been determined by an automa . . .tic image matching and PCI system yielded a DEM with 30m cell size. For the validation of extracted DEM, different groups of GCPs selected over the testfield were utilized. In this analysis, GCPs were located in the raster DEM in according to their planimetric coordinates, then the heights are estimated by the bilinear interpolation of the neighboured grid cells. This was done by the program DEMINT and mean square differences was obtained in the range of 12 to 14m. Moreover., matched DEM was checked against reference DEM based on digitised contour lines from the 1:25000 scale topographic maps using program DEMANAL. The discrepancies between the two DEMs were determined as reference DEM minus matched DEM. Then positive biases resulted which show that matched DEM occurred under the reference DEM. These biases appeared also in the superimposition of contours from two DEMs. Image of DZ discrepancies is dispayed as a function of grey values as well and highest residuals occurred mainly at the ridges. In the meantime, RMSE-Z from the comparison of both DEMs obtained very close in the range of +/- 21-22m. Finally, orthoimage was generated using matched DEM and nadir image component of ASTER stereopair without problem. Planimetric accuracy check of this product was realized using the GCPs and shows no systematic error pattern overall Daha fazlası Daha az

Semantic analysis of space imagery for mapping purposes

Karakis, S | Topan, H | Buyuksalih, G | Marangoz, A | Jacobsen, K

Conference Object | 2005 | RAST 2005: Proceedings of the 2nd International Conference on Recent Advances in Space Technologies , pp.500 - 504

From the area around Zonguldak several space images with different ground sampling distance (GSD) from 30m down to 62cm are available. The semantic information of Landsat images is too poor for the generation of topographic maps, while QuickBird images do allow a mapping in the scale I : 5000. Not only the GSD is determining the possible map scale, also the spectral and radiometric resolution is important. The imaging conditions, especially the sun elevation with the corresponding length of shadows, do lead to quite different results especially in cities with narrow streets. The possibilities and limitations of mapping with the diff . . .erent space images, partially with the same image type taken in different month, has been analysed Daha fazlası Daha az

Monitoring of mining induced land subsidence using L- and C-band SAR interferometery

Deguchi, Tomonori | Kato, Masatane | Akcin, Hakan | Kutoglu, Hakan S.

Conference Object | 2007 | IGARSS: 2007 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOLS 1-12: SENSING AND UNDERSTANDING OUR PLANET , pp.500 - 504

In this study, we applied InSAR technique to Zonguldak Hardcoal Basin in Republic of Turkey using JERS1/SAR, RADARSAT and PALSAR data in order to monitor mining induced surface displacement.

Use of Support Vector Machines to Predict the Success of Wart Treatment Methods

Uzun, Rukiye | Isler, Yalcini | Toksan, Mualla

Conference Object | 2018 | 2018 INNOVATIONS IN INTELLIGENT SYSTEMS AND APPLICATIONS CONFERENCE (ASYU) , pp.1 - 4

Warts are virus-based dermatosis that are common in the society. In this study, it was predicted if the method to be applied in the treatment of warts will success or not using a machine learning method. For this purpose, two online and freely available datasets of 180 patients with common warts and plantar warts, who are treated with cryotherapy and immunotherapy methods, were used together. As a result, the algoerithm of support vector machines predicted whether the selected treatment success with an accuracy of 85.46%.

Performance of direct sequence ultra wide band signals over log-normal fading channels

Oeztuerk, Ertan | Yilmaz, Ergin

Conference Object | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.584 - 587

In this paper, the probabilities of error performances of bipolar Direct Sequence Ultra Wide Band (DS-UWB) signals are investigated over a log-normal fading channel. Since the bandwidth of UWB signals is in the level of giga Hertz, the number of the resolvable paths in the channel is large. Consequently, in the receiver, a Rake receiver in conjunction with a maximum ratio combiner is used. By using the derived probability of error expression, the numerical values of the performances are calculated for the first derivative of Gaussian, the second derivative of Gaussian, Rayleigh and Daubechies-5 (db-5) pulse signals. Results show tha . . .t the db-5 pulse based UWB system gives the best performance Daha fazlası Daha az

ASSESS ENT OF HIGH-ORDER IONOPSHERIC EFFECTS ON GPS-ESTIMATED PRECIPITABLE WATER VAPOR

Akgul, Volkan | Jin, Shuanggen | Gurbuz, Gokhan

Conference Object | 2017 | 2017 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS) , pp.4417 - 4420

The precipitable water vapor (PWV) can be estimated from dual-frequency GPS observations, which has been widely used for atmospheric study and weather forecasting. However. high-order ionospheric delays are normally ignored in GPS applications. In this paper, high-order ionospheric effects on GPS-estimated precipitable water vapor are investigated from 30 days of GPS data in June 2011 at 8 GPS stations in Turkey. Firstly, the second- and third-order effects on GPS data are corrected in RINEX using IGRF11 model. and then the precipitable water vapor (PWV) is obtained from raw and corrected RINEX data with GAMIT software. Results show . . . that high-order ionospheric effects arc up to 1 millimeter on PWV during this period. Solar activity is an important effect on ionospheric activities. When data during the peak solar activity days arc used for same stations in 2011, high-order ionospheric effects on PWV is increasing, while low solar activities, high-order ionospheric effects arc much smaller Daha fazlası Daha az

Automatic Transcription of Open String Notes from Violin Recordings

Avci, Kemal | Acuner, Tamer Sevki

Conference Object | 2017 | 2017 25TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.4417 - 4420

In this paper, a study which automatically detects four open string notes of the violin from the recorded violin sounds is presented for the purpose of using in the beginner level violin education. First, in order to be able to analyze the violin sound recordings, it is necessary for the music piece to be segmented into the notes forming the music piece itself For this, it is necessary to correctly determine the starting times (onsets) of the notes. Because of the envelope characteristic that the violin sound has, it is more difficult to detect the note onset than other musical instrument sounds such as piano and guitar. By using th . . .e complex spectral difference method, the note onsets were determined, then by determining the fundamental frequency the note of the violin sound was found. The proposed system was applied to the open string sound tracks obtained from eight people by using the iPad-based professional recording system, and the results showed that the proposed system worked successfully Daha fazlası Daha az

WLAN indoor coverage area simulator

Uysal, Murat | Ozturk, Ertan

Conference Object | 2006 | 2006 IEEE 14TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1 AND 2 , pp.4417 - 4420

In this work, new indoor coverage area simulator for Wireless Local Area Networks (WLAN) is developed. Ray tracing methods used to model indoor propagations give accurate results, on the other hand, these algorithms are much more time consuming due to their high order complexities. A new algorithm decreasing the calculation load of the ray tracing method is implemented in the simulator developed. The walls in buildings whose floor plans drawn by using the graphical user interface of the simulator are grouped with respect to the rooms housing them. With the help of this structure, the number of obstacles considered to determine ray p . . .aths observed are decreased, which results in a decreased calculation load Daha fazlası Daha az

Performance of Shift Register Based Frequency Hopping OFDM Under Doppler Spread

Oturak, Ahmet | Ozturk, Ertan | Yanik, Koray

Conference Object | 2013 | 2013 21ST SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.4417 - 4420

In this work, the performances of Shift Register based Frequency Hopping Orthogonal Frequency Multiplexing (SR-FH-OFDM) signals over a Doppler spread flat Rayleigh channel is investigated. Besides, the frequency hopping system is compared with the conventional OFDM system in terms of Bit Error Rate (BER). In the flat Rayleigh fading channel, a Doppler effect is modeled by Jakes Channel model. Considered baseband modulation techniques are 16 level Quadrature Amplitude Modulation (QAM) and 16 level Phase Shift Keying (PSK). Numerical results show that conventional and the frequency hopping schemes have similar BER results over the con . . .sidered channel Daha fazlası Daha az

Change in response time of neuronal populations with noise, synaptical interactions and stimulus frequency

Özsoy, Muhammet Ali | Uzuntarla, Muhammet | Özer, Mahmut

Proceedings | 2007 | 2007 IEEE 15TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS, VOLS 1-3 , pp.4417 - 4420

Neurons which are the fundamental elements of the nervous system, encode the information about stimulus they received from the external world by sensory system into action potential (spike) sequences before transmitting to the brain. In this study, a neuron population is modeled in mathematical manner and then first spike appearance time in a spike train is examined against changes in the characteristics of the periodic forcing. We also examine the effect of noise which stems from the biophysical structure of neurons and the effect of synaptic coupling which is the consequence of synaptic interaction of neurons with each other in th . . .e population to the appearance time of first spikes. The obtained results show that the mean response time of the population decreases with the increasing frequency. When the intensity of inherent noise in the neuronal environment increased, it shows a decreasing effect on the mean response only for low frequency range of the stimulus. Although the synaptic interaction coefficient does not affect substantially the mean response time of the population, it was shown that it is the fundamental parameter controlling the standard deviation of the response time Daha fazlası Daha az

SEIGA Technique for Multiple Access Interference Computation in DS-CDMA Systems

Oturak, Ahmet | Ozturk, Ertan | Demirkol, Askin

Conference Object | 2009 | 2009 IEEE 17TH SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE, VOLS 1 AND 2 , pp.4417 - 4420

In literature, the performance of Direct Sequence Code Division Multiple Access (DS-CDMA) systems over multipath fading channels are evaluated by using Standard Gaussian Approximation (SGA) and Simplified Expression of Improved Gaussian Approximation (SEIGA). Especially, time-limited DS-CDMA chip waveforms are employed in the analysis by using SEIGA. In this work, the performance analysis of DS-CDMA signals having time-limited and band-limited (used in third generation communication) chip waveforms are conducted over multi-path Rayleigh fading channels by utilizing SEIGA method. The effects of classical time-limited chip waveforms a . . .nd band-limited square root raised cosine (SRRC) on the Bit Error Rate (BER) performance are compared. The obtained numerical results show that time-limited raised cosine gives the best performance, whereas band-limited SRRC gives the worst in terms of the BER over Rayleigh fading channels Daha fazlası Daha az

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