• Journal of the Semiconductor & Display Technology
• /
• v.15 no.1
• /
• pp.47-51
• /
• 2016

Human visual system infers 3D vision through stereo disparity in the stereoscopic images, and stereo visioning are recently being used in consumer electronics which has resulted in much research in the application field. Basically, stereo vision system consists of four processes, which are cost computation, cost aggregation, disparity calculation, and disparity refinement. In this paper, we present and evaluate the existing various methods, focusing on cost aggregation for stereo vision system to comparatively analyze the performance of their algorithms for a given set of resources. Experiments show that Normalized Cross Correlation and Zero-Mean Normalized Cross Correlation provide higher accuracy, however they are computationally heavy for embedded system in the real time systems. Sum of Absolute Difference and Sum of Squared Difference are more suitable selection for embedded system, but they should be required on improvement to apply to the real world system.

• The KIPS Transactions:PartB
• /
• v.10B no.1
• /
• pp.73-80
• /
• 2003

In this paper we propose an algorithm which matches the corresponding feature points between the reference image and the search image. We use Harris's corner detector to find the feature points in both image. For each feature point in the reference image, we can extract the candidate matching points as feature points in the starch image which the normalized correlation coefficient goes greater than a threshold. Finally we determine a corresponding feature points among candidate points by using dynamic programming. In experiments we show results that match feature points in synthetic image and real image.

• Tribology and Lubricants
• /
• v.11 no.1
• /
• pp.27-36
• /
• 1995

Maximum allowable PV values of oilless composite bearing materials (70% epoxy-resin/30% Graphite) were measured and compared at various types of test rigs that have different contact geometry and the operating conditions. Test results showed that material failure was mainly characterized by the sharp increase in both coefficient of friction and surface temperature, and different PV values were measured under different Contact geometry. The discrepancy in measurement of PV values was analyzed in the light of theoretical frictional heating analysis. Results show that surface temperature rise depends on its contact geometry, and PV values could be overestimated in the testing conditions of high sliding velocity. Test data of different contact geometry were normalized by using a normalized contact pressure and sliding velocity; it showed a good correlation. This work suggests that normalized PV values could be more effective in evaluating bearing materials than conventional PV values for a design parameter of journal bearings.

• Structural Engineering and Mechanics
• /
• v.50 no.2
• /
• pp.231-240
• /
• 2014

In the present research, fatigue behavior of chopped strand mat/epoxy composites has been studied with two different techniques. First, the normalized stiffness degradation approach as a well-known model for unidirectional and laminated composites was utilized to predict the fatigue behavior of chopped strand mat/epoxy composites. Then, the capability of the fatigue damage accumulation model for chopped strand mat/epoxy composites was investigated. A series of tests has been performed at different stress levels to evaluate both models with the obtained results. The results of evaluation indicate a better correlation of the normalized stiffness degradation technique with experimental results in comparison with the fatigue damage accumulation model.

• The Journal of the Acoustical Society of Korea
• /
• v.31 no.7
• /
• pp.427-434
• /
• 2012

The overlap-add technique based on waveform similarity (WSOLA) method is known to be an efficient high-quality algorithm for time scaling of speech signal. The computational load of WSOLA is concentrated on the repeated normalized cross-correlation (NCC) calculation to evaluate the similarity between two signal waveforms. To reduce the computational complexity of WSOLA, this paper proposes a fast NCC computation method, in which NCC is obtained through pre-calculated sum tables to eliminate redundancy of repeated NCC calculations in the adjacent regions. While the denominator part of NCC has much redundancy irrespective of the time-scale factor, the numerator part of NCC has less redundancy and the amount of redundancy is dependent on both the time-scale factor and optimal shift value, thereby requiring more sophisticated algorithm for fast computation. The simulation results show that the proposed method reduces about 40%, 47% and 52% of the WSOLA execution time for the time-scale compression, 2 and 3 times time-scale expansions, respectively, while maintaining exactly the same speech quality of the conventional WSOLA.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.48 no.4
• /
• pp.6-13
• /
• 2011

Due to its robustness to illumination change, normalized cross-correlation based similarity measurement is widely used in many machine vision applications. However, its inefficient computation structure is not adequate for real-time embedded vision system. In this paper, we present an efficient hardware architecture based on a normalized cross correlation (NCC) for fast image similarity measure. The proposed architecture simplifies window-sum process of the NCC using the integral-image. Relieving the overhead to constructing integral image, we make it possible to process integral image construction at the same time that pixel sequences are inputted. Also the proposed segmented integral image method can reduce the buffer size for storing integral image data.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.7
• /
• pp.605-618
• /
• 2012

In this study, the possibility of decision error is investigated to identify and improve the reliability of participants in the process of conducting the sound quality analysis for laser printers. So far, there is not a way to identify and express the possibility of individual participant quantitatively. Thus, the decision error model is proposed which is based on the expectation value between the perceived sounds. Through the experimental verification on the laser printers, it was found that the possibility of decision error is affected according to the normalized difference. The possibility of decision error has inversely proportional to the normalized difference between the perceived sounds. When the normalized difference becomes small value, the uncertainly between decisions is inversely increase, and then it is difficult to obtain the proper result in the process of the jury evaluation for laser printers. For this reason, in this study, the proposed decision error model is added in the previous step of the correlation verification. Comparing to the conventional process only using the correlation based method, after the reliability of each participant is verified, the correlation with the mean response of participants is verified. It was found that the participants who were recognized as having unusual preferences are actually identified as having the reliability problem. Based on the results of this study, the proposed decision error model will be helpful to identify and improve the reliability of participants in the following study for the sound quality analysis.

• Korean Journal of Clinical Pharmacy
• /
• v.6 no.2
• /
• pp.7-13
• /
• 1996

The purposes of this study were to define the pharmacokinetic parameters of vancomycin in Korean neonates, to evaluate current neonatal vancomycin dosing guideline being used in a teaching hospital, and to develop the optimal vancomycin dosing guideline. The evaluation of 35 sets of peak and trough concentrations drawn on current dosing regimen showed that $29\%$ of peak concentrations and $46\%$ of though concentrations were within therapeutic range. Otherwise, pharmacokinetic parameters, based on 62 sets of peak and trough serum concentrations obtained from 39 neonates, showed that mean vancomycin clearance (CL), volume of distribution (Vd), and terminal elimination half-life were $0.13\pm0.08\;L/hr,\;0.94\pm0.48\;L,\;and\;5.6\pm2.13$ hours, respectively. Volume of distribution (Vd) normalized for body weight remained constant throughout PCA range, whereas the absolute CL (r=0.74) and normalized CL (r=0.36) showed high correlation with PCA. Also, the normalized CL showed a strong inverse correlation (r=-0.55) with serum creatinine concentrations (SrCr). Based on the high correlation among PCA serum creatinine concentration, CL, and the daily dosage requirements, the following dosing guideline for vancomycin in neonates was suggested: 10 mg/kg $12{\sim}18$ hourly for < 30 weeks PCA and < 0.6 mg/dl SrCr; 10 mg/kg 18 hourly for < 30 weeks PCA and $0.6{\sim}1.2$ mg/dl SrCr; 10 mg/kg 8 hourly for $30\sim44$ weeks PCA and < 0.6 mg/dl SrCr; 10 mg/kg 12 hourly for $30\sim44$ weeks PCA and $0.6{\sim}1.2$ mg/dl SrCr.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.7
• /
• pp.582-589
• /
• 2012

This paper describes the algorithm recognizing car type from the image received from UAV and the recognition results between three types of car images. Using the NCC(Normalized Cross-Correlation) algorithm, geometric information is matched from template images. Template images are obtained from UAV and satellite map and indoor experiment is performed using satellite map. After verification of the possibility, experiment for verification of same car type recognition is performed using small UAV. In the experiment, same type cars are matched with 0.6 point similarity and truck with similar color distribution is not matched with template image of a sedan.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.5C
• /
• pp.478-486
• /
• 2007

Double-talk detection errors can result in either large residual echo or distorting the near-end talker's input speech. Thus accurate double-talk detection is an important problem in the acoustic echo canceller to improve the speech quality. In the double-talk detection algorithm using a cross-correlation coefficient, double-talk detection errors can occur in the initial convergence period of an adaptive filter or in noisy environment since the cross-correlation coefficient becomes large in such situations. In this paper, we propose a new double-talk detection algorithm based on the cross-correlation method using a normalized error signal power to reduce the double-talk detection errors. The experimental results have shown the performance improvement of an acoustic echo canceller as well as the noise-robustness of the proposed double-talk detector.