• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.85-95
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• 2009

In the binaural synthesis environments, wide varieties of the head-related transfer functions (HRTFs) that have measured with a various direction would be desirable to obtain the accurate and various spatial sound images. To reduce the size' of HRTFs, interpolation has been often employed, where the HRTF for any direction is obtained by a limited number of the representative HRTFs. In this paper, we study on the distortion measures for interpolation, which has an important role in interpolation. With lhe various objective distortion metrics, the differences between the interpolated and the measured HRTFs were computed. These were then compared and analyzed with the results from the listening tests. From the results, the objective distortion measures were selected, that reflected the perceptual differences in spatial sound image. This measure was employed in a practical interpolation technique. We applied the proposed method to four kinds of an HRTF set, measured from three human heads and one mannequin. As a result, the Mel-frequency cepstral distortion was shown to be a good predictor for the differences in spatial sound location, when three HRTF measured from human, and the time-domain signal to distortion ratio revealed good prediction results for the entire four HRTF sets.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.82-92
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• 2024

Purpose: The purpose of this study is to find a solution to the massive data construction that occurs when fire simulation data is linked to augmented reality and the resulting data overload problem. Method: An experiment was conducted to set the interval between appropriate input data to improve the reliability and computational complexity of Linear Interpolation, a data estimation technology. In addition, a validity verification was conducted to confirm whether Linear Interpolation well reflected the dynamic changes of fire. Result: As a result of application to the underground common area, which is the study target building, it showed high satisfaction in improving the reliability of Interpolation and the operation processing speed of simulation when data was input at intervals of 10 m. In addition, it was verified through evaluation using MAE and R-Squared that the estimation method of fire simulation data using the Interpolation technique had high explanatory power and reliability. Conclusion: This study solved the data overload problem caused by applying digital twin technology to fire simulation through Interpolation techniques, and confirmed that fire information prediction and visualization were of great help in real-time fire prevention.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.15-18
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• 2001

Recently, CMOS image sensor is rapidly used as an image capture device such as mobile phone or notebook PC. Because of poor quality of image by CMOS image sensor, ISP is essential step to improve image quality. In this paper, we implemented and simulated ISP algorithm for real time moving picture of CMOS image sensor. Especial Iy, we concentrated on color interpolation, which extracts three color component from uncompleted color information. Several algorithms for color interpolation are implemented and analyzed to acquire a good quality of picture. Finally, we proposed an improved algorithm and confirmed the effectiveness by experimental simulation results.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.83-84
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• 2008

It is efficient to use the time-domain beamforming to operate the various pulse with the different pulse length, frequency, bandwidth in active sonar system. In this paper, we propose a time-domain beamformer with the cumulative processing in the decomposed channel using the polynomial interpolation to solve the problem of the computational cost, high transmission data rate, and the lack of internal memory.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.405-410
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• 2001

In this paper, a new parametric curve interpolator is proposed based on a 3D(3-dimensional) NURBS curve. A free curve is generally divided into small linear segments or circular arcs in CNC machining. The method has caused to a command error, the limitation of machining speed, and the irregular machining surface. The proposed real-time 3D NURBS interpolator continuously generates a linear segment within the range of allowable acceleration/deceleration in the motion controller. Therefore, the algorithm calculates the curvature and the remained distance of a command curve for the smoothing machining. It is expected to attaining high speed and high precision machining in CNC Machine Tool.

• Journal of computational fluids engineering
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• v.17 no.1
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• pp.70-77
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• 2012

In this paper, diagonal implicit harmonic balance method with overset grid technique is applied to analyze helicopter rotor blade flow in hover and forward flight condition. The chimera grid need interpolation time with sub-grid and background grid in moving problem such as forward flight on every time step. Present method is available enough to reduce the grid module interpolation time. In order to demonstrate present method, Caradonna & Tung's and AH-1G rotor blades are used and the results are compared to other researchers' result and experimental data.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.352-356
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• 1998

This paper is a study about Ac servo motor position and speed control characteristics which depend on feedforward control, the acceleration / deceleration time constant after the interpolation, and PI control, automatic deceleration at corner in order to shape cutting control of feed drive system of the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control. The shape error generated by the position command delay is minimized by using the acceleration / deceleration time constant after the interpolation. The results were verified to optical machining center experimentation of the machine tool.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.693-694
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• 2006

The high definition digital TV display devices need real-time gamut mapping. This paper proposes a gamut mapping algorithm that used three dimensional reduced resolution look up table and tetrahedral interpolation for real-time processing. The proposed hardware architecture is successfully implemented in FPGA and ASIC.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.117-126
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• 2023

To improve the overall performance and realism of your game, it is important to calculate the trajectory of a projectile accurately and quickly. One way to increase realism is to use a ballistic model that takes into account factors such as air resistance, density, and wind when calculating a projectile's trajectory. However, the more these factors are taken into account, the more computationally time-consuming and expensive it becomes, creating a trade-off between overall performance and efficiency. Therefore, we present an optimal solution to find a balance between ballistic model accuracy and computation time. We perform ballistic calculations using numerical methods such as Euler, Velocity Verlet, RK2, RK4, and Akima interpolation, and measure and compare the computation time, memory usage (RSS, Resident Set Size), and accuracy of each method. We show developers how to implement more accurate and efficient ballistic models and help them choose the right computational method for their numerical applications.

• Journal of KIISE:Databases
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• v.33 no.2
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• pp.201-213
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• 2006

A time-series database is a set of time-series data sequences, each of which is a list of changing values of the object in a given period of time. Subsequence matching is an operation that searches for such data subsequences whose changing patterns are similar to a query sequence from a time-series database. This paper addresses a performance issue of time-series subsequence matching. First, we quantitatively examine the performance degradation caused by the window size effect, and then show that the performance of subsequence matching with a single index is not satisfactory in real applications. We argue that index interpolation is fairly useful to resolve this problem. The index interpolation performs subsequence matching by selecting the most appropriate one from multiple indexes built on windows of their inherent sizes. For index interpolation, we first decide the sites of windows for multiple indexes to be built. In this paper, we solve the problem of selecting optimal window sizes in the perspective of physical database design. For this, given a set of query sequences to be peformed in a target time-series database and a set of window sizes for building multiple indexes, we devise a formula that estimates the cost of all the subsequence matchings. Based on this formula, we propose an algorithm that determines the optimal window sizes for maximizing the performance of entire subsequence matchings. We formally Prove the optimality as well as the effectiveness of the algorithm. Finally, we perform a series of extensive experiments with a real-life stock data set and a large volume of a synthetic data set. The results reveal that the proposed approach improves the previous one by 1.5 to 7.8 times.