• Journal of the Institute of Convergence Signal Processing
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• v.10 no.2
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• pp.146-150
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• 2009

An Intelligent active roll angle controller design algorithm is discussed. The detailed mathematical formulation and analysis are discussed, and then modeling and design method for active roll angle controller are presented. This paper proposes a design method based upon intelligent robust controller design algorithm to control actively roll angle for improving cornering performance problems. The intelligent robust controller is designed for steady speed driving vehicle system model with representation of steering angle and yaw angular velocity parameters for cornering stability. And the detailed formulation and analysis for the objective vehicle system are investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3087-3093
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• 2009

Digital filters are indispensible element in digital signal processing area. The performance of digital filter based on adding and multiplying operation, such as computational speed and power consuming is determined by the orders and coefficients of filter which has on effect area of semiconductor chip when it is implemented by VLSI technology. In this research, in order to performance improvement of digital filter, we proposed the algorithm to speed-up the operation of digital filter associated with the minimum signed digit representation of binary number system and method to simplify the digital filter design associated with common subexpression elimination. The performance of proposed method is evaluated by the computational speed and design-simplicity by experimental implemented digital filter on FPGA.

• Journal of IKEEE
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• v.23 no.3
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• pp.893-898
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• 2019

Time-frequency representations are methods to display the magnitude or energy density of a signal on the two dimensional plane of both time and frequency. They are useful in analyzing the characteristics of time-varying signals. Music is a typical time-varying signal, and it can be analyzed by time-frequency representations. Recently, it is popular to change the sound quality by attaching a safety sounder to an instrument. It is performed to improve perception subjectively by spending little cost and modifying sound quality. In time domain, it is difficult to notify the difference between music signals with and without the sounder. But, it is easy to find the difference in frequency domain or in time-frequency domain. In this paper, the music signal from a flute with sounder is analyzed both in the frequency domain and in the time-frequency domain. It is confirmed that the frequency components in the mid-frequency range of 500~2500 are reinforced.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.65-80
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• 2007

The input and output device requires precise color representation and CMS (Color Management System) because of the increasing number of ways to apply the digital image into electronic publishing. However, there are slight differences in the device dependent color signal among the input and output devices. Also, because of the non-linear conversion of the input signal value to the output signal value, there are color differences between the original copy and the output copy. It seems necessary for device-dependent color information values to change into device-independent color information values. When creating an original copy through electronic publishing, there should be color management with the input and output devices. From the devices' three phases of calibration, characterization and color conversion, the device-dependent color should undergo a color transformation into a device-independent color. In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After undergoing a color transformation in the input and output devices, the best results were created when the original target underwent a color transformation by the scanner and digital camera input device by the linear multiple regression, and the LCD output device underwent a color transformation by the GOG model.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.289-293
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• 2009

This study proposes a novel double-base log encoder (DBLE) for flash Analog-to-Digital converters (ADCs). Analog inputs of flash ADCs are represented in logarithmic number systems with bases of 2 and 3 at the outputs of DBLE. A look up table stores the sets of exponents of base 2 and 3 values. This algorithm improves the performance of a DSP (Digital Signal Processor) system that takes outputs of a flash ADC, since the double-base log number representation does multiplication operation easily within negligible error range in ADC. We have designed and implemented 6 bits DBLE implemented with ROM (Read-Only Memory) architecture in a $0.18\;{\mu}m$ CMOS technology. The power consumption and speed of DBLE are better than the FAT tree and binary ROM encoders at the cost of more chip area. The DBLE can be implemented into SoC architecture with DSP to improve the processing speed.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.11-26
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• 2007

In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After the input device underwent a color transformation, a $3\;{\times}\;20\;size$ matrix was used in a linear multiple regression and the scanner's color representation of scanner was better than a digital still camera's color representation. When using the sRGB color space, the original copy and the output copy had a color difference of 11. Therefore it was more efficient to use the linear multiple regression method than using the sRGB color space. After the input device underwent a color transformation, the additivity of the LCD monitor's R, G and B signal value improved and therefore the error in the linear formula transformation decreased. From this change, the LCD monitor with the GOG model applied to the color transformation became better than LCD monitors with other models applied to the color transformation. Also, the color difference varied more than 11 from the original target in CRT and LCD monitors when a sRGB color transformation was done in restricted conditions.

• ETRI Journal
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• v.41 no.1
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• pp.93-108
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• 2019

Guaranteeing interoperability between devices and applications is the core role of standards organizations. Since its first JPEG standard in 1992, the Joint Photographic Experts Group (JPEG) has published several image coding standards that have been successful in a plethora of imaging markets. Recently, these markets have become subject to potentially disruptive innovations owing to the rise of new imaging modalities such as light fields, point clouds, and holography. These so-called plenoptic modalities hold the promise of facilitating a more efficient and complete representation of 3D scenes when compared to classic 2D modalities. However, due to the heterogeneity of plenoptic products that will hit the market, serious interoperability concerns have arisen. In this paper, we particularly focus on the holographic modality and outline how the JPEG committee has addressed these tremendous challenges. We discuss the main use cases and provide a preliminary list of requirements. In addition, based on the discussion of real-valued and complex data representations, we elaborate on potential coding technologies that range from approaches utilizing classical 2D coding technologies to holographic content-aware coding solutions. Finally, we address the problem of visual quality assessment of holographic data covering both visual quality metrics and subjective assessment methodologies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4268-4289
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• 2020

Advanced traffic signal timing method plays very important role in reducing road congestion and air pollution. Reinforcement learning is considered as superior approach to build traffic light timing scheme by many recent studies. It fulfills real adaptive control by the means of taking real-time traffic information as state, and adjusting traffic light scheme as action. However, existing works behave inefficient in complex intersections and they are lack of feasibility because most of them adopt traffic light scheme whose phase sequence is flexible. To address these issues, a novel adaptive traffic signal timing scheme is proposed. It's based on actor-critic reinforcement learning algorithm, and advanced techniques proximal policy optimization and generalized advantage estimation are integrated. In particular, a new kind of reward function and a simplified form of state representation are carefully defined, and they facilitate to improve the learning efficiency and reduce the computational complexity, respectively. Meanwhile, a fixed phase sequence signal scheme is derived, and constraint on the variations of successive phase durations is introduced, which enhances its feasibility and robustness in field applications. The proposed scheme is verified through field-data-based experiments in both medium and high traffic density scenarios. Simulation results exhibit remarkable improvement in traffic performance as well as the learning efficiency comparing with the existing reinforcement learning-based methods such as 3DQN and DDQN.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.322-331
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• 2009

This paper proposes an efficient data representation of stereo images using edge-based mesh optimization. Mash-based two dimensional warping for stereo images mainly depends on the performance of a node selection and a disparity estimation of selected nodes. Therefore, the proposed method first of all constructs the feature map which consists of both strong edges and boundary lines of objects for node selection and then generates a grid-based mesh structure using initial nodes. The displacement of each nodal position is iteratively estimated by minimizing the predicted errors between target image and predicted image after two dimensional warping for local area. Generally, iterative two dimensional warping for optimized nodal position required a high time complexity. To overcome this problem, we assume that input stereo images are only horizontal disparity and that optimal nodal position is located on the edge include object boundary lines. Therefore, proposed iterative warping method performs searching process to find optimal nodal position only on edge lines along the horizontal lines. In the experiments, we compare our proposed method with the other mesh-based methods with respect to the quality by using Peak Signal to Noise Ratio (PSNR) according to the number of nodes. Furthermore, computational complexity for an optimal mesh generation is also estimated. Therefore, we have the results that our proposed method provides an efficient stereo image representation not only fast optimal mesh generation but also decreasing of quality deterioration in spite of a small number of nodes through our experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.729-734
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• 2010

In the initial stage of the communications between a base station and a satellite transponder, the base station transmits the frequency-sweeping un-modulated up-link carrier within a certain frequency range to acquire the doppler frequency shift and signal power between the base station and the satellite in orbital flight. The satellite transponder acquires and tracks the carrier in order to initialize the communication. To control such initialization process, the satellite receiver should analyze the input carrier signal in various ways. This paper presents an SNR estimation algorithm to control the initialization process. The proposed algorithm converts the input signal into the baseband polar coordinate representation and estimates the SNR via the statistics of the angular signal components as well as the status parameters to control the receiver. The Monte-Carlo simulations shows the validity of the estimation proposed.