• The Journal of the Acoustical Society of Korea
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• v.23 no.3E
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• pp.74-78
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• 2004

As analog audio systems are changing to digital systems, the DAB (Digital Audio Broadcasting) is expected to provide CD quality audio, various data services with interactiveness and excellent mobile reception ability. The DMB (Digital Multimedia Broadcasting), as more advanced successor of the DAB, adds video capability on the audio and data services. The DAB system assures high quality audio services even when the reception is through portable and mobile receivers. In this paper, USB-DAB receiver and PCI-DMB receiver are designed and implemented. The DAB receiver and the DMB receiver incorporate with PC to make use of computational power and application software of Pc. This enables the developed system to be more flexible and to meet various applications easier.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.117-123
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• 2012

This paper implements mobile Worldwide Interoperability for Microwave Access (WiMAX) receiver using Software Defined Radio (SDR) technology. SDR system is difficult to implement on the mobile handset because of restrictions that are computing power and under space constraints. The implemented receiver processes mobile WiMAX software modem on Open Multimedia Application Platform (OMAP) System on Chip (SoC) and Field Programmable Gate Array (FPGA). OMAP SoC is composed of ARM processor and Digital Signal Processor (DSP). ARM processor supports Single Instruction Multiple Data (SIMD) instruction which could operate on a vector of data with a single instruction and DSP is powerful image and video accelerators. For this reason, we suggest the possibility of SDR technology in the mobile handset. In order to verify the performance of the mobile WiMAX receiver, we measure the software modem runtime respectively. The experimental results show that the proposed receiver is able to do real-time signal processing.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.396-403
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• 2000

A thermal imaging system is implemented for the measurement and the analysis of the thermal distribution of the target objects. The main part of the system is a thermal camera in which a focal plane array typed sensor is introduced. The sensor detects the mid-range infrared spectrum of target objects and then it outputs a generic video signal which should be processed to form a frame thermal image. Here, a digital signal processor(DSP) is applied for the high speed processing of the sensor signals. The DSP controls analog-to-digital converter, performs correction algorithms and outputs the frame thermal data to frame buffers. With the frame buffers can be generated a NTSC signal and transferred the frame data to personal computer(PC) for the analysis and a monitoring of the thermal scenes. By performing the signal processing functions in the DSP the overall system achieves a simple configuration. Several experimental results indicate the performance of the overall system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.364-367
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• 2009

This paper presents a scheme that generates a caption file by extracting a Closed Caption stream from DTV signal. Note that Closed-Captioning service helps to bridge "digital divide" through extending broadcasting accessibility of a neglected class such as hearing-impaired person and foreigner. In Korea, DTV Closed Captioning standard was developed in June 2007, and Closed Captioning service should be supported by an enforcing law in all broadcasting services in 2008. In this paper, we describe the method of extracting a caption data from MPEG-2 Transport Stream of ATSC-based digital TV signal and generating a caption file (SAMI and SRT) using the extracted caption data and time information. Experimental results verify the feasibility of a generated caption file using a PC-based media player which is widely used in multimedia service.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.116-121
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• 1998

As digital audio video data compression and transmission techniques are matured, huge amount of digital multimedia material is produced and delivered via broadcasting, digital storage media and world-wide web(WWW). Thus it became very important to provide a standardized way of multimedia data content description, so that efficient and effective access and reuse of valuable multimedia information can be possible. In this paper, enabling core technologies and our research directions on this are presented with brief introduction on the scope of the multimedia content description interface, called MPEG-7, in terms of objective, application and requirements.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.49-52
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• 2007

The recent advances in digital imaging and computing technology have resulted in a rapid accumulation of digital media in the personal computing and entertainment industry. In addition, large collections of such data already exist in many scientific application domains such as the geographic information systems (GIS), digital library, trademark imaging, satellite imaging and medical imaging. Thus, the need for content-based retrieval from visual media, such as image and video data, is ever increasing rapidly in many applications.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.172-178
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• 2008

Orthogonal Frequency Division Multiplexing (OFDM) is one of the most promising technologies for high data rate wireless communications. OFDM has been adopted in wireless standards such as digital audio/video broadcasting. The combination of OFDM and cooperative diversity techniques can provide the diversity gain and/or increased capacity. In this paper, the cooperative coding using cyclic delay diversity (CDD) for multiuser OFDM systems is introduced. To improve the beneficial effects of relays's cooperation, CDD is adopted in cooperative transmission of relays. Simulation results show the bit error rate (BER) for various consideration. The proposed scheme provides improved performance compared to delay.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.695-706
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• 2012

The purpose of this paper is to propose a service system for a digital hologram video, which has not been published yet. This system assumes the existing service frame for 2-dimensional or 3-dimensional image/video, which includes data acquisition, processing, transmission, reception, and reconstruction. This system also includes the function to service the digital hologram at the viewer's view point by tracking the viewer's face. For this function, the image information at the virtual view point corresponding to the viewer's view point is generated to get the corresponding hologram. Here in this paper, only a prototype that includes major functions of it is implemented, which includes camera system for data acquisition, camera calibration and image rectification, depth/intensity image enhancement, intermediate view generation, digital hologram generation, and holographic image reconstruction by both simulation and optical apparatus. The proposed prototype system was implemented and the result showed that it takes about 352ms to generate one frame of digital hologram and reconstruct the image by simulation, or 183ms to reconstruct image by optical apparatus instead of simulation.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.923-926
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• 1998

비디오 스트림과 오디오 스트림 그리고 제어신호등의 서로 다른 종류의 digital data 들을 저장 또는 전송하기 위해서는 하나의 스트림으ㅗ 통합하기 위해 다중화 과정을 거쳐야 한다. 이러한 다중화 과정에서 가장 중요한 문제점은 하나로 묶여진 일련의 스트림을 원래의 순차대로 복원해주는 동기화 문제이고, DVD-Video에서는 MPEG2 system를 이용한 동기방식을 사용한다. 본 논문은 DVD 규격에 맞추어 Microsoft의 Visual C++5.0을 이용하여 software로 VOB를 구현하였다. 입력 스트림은 MPEG2로 압축된 비디오스트림과 최대 8개의 5.1채널 AC3 오디오스트림이고 각 스트림은 frame단위로 구성이 된다. 이 frame들을 단위로 time stamp가 부여되며 time stamp의 비교에 의해 우선 순위를 부여하여 encoding을 하게된다. 그리고 같은 time stamp를 가졌을 경우 발생하는 encoding 순서의 문제는 스트림별로 미리 우선 순위를정함으로써 해결했다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.7
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• pp.302-307
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• 2002

Digital watermarking is the technique, which embeds an invisible signal including signal including owner identification and copy control information into multimedia data such as audio, video, and images for copyright protection. A new MPEG watermark embedding algorithm using complex block effect based on the Human Visual System(HVS) is introduced in this paper. In this algorithm, $8{\times}8$ dark blocks are selected, and the watermark is embedded in the DC component of the discrete cosine transform(DCT) by using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust against MPEG coding, bitrate changes, and various GOP(Group of Picture) changes.