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Whereas the closed-caption broadcasting is provided for almost the whole broadcast time in Korea, the sign language interpretation is not. By translating the realtime closed captions, it is possible to provide three-dimensional (3D) sign language translations for more broadcast time. We propose a sign language broadcasting system for weather forecasts and extend it for all kinds of TV programs. To find the frequency of each word, we analyzed the last three years' weather forecast scripts, and an open-domain corpus of about 1.2 million words from the Korean Broadcasting System. We use KorLex, the Korean wordnet, to build the sign language synonym dictionary and for the word sense disambiguation to improve the translation performance. Optically captured sign language motions are used for the 3D avatar to present sign language with motion blending. We developed a mobile on-demand sign language weather forecast application and a realtime sign language interpretation system for all kinds of TV programs.

Holographic data storage is a strong contender to become the next-generation data storage method. Its major weaknesses are two-dimensional intersymbol interference between neighboring pixels and interpage interference caused by storing multiple pages in a single volume of hologram. In this paper, we present a trellis encoding scheme of 6/8 balanced modulation code, to address the two weaknesses. The proposed modulation coding scheme captures on characteristics of the balanced code: the scheme relaxes IPI and enables error correction by exploiting the trellis structure. The proposed method showed improved SNR over the conventional 6/8 modulation

The shingled magnetic recording method has interference between adjacent tracks. Furthermore, when read-head reads the data along the track, the head can be skewed by some physical effects. In this paper, in order to solve this problem, we propose a two-dimensional equalizer that uses two heads. If the head is skewed, it is possible to complement the performance by positioning the two heads at the center of the current track. ※ 이 논문은 2013년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(NRF-2013R1A1A2059077). First Author : Soongsil University, School of Electronic Engineering, kimbs@ssu.ac.kr, 학생회원 ° Corresponding Author : Soongsil University, School of Electronic Engineering, zlee@ssu.ac.kr, 종신회원 논문번호:KICS2014-08-326, Received August 27, 2014; Revised September 4, 2014; Accepted September 4, 2014 I. 서 론 자기기록 저장 장치의 저장 밀도 향상을 위해 수평 자기기록 방식에서 수직 자기기록 방식으로 변화되었 다. 하지만 수직 자기기록 저장장치 역시 초성자성 현 상에 의한 밀도 증가의 한계에 도달하였다. 이러한 트 랙 내에서의 기록 밀도 향상의 한계를 극복하기 위해 트랙간의 간격을 줄이는 방법이 연구되어왔고, 근래에 는 트랙과 트랙을 겹쳐서 쓰는 SMR (Shingled Magnetic Recording) 방식이 연구되어왔다. SMR 방 식은 이전 트랙의 일부분에 새로 쓰이는 트랙이 일부 겹쳐지는 방식으로 겹쳐지는 양 만큼 이전 트랙의 폭 이 원래의 트랙 폭 보다 실질적으로 좁아지는 결과를 가져오게 된다. 따라서 전체적인 기록밀도의 향상을 얻을 수 있게 된다. 하지만 트랙간의 간격이 좁아짐에 따라 인접 신호간 간섭 (Inter-Symbol Interference, ISI)과 함께 인접 트랙간 간섭 (Inter-Track Interference, ITI) 역시 심각한 문제가 되었다 . 자기기록 장치에서 리드헤드가 트랙을 따라 돌면서 데이터를 읽을 때, 물리적인 영향으로 리드헤드가 방 향이 틀어 질 수 있다 . 그림 1은 이러한 경우를 그림으로 나타냈다. 그림 1의 첫 번째 그림과 세 번째 논문 / 트랙을 겹쳐서 쓰는 자기기록 방식에서 리드헤드가 틀어진 경우의 성능 분석 515 Fig. 1. Three types of skewed head Fig. 2. Block diagram of two-dimensional equalizer 그림은 각각 리드헤드가 음(-)의 방향과, 양(+)의 방향 으로 틀어진 경우이고, 두 번째 그림은 리드헤드의 틀 어짐이 없이 정상적으로 데이터를 읽어 들이는 경우 이다. 리드헤드가 음 또는 양의 방향으로 틀어진 경우 그림과 같이 인접한 트랙으로 부터의 간섭이 더 심해 져 성능이 열화된다. 본 논문에서는 SMR 방식에서의 ITI 문제와 리드 헤드의 틀어짐에 따른 성능 문제를 해결하기 위해 두 개의 리드헤드를 사용하는 이차원 이퀄라이저를 제안 하였다. II장에서는 본 논문에서 제안된 이차원 이퀄 라이저의 알고리즘에 대해서 설명한다. III장에서는 시 뮬레이션 환경 및 결과를 보여주고, 마지막 IV장에서 는 앞 장의 결과로 결론을 내린다.

In this paper, we introduce a 2-D non-isolated pixel modulation code to mitigate the problem of 2-D inter-symbol interference, the major obstacle of holographic data storage systems. The proposed modulation code does not allow a pixel to be isolated from its adjacent bits. We compare the bit error rate (BER) performance between the proposed and the conventional 6/8 balanced modulation codes. The proposed code shows better BER performance than that of the conventional 6/8 balanced code in a poor channel environment, such as large blur and misalignments.

In holographic data storage (HDS), a high transmission rate is accomplished through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data. Although HDS has many advantages in terms of storage capacity and data transmission rates, it also features problems, such as 2D intersymbol interference (ISI) by neighboring pixels and interpage interference (IPI) by multiple images stored in the same holographic volume. Modulation codes can be used to remove these problems. We introduce a 2D 8/9 error-correcting modulation code. The proposed modulation code exploits the trellis-coded modulation scheme, and the code rate is larger (about 0.889) than that of the conventional 6/8 balanced modulation code (an increase of approximately 13.9%). The performance of the bit error rate (BER) with the proposed scheme was improved compared with that of the 6/8 balanced modulation code and the simple 8/9 code without the trellis scheme.

Holographic data storage (HDS) has a number of advantages, including a high transmission rate through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data, and a high density capacity. HDS also has disadvantages, including 2d intersymbol interference by neighboring pixels and interpage interference by multiple pages stored in the same holographic volume. These problems can be eliminated by modulation codes. We propose a 7/9 error-correcting modulation code that exploits a Viterbi?trellis algorithm and has a code rate larger (about 0.778) than that of the conventional 6/8 balanced modulation code. We show improved performance of the bit error rate with the proposed scheme compared to that of the simple 7/9 code without the trellis scheme and the 6/8 balanced modulation code.

Recently, 3DTV has drawn much attention as a new broadcasting service. In spite of technical advances in 3DTV broadcasting services, there are two barriers that hinder the new services from being launched for terrestrial broadcasting: the lack of available bandwidth for transmission of additional-view video via terrestrial channel and backward compatibility with the legacy 2-D HDTV services. As an alternative, a hybrid stereoscopic video coding scheme is proposed for a stereoscopic 3DTV service, where one-view video is transmitted through the legacy broadcasting systems and the other one is delivered via broadband networks to which TV terminals are connected. In this paper, the proposed hybrid stereoscopic video coding scheme incorporates an MPEG-2 codec for backward compatibility with a legacy 2-D HDTV service and an HEVC codec with inter-view prediction coding as an extension to encode additional-view video sequences with high coding efficiency. The proposed inter-view prediction coding scheme in the extended HEVC incorporates an advanced motion and disparity vector prediction (AMDVP) method for enhanced motion- and disparity-compensated coding. The experimental results demonstrate that the proposed hybrid stereoscopic video coding scheme achieves an average coding efficiency of 38.22% (32.86%) in BD-rate or 1.394 dB (1.235 dB) in BD-PSNR for the out-band (in-band) scenario.

This paper investigates how authentic listening texts affect a whole group or different levels of listeners and verifies how task sequence actually influences task difficulty. For this, three authentic texts, animation, TV news, and Internet video clip, are used and three sets of tasks using text are developed based on ‘function-response matrix for listening activities’. The test result shows that animation, the easiest text of the three, may be usable for most listeners with different listening skills. TV news or Internet video clip may be acceptable only for learners with higher listening proficiency. Task analysis shows that task difficulty or task sequence may vary depending upon texts. Finding particular information in an animation is a relatively easy task while the task of describing the main storyline in Korean is shown to be more demanding. On the other hand, the task of completing a main idea of TV news and video clip is the most appealing for listeners, and the task requiring listeners to duplicate what they hear has higher task difficulty. Task difficulty is subject to change depending on both listening texts and tasks. Thus, teachers first have to recognize specific properties of authentic texts and listening tasks, and select texts and design tasks, considering a learner’s listening proficiency and classroom instructional purpose.

In this paper, a fast intermode decision scheme is introduced by efficiently performing the mode decision using statistical hypothesis testing for hierarchical B-picture coding of SVC, in which much computational power is expensed for combined variable block sizes and hierarchical B-pictures. The hypothesis testing in the proposed method is performed on blocks to have early termination for RD computation of all possible modes. The early termination in intermode decision is performed by comparing the pixel values of current blocks and corresponding motion-compensated blocks. The proposed scheme exhibits effective early termination behavior in intermode decision and leads to a significant reduction up to 69% in computational complexity with slight increment in bit amounts. The degradation of visual quality turns out to be negligible in terms of PSNR values.

New broadcasting services such as 3DTV and UHDTV are turning up and catching the public attention, because people nowadays like to have more realistic watching experience in TV. However, terrestrial broadcasters have difficulties in launching them, because new terrestrial broadcasting services necessarily need new frequency allocation. As frequency is public goods and the frequency for broadcasting is limited. To solve the lack of frequency, we designed hybrid 3DTV broadcasting technology combining terrestrial broadcasting channel and broadband network. For the hybrid 3DTV, the left view is transmitted through the terrestrial broadcasting channel and the right view is delivered using the internet. The difference of two transport networks causes inevitable receiving time delay. To synchronize the left view and the delayed right view by frame accuracy, we insert SMPTE time code into the left and right elementary streams respectively and transmit them. To verify the validity and practicality of hybrid 3DTV service, we performed live broadcasting of ‘IAAF World Championships’ in August 2011 via hybrid 3DTV technology.

A hybrid stereoscopic broadcasting service is considered a possible solution to the lack of frequency bandwidth for transmission of additional view sequences and to the backward compatibility for the existing MPEG-2 based DTV services. In this paper, a hybrid stereoscopic encoder based on MPEG-2 and HEVC is first considered where left-view sequences are encoded by MPEG-2 to provide the backward compatibility while right-view sequences are encoded by HEVC for delivery over Internet. In the hybrid stereoscopic encoder, we propose an inter-view coding scheme between the left- and right-view sequences to enhance the coding performance of HEVC for right-view sequences. Therefore, in this paper, an extension to HEVC is made with an inter-view coding scheme by having disparity based motion-compensated prediction. For this, MPEG-2 motion vectors from left-view sequences and global disparity vectors between two-view sequences are utilized. The experimental results show that the proposed hybrid stereoscopic encoder achieves average 37.75% coding gain in BDBR compared with the performance of HEVC simulcast encoding for right-view sequences.

Quantization in video coding plays an important role in controlling the bitrate of compressed bitstreams to adjust with the allowed bandwidth of delivery networks and storage. Since scalable video coding (SVC) being currently standardized exhibits highly dependent coding nature not only between frames but also in the lower and higher layers, we propose a dependent quantization scheme for SVC and compare its performance in visual qualities and bitrates with the current technique in JSVM reference software. The experimental results show that the dependent quantization outperforms the current technique in JSVM reference software with 0.5 ~ 1.25 dB PSNR increment or 5 ~ 20% bits saving for the enhancement layer of SVC.

For video streaming, we must consider terminal and network characteristics. The scalable video coding (SVC) can represent video bitstreams in different scalable layers for flexible adaptation to terminal and network characteristics. The SVC can allow for extraction of appropriate partial bitstreams to meet specific target bitrates and spatial resolutions from an SVC bitstream with several spatial, temporal and quality scalability layers. Moreover, the extraction process is fast, so it is possible to extract the partial video streams online to cope with the delivery networks with changing characteristics such as bandwidth etc. With all the advantages of SVC, we design and implement a network-adaptive SVC streaming system to extract partial SVC bitstreams to meet the required target bitrates and spatial resolutions. We present the implementation of our SVC streaming system with experimental results.

A holographic data storage (HDS) system can provide high storage capacity, faster transmission, and shorter access time. However, there are two major concerns with such systems: two-dimensional (2D) inter-symbol interference (ISI) and inter-page interference (IPI). The use of existing partial response maximum likelihood (PRML) detection can somewhat mitigate the problem of ISI. However, if the channel is subject to misalignment, the performance of PRML detection can be degraded. This problem can be remedied by a modulation code. Thus, this paper proposes a 6/9 modulation code, which mitigates ISI, and a modulation/demodulation scheme.