• Journal of Korea Multimedia Society
• /
• v.18 no.7
• /
• pp.793-805
• /
• 2015

Nowadays the amount of data obtained from advanced weather radars is growing to provide higher spatio-temporal resolution. Accordingly radar data compression is important to use limited network bandwidth and storage effectively. In this paper, we proposed a hierarchical compression method for weather radar data having high spatio-temporal resolution. The method is applied to radar reflectivity and evaluated in aspects of accuracy of quantitative rainfall intensity. The technique provides three compression levels from only 1 compressed stream for three radar user groups-signal processor, quality controller, weather analyst. Experimental results show that the method has maximum 13% and minimum 33% of compression rates, and outperforms 25% higher than general compression technique such as gzip.

• Journal of Korea Multimedia Society
• /
• v.17 no.4
• /
• pp.405-412
• /
• 2014

Due to the popularity of mobile phones, Peer-to-Peer (P2P) content sharing in mobile phones is highly desirable, especially in a mobile data connection. In addition, there has been an increasing demand for content sharing applications for P2P communication in Android-based smartphones as ubiquitous mobile devices. However, due to wireless network limits, unstable characteristic and restricted storage space, mobile users confront challenges in establishing connections and sharing video frames with other users. To solve this issue, we propose an architectural design and implementation of key frame sharing application that uses Chord, a distributed lookup protocol to establish a content sharing platform for mobile devices, combined with the Chord SDK based on Android. Our proposed system enables users easily to share key information on video data in real-time over a wireless network without manual processing of devices which join or leave the group and cost associated with the 3G/4G network.

• Journal of Korea Multimedia Society
• /
• v.20 no.2
• /
• pp.371-381
• /
• 2017

The performance of the statistical context-sensitive spelling error correction depends on the quality and quantity of the data for statistical language model. In general, the size and quality of data in a statistical language model are proportional. However, as the amount of data increases, the processing speed becomes slower and storage space also takes up a lot. We suggest the improved statistical language model to solve this problem. And we propose an effective spelling error candidate generation method based on a new statistical language model. The proposed statistical model and the correction method based on it improve the performance of the spelling error correction and processing speed.

• Journal of Korea Multimedia Society
• /
• v.21 no.1
• /
• pp.61-68
• /
• 2018

In this paper, we present an effective encryption algorithm for 3D printing models in the frequency domain of discrete cosine transform to prevent illegal copying, access in the secured storage and transmission. Facet data of 3D printing model is extracted to construct a three by three matrix that is then transformed to the frequency domain of discrete cosine transform. The proposed algorithm is based on encrypting the DC coefficients of matrixes of facets in the frequency domain of discrete cosine transform in order to generate the encrypted 3D printing model. Experimental results verified that the proposed algorithm is very effective for 3D printing models. The entire 3D printing model is altered after the encryption process. The proposed algorithm is provide a better method and more security than previous methods.

• The Journal of the Korea Contents Association
• /
• v.2 no.3
• /
• pp.105-112
• /
• 2002

MPEG-4 is an international standard for interactive multimedia data that is used for next generation audio-visual service. It presents an two types of storage formal such as XMT (eXtensible MPEG-4 Textual fount) and MP4 file format D store the interactive multimedia contents. The XMT, a textual format, has advantage of readability and it can be used in many applications since designed based on the XML In this paper, we present the way how to author the MPEG-4 contents using XMT.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04d
• /
• pp.253-255
• /
• 2003

Electricity is the prime commodity in mobile device, e.g. smart phone, PDA, MP3 player and etc. This strict restriction on power consumption requirement of the mobile device puts unique demand in designing hardware and software components of the device. In this paper, we address the issue of minimizing the power consumption in retrieving the continuous media data from the disk drive for real-time playback purpose. Different from the legacy text based data, real-time multimedia playback requires that the storage supplies the data block continuous fashion. This may put immense burden on the power scarce environment since the disk Is required to be active for the entire playback duration. We develop elaborate algorithm which carefully analyzes the power consumption profile of the disk drive and which establishes the data retrieval schedule for the given playback. It computes the amount of data blocks to read, the length of active and standby period. According to our simulation result, the ARM algorithm exhibits superior performance in continuous media retrieval from the aspect of power consumption to legacy playback scheme.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05c
• /
• pp.410-415
• /
• 2002

최근 초고속인터넷과 다채널 방송, VOD(Video on Demand), HDTV 등의 광대역 통합 서비스와 음성, 음악, 원격강시, 화상전화/회의 등의 부가기능을 제공하는 통신 서비스를 동시에 수용하기 위해 VDSL(Very high speed Digital Subscriber Loop)에 대한 연구가 진행중이다. 본 논문에서는 DSL 포럼 및 FS-VDSL 위원회의 기고서와 규격를 바탕으로 ATM과 IP 기반의 VDSL물 이용한 디지털 방송 서비스를 제공하기 위한 종단간 ATM 모델과 ATM-IP 연동 모델에 대한 망의 구성 및 프로토콜 스택을 제시하고 비교 분석한다. 그리고 ATM/VDSL 기반에서 DSM-CC(Digital Storage Media Command and Control)와 IGMP(Internet Group Management Protocol) 프로토콜을 이용한 디지털 방송 서비스 제공 절차를 제안한다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2004.05a
• /
• pp.612-615
• /
• 2004

정보 시스템과 인터넷의 급속한 성장으로 다양하고 효율적인 교수-학습자료의 개발이 요구되고 있다. 특히 VRML을 이용한 삼차원 공간의 학습자료 개발은 정보화 사회에서의 교수-학습효과를 더욱 증가시킬 수 있다. 기존의 VRML 저작도구에서는 순차접근방식을 사용한 파일저장시스템을 이용하여 객체를 저장함으로서 객체의 효율적인 관리가 용이하지 않다. 본 논문에서는 데이타베이스 관리시스템의 저장구조를 이용하여 삼차원 객체를 저장하고 관리할 수 있도록 VRML 학습자료 저장시스템을 설계하고 구현한다. 또한 본 시스템을 이용하여 중학교 과학 교과서의 화학물구조에 대한 삼차원 학습자료 생성을 예로 들어 보임으로서 그 효율성을 입증한다. 따라서 본 VRML 학습자료 저장 시스템은 교사들로 하여금 삼차원 학습자료를 상호간에 공유하여 재사용할 수 있으며 삼차원 학습자료의 생성에 있어서 시간과 경비 절감의 효과를 얻을 수 있다.

• Journal of Korea Multimedia Society
• /
• v.21 no.11
• /
• pp.1237-1243
• /
• 2018

In the HDTV video codec, conventional the padding method of DEPA(DTV essential padding area) region is aimed at minimizing the redundant information to be transmitted. This article propose a method to transmit additional data by using DEPA region. The proposed method is effective for the channel and storage because it can reduce the amount of bits while preventing deterioration of image quality by inserting binary gray image blocks into the DEPA region. Additionally this algorithm can be used in various fields because it conforms to the standards of MPEG-2, ATSC, and DVB encoders.

• Journal of Korea Multimedia Society
• /
• v.22 no.9
• /
• pp.1055-1068
• /
• 2019

As the container market is expected to continue to increase, the volume of containers will increase, and the volume of empty containers will be proportional to this. Imbalances between imports and exports in each country have emerged, and the issue of collection and storage of empty containers is becoming more and more important, and it is necessary to appropriately deal with container demand for container presents. Therefore, in this paper, we are trying to develop a website that provides various empty container information and provides empty container leasing services based on this information. Through the development of these empty container websites, we would like to make empty container leasing and operations more efficient, improve empty container-related services and reduce costs.