• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.345-356
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• 2004

In this paper, we present a design and implementation of a personalized broadcasting system using TV-Anytime metadata for providing personalized services. The TV-Anytime specifies metadata schema, metadata coding and delivery, and provides service models to provide personalized broadcasting content services at anytime when users want to consume using metadata, which includes ECG (Electronic Content Guide) and content descriptive information in a PDR (Personal Digital Recorder)-centric environment. The proposed personalized broadcasting system consists of a server that provides metadata binary-coding, encapsulation and multiplexing, and a client terminal that takes charge of de-multiplexing, metadata decoding, and metadata processing for personalized content accessing and consumption. This paper presents the details of the design of each functional module, and the evaluation results with a set of service scenarios in an end-to-end broadcasting test-bed.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.87-96
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• 2013

In this paper, we suggest redesigned RTP protocol that is able to perform encryption of VoIP media information for single private network and between the different private networks. And we conduct a test for performance analysis. Such as SRTP or ZRTP methods have been used for VoIP media encryption. But, the existing encryption techniques have problem that can not perform end-to-end encryption between different private networks. In order to solve this problem, in this paper, we redesign RTP protocol. Redesigned RTP includes all information for encryption of VoIP media. Therefore the encryption is not affected by modification of SIP and SDP information that occurred in gateway. Also, redesigned RTP includes code for whether or not to apply encryption. By using the code, modification of RTP header from gateway prevents. As a result, redesigned RTP maintain the integrity and the RTP is able to perform encryption between the different private networks. Also, we conduct a test for performance analysis of SRTP, ZRTP and redesigned RTP.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.526-531
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• 2014

Vehicular communications have been receiving much attention in intelligent transport systems(ITS) by combining communication technology with automobile industries. In general, vehicular communication can be used for vehicle-to-vehicle(V2V) and vehicle-to-infrastructure( V2I) communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environment(WAVE). WAVE system transmits signal in 5.835~5.925 GHz frequency band with orthogonal frequency division multiplexing(OFDM) signaling. In this paper, after 32 bit processed the channel monitoring in MAC(Media Access Control) layer of WAVE system implemented according to IEEE 802.11p standard, data were received and we evaluated the performance, we built the test bed consisting of OBU(On Board Unit) in the real expressway. We transmitted WSM(WAVE Short Message) and received WSM between OBU wirelessly. And then, we calculated channel occupancy time per one frame and throughput, and evaluated the performance.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.488-500
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• 2009

In this paper, we study on making a use of value-added services using DTV closed caption data. 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 provided by an enforcing law in all broadcasting services in April 2008. Here, 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 using the extracted caption data and time information. In addition, we present the segmentation method of broadcasting content using caption file. Experimental results show that implemented S/W tool provides the feasibility of the proposed methods and the usability of closed caption for a variety of data application service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.690-696
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• 2004

Advanced Television Systems Committee (ATSC) -A/90, which is a standard for terrestrial data transmission in Korea, defines synchronized data that has a strong timing association with a separate Program Element. It is classified as synchronized streaming data that is carried in packetized elementary stream (PES) packets or a synchronized non-streaming data that shall be carried in digital storage media command and control (DSM-CC) section. In this paper, we study the design and verification of synchronized streaming data processing algorithm based on ATSC -A/90. We designed a parser and a player for the algorithm development. The received PES packet including synchronized streaming data is parsed in the parser. The parsed synchronized streaming data is synchronized and displayed by player. Finally, we ascertained that STB was working properly with MPEG-2 transport stream (TS) containing synchronized streaming data, as the proposed algorithm is implemented on a set-top box.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.82-87
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• 2009

Recently, a great variety of radio services are provided and interference problem between radio systems is being watched remarkably. Therefore, a study of interference between radio systems is needed. In this paper, compatibility between Ultra Wideband (UWB) and Terestrial Digital Multi-media Broadcasting (T-DMB) is analyzed and then distance between them is computed. UWB systems have a very broad frequency characteristic. A big advantage is to share frequency that is already allocated to other systems. T-DMB is a good point that while L-Band is already used for DAB, T_DMB is free of charge. AT-DMB (Advanced T-DMB) is being standardized recently. The result which is analyzed for the interference effects between UWB and T-DMB Systems is 10 [dB], which is value calculated by C/(N0+I), at 80 [m] and then the value is saturated at 150 [m].

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.231-238
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• 2006

Transports of heterogeneously charged particles were investigated based on column experiments. Synthesized mono-dispersed ferrihydrite (${\sim}100nm$) and amorphous $SiO_2\;({\sim}40nm\;and\;{\sim}80nm)$ particles, of which surfaces are oppositely charged under pH < 9.0 (ferrihydrite, positive; amorphous silica, negative), were used. $177{\sim}250{\mu}m$ quartz sand was used as a stationary matrix. The results show that even favorable particles (i.e., ferrihydrite) can show a conservative transport through the oppositely charged media (i.e., quartz) when they coexist with humic acid or with much greater number of oppositely charged particles. These results imply that transports of both negatively and positively charged contaminants may be possible at the same time under a condition of heterogeneous colloidal system.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.303-308
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• 2011

Vehicle black boxes that have similar functions as airplane black boxes are currently being used due to the loss of many lives and properties arising from vehicle accidents. Both black-box products and Event Data Recorder(EDR) systems are currently available in the market. Most of the existing in-vehicle black boxes, however, record only external videos and images and cannot show the vehicle's driving status, whereas EDR products record only the driving status and not external videos. To address the problem of black boxes that can record only videos and images and that of EDR systems that can record only driving data, an integrated vehicle state and video recording system that uses MOST(Media-oriented System Transport) and OBD-II(Onboard Diagnostics II) and CAM (camera) and GPS (global positioning system).

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.72-79
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• 2003

The Eureka-147 Digital Audio Broadcasting(DAB) system is the new international standard for mobile broadcasting services including high-quality audio, program associated data and other multimedia data. In this paper, we design the transport frame structures for the mobile multimedia services by using the configuration of the Eureka-147 DAB multiplex and MPEG system specifications, and then compare their performances in terms of functionality and overhead. Especially, we suggest and analyze the effective transport structures, which are improved in the efficiency of media multiplexing architecture, by removing the functionally overlapped parts between DAB and MPEG systems. In addition, we evaluate the transmission environments of various DAB data channels and demonstrate the transmission error effects on the low bit rate video stream.

• Nuclear Engineering and Technology
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• v.20 no.2
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• pp.132-136
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• 1988

A strategic question in groundwater contaminant transport modeling is whether we need to treat waste packages or drums as individual, discrete sources or as approximately lumped sources. In this paper we present analyses of array sources in porous media. We analyze a planar array of sources in porous media with groundwater flow. We compare the concentration field predicted by a detailed model of individual point sources to concentration fields predicted by an infinite plane source and a single point source, all of the same equivalent strength. From this study we identified three regions: (1) a region close to the sources where the effects of adjacent sources are significant and individual source models should be used, (2) a region extending from a few meters to hundreds to thousands of meters downstream, where an equivalent source of infinite extent gives accurate results, and (3) a far-field region, where in an equivalent source of finite extent gives accurate results.