• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.77-82
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• 2014

SD memory cards are widely used in portable digital devices, and most of them exploit NAND flash memory as their storage, so that they have a feature of storing users' important data safely with low costs. In case of using NAND flash memory as storage, however, there is no method to store users' data if memory capacity is insufficient when transferring a large volume of data. This paper proposes a virtual SD memory card system. It used a SD memory card device driver to process data requested from a host by exploiting external storage rather than by exploiting flash memory as a memory core for storing data to the SD memory card. For experiment, it used the FPGA-based SD card slave controller IP on the SMC controller with a S3C2450 ARM CPU to test.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.305-310
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• 2006

TV 프로그램 전송 방식이 아날로그에서 디지털로 바뀌며, TV방송의 다채널화 현상이 일어나고 있다. 동시에 많은 채널을 시청하며, 정보를 습득하고자 하는 바쁜 현대인들에게 두 개 이상의 채널을 동시에 시청하면서, 이를 녹화하거나 모니터링 하고자 하는 Need가 점점 높아져 가고 있다. 두 개의 튜너를 이용하여 두 채널의 방송을 동시에 시청 할 수 있는 PIP(Picture in Picture-동시화면) 기능은 이러한 사용자 욕구를 해소함과 동시에, 프리미엄 TV의 기술적 특성으로 자리잡고 있다. 현재 LG전자 TV의 경우, PIP관련 기능은 5가지로 [동시화면] [부채널+] [부채널 -] [부화면 입력][주부전환] 이 있다. 이러한 PIP관련 기능은 리모컨에서 부가기능 버튼으로 동작하고 있으며, 리모컨 레이아웃의 복잡성을 증대시키는 큰 원인이 되고 있다. 특히 관련 버튼이 숨김 버튼으로 배치되어 있어 사용자는 버튼을 찾지 못하고 오히려TV OSD 메뉴 상에서 PIP기능을 찾는 오류를 범하고 있어 직관적인 사용성을 제안하지 못하고 있다. 따라서 본 연구에서는 리모컨에서 PIP관련 버튼을 줄임과 동시에 PIP 사용성을 높일 수 있는 개선안을 제안하고자 하였다. 연구 방법은 PIP 사용행태 분석을 통한 문제점 파악 후 2가지 개선안을 도출한 후 각각의 개선안에 대한 사용성 검증을 실시하였다. 그 결과, 기존의 리모컨 버튼으로 접근하는 것이 사용성이 더 좋을 것이라는 예상을 깨고, PIP기능 사용 시 OSD메뉴로 접근하는 것이 수행시간이 줄어들었음을 알 수 있었다. 이것은 TV라는 매체의 특성상 사용자는 TV화면에서 기능 수행 후 Feedback을 기대하며, TV화면 상에서 동작하는 것에 더 익숙하기 때문이다. 이는 향후 새로운 TV기능 구현 시 중요한 Impact로 작용할 수 있다. 그 이유는 리모컨 버튼을 활용하여 모든 기능을 수행하는 것보다, 특정 기능은 OSD상에서 구현하는 것이 TV의 직관적인 사용 Scene에 더 적합한 것을 파악할 수 있었기 때문이다.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.436-449
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• 2016

This paper compares the transport overhead of MMT (MPEG Media Transport) with that of MPEG-2 TS (Transport Stream). MPEG-2 TS is globally used in multiplexing compressed audio and video data in digital broadcast industry, including areas of DTV (Digital Television), IPTV (Internet Protocol Television), and DMB (Digital Multimedia Broadcasting). It was the early 1990s when MPEG-2 TS standard was established. After more than two decades of years since its first establishment, many parts of MPEG-2 TS turned out to be inappropriate to today's broadcast and communication environment. Given the situations, in 2014 MPEG (ISO/IEC JTC 1 SC 29/WG 11) standardized MMT as the next-generation multimedia transport standard hopefully that can replace MPEG-2 TS. In this paper, with assumptions of broadcast service scenarios we applied both MMT and MPEG-2 TS to each scenario and we calculated their transport overheads. We used a software program that counts the transport overhead, which was developed in our laboratory for this paper. And we conducted a comparative analysis based on the calculated result of transport overhead.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.311-321
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• 2009

In a single frequency network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interference due to the use of same frequency among multiple transmitters or repeaters is inevitable for receivers. This problem can be solved by adjusting transmit power and time of each transmitter and repeater. To adjust SFNs, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal which is embedded in a signal from each transmitter or repeater. This paper proposes an efficient method to estimate the individual reception power from each transmitter or repeater based on the channel profile of SFN and the total reception power. Moreover, field test results are provided to evaluate the performance of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.242-246
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• 2005

RFID(Radio Frequency Identification) which is emerging from a change in digital convergence paradigm and recently rapidly advancing throughout the overall society is the core technology based on Ubiquitous network. In other words, This is a technology to identify the information of the object and recognize the situation by attaching electrical tag to an object and using Reader that can read the information of the object. With the emergence of the technology, it has turned the existing maintenance of the product into the network and intelligence of the product control by using the bar cord to maintain the product and will lead a revolution throughout overall society by affecting the fields of distribution and product maintenance as well as those of medicines, chemicals and food which the electrical tag can be attached to. his paper shows that utilizing the Bluetooth which is a local wireless telecommunication in the standalone imbedded system can implement the piconet configuration among the Readers and the data telecommunication with the main server.

• Journal of Korea Multimedia Society
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• v.16 no.10
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• pp.1196-1203
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• 2013

In general, the cost of transceiver for wireless network configuration is more expensive than that for wired network. However, in case of environmental management system in a tunnel, the cost can be minimized by adopting low rate tranceiver because the amount of the exchanged data for tunnel monitoring is very small. When the obtained data from sensor node is sent directly to the corresponding command node, there is no need to consider routing problem of the data transfer. However in this case, sensor nodes are required to be implemented with high power transmitter and experience high energy consumption. To tackle this problem, relay nodes can be used to transfer the data of tunnel monitoring, and suitable routing protocols for selecting optimum path are needed. Therefore, in this paper, we propose a routing algorithm and a self-configuration protocol for environment management system in tunnel.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.137-143
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• 2010

This paper deals with the performance comparison of self adaptive equalizer by the weighting factor of MCMA cost function for the compensate the amplitude and phase distortion which occurs in the communication channel. The MCMA is improves the cost function of present CMA at the output of equalizer for the minimize of error function in the amplitude and phase, the value of weighting factor is used at this time. When the comparison of equalizer performance, we classified to initial state and steady state, then it represents the convergence time and convergence speed and steady state operation of equalizer to the predetermined level, it is determined by the weighting factor. We confirm to the different result to this 2 state by weighting factor values using computer simulation. By using the result of this paper, if we appropriately choose the weighting factor values in the environment of communication channel, it is expected that the high quality digital transmission is possible.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.3-9
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• 2012

In this paper, we present novel analysis results of sonar communication using parametric array. We consider transducer diameter, primary frequency, difference frequency and acoustic power as analysis parameters of communication performance. We calculate theoretical BER(Bit Error Rate) and channel capacity of MIMO(Multi Input and Multi Output) communication system. By considering practical parameters, we obtain optimum difference frequency generation condition. The obtained primary frequency is 560 kHz, difference frequency 45kHz and acoustic power is 28.05Watt. For BER of $10^{-4}$, the range gain of parametric array communication is 3.35km compared to primary frequency communication. For channel capacity of 10bps/Hz, the SISO and $2{\times}2$ MIMO communication range of parametric array communication are 3.8km and 3.98km respectively, while primary frequency communication range is 0.83km.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.1-8
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• 2004

A novol clock distribution scheme is proposed for high-speed and low-power digital system to minimize clock skew and reduce dynamic power consumption. This scheme has ideal zero-skew characteristic by using folded clock lines (FCL) and phase blending circuit. For analyzing suitable line structures to FCLs, microstrip line and coplanar line are placed with folded clock lines. Simulation results show that the maximum clock-skew between two receivers located 10mm apart is less than lops at 1㎓ and the maximum clock-skew between two receivers located 20mm apart is less than 60ps at 1㎓. Also the results show that the minimum skews of clock signals regardless of process, voltage, and temperature variation are invariant.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.350-364
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• 2008

Single frequency network (SFN) design based on the Advanced Television Systems Committee (ATSC) specification, a terrestrial digital television (DTV) system, normally causes a interference problem, among signals from multiple transmitters or repeaters. To solve this, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal embedded in a signal from each transmitter or repeater. A TxID signal analyzer is then used to detect the TxID signal, and following the analysis results, a SFN design can be adjusted. This paper discusses the generation and usages of Kasami sequence, is used the TxID signal. The configuration of the TxID signal analyzer to efficiently detect TxID signal is proposed and the results of theoretical performance analysis are provided. Moreover, computer simulation and laboratory test results are provided to evaluate the performance of TxID signal analyzer and the theoretical performance analysis.