• International journal of advanced smart convergence
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• v.6 no.2
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• pp.51-58
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• 2017

Recently, rapid advances of Ethernet and IP technology have brought many changes in the sound industry. In addition, due to AoIP-based audio transmission technology, various problems of the acoustic system (sound quality deterioration due to long distance transmission, complicated wiring) have improved dramatically. However, when many distributed audio systems are connected with AoIP equipment, if there is a problem in the equipment, it is impossible to operate the connected system. AoIP equipment only can transmit audio signals but cannot adjust the system for acoustic environment. In this paper, AoIP equipment is to be installed with sound equipment on a one-to-one basis, so that various existing problems can be solved and adjustment of sound quality (reverberation, echo, delay and EQ) can be possible by AoIP-based OAC (On-site Audio Center) with built-in DSP function. As a result, uncompressed real-time transmission by distributed transmission/receipt module in OAC (On-site Audio Center) and high quality sound by adjustment of sound quality with built-in DSP can be acquired. It is expected that OAC based sound system will be the industry standard in ubiquitous environment.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.716-720
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• 2006

In this paper, we designed and proposed new routing algorithm that can support a variety of vital-sign traffic characteristic and could be applicable to USN for telemedicine by using adaptive transmission power level and increase frequency of routing request message. In proposed routing algorithm, when an emergency vital-sign traffic is applied, we use large transmission power to reduce route query response time and make the priority order in route process. On the other hand, for non emergency vital-sign traffic, we use low transmission power and adaptive decrease frequency of routing request message. which is insensitive to delay. The proposed scheme should be better QoS performance in complex USN than conventional method, which is performed based on uniform transmission power level.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.177-185
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• 2008

Research on media access control (MAC) scheme for Wireless Sensor Network (WSN) has been mainly focused on energy efficiency improvement, while interest on latency is relatively weak. However, end-to-end latency could be a critical limitation specifically in the multi-hop network such as wireless multimedia sensor networks. In this paper we propose a media access control scheme with distributed transmission power control to Improve end-to-end transmission latency as well as reduce power consumption in multi-hop wireless sensor networks. According to the simulation results, the proposed scheme is turned out to be an energy efficient scheme with improved end-to-end transmission latency.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.303-310
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• 2007

Compressed video bitstreams are intended for real-time transmission over communication networks. Because video compression algorithms eliminate the temporal, spatial, and statistical redundancies, the coded video bitstreams are very sensitive to transmission errors. We propose an error resilient video coding technique to limit the effect of error propagation in low bit-rate video coding. The success of error resilient coding techniques relies on how accurately the transmission errors can be detected. To detect the transmission error, we propose a very simple error detection technique based on data hiding Next, we conceal the corrupted MB data using intra MB refresh and motion compensation with the estimated motion vector and compare the simulation results. This method will be useful in video communication in error Prone environment such as WCDMA networks.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.219-224
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• 2011

To improve medical service and customers' satisfaction by reducing actual waiting time for medical inspection by personalized examination guidance contents (PEGC) linked with medical information system (MIS). The suggested PEGC was completed with preparing transmission for data and PEGC by using transmission control protocol internet protocol (TCP/IP) which can be built up creditable data transmission service. When patient signal event appeared in MIS while the communication was in standby, the ID and data of the customer were shown as text and image on monitors in waiting room. Guiding inspections, steps of examination, and undressing information extracted from the PEGC was also shown to the appropriate patient. After installation of the suggested PEGC, we rechecked satisfaction rates of 60 customers who visited the hospital with a same method as initial survey. The results of this study suggest that 3.6 point of waiting time satisfaction index were improved, after installation of the suggested PEGC, as 4.6 point.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.69-78
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• 2006

In this paper, we presents the efficiency and a transmission quality of the system which is composed of the optical elements from physical layer of the active optical ring network. For a simulation it will use the Transmissionmaker WDM and it will be able to observation a optical transmission quality of the optical transmission system. The active optical network is composed of two rings(main ring and sub-ring). It measures the BER(Bit Error Rate) quality which it follows node number from the sub ring and physical distance of the node. Performance analysis from the physical layer becomes the standard of the plan for the efficiency optimization of the active optical ring network. Consequently it will be able to compose the efficient optical transmission system which reflects the physical distance, a traffic demand quantity of each node and a number of users from actual network.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.65-72
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• 2003

In this paper, the new scheme using a Combined Cache(CC) that combing the Paging and Routing Cache(PRC) and an alternative handoff method according to the type of data transmission for achieving the efficient realtime communication. The PRC and quasi-soft handoff method reduce the path duplication. But they increase the network traffic load because of the handoff state packet of Mobile Host(MH). Moreover the use the same handoff method without differentiating the type of transmission data. Those problems are solved by operating U with a semi-soft handoff method for realtime data transmission and with a hard handoff method for non-realtime data transmission. As a result or simulation a better performance is obtained because of the reduction of the number of control packet in case that the number of cells are below 20. And the packet arrival time and loss of packet decreased significantly for realtime data transmission.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.535-539
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• 2008

Recently mobile devices can transmit mass data contained multi-media contents. According these flow, a demand for fast data transmission is being risen, so we acutely require remarkable technology that overcome mobile communication's poor environment and rise data transmission volume. Because it can be satisfied these needs, the OFDM(Orthogonal Frequency Division Multiplexing) that rise data transmission volume using efficient frequency, and MIMO(Multiple Input Multiple Output) that rise transmission confidence and data transmission volume using numbers of antenna is attended. Before design of MIMO-OFDM System we want to make an analysis for theory of its systems, and we want to design MIMO-OFDM simulator for verify an ability of modulation, data volume and numbers of antenna.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.29-30
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• 2013

차세대 전자 소자용 전송 선로로 사용될 수 있는 나노 원기둥 배열의 분산 관계 특성을 모드 정합법을 사용하여 계산하였다. 서로 떨어진 나노 원기둥 배열에도 배열이 놓인 방향으로 전자파 모드가 형성되는 것을 수치 해석 결과로 제시한다. 또한 나노 원기둥 배열에 생기는 전기장의 분포 특성도 제시한다.

• Current Research on Agriculture and Life Sciences
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• v.10
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• pp.41-47
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• 1992

In general, the behavior of moisture transmission is estimated by vapor permeability or vapor transmission resistance, but its values obtained by experiments do not have great adaptability for practical situations because of changes in the experimental conditions. This fact is why only theoretical discussions have advanced. Thus, the fundamental study of the moisture transmission phenomenon has been treated lightly. Here, as the first step toward the basic research of moisture transmission, the amount of moisture transmission and the moisture distribution in specimens were investigated. The experiment was conducted in a steady state, and the moisture distribution was measured by slicing and weighing the specimens. From the examination of the vapor transmission resistance, the phenomenon of moisture transmission was dealt with devide the moisture transfer on the wood surface and moisture diffusion in wood. The following results were obtained. 1) The phenomenon of moisture transmission should be approached by its division into moisture transfer on the wood surface and moisture diffusion in the wood because the positive values of vapor transmission resistance exist in the extrapolation of thickness 0mm. 2) The distribution of moisture in wood can be illustrated by two straight lines intersecting at the point of nine percent moisture content : namely, diffusion coefficients have two constant values at moisture contents below and above nine percent. The shape of the distribution curve of moisture content is similar irrespective of the wood thickness. On the other hand, when the moisture contents on both sides was more than nine percent, the distribution of the moisture content could be illustrated by one straight lines. 3) The amount of moisture movement is determined by the moisture gradient in wood. 4) Coefficients of the moisture transfer depend on the thickness of the specimens.