• Journal of electromagnetic engineering and science
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• 제15권2호
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• pp.104-110
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• 2015

As civil infrastructures continue to deteriorate, the demand for structural health monitoring (SHM) has increased. Despite its outstanding capability for damage identification, many conventional SHM techniques are restricted to huge structures because of their wired system for data and power transmission. Although wireless data transmission using radio-frequency techniques has emerged vis-$\grave{a}$-vis wireless sensors in SHM, the power supply issue is still unsolved. Normal batteries cannot support civil infrastructure for no longer than a few decades. In this study, we develop a magnetic resonance-based wireless power transmission system, and its performance is validated in three different mediums: air, unreinforced concrete, and reinforced concrete. The effect of concrete and steel rebars is analyzed.

• 대한전기학회논문지:전력기술부문A
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• 제49권12호
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• pp.608-613
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• 2000

This paper describes a fault location technique using wavelets in underground transmission power cable system. Estimation of fault location is performed using data smapled at two ends underground system. In the case of 50% fault of total underground transmission line, fault location is calculated using sampled single-end data in underground transmission line. Traveling wave is utilized in capturing the travel time of the transients along the monitored lines between the relay and the fault point. This traveling time information is provided by the wavelet. Simulation was performed using EMTP, ATP Draw and MATLAB. The results of fault location shown in this paper will be evaluated as an effective suggestion for fault location in real underground transmission line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.264-267
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• 2002

This paper proposed a effective priority selection algorithm named weighted round-robin algorithm and show the implementation result of DMAC priority selection module using prosed weighted round-robin algorithm. I parameterize timing constraints of each functional module, which decide the effectiveness of system. Proposed weighted round-robin algorithm decide the most effective module for data transmission using parameterize timing constraints and update timing parameter of each module for next transmission module selection. I implement DMAC priority selection module using this weighted round-robin algorithm and can improve the timing effective for data transmission from memory to functional module or one functional module to another functional module.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1796-1798
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• 2002

Speech transmission is common in many communications systems. In this paper, a technique to reduce the total bits required for expressing the speech data is proposed for the purpose of a packet transmission. A novel coding method is derived based on the concept of finding common information in sequential speech samples. Computer simulations demonstrate that the proposed scheme reduces the total bits re- quired in PCM approximately by half.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1152-1156
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• 2003

For pneumatic valve system control, we need a serial data transmission system with high speed and reliability for information interchange between main computer and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic valve system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid control valves. in addition, we developed a communication protocol for construction of rs-485 based multi-drop network and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. the field test results show that, even under high noise environment, the data transmission of 375kbps rate is possible up to 1,500meter without using repeater. In addition, the system developed in this research is easily to be extended for a communication network because of its modular structure.

• 방송공학회논문지
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• 제9권2호
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• pp.119-130
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• 2004

We have developed a prototype super-high-definition (SHD) digital cinema distribution system that can store, transmit, and display eight-million-pixel motion pictures that have the image quality of a 35-mm film movie. The system contains a movie server, a real-time decoder, and an SHB projector. Using a Gigabit Ethernet link and TCP/IP, the server transmits JPEG2000 compressed motion picture data streams to the decoder at transmission speeds as high as 300 Mbps. The received data streams are decompressed by the decoder, and then projected onto a screen via the projector. By using an enlarged TCP window, multiple TCP streams, and a shaping function to control the data transmission quantity, we achieved real-time streaming of SHD movie data at about 300 Mbps between Chicago and Los Angeles, a distance of more than 3000 km. We also improved the decoder performance to show movies with Image qualities of 450 Mbps or higher. Since UDP is more suitable than TCP for fast long-distance streaming, we have developed an SHD digital cinema UDP relay system, in which UDP is used for transmission over a fast long-distance network. By using four pairs of server-side-proxy and decoder-side-proxy, 450-Mbps movie data streams could be transmitted.

• 대한임베디드공학회논문지
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• 제11권4호
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• pp.243-249
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• 2016

Energy-harvesting nodes in wireless sensor networks(WSNs) can be exhausted due to a heavy workload even though they can harvest energy from their environment. On contrast, they can sometimes fully charged, thus waste the harvested energy due to the limited battery-capacity. In order to utilize the harvested energy efficiently, we introduce a selective data compression and transmission range control scheme for energy-harvesting nodes. In this scheme, if the residual energy of a node is expected to run over the battery capacity, the node spends the surplus energy to exploit the data compression or the transmission range expansion; these operations can reduce the burden of intermediate nodes at the expanse of its own energy. Otherwise, the node performs only basic operations such as sensing or transmitting so as to avoid its blackout time. Simulation result verifies that the proposed scheme gathers more data with fewer number of blackout nodes than other schemes by consuming energy efficiently.

• 전기학회논문지
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• 제58권2호
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• pp.407-414
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• 2009

The foundation fieldbus(FF) is one of the fieldbuses most widely used for process control and automation, In order for system designer to optimize medium management, it is imperative to predict transmission delay time of data. In a former research, mathematical modeling to analyze transmission delay of FF token-passing system has been developed based on the assumption that a device node has only one priority data(1Q model), From 1Q model, all of the device nodes, which are connected on the FF system, are defined priority level in advance, and as system operates, data are generated based on given priority level. However, in practice, some non-periodic data can have different priority levels from one device. Therefore, new mathematical model is necessary for the case where different priority levels of data are created under one device node(2Q model). In this research, the mathematical model for 2Q model is developed using the equivalent queue model. Furthermore, the characteristics of transmission delay of 2Q model which is presented in this paper were compared with 1Q model. The validity of the analytical model was verified by using a simulation experiment.

• 한국통신학회논문지
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• 제39C권11호
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• pp.1146-1150
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• 2014

최근 스마트선박 기술 관련 연구에 대한 관심이 증가하고 있다. 또한 스마트선박 기술의 발달로 데이터가 sensor node들에 의해 수집되면서 전송횟수의 증가로 인해 network의 과부하를 야기할 수 있다. 따라서 본 논문에서는 스마트선박 내부의 sensor node에 대한 data 전송횟수에 대한 빈도수를 줄이기 위해 data fusion를 이용하여 data를 가공 처리하는 기법을 적용하였다. 스마트선박 내부에서 수집되는 data는 의미 있는 data 가공하여 센터로 전송되어 network의 부하를 줄이고 효율적으로 data를 전송할 수 있는 방안을 제시하였다.

• 대한의용생체공학회:의공학회지
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• 제12권2호
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• pp.113-120
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• 1991

This paper describes the implementation of a 3 channel ECG monitoring system. This system consists of an IBM-PC and simple accessory only. A PDTS (parallel data transmission system ) was designed to do monitor the data being operated with no effect and no exchange of software and hardware on the main transmission system in LOCAL mode. And it receives patient's ECG data from EPTS ( ECG processing and transmission system) of distant region. It provides on-line ECG waveform display, waveform storage, recall and editing the waveform. We have implemented the monitoring system by tw methods, and with system, we could directly monitor the EPTS and also receive the data from the remote ㅁe잉ion. This system was tested by experiments and examined its practical use.