• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.48-50
• /
• 2009

This paper presents an IAQ(Indoor Air Quality) Monitoring System using equipments for measurement of fine Particle($PM1{\sim}PM10$), $CO_2$, VOCs(Volatile Organic Compounds), temperature and humidity for IAQ monitoring of subway station which millions of people use a day. The necessity of IAQ monitoring system is getting increased for more effective subway station monitoring in line with the recent government's regulation for IAQ is reinforcing. Subway Station is an unusual case. The structure of subway station is closed and complicated. Therefore when data of equipments are transferred, transmission error can happen occasionally. To prevent transmission error, an IAQ Monitoring System is needed the appropriate position and selection of equipments or sensor module. In addition IT(Information Technology) can be utilized like "WiBro(Wireless Broadband)" and "GateWay" for facilitate movement of data and construction of IAQ monitoring system of subway station.

• Transactions on Semiconductor Engineering
• /
• v.1 no.1
• /
• pp.14-22
• /
• 2023

This paper presents a low-power flip-flop(FF) circuit that minimizes the transition of internal nodes by using a dual change-sensing method. The proposed dual change-sensing FF(DCSFF) shows the lowest dynamic power consumption among conventional FFs, when there is no input data transition. From the measured results with 65nm CMOS process, the power consumption has been reduced by 98% and 32%, when the data activity is 0% and 100%, respectively, compared to conventional transmission gate FF(TGFF). Further, compared to change-sensing FF(CSFF), the power consumption of proposed DCSFF is smaller by 30%.

• Journal of Power Electronics
• /
• v.15 no.3
• /
• pp.685-694
• /
• 2015

The power loss of the controllable switches in modular multilevel converter (MMC) HVDC transmission systems is an important factor, which can determine the design of the operating junction temperatures. Due to the dc current component, the approximate calculation tool provided by the manufacturer of the switches cannot be used for the losses of the switches in the MMC. Based on the enabled probabilities of each SM in an arm, the current analytical models of the switches can be determined. The average and RMS currents can be obtained from the corresponding current analytical model. Then, the conduction losses can be calculated, and the switching losses of the switches can be estimated according to the upper limit of the switching frequency. Finally, the thermal resistance model of the switches can be utilized, and the junction temperatures can be estimated. A comparison between the calculation and PSCAD simulation results shows that the proposed method is effective for estimating the junction temperatures of the switches in the MMC.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.51-55
• /
• 2007

In this paper Statistical Energy Analysis has been considered to predict high frequency air borne interior noise. Dash panel Insulation is major part to reduce engine excitation noise. Transmission loss and absorption coefficient are considered to predict dash insulation performance. Transmission lose is derived from coupling loss factor and absorption coefficient is derived from internal damping loss factor. Material Biot properties were used to calculate each loss factors. Insulation geometry thickness distribution was hard to measure, so FeGate software was used to calculate thickness map from CAD drawing. Each predicted transmission losses between conventional insulation and light weight insulation were compared with SEA. Transmission loss measurement was performed to validate each prediction result, and it showed good correlation between prediction and measurement. Finally interior noise prediction was performed and result showed light weight insulation system can reduce 40% weight to keep similar performance with conventional insulation system, even though light weigh insulation system has lower sound transmission loss and higher absorption coefficient than conventional system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.10B
• /
• pp.644-654
• /
• 2007

ZigBee is one of wireless communication standards and many applications based on Zigbee have been developing for commercial applications. Most of those applications require links to Internet like Zigbee service gateways. However, ZigBee service gateway should provides following functions to be effectively utilized itself: translation of messages between diverse ZigBee application profiles and message formats used in Internet, addition/removal of a new ZigBee service without stopping existing services according to addition/removal of a Zigbee node, and no transmission of unwanted packets to ZigBee network. Therefore, this paper proposes a new type of ZigBee Service Gateway, called ZiGate to provide the functions. The proposed ZiGate is capable of re-configurating message translation modules required in case of addition/removal of nodes and doesn't transmit unnecessary packets to the ZigBee networks by synchronizing itself with ZigBee network. And ZiGate provides translation modules between messages defined in Zigbee application profiles and both text-based and binary-based messages used in Internet. In this paper we implements the ZiGate and evaluates it on the test bed. This evaluations show that the proposed ZiGate works efficiently.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.12
• /
• pp.136-144
• /
• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.

• IEIE Transactions on Smart Processing and Computing
• /
• v.5 no.3
• /
• pp.199-206
• /
• 2016

This paper describes a simple routing control system. We propose achieving high-speed data transmission without modifying the data frame configuration. To add a routing control signal, called the "labeling signal" in this paper, to the data frame, we use a frequency modulation technique on the transmitted frame. This means you need not change the data frame when you transmit additional signals. Using a prototype system comprising a field-programmable gate array and discrete elements, we investigate the system performance and devise a method to achieve high resolution. A three-channel routing control for a 10 Gb/s data frame was achieved, which confirms the advantages of the proposed system.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.468-473
• /
• 2003

CCTV network has been implemented to transmit the image information of platfo gate and transfer section to local headquarters in the KNR(Korean National Railroa But. communication system for transferring image information around accident field has not been established yet. thus, at present implementation of communication equipment is necessary for dyn of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installatio optics cable in connection with the implemental plan for high-speed network from n And, the capacity of communication channel will be guaranteed much more than een station and station, station and central headquarters when fiber optics cable is This study analyzes the image equipment of field for transmission and estimated m transmit image information of accident field to headquarters with using communicat ucture. And, the study considers implemental method of communication network for nce image transmission from dozens to hundreds kilometers.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1300-1302
• /
• 2003

CCTV network has been implemented to transmit the image information of platform, ticket gate and transfer section to local headquarters in the KNR(Korean National Railroad). But, communication system for transferring image information around accident field or wayside has not been established yet. thus, at present implementation of communication equipment is necessary for dynamic image of unspecified accident to be transmitted to headquarters. Copper cable communication network is run by KNR, but it is processing installation of optical cable in connection with the implemental plan for high-speed network from now on. And, the capacity of communication channel will be guaranteed much more than now between station and station, station and central headquarters when optical cable is completed. This study analyzes the image equipment of field for transmission and estimated matters to transmit image information of accident field to headquarters with using communication infrastructure. And, the study considers implemental method of communication network for long-distance image transmission from dozens to hundreds kilometers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.397-400
• /
• 2004

The design concept for 8kV light triggering thyristor(LTT) with integrated BOD was discussed here in detail. The trade-off between light triggering input source againsthigh dV/dt limitation has been treated via grooved P-base for gate design. The main application point used for high voltage DC transmission(HVDC) was represented.