• Journal of Sensor Science and Technology
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• v.27 no.2
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• pp.86-92
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• 2018

In recent times, motion capture technology using inertial measurement unit (IMU) sensors has been actively used in sports. In this study, we developed a canoe paddle, installed with an IMU and a water level sensor, as a system tool for training and calibration purposes in water sports. The hardware was fabricated to control an attitude heading reference system (AHRS) module, a water level sensor, a communication module, and a wireless charging circuit. We also developed an application program for the mobile device that processes paddling motion data from the paddling operation and also visualizes it. An AHRS module with acceleration, gyro, and geomagnetic sensors each having three axes, and a resistive water level sensor that senses the immersion depth in the water of the paddle represented the paddle motion. The motion data transmitted from the paddle device is internally decoded and classified by the application program in the mobile device to perform visualization and to operate functions of the mobile training/correction system. To conclude, we tried to provide mobile knowledge service through paddle sport data using this technique. The developed system works reasonably well to be used as a basic training and posture correction tool for paddle sports; the transmission delay time of the sensor system is measured within 90 ms, and it shows that there is no complication in its practical usage.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.641-648
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• 2012

The up-streams of the continuous streaming of data packets with lower importance level in the wireless sink node can cause congestion and delay, they affect on energy efficiency, memory size, buffer size, and throughput. This paper proposes a new wireless sink congestion control mechanism based on tournament scheduling. The proposed method consists of two module parts: stream decision module part and service differentiation module part. The final winner in the tournament controls congestion effectively, minimizes packet loss due to congestion, decreases energy consumption, and improves QoS. The simulation result shows that the proposed method is more effective and has better performance compared with those of congestion descriptor-based control method, reliability-based control method, and best-effort transmission control method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.372-379
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• 2003

In order to improve a damage of connection part of Main Board Memory, we developed a hazard extension card(Socket Jig). The damage occurs during the test of the memory module product of the Desktop-PC. The connection part of main board was broken by 15％ per a day before the development. There existed two major problems; One was that we must obtain more than 15％ of surplus equipment. while the other was that we needed people who were wholly responsible for repair. The development of extension card decreased operation delay. Besides, it improved capacity of surplus equipment and operation efficiency. Therefore, we can save 78,000,000 won per year.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.175-182
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• 2000

(A hybrid-type wireless infrared data communication module was fabricated by using the light emitting andabsorption diodes with the one-chip of integrated digital circuits. The light emitting diode with the peak spectrum of 850 nm was made from compound semiconductor material of AIGaAs and shows high speed signal transmission with the delay time of 60 nsec for the light direction angle of 30". The Si PIN photodiode showsthe good absorption rate for the range of wavelength of 450-1050 nm and convex-type epoxy lens was utilized for the spectrum filtering on the visible-range spectrum below 750 nm, The data transmission speed is 115.2 kbps and the fabricated module satisfies on the IrDA 1.0 SIR standard requirements.)ments.)

• Journal of Sensor Science and Technology
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• v.27 no.4
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• pp.254-258
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• 2018

A Wi-Fi signal network (WSN) system is introduced in this paper. This system consists of several data-transmitting sensor modules and a data-receiving server. Each sensor module and the server contain a unique intranet IP address. A piezoelectric accelerometer with a bandwidth of 12 kHz, a 24-bit analog-digital converter with a sampling rate of 15.625 kS/s, a 32-bit microprocessor unit, and a 1-Mbps Wi-Fi module are used in the data-transmitting sensor module. A 300-Mbps router and a PC are used in the server. The system is verified using an accelerometer calibrator. The voltage output from the sensor is converted into 24-bit digital data and transmitted via the Wi-Fi module. These data are received by a Wi-Fi router connected to a PC. The input frequencies of the accelerometer calibrator (320 Hz, 640 Hz, and 1280 Hz) are used in the data transfer verification. The received data are compared to the data retrieved directly from the analog-to-digital converter used in the sensor module. The comparison shows that the developed system represents the original data considerably well. Theoretically, the system can acquire vibration signals from 600 sensor modules at an accelerometer bandwidth of 15.625 kHz. However, delay exists owing to software processes, multiplexing between sensor modules, and the use of non-real time operating system. Hence, it is recommended that this system may be used to acquire vibration signals with up to 10 kHz, which is approximately 70% of the theoretical maximum speed of the system. The system can be upgraded using parts with higher performance

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1091-1100
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• 2004

In this paper, we present a reducing power conswnption of a scheduling for module selection under the time constraint. The proposed low power scheduling executes FDS_LP considering low power to exist the FDS scheduling by inputted the behavioral language. The proposed FDS_LP perfonns lower power consumption with dynamic power which is minimized the switching activity, based on force conception In the time step of module selection, an optimal RT(Register Transfer) library is composed by exploration of the parameters such as power, area, and delay. To find optimal parameters of RT library, an optimal module selection algorithm using Branch and Bound algorithm is also proposed. In the comparison and experimental results, The proposed FDS_LP algorithm reduce maximum power saving up to 23.9% comparing to previous FDS algorithm.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.765-768
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• 2008

To make 3D camera system, we check the possibility of advanced range camera module based on measuring the time delay of modulated infrared light, using a single detector chip fabricated on standard CMOS process. To depth information, electronic shutter and interlaced scanning method of 2D sensor is needed. Especially, we design "lens system, illumination unit" and review simulation result.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.307-309
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• 2001

In this paper, we present a scheme for the improving reliable transport and the efficient multicast support in mobile environment. The proposed scheme solves a problem of TCP layer resulted from mobility by using a Representative FA. RFA has a mechanism like a snoop module which has a cache and can provide retransmission of a multicast packet lost and solve the rock implosion problem. Also, we present an additional IGMP message. By using it, We can remove a delay for IGMP query cycle and serve a multicast service more promptly.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.149-158
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• 1994

Through high level synthesis, designers can obtain the precious information on the area and speed trade-offs as well as synthesized datapaths from behavioral design descriptions. While previous researches were concentrated on the synthesis of pipelined, datapaths with fixed DII (Data Initiation Interval) by inserting delay elements where needed, we propose a novel methodology of synthesizing pipeline structures with variable DIIs. Determining the time-overlapping of pipeline stages with variable DIIs, the proosed algorithm performs scheduling and module allocation using the time-overlapping information. Experimental results show that significant improvement can be achieved both in speed and in area.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.190-196
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• 2011

Bandwidth extension is a technique to improve speech quality and intelligibility, extending from 300-3400 Hz narrowband speech to 50-7000 Hz wideband speech. This paper designs an artificial bandwidth extension (ABE) module embedded in the AMR (adaptive multi-rate) decoder, reducing LPC/LSP analysis and algorithm delay of the ABE module. We also introduce a fast search codebook mapping method for ABE, and design a low power BWE technique based on the AMR decoder. The proposed ABE method reduces the computational complexity and the algorithm delay, respectively, by 28 % and 20 msec, compared to the traditional DTE (decode then extend) method. We also introduce a weighted classified codebook mapping method for constructing the spectral envelope of the wideband speech signal.