• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1784-1788
• /
• 2008

전자파표면유속계는 여러 측정지점을 가능한 신속하게 이동하면서 홍수시 유속을 측정하는데 그 목적이 있다. 또한 홍수시 유속은 시간대 별로 급격히 변하는 속성을 가지고 있으므로 유량측정 지점의 유량을 실시간으로 획득하기 위해서는 현장 측정에서 측정한 유량데이터가 실시간으로 집계 되어야한다. 현재의 시스템은 측정 정보를 실시간으로 전송하기 위하여 현장 측정자에게 PDA가 보급되어 있으며 CDMA망을 통해서 유량 측정을 위한 각종 정보 및 측정결과를 실시간 전송하도록 되어있다. 그러나 전자파표면유속계를 비롯한 각종 유속계가 PDA와 무선으로 통신을 할 수 있게 되어있지 않기 때문에 열악한 여건의 현장에서 측정한 데이터를 야장에 수기로 기록한 후 이를 다시 PDA에 수동으로 입력시켜야하는 불편함이 있다. 전자파표면 유속계를 제외한 다른 측정 장비는 제조회사가 수자원공사와 독립적인 업체이므로 통신 접속을 하기위한 특정 인터페이스를 알아내기가 어려운 실정이다. 그러나 전자파표면유속계는 수자원공사에서 개발한 장비로서 핵심기술을 수자원공사에서 보유하고 있으므로 PDA와 통신을 가능하게 하는 장치의 개발이 가능하다. 이에 이러한 불편한 문제점을 개선하여 현장에서 홍수 유량 측정시 작업자들의 편이성을 증대시키고자 전자파표면유속계와 PDA간에 근거리통신기법을 적용하였다. 이를 위하여 Bluetooth, UWB(Ultra-Wide Band, 초광대역통신), Zigbee 등 적용가능한 근거리 통신기법을 조사하였다. 그 결과 Zigbee가 소비전력이 적어 현장에서 홍수유량측정에 이용되는 전자파표면유속계에 적용성이 가장 뛰어난 것으로 나타났다. 무선통신 모듈과 연동되는 전자파표면유속계는 이동식을 기준으로 적용하였으며 기존 신호처리부에 무선통신 모듈을 장착할 수 있는 구조로 설계하였다. 장착 방식은 기존 이동식 유속계의 신호처리부의 RS-232 포트에 무선통신 모듈을 장착하면 사용할 수 있는 구조로 되어있다. 신호처리부 RS-232 포트는 현재까지는 측정한 유속값을 PC로 전송받는 용도로 활용되었으나 무선모듈 장착 시에는 무선통신 할 수 있는 이중화 구조를 채택하였다. 두 가지 방식에 대한 통신구별은 초기에 송수신하는 데이터에 따라 구별되도록 하였다. 신호처리부에서 무선통신 추가에 따른 운용 방식은 별도의 수자원공사 모드를 추가하여 운용하도록 수정하였다. 유속 측정 시에는 무선통신 모듈을 제거한 상태에서 측정한 후, 측정한 데이터를 PDA로 전송할 때 아를 부착하여 사용할 수 있는 구조를 갖도록 제작하였다. 이러한 방식을 적용시킨 이유는 기존에 보급된 유속계에 무선모듈을 장착한 후, 신호처리부 운용 프로그램을 업그레이드하면 바로 사용할 수 있도록 하기 위함이다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.12A
• /
• pp.1279-1284
• /
• 2004

In this paper, we propose a novel and simple optical technique for the detection of subcarrier-multiplexed(SCM) labels using optical interleavers. Optical-baseband packet signals with suppressed subcarriers appear at the through-pass port of the optical interleaver and SCM labels with suppressed optical carrier exit from the optical SCM extraction port. Since it does not require optical circulators, this structure shows less insertion loss than the previously proposed optical label detectors. The periodic nature of the interleaver transfer function makes it possible to detect multiple SCM channels simultaneously from an incoming wavelength-multiplexed signal stream. Detection of a 155-Mb/s ASK modulated 9.79-GHz subcarrier using a 10-GHz SCM optical label detector has been performed successfully and verified through optical spectra and bi t-error-rate measurements.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.6 s.336
• /
• pp.67-74
• /
• 2005

Crypto-systems have difficulties in designing hardware due to the various standards. We propose a programmable and configurable architecture for cryptography coprocessors to accommodate various crypto-systems. The proposed architecture has a 32 bit I/O interface and internal bus width, and consists of a programmable finite field arithmetic unit, an input/output unit, a register file, and a control unit. The crypto-system is determined by the micro-codes in memory of the control unit, and is configured by programming the micro-codes. The coprocessor has a modular structure so that the arithmetic unit can be replaced if a substitute has an appropriate 32 bit I/O interface. It can be used in many crypto-systems by re-programming the micro-codes for corresponding crypto-system or by replacing operation units. We implement an elliptic curve crypto-processor using the proposed architecture and compare it with other crypto-processors

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.10
• /
• pp.2209-2216
• /
• 2011

In this paper, we design a 32-bit eFuse OTP memory for PMICs using MagnaChip's $0.18{\mu}m$ process. We solve a problem of an electrical shortage between an eFuse link and the VSS of a p-substrate in programming by placing an n-well under the eFuse link. Also, we propose a WL driver circuit which activates the RWL (read word-line) or WWL (write word-line) of a dual-port eFuse OTP memory cell selectively when a decoded WERP (WL enable for read or program) signal is inputted to the eFuse OTP memory directly. Furthermore, we reduce the layout area of the control circuit by removing a delay chain in the BL precharging circuit. We'can obtain an yield of 100% at a program voltage of 5.5V on 94 manufactured sample dies when measured with memory tester equipment.

• Journal of the Institute of Convergence Signal Processing
• /
• v.10 no.3
• /
• pp.193-197
• /
• 2009

In this paper, we study on design of vehicle control system which is based on ${\mu}C/OS-II$, We component a electric motor drive system for simulator because the most of vehicle part use electric motor for actuator. We use the XC2287 microcontroller which is often used vehicle body controller because XC2287 guarantee high confidence and durability in vehicle industry. The electric motor control system derive PWM from general I/O port in XC2287 microcontroller. The signal is supplied at electric motor after amplifying that using driver circuit. The user control duty of PWM signal through controlling potentiometer which is connected to XC2287. through that, the user control speed of electric motor. we synchronize both input process via controlling potentiometer and PWM output process using semaphore. we verify porting of ${\mu}C/OS-II$ via experimentation.

• Journal of Advanced Navigation Technology
• /
• v.24 no.4
• /
• pp.299-304
• /
• 2020

This paper proposes the design of circular sector shaped power divider-combiner with a planar structure. This structure can be constructed in series, and due to the circular sector shape, it is possible to simplify circuit configuration and improve the amplitude and phase balanced characteristics of the output. It has a simple input matching circuit and an RC parallel circuit was inserted between the output ports to improve the reflection coefficient and isolation of the output. Since the designed divider-combiner are structurally designed in a symmetrical shape of a sector, even if the output ports are composed of two or four output ports, they have excellent characteristics with an amplitude balance of ± 0.1 dB and a phase balance of ± 1o between outputs. To prove these characteristics, it was confirmed that the characteristics of the planar power divider-combiner fabricated at an operating frequency of 2 GHz are in good agreement with the simulation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.1 s.116
• /
• pp.37-43
• /
• 2007

In this.paper, we introduce design and implementation results of the single balanced diode mixer for European point-to-point microwave radio in order to improve flatness performance. When a resonator such as RF filter is integrated with a mixer, impedance characteristic of 50 ohm is maintained only in RF band, not in LO band resulting deterioration of flatness performance because of LO power variation on the diode. In the paper, we suggest a design method of mixer integrated with image rejection filter and LO harmonic filter to have a better performance of flatness using embedding electrical length between filter and mixer's port. Frequency specification of fabricated mixer is $21.2{\sim}22.6\;GHz$ for RF, $19.32{\sim}20.72\;GHz$ for LO and 1.88 GHz+/-50 MHz for IF, respectively. Measured results show conversion loss of 8.5 dB, flatness of 2 dB, input PldB of 8 dBm, IIP3 of 15 dBm under LO power level of 10 dBm. Return losses of RF, LO and IF port are under -12 dB, -10 dB and -5 dB, respectively. Isolations of LO/RF and LO/IF are 20 dB and 50 dB, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.2
• /
• pp.151-158
• /
• 2012

This paper proposes a H-plane 8-way rectangular waveguide power divider using Y-junction. A general N-way power divider can be composed of multi-stage T-junctions. However, if the distances of output ports are close, the matching characteristic is not improved by using only T-junctions because of space limitation. In this case, since other types of 3-port junctions should be used to final output stage, Y-junctions are used with T-junctions in this paper. The proposed Y-junction uses the tapered-line impedance transformer and inductive irises to improve impedance matching characteristic. The 8-way power divider using Y-junction is fabricated and measured. The measured return loss and insertion loss from input port to output port are -30.8 dB and -9.3 dB at operating frequency, respectively. The measured maximum phase difference is about $1^{\circ}$. Therefore, the proposed power divider will be useful to apply to various microwave systems, which need to divide the input power equally, such as feed networks for array antennas.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.1
• /
• pp.111-116
• /
• 2017

We propose the compact circular polarized antenna. The radiation elements of the proposed antenna is designed using FR4 substrate with the size of $25mm{\times}3.2mm{\times}5mm$ and stand on four corners of the feed network substrate. The feeder network is designed on FR4 substrate with the size of $40mm{\times}40mm{\times}0.8mm$ and has four oupt signals with same magnitude and $90^{\circ}$ phase difference. The input impedances of the designed radiation elements and the output impedances of the feeder network are $100{\Omega}$. The designed antenna has the dimension of $40mm{\times}40mm{\times}5.8mm$ and the operated frequency band of 1.559 - 1.609 GHz. The fabricated antenna has RHCP radiation pattern and the measured results of axial ratio less than 3.5 dB and radiated gain more than 1.5 dBic. The fabricated antenna can apply to GLONASS and Beiodu systems as well as GPS system.

• Journal of Astronomy and Space Sciences
• /
• v.24 no.4
• /
• pp.349-366
• /
• 2007

We designed and developed a multi-purpose CCD camera system for three kinds of CCDs; KAF-0401E($768{\times}512$), KAF-1602E($1536{\times}1024$), KAF-3200E($2184{\times}1472$) made by KODAK Co.. The system supports fast USB port as well as parallel port for data I/O and control signal. The packing is based on two stage circuit boards for size reduction and contains built-in filter wheel. Basic hardware components include clock pattern circuit, A/D conversion circuit, CCD data flow control circuit, and CCD temperature control unit. The CCD temperature can be controlled with accuracy of approximately $0.4^{\circ}C$ in the max. range of temperature, ${\Delta}33^{\circ}C$. This CCD camera system has with readout noise $6\;e^-$, and system gain $5\;e^-/ADU$. A total of 10 CCD camera systems were produced and our tests show that all of them show passable performance.