• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.3
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• pp.141-146
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• 2016

The AMR(automatic meter reading) system has been increasingly and widely used for its efficient and intelligent management, which is a technology that automatically collects consumption data from a water meter or energy metering device. The digital meter instead of the mechanical meter should be used in the system. Up to now, various types of sensor to measure the water flow rate have been used in the digital water meter, for example, reed switch, photo IR approximate sensor, ultrasonic sensor, electromagnetic sensor, etc. In this paper, a new sensing technology, where a variable capacitor and digital circuit were used for sensing the water flow rate, was proposed. The circuit was designed and verified by Pspice simulation. And a PCB board for the circuit was fabricated. After then, a prototype of digital water meter using a variable capacitor to measure the water flow rate was fabricated. The function tests of the fabricated digital water meter were performed, and it was found that the meter worked properly. Since the new technology has much better properties in terms of cost and power consumption compared to conventional technologies, it should be one of the major digital water meter technologies in the future.

• Korean Journal of Remote Sensing
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• v.22 no.4
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• pp.255-264
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• 2006

GRACE (Gravity Recovery and Climate Experiment) is the first dedicated gravity mapping mission. Its primary measurements are the distance changes between two co-orbiting low earth satellites. GRACE is a joint development by NASA and German DLR and was launched in March 2002. GRACE improves the Earth gravity model accuracy by nearly two factor of magnitude over pre-launch models. After brief description of the GRACE primary instrument, inter-satellite ranging system, its flight status and preliminary performance evaluation is presented. Ranging system error models, which were not included in the pre-launch performance model and design specifications, are identified through analyzing the flight data. Base on this analysis, future research topics on the GRACE instrument performance analysis are discussed.

• Convergence Security Journal
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• v.10 no.2
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• pp.37-41
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• 2010

The object of this paper is to design a embedded system based on sensor networks. The proposed system can manage the heating by sensing and analyzing the temperature and humidity in apartment house and others. For implementing this system, we devide JAVA API into the platform-independent JAVA part and platform-dependent native part for the implementation of JAVA API to manage the linux based embedded system devices, and focus on the control of the embedded system devices using JAVA API.

• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.162-167
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• 1996

This paper deals with an implementation method for the one chip microprocessor(8097)-based capacitance type wave recorder for a measuring real-time wave height. The system was developed to make it possible to real-time remote sensing the wave height by deploying the RS-232/422/485 communication methods. The system test results for the developed system such as linearity, system stability and robustness of the disturbance was also verified through the performance tests of the system. Furthermore, the system was developed after due consideration with connecting the public network such as satellite mobile communication system and LAN, through the deploying VLSI(Very Large Scale Integration) design techniques.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.89-94
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• 2002

Recently, DARI implemented the receiving and processing system for MODIS sensor data from NASA EOS satellites (TERRA and AQUA). This paper shows the development strategy considered, system requirement derived, system design, characteristic and test results of processing system. System operation concept and sample image are also provided. Implemented system was proven to be fully operational through lots of pass operations activities from RF signal reception to level-1 processing.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1235-1239
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• 2003

On the base of network frame and protocol system of Ethernet the networked sensing technology based on Ethernet is studied and the design principles of industrial Ethernet measurement of control system is put forward, and the general structure model is built in the paper. An eight-bit economical MCU scheme is proposed, and a general scheme of distributed intelligent networked measuring and control equipment based on TCP/IP is designed too. A compact TCP/IP protocol stack are successfully implemented in eight-bit MCU. With C51 program language, method of modularized programming is applied in soft design. The problem of in-system modifying measuring and control strategy of its system is solved successfully by assigning memory dynamically and saving parameter with EEPROM, and it makes the intelligent networked measurement and control system can explain and analyses control strategy from PC. Experiment result shows that, the research of intelligent networked measurement and control equipment and system base on TCP/IP is successful, with flexible network, convenient usage, and good commonality.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.604-613
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• 2015

An unobstructed off-axis two-mirror system is presented in this paper. First a suitable initial configuration is established based on third-order aberration theory. In order to achieve a wide field of view (FOV) with high image quality , the diffractive mirror is adopted in the two-mirror system to increase the optimization freedom and the aberration relationship between diffractive phase coefficients and Zernike coefficients is derived. Furthermore, a complete comparison design example with a focal length of 1200 mm, F-number of 12, and FOV of 40° × 2° is given to verify the aberration correction ability of the diffractive mirror. The system average wavefront error is 0.007 λ (λ=0.6328 μm) developed from 0.061 λ when the system didn’t adopt the diffractive mirror. In this system the phase modulation function of the diffractive mirror is established as an even function of x, so we could obtain a symmetrical imaging quality about the tangential plane, and the symmetric aberration performance also brings considerable convenience to alignment and testing for the system.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.245-248
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• 2004

In this paper, we propose a framework for synchronization of spatial data between mobile devices and a server by using SyncML(Synchronization Markup Language) that is standard specification for synchronization protocol. We used GML (Geographic Markup Language) to support interoperability of spatial data between various data sources. We also used metadata and catalog service to access and integrate distributed spatial data, considering relationships of spatial data and non-spatial data.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.85-89
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• 2004

This paper presents Power Control and Distribution Unit development of GEO satellite with 3kW power output. The sensing error of bus voltage produce control signal of the shunt switch assembly and battery power converter, and the tolerance of error signals generated decide the stability of proposed system. The dynamic characteristics of main bus according to the load changing and the control logic of FPGA are simulated. In order to verify the proposed design, the simulation and experimental results for solar array shunt switch, battery power converter and bus controller are shown.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.615-619
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• 2000

This paper presents an implementation of digital motion control system of Surface Permanent-Magnet Synchronous Motor(SPMSM) vector drives with a direct torque control(DTC) using the 16bit DSP TMS320F240 The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent control for motors which can be yield enhanced operation fewer system components lower system cost increased efficiency and high performance The system presented are stator flux and torque observer of stator flux feedback model that inputs are current and voltage sensing of motor terminal and angle for a low speed operating area two hysteresis band controllers an optimal switching look-up table and IGBT voltage source inverter by using fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 1.0Kw purposed servo drive SPMSM.