• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5427-5433
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• 2012

In this paper a ultrasonic level meter for accurately and simply measuring oil levels of vehicle transmission is developed and its effectiveness is shown by experiments. By using a FPGA, all digital signal processes for the oil level calculation is fulfilled, and the programming on a FPGA project IDE enables very short developing time. And besides, analog circuits including a transmit/receive switch, multi-stage active filters and an envelope detect circuit are designed to process low-level ultrasonic echo signal. Under experiments, the designed level meter has proven to have the accuracy of about within 1[mm] scale.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1517-1522
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• 2001

In this paper, We propose digital protective relay which monitors the status of distribution line and controls power apparatus with real time operation. Digital protective relay improves the performance of basic functions which are measurement, display and communication. The Int one we consider is that the protective device has the standard method for protecting the distribution systems which are circuit brakers, switch and emergency generators. These are Protected by analog type Protective relay and devices. The security requirements should be activated within a few seconds, and with real time operation. The second one is an efficient method for adapting the one chip micro-processor(PIC16F84) which is enable to digital control system. The proposed methods are implemented with experimental results and have an high fidelity characteristics in local experiment tests.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.5
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• pp.470-474
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• 2014

This study proposes an improved synchronization control scheme for a low-cost 400Hz power supply for a no-break power transfer system. In the case of aircraft applications, the 400Hz power supply called ground power units is accepted and used as the external electrical power system during stopovers on ground. A momentary break in the supply occurs when shifting from one power source to another. To allow shifting without a break in the supply, the two power sources are momentarily connected in parallel. The proposed synchronization control is achieved by connecting an existing synchronization bus to the voltage zero-crossing signal of a generator power with discrete logic ICs and analog circuits. Therefore, unlike expensive controllers, such as DSP and CAN, the proposed control scheme is rather simple and may decrease operational cost. The practical feasibility of the proposed control scheme is proven by experimental results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.173-179
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• 2009

Recently, the super capacitor(EDLC) which has drawn attention as a new energy storage element has a lot of advantage such as no maintenance, long lifetime and quick charge/discharge characteristics with large current. The objective of this paper is propose a parameter measurement method to detect the changes in equivalent series resistor (ESR) and the capacitance value of a super capacitor in order to analysis the internal characteristic and worn-out state of a super capacitor. For proposed method, only the capacitor voltage measurement using simple analog switch is required. In addition, experimental results of voltage sag compensation system in order to compensate the input voltage drop during short-term power interruption adopted super capacitor are presented.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.41-49
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• 2011

The automatic fire detection system is an important facility installed with focusing on minimizing the damage from a fire. This paper presents in the followings as the methods to reduce the false alarm of the automatic fire detection system; first, to prepare for legal standard so that revised legal standard can be applied to the fire fighting property prior to revision; second, to introduce the performance based fire detection protection design in the law based fire protection design; third, to maintain the wiring of worn-out detector; forth, to introduce an evaluation system to the education for the fire warden; fifth, to extend the standard of MTBF(meantime between failure) of the detector; sixth, to extend of installing the analog type detector; seventh, to improve the structure of reset switch.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.1
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• pp.54-61
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• 2000

Conventionally, ZVS FB DC/DC converter was controlled by monolithic IC UC3879, which includes the functions of oscillator, error amplifier and phase-shift circuit. Also, microprocessor and DSP have been widely used for the remote control and for the immediate waveform control in ZVS FB DC/DC converter. However the conventional microprocessor controller is complex and difficult to control because the controller consists of analog and digital parts. In the case of the control of FB DC/DC converter, the output is required of driving a direct signal to the switch drive circuits by the digital controller. So, this paper presents the method and realization of designing the digital-to-phase shift PWM circuit controlled by DSP (TMX320C32) in a 2,500A, 40㎾ ZVS FB DC/DC converter.

• Proceedings of the KIEE Conference
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• summer
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• pp.953-955
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• 2004

This paper describes the information transmission method using communication networks between Remote Terminal Unit(RTU) and Protection and Control system(PCU) of the direct current switchgear for Light Railway Vehicle, and also represents the test result, which carried out in the laboratory. In this test, transmission signal waveform, polling time, response time and request/response frame were measured between RTU and PCU. The field test including the measurements of analog signal and status of the digital logic operation of PCU will be conducted in near future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.906-909
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• 2006

This paper proposes a new body-effect compensated switch configuration for low voltage and low distortion switched-capacitor (SC) applications. The proposed circuit allows rail-to-rail switching operation for low voltage SC circuits and has better total harmonic distortion than the conventional bootstrapped circuit by 19 dB. A 2-1 cascaded sigma-delta modulator is provided for performing the high-resolution analog-to-digital conversion on audio codec in a communication transceiver. An experimental prototype for a single-stage folded-cascode operational amplifier (opamp) and a 2-1 cascaded sigma-delta modulator has been implemented in a 0.25 micron double-poly, triple-metal standard CMOS process with 2.7 V of supply voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.511-512
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• 2007

The monitoring system has won acceptance as a premium mark that identifies the highest standard of product quality in advanced industry. The TOP features with multi-I/O ports and VGA & RCA TV-out ports supporting mirroring & multiple dual-display modes by windows 0/5. With the choice of versatile stands, panel mount, or VESA wall-mount swing arm and connecting to modem. Wireless keyboard, Customer Display and Card Reader, is your idea Panel system for the application of TOP(Touch Operation Pannel), KIOSK, or Office / Factory Automation. TOP is the hardware and software product that transacts all kind of functions for advanced technology equipment to button, switch, voice and graph etc so that let consumer use easily Industrial HMI System Touch Panel. System characteristics: Easy of use and flexibility to the user, Present a high value solution and advanced function for many Application, Factory Automation, Office Automation, Building Automation System, Information Service System, etc. Analog Touch - 2MB Flash Memory for Saving Screen Data - RS-232C/422 Serial Port - Multi Language Support.

• Journal of Drive and Control
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• v.15 no.4
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• pp.30-38
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• 2018

Electronic control units (ECUs) are currently popular, and have evolved further towards the high-end application of autonomous vehicles in the automotive industry. Such digital technologies have also become widespread, in agriculture and construction equipment. Likewise, transmission control of high-speed tracked vehicles is based on the transmission control unit (TCU), performing complex gear change control functions, and diagnostic algorithms (a TCU's self-diagnostic and reporting capability of malfunction data through CAN communication). Since all functions of TCU are implemented by embedded-software, it is hardly possible to analyze specifications by reverse engineering. In this paper a real-time transmission simulator adaptable to TCU is presented, for analysis of diagnosis algorithm and standards. Signal simulation circuits are deliberately designed considering electrical characteristics of TCU inputs and various analysis tools, such as analog input auto scan function, and global output enable switch, are implemented in software. Test results from hardware-in-the-loop simulator verify tolerance time for each error, as well as cause of fault, error reset conditions.