• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1798-1799
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• 2011

In this paper, A new cost-effective and accurate input noise rejection method for High Speed Counter module of PLC (Programmable Logic Controller) is proposed. By using combination of simple additional logic circuit and the Timer Pulse function of general purpose MPU, Cost-effectiveness and improvement of accuracy of filtering function can be achieved. This proposed method is verified by simulation. This proposed method is much useful for simple industrial controller based on simple microprocessor because of simplicity, accuracy and low cost.

• Journal of Korea Multimedia Society
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• v.18 no.6
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• pp.723-733
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• 2015

High availability is of utmost importance in real-time embedded systems. Temporary failures due to software or hardware faults should not result in a system crash. To achieve high availability, embedded systems typically use a combination of hardware and software techniques. A watchdog timer is a hardware component in embedded microprocessors that can be used to automatically reset the processor if software anomalies are detected. The embedded system relies on a single watchdog timer, however, can be permanently disabled if the timer is not properly configured, e.g. falling into an indefinite loop. STM32F4 provides two different types of watchdog timer in terms of timing accuracy and robustness. In this paper, we propose a hybrid approach, called long-tail watchdog timer, to utilize both timers to achieve self-reliance in embedded systems even though one of timers fails. Experimental results confirm that the proposed approach successfully handles various failure scenarios and present performance comparisons between single watchdog timer and hybrid approach in terms of configuration parameters of watchdog timers in STM32F4, counter value and window size.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.4
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• pp.368-373
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• 2021

This paper presents a method of independent pulse repetition frequency(PRF) generation and control for frequency phase calibration on mono-pulse radar at a remote location. In order to generate an independent PRF signal of 320[Hz], pulse width modulation(PWM) of 16-bit timer/counter was applied. For a precision control of PRF signal, 16-bit timer/counter interrupt was changed for each period. Therefore, average frequency of PRF could be controlled by 0.0001[Hz]. To calibrate a frequency phase of mono-pulse radar at a remote location, the proposed PRF generator with a precision control of frequency was used regardless of receiving PRF signal from a radar. For the verification of the proposed PRF generator, theoretical analysis and experimental results are included.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.4
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• pp.16-23
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• 1983

A programmable controller (PC) which can control general sequential process is developed. The Z-8OA microprocessor-based PC includes hardwares such as programming device, input/output modules, timer/counter modules, and power-failure recovery module which for soft-ware, initialization program, monitor program, execution program, and power-failure recovery program are developed. In particular, the PC is designed in such a way that a timer can be used several times in different time intervals and a skip capability is incorporated in the user program to reduce scan time.

• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.95-105
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• 2021

In the case of laptops and tablet PC's that replace desktop, it uses the Windows operating system to provide various functions depending on operating system dependency, the Windows operating system does not support real-time processing because it uses multi-level feedback queue scheduling that extends round-robin scheduling. Also, since the initial value of Local APIC Counter can not be obtained from the Windows 8, the real-time processing function provided through the existing RTiK does not work. In this paper, we calculate Local APIC Counter value by using MSR_FSB_FREQ register to support real-time processing function on tablet PC's. We designed and implemented RTiK+, which provides real-time processing function to guarantee the periodicity by calculating the operation time of accurate timer. In order to verify and evaluate the performance of the implemented the RTiK+, the period was measured by using the Read Time-Stamp Counter(RDTSC) instruction and it was confirmed that it operates normally at 1ms and 0.1ms period.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.682-686
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• 2016

A fully differential RC calibrator for accurate cut-off frequency of a programmable channel selection filter is proposed. The proposed RC calibrator consists of an RC timer, clock generator, synchronous counter, digital comparator, and control block. To verify the proposed RC calibrator, a six-order Chebyshev programmable low-pass filter with adjustable 3 dB cut-off frequency, which is controlled by the proposed RC calibrator, was implemented in a $0.18-{\mu}m$ CMOS technology. The channel selection filter with the proposed RC calibrator draws 1.8 mA from a 1.8 V supply voltage and the measured 3 dB cut-off frequencies of the channel selection LPF is controlled accurately by the RC calibrator.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.198-210
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• 1998

A crank angle-based engine control system has been developed for use as an engine research tool to provide precise control of the fuel injection(timing and duration) and ignition(timing and dwell) in real-time. The engine event information is provided by the engine shaft encoder, and the engine control system uses this information to generate spark and injector control signals for relevant cylinders. Eight different engine types and four different rotary encoder resolutions can be accommodated by this system. Also this system allows a user to individually control the ignition and fuel injection for each cylinder in a simple manner such as through a keyboard or in a real-time operation from a closed-loop control program.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.54-62
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• 1999

This paper describes the design and implementation of a PC(personal computer) based open architecture machine tool controller. The hardware of open architecture CNC has generally a motion control board on a PC for controlling a servo motor. But this paper describes open architecture hardware that consists of a PC, a counter board a DAC board and a DIO board only. This makes it easy to generate CNC software module in a hardware-independent way. The proposed open architecture CNC software runs on the MS-Windows NT. The paper describes a method of con-trolling servo motors using a real-time timer of MS-Windows NT and a commercial real-time operating system on the MS-Windows. NT. An open and reconfigurable software module is made up of an object and an API(application programming interface). Using the object and the API a new CNC system can be quickly configured to control dif-ferent machine tools. The proposed open architecture CNC system is applied to 4-axis lettering center.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.298-301
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• 1995

In this study, the properties of Thermally Stimulated Current is measured automatic Data Acquisition System with a A/D Converter set. The A/D Converter set is configured with DIO 8255(Intel), AMD 9513 Timer/Counter and some Programed Controllers. Especially, the numerical method of asymtotic estimation to separate single relaxation curve and physical factors related to charged particles were obtained rapidely and completely. As a result, the data obtained by automatic Acquisition System need to be corrected to average value and the whole control and inspectation system is needed.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.1
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• pp.63-73
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• 1990

Low cost automatic welding machine is developed for the purpose of welding process automation of automobile parts with two dimensional welding joints. Developed gantry type machine is equipped with X, Y and roll axis stepping motors, and dirive units units are designed by two phase on drive scheme using shift registers. Control system is constructed by single board microcomputer of Z80A CPU, and also it is equipped with parallel input output ports and counter-timer chips. Linear and circular interpolation of welding head movement is accomplished by employing software digital differential analyzers. It has been shown that contour error of develped system is withi ${\pm}1.0mm$, meaning that the machine is suitable for CO2 arc welding process of automoble parts and is expected it's application to industry.