• ETRI Journal
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• v.6 no.3
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• pp.67-72
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• 1984

• JOURNAL OF ELECTRICAL WORLD
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• no.11 s.119
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• pp.34-37
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• 1986

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.156-164
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• 2014

In a delay line type of a time-to-digital converter implemented in Field Programmable Gate Array, the timing accuracy decreases for a longer carry chain. In this paper, we propose a structure that has a multi-phase clock and a state machine to check metastability; this would reduce the required length of the carry chain with the same time resolution. To reduce the errors caused by the time difference in the four delay lines associated with a four-phase clock, the proposed TDC generates a single input pulse from four phase clocks and uses a single delay line. Moreover, the state machine is designed to find the phase clock that is used to generate the single input pulse and determine the metastable state without a synchronizer. With the measurement range of 1 ms, the measured resolution was 22 ps, and the non-linearity was 25 ps.

• Journal of KIISE
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• v.43 no.5
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• pp.569-578
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• 2016

The PLC (Programmable Logic Controller) has been widely used for the development of digital control system of nuclear power plant. The PLC has high maintenance costs and increasing complexity, hence, FPGA (Field Programmable Gate Array) based digital control system has been considered as an alternative. However, the development of FPGA based digital control system is a challenge for PLC engineers because they are required to learn about new language to develop FPGA and knowledge and know-how acquired in the development of PLC is not transferable. In this study, we proposed and implemented an automatic translation tool for translation of FBD (Function Block Diagram), a programming language of PLC software, into VHDL (VHSIC Hardware Description Language). Automatically translating the FBD to VHDL using this tool allows PLC engineers to develop FPGA without any knowledge of the hardware description language.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1117-1123
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• 2014

Nuclear industries have faced unfavorable circumstances such as an obsolescence of the instrumentation and control system, and therefore nuclear society is striving to resolve this trouble fundamentally. FPGAs are currently highlighted as an alternative means for obsolete control systems. Because of the obsolescence-unaffected characteristics, FPGA should be highly reliable in order to be a replacement for PLC (Programmable Logic Controller). Therefore, it is necessary to establish a software development aspect strategy that enhances the reliability of an FPGA-based controller. The reliability analysis including the MTBF (Mean Time Between Failures) is carried out based on the MIL-HDBK-217F. MTBFs are compared with the FPGA-based controller COMMON-Q PLC. As an analysis result, it shows that the reliability of the FPGA-based controller is better than or equal to that of PLC.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.23-30
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• 2014

This paper proposes a dead time compensation method for an AC motor drive using phase current polarity information which is detected based on a digital programmable low-pass filter (PLPF). The polarity detection using the PLPF is an alternative solution of a conventional method which uses a general low-pass filter (LPF) and hysteresis bands in order to avoid jittering due to noises. The PLPF not only adjusts its cutoff frequency according to the synchronous frequency of AC motors but also eliminates a gain attenuation and phase delay which are main problems of the general LPF. Through the PLPF, a fundamental component signal without gain and phase distortions is extracted from the measured raw current signal with noise. By use of the fundamental component, the polarity of current is effectively detected by reducing the hysteresis band. Finally, the proposed method compensates the dead time effects by adding or subtracting average voltage value to voltage references of the controller according to the detected current polarity information. The proposed compensation method is experimentally verified by compared with the conventional method.

• Journal of Acupuncture Research
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• v.28 no.2
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• pp.49-55
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• 2011

Objectives : This study was to develop programmable and rechargeable electronic moxibustion device as an interdisciplinary research focusing on traditional Korean medicine. Methods : This device deployed several advances on safety and conveniences with the advantage of programmable heat stimulation, heating material and recharging method. The gradient of heat stimulation was programmed with the reference of previous studies and own measurements. The heat curve reached its efficacious stimulus temperature after three minutes, and maintained until 13 minutes with $42^{\circ}C$. We also incorporated feedback from field hospital experiences with the help of hospital staffs. Results : This device can prevent damages from skin burn and fire accidents, and control the smoke, smell and residue of moxa itself. Conclusions : This study will contribute for the development and improvement of efficacious and safe treatment methods for the traditional Korean medicine.

• Journal of Sensor Science and Technology
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• v.7 no.5
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• pp.364-371
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• 1998

A novel antifuse has been developed for field programmable gate arrays (FPGA's) as a voltage programmable link with Al/$BaTiO_3/SiO_2$/TiW-silicide. The proper program voltage can be obtained by adjusting the deposition thickness of $BaTiO_3$ film. When a negative voltage was applied at bottom TiW-silicide electrode of the antifuse, based on $BaTiO_3(120{\AA})$/$SiO_2(120{\AA})$, the program voltage was about l4.4V and on-resistances were ranged between 40 and $50{\Omega}$. The current-voltage characteristics of antifuses are consistent with a Frenkel-Poole conduction model. However, there are some deviations depending on bias polarity that are probably due to the difference in the interface properties between Al/$BaTiO_3$ and TiW-silicide/$SiO_2$.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.207-215
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• 2004

The PLC programming by IEC1131-3 is hard to handle to ordinary users as well as professionals. Also it has not a generality, so that it couldn't be debugging some logic errors easily. In order to be adapted for such environment, In this paper, I have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user is converted to the C code which can be used in a commercial editor such as Visual C++. The detection of logical errors in C code is more effective than PLC programming itself. ISPLC provides the GUI-based interface in web environment and an easy programming platform to such beginners as well as professionals. The study of code conversion of LD to IL as well as IL to C is firstly tried in the world as well as KOREA. To show the effectiveness of the developed system, I applied it to a practical case, a real time traffic control system. ISPLC is minimized the error debugging and programming time owing to be supported by windows application programs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.9
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• pp.13-21
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• 2011

In this paper, the CMOS programmable interface circuit for MEMS gyroscope is presented, and evaluated with the MEMS sensing element. The circuit includes the front-end charge amplifier with 10 bit programmable capacitor arrays, 9 bit DAC for accurate offset calibration, and 10 bit PGA for accurate gain calibration. The self oscillation loop with automatic gain control operates properly. The offset error and gain error after calibration are measured to be 0.36 %FSO and 0.19 %FSO, respectively. The noise equivalent resolution and bias instability are measured to be 0.016 deg/sec and 0.012 deg/sec, respectively. The calibration capability of this circuit can reduce the variations of the output offset and gain, and this can enhance the manufacturability and can improve the yield.