• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2587-2589
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• 1999

In this paper, we propose a new control scheme for a PWM inverter using digital control. Digital control has various advantages in comparison with conventional analogue control. It can achieve high frequency switching of inverter and can be little influenced for temperature variations and aging of devices. This digitally-controlled PWM inverter is implemented using a Digital Signal Processor(DSPTMS320F240). The simulation results are given to verify the DSP based PWM inverter design and implementation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.9-15
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• 2021

In this paper, the Embedded MEMS system to the power apparatus used Edge Impulse machine learning tools and therefore an improved predictive system design is implemented. The proposed MEMS embedded system is developed based on nRF52840 system and the sensor with 3-Axis Digital Magnetometer, I2C interface and magnetic measurable range ±120 uT, BM1422AGMV which incorporates magneto impedance elements to detect magnetic field and the ARM M4 32-bit processor controller circuit in a small package. The MEMS embedded platform is consisted with Edge Impulse Machine Learning and system driver implementation between hardware and software drivers using SensorQ which is special queue including user application temporary sensor data. In this paper by experimenting, TensorFlow machine learning training output is applied to the power apparatus for analyzing the status such as "Normal, Warning, Hazard" and predicting the performance at level of 99.6% accuracy and 0.01 loss.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.450-453
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• 2009

Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of SiC-based electroconductive ceramic composites. Compare economic estimation of SiC ceramic heater with sheathe heater are as followings. (1) Temperature rising time of sheath heater is 1.1 times faster than SiC ceramic heater. (2) Heating insulation of SiC ceramic heater is 2.7 times larger than sheath heater. If SiC ceramic heater is one body type of a product application, contact resistance will decrease. I think that temperature initial rising time is faster than now. The more SiC ceramic heater is used for a long time, the more economic benefit is larger in the view point of heat insulation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1425-1435
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• 2019

The expanded application of digital controls has raised the issue of cyber security for nuclear facilities. To cope with this, the cyber security technical standard RS-015 for Korean nuclear facilities requires nuclear system developers to apply security functions, analyze known vulnerabilities, and test and evaluate security functions. This requires the development of procedures and methods for testing the suitability of security functions in accordance with the nuclear cyber security technical standards. This study derived the security requirements required at the device level by classifying the details of the technical, operational and administrative security controls of RS-015 and developed procedures and methods to test whether the security functions implemented in the device meet the security requirements. This paper describes the process for developing security function compliance test procedures and methods and presents the developed test cases.

• Journal of Korea Foundry Society
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• v.29 no.3
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• pp.144-149
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• 2009

In this study, we investigated optimum condition of cooling plate method to obtain semi-solid AM100A Mg alloy with fine and globular morphology. AM100A Mg alloy were hot extruded at $380^{\circ}C$ extrusion temperature under extrusion ratio of 25 : 1 and ram speed of 2.4 mm/sec. Vickers hardness test, optical microscopy, scanning electron microscopy, and image analyzer were performed to identify the optimum conditions of cooling plate method. Optimum conditions of cooling plate method to fabricate semi-solid AM100A Mg alloy with fine and globular microstructures were achieved at a pouring temperature of $602^{\circ}C$ and the angle of cooling plate of 60 degree.

• Education of Primary School Mathematics
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• v.17 no.1
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• pp.41-56
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• 2014

The purpose of this study was to investigate how Storytelling in Mathematics Instruction effects students' mathematical communication apprehension. In order to do this, I selected two grade six classes with no significant difference on the Communication Apprehension(CA) test. I applied normal story telling and digital story telling to each of the classes for ten weeks then analyzed the effects through the post CA test. As a result, for Normal Storytelling Class (NSC), there was no meaningful difference in the ex ante and ex post CA test results. However, for Digital Storytelling Class (DSC), there was a meaningful difference in regards to the communication apprehension subgroup. Also, between the two NSC and DSC groups' post CA results, there was a meaningful difference in mathematics lesson and subgroup factors. Consequently, these results suggest the appliance of Digital Storytelling helps lower CA in $6^{th}$ graders participation in math class and subgroup.

• Journal of Korean Foot and Ankle Society
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• v.22 no.3
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• pp.105-110
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• 2018

Purpose: This study examined the effects of beraprost sodium on digital infrared thermal images in patients with peripheral arterial disease caused by type 2 diabetes mellitus. Materials and Methods: Twenty-five diabetic patients with peripheral arterial disease were treated with beraprost sodium in a prospective, multicenter, cohort study from February 2013 to December 2014. Beraprost sodium ($40{\mu}g$) was administered orally 3 times daily ($120{\mu}g/day$) for 6 months. The visual analogue scale (VAS) and digital infrared thermal imaging (DITI) were performed to compare the blood flow improvement between before and after dosing. Results: Among the 25 patients included in the evaluation, 22 patients completed the study. A significant increase in body temperature was observed in the front and left side, particularly in the plantar side in DITI compared to that before and after administration. An increase in body temperature was observed at the frontal part from $28.1^{\circ}C{\pm}2.3^{\circ}C$ to $29.1^{\circ}C{\pm}2.1^{\circ}C$ (p=0.021), at the left side from $27.8^{\circ}C{\pm}2.4^{\circ}C$ to $28.6^{\circ}C{\pm}1.9^{\circ}C$ (p=0.028), at the plantar part at $24.0^{\circ}C{\pm}1.5^{\circ}C$, and at the plantar part at $27.1^{\circ}C{\pm}2.4^{\circ}C$ (p<0.01). The VAS decreased significantly from $5.4{\pm}1.3$ to $2.7{\pm}2.0$ after 6 months of treatment (p<0.01). Conclusion: Beraprost sodium is a safe and easy-to use oral medication for diabetes peripheral arterial disease. It can be expected to increase the blood flow and decrease the lower extremity pain statistically after being taken for 6 months.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.1-8
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• 2015

Arduino is an open-source prototyping platform. It has been used in diverse areas including media-art, simulation and interaction devices. The Arduino application does not provide an effective form of software design specification, since it is basically developed in C Programming language. In this paper, we propose a design method for the Arduino applications using the extension mechanism of the UML(Unified Modeling Language). The proposed method is enable to specify the main function of Arduino applications like digital I/O and analog I/O in UML notations.

• Electronics and Telecommunications Trends
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• v.20 no.4 s.94
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• pp.3-15
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• 2005

최근 흥행에 성공을 거둔 대부분의 영화는 첨단 CG 기술을 제작 공정의 50% 이상 활용하고 있으며 점차 영상 콘텐츠 제작에 CG 기술 사용 비율이 증가하는 추세이다. 본 논문에서는 ETRI 디지털 콘텐츠 연구단에서 연구 개발중인 실사 수준의 디지털 영상콘텐츠 제작기술에 관해 소개한다. 개발 기술은 현장 요구가 많은 대표적인 CG 기술인 영상기반 모델링, 영상기반 렌더링, 디지털액터 표현, 디지털액터 상호작용, CG/실사합성 기술을 포함한다. 엑스트라급 디지털액터 및 디지털 환경 제작 도구를 개발하였으며, 최종적으로는 주연급 디지털액터 및 디지털 환경 제작 도구를 개발할 예정이다.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.1
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• pp.35-41
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• 2000

This paper considers the consturction of 24/25 I-NRZI (Interleaved - Non Return to Zero Inverse) modulator designs for DVCR (Digital Video Cassette Recorder), and size of validity bit in order to store the amplitude value of square-wave and the standard data ( sine and cosine coefficients) at ROM Table that to acceptable the spectrum standard. The validity bit size of the standard data and the amplitude value of square-wave that to store at ROM Table are affected the size of pilot signal on the output spectrum, and the hardware size of modulator. At the designable 24/25 I-NRZI modulator, we simulated using random pattern (F0,F1,F2) that to verification the output data of the spectrum. Moreover, the resultant of the spectrum analysis, at the optimizing value, is 0.065 on the amplitude value of square-wave, and 3bit on the size of bit in order to store the standared data at ROM Table. In order to verify the hardware of designable 24/25 I-NRZI modulator, we perform to modeling of C-language firstly, and coding to Verilog HDL (Cadence Verilog XL) and synthesized using Synopsys (Library "Samsung KG75") tool as a base of spectrum results. In a foundation of this result, we are considered the size of hardware. In this paper, a considerable 24/25 I-NRZI modulator designable less than 10,000 gates as that is improved consturction as regards the path method of pre-coder etc, and able to application digital camcorders as now practical use.