코일전류 계산 및 AISI 1552 상변태를 고려한 주차기어의 고주파 열처리 시뮬레이션

최진규,이석순 한국정밀공학회 2023 한국정밀공학회지 Vol.40 No.5

This study performed high-frequency heat treatment experiments and simulations of the park gear of an automobile transmission. The heating temperature and hardening depth were measured during high-frequency heat treatment. Moreover, by applying the resonance RCL circuit, the current value of the coil during high-frequency heat treatment, the electromagnetic and heat transfer material properties dependent on the temperature, and the phase transformation function were all applied to the simulation. In the high-frequency heat treatment experiment, the heating temperature was 977.4oC and the 1st direction hardening depth was 1.5 mm, the 2nd direction hardening depth was 3 mm, and the 3rd direction hardening depth was 2.5 mm, and the reliability was verified by comparing the simulation heating temperature of 1,097oC and the 1st direction predicted hardening depth of 1.6 mm, the 2nd direction predicted hardening depth of 2.8 mm, and the 3rd direction predicted hardening depth of 2.7 mm. The error rate of the heating temperature results was 12.2% whereas that of the hardening depth results was 7.1%.

동진강 유역의 농업용수 급수체계 분석

최진규,손재권,김영주,Choi, Jin-Kyu,Son, Jae-Gwon,Kim, Young-Joo 한국농공학회 2012 한국농공학회논문집 Vol.54 No.1

This study was investigated agricultural water supply system of major agricultural waterway for Gimje canal, Jeongeup canal, Dongjin river conduit of Dongjin river basin. Furthermore, this result will be used for water resources and agricultural demand in Saemangeum reclaimed arable land. Annual precipitation for 5 years in Dongjin river basin was 1,311.7mm. The average discharges in Dongjin river basin was $1,390{\times}10^6\;m^3$ and $1,516{\times}10^6\;m^3$ and $744{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Also, annual average amount of water resources was 1,861${\times}10^6\;m^3$ and $2,279{\times}10^6\;m^3$ and $1,227{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Dongjin river basin water system for the analysis of agricultural water in water resources, runoff, agricultural water demand and usage surveys were analyzed, resulting in the total amount of water due to precipitation of the watershed of the $12.3{\times}10^9\;m^3$ ~$22.8{\times}10^9\;m^3$ and Dongjin River basin in waters flowing discharge is $7.4{\times}10^9\;m^3$~$16.1{\times}10^9\;m^3$, agricultural water demand and usage of each of $6.8{\times}10^9\;m^3$~$6.9{\times}10^9\;m^3$ and $4.9{\times}10^9\;m^3$~$7.1{\times}10^9\;m^3$ compared to the agricultural water demand was more likely. Agricultural water supply system in Dongjin river basin is complex because of devided branches to the main canal and branch canal. In this process, accurately assessment of water usage is very difficult. Therefore, systematic management of water resources and supply of agricultural water supply system to use the terms of the complexity and diversity by considering the appropriate level of agricultural water management systems will be needed. As a result of this study, it can be used water resources assessment in quantity, rational usefulness and basic planning of water resources development for water distribution.

소형 밀리미터파 레이더를 위한 실시간 데이터 전처리 방법 연구

최진규,신영철,홍순일,박창현,김윤진,김홍락,권준범 한국인터넷방송통신학회 2019 한국인터넷방송통신학회 논문지 Vol.19 No.6

최근 소형 레이더는 한번의 타격으로 표적의 시스템을 무능화시키기 위해 높은 거리해상도를 갖는 소형 밀리미터파 레이더 개발을 요구한다. 높은 거리해상도를 갖는 소형 밀리미터파 레이더가 표적을 획득하고, 추적하기 위해서는대용량의 데이터를 실시간으로 처리해야한다. 본 논문에서는 소형 밀리미터파 레이더에서 요구하는 대용량의 데이터를실시간으로 처리하기 위한 실시간 데이터 전처리 방법을 정리하였다. 또한 실시간 데이터 전처리 방법으로 제시한 디지털 IF(Intermediate Frequency) 수신기, Window처리, DFT(Discrete Fourier Transform)를 FPGA (Field Programmable Gate Array)를 활용하여 구현하였다. 마지막으로 구현한 실시간 데이터 전처리 모듈은 소형 밀리미터파 레이더를 위한 신호처리기에 적용하여 실시간 데이터 전처리 기능과 관련된 성능시험으로 검증하였다. Recently, small radar require the development of small millimeter wave radar with high distance resolution to disable the target’s system with a single strike. Small millimeter wave radar with high distance resolution need to process large amounts of data in real time to acquire and track target. In this paper, we summarized the real-time data preprocessing method to process the large amount of data required for small millimeter wave radar. In addition, the digital IF(Intermediate Frequency) receiver, Window processing, and, DFT(Discrete Fourier Transform) functions presented by real-time data preprocessing are implemented using FPGA(Field Programmable Gate Array). Finally the implemented real-time data preprocessing module was applied to the signal processor for small millimeter wave radar and verified by performance test related to the real-time preprocessing function.

A Comparative Study on Mechanical/Thermal Properties of Silicone Rubber with Different Fillers for Environmentally Friendly Composite

최진규,김영선,황소산,류현준,심상은 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.2

소형 밀리미터파 레이더를 위한 고성능 신호처리기 개발

최진규,류한춘,박승욱,김지현,권준범 한국인터넷방송통신학회 2017 한국인터넷방송통신학회 논문지 Vol.17 No.6

Recently, small radar has been reduced in size and power consumption to cope with various operating environments. It also requires the development of a small millimeter wave radar with high range resolution to disable the system of target with a single strike. In this paper, we design and implement a signal processor that can be used in small millimeter wave radar. The signal processor for the small millmeter wave radar is designed with a digital IF(Intermediate Frequency) receiver and DFT(Discrete Fourier Transform) module capable of real time FFT operation for miniaturization and low power consumption. Also it was to leverage the FPGA(Field Programmable Gate Array) and DAC(Digital Analog Converter) as a means for correcting the distortion of signals that can occur in the receive path of the small millimeter wave radar to create a RF signal that is used by the system. Finally, we verified the signal processor presented through performance test. 최근 소형 레이더는 다양한 운용환경에서 대응하기 위하여 소형화와 저전력화를 추진한다. 또한 한번의 타격으로 표적의 시스템을 무능화시키기 위해 높은 거리해상도를 갖는 소형 밀리미터파 레이더 개발을 요구한다. 본 논문에서는 소형 밀리미터파 레이더에서 사용할 수 있는 신호처리기를 설계하고 구현하였다. 소형 밀리미터파 레이더를 위한 신호처리기는 소형화와 저전력화를 위해 디지털 IF(Intermediate Frequency) 수신기와 실시간 FFT 연산이 가능한DFT(Discrete Fourier Transform) 모듈을 설계하였다. 또한 소형 밀리미터파 레이더의 수신 경로에서 발생할 수 있는 신호의 왜곡을 보정하기 위한 수단으로 FPGA(Field Programmable Gate Array)와 DAC(Digital Analog Converter)를 활용하여 시스템에서 사용하는 RF(Radio Frequency) 신호를 생성할 수 있도록 하였다. 마지막으로 성능시험을 통해 구현한 신호처리기를 검증하였다.

Predicting the hardening depth of a sprocket by finite element analysis and its experimental validation for an induction hardening process

최진규,박관석,이석순 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

Case hardening, or surface hardening, is the process of hardening of a metal object at its outer surface while allowing its core to remain relatively soft, thereby forming a thin layer of harder metal at the surface. Currently, induction heating using high frequency current is applied to carry out this hardening process. We modeled this hardening process using the powerful Abaqus finite element tool and validated the results of the numerical analysis by comparing them with experimental results. Our model accurately predicted the hardened area at the outer surface of the metal for a steel sprocket. Future research will optimize the coil geometry and other parameters.

Correlation between the Symptomatic Lumbar Synovial Cyst and Facet Degeneration: Retrospective Study of 13 Surgical Cases

최진규,류경식,이홍재,이기열,박춘근 대한척추신경외과학회 2011 Neurospine Vol.8 No.2

Objective: This retrospective study of 13 patients who underwent surgical treatment for symptomatic lumbar synovial cyst was performed to evaluate the clinical findings and pathogenesis of lumbar synovial cyst. Methods: The clinical characteristics of the patients were investigated by reviewing the hospital records, preoperative radiological images, and operation records. By observing preoperative CT scans Facet degeneration grade at the lesion and opposite side of pathologic level and adjacent levels were assessed and compared. Results: There were 5 males and 8 females (average 65.8 year-old). Six patients presented with low back pain and leg pain, and 7 patients presented only leg pain. Most common pathologic level was L4-5. All patients nderwent the cyst resection with/without decompressive laminectomy or discectomy. The additional instrumentation was not performed in all patients. No complications or recurrence was observed during average 34.5 months follow-up. There was no significant difference of facet degeneration grade between the lesion side of pathologic level and opposite side of same level or lower adjacent level. Conclusion: In the present study, all patients showed clinical improvement by the simple surgery without any instrumentation. No significant correlation between the occurrence of synovial cyst and the degeneration grade of facet joint was revealed. Objective: This retrospective study of 13 patients who underwent surgical treatment for symptomatic lumbar synovial cyst was performed to evaluate the clinical findings and pathogenesis of lumbar synovial cyst. Methods: The clinical characteristics of the patients were investigated by reviewing the hospital records, preoperative radiological images, and operation records. By observing preoperative CT scans Facet degeneration grade at the lesion and opposite side of pathologic level and adjacent levels were assessed and compared. Results: There were 5 males and 8 females (average 65.8 year-old). Six patients presented with low back pain and leg pain, and 7 patients presented only leg pain. Most common pathologic level was L4-5. All patients nderwent the cyst resection with/without decompressive laminectomy or discectomy. The additional instrumentation was not performed in all patients. No complications or recurrence was observed during average 34.5 months follow-up. There was no significant difference of facet degeneration grade between the lesion side of pathologic level and opposite side of same level or lower adjacent level. Conclusion: In the present study, all patients showed clinical improvement by the simple surgery without any instrumentation. No significant correlation between the occurrence of synovial cyst and the degeneration grade of facet joint was revealed.

수자원 분야에서의 신경망 이론 적용

최진규,강문성,Choi Jin Kyu,Kang Moon Seong 한국관개배수위원회 2000 한국관개배수논문집 Vol.7 No.2

폐 비지 및 폐 한약재를 이용한 곤충병원성 진균 Beauveria bassiana의 배양 조건에 대한 연구

최진규,임정수,최우진,이은영,박장우 대한환경공학회 2004 대한환경공학회 학술발표논문집 Vol.2004 No.12

직립식 방파제 성능기반 내진 설계 Platform 개발을 위한 기초연구 - 전단파 횟수 누적에 따른 지반 강도 감소를 중심으로

최진규,조용준 한국해안,해양공학회 2018 한국해안해양공학회 논문집 Vol.30 No.6

지난 이십여 년 간 우리나라 연안에 집중적으로 거치된 직립식 방파제의 내진 성능을 검토하기 위한 예비 수치모의를 포항, 경주, Hachinohe1, Hachinohe2, Ofunato, 인공지진파를 대상으로 수행하였다. 예비 수치모의 결과 지진으로 인한 전단파가 지반을 통해 전파되는 과정에서 지진에너지가 장주기 대역으로 이동한 Hachinohe2의 경우 항 외곽시설의 활동량이 상당하다는 것을 확인하였다. 지진으로 인한 전단파는 항만시설이 거치된 지표방향으로증폭되며, 지진에너지의 상당부분은 장주기 대역으로 이동된다. 이 중 장주기 대역으로 이동되는 현상은 지반의 점성 혹은 내부 마찰에 기인하며, 전단파 증폭은 구속 응력의 감소로 인해 지표면 방향으로 감소하는 전단계수와 내습하는 전단파 횟수 누적에 따른 지반 강도 감소에 기인하는 것으로 판단된다(Das, 1993). 이러한 인식에서 본고에서는 먼저 전단파 횟수 누적에 따른 전단계수의 감소의 기술이 가능한 Hardin과 Drnevich(1972) 모형과 파동방정식에 기초하여 수치모형을 구성하고, 이어 전단파 횟수 누적에 따른 전단계수의 감소가 전단파 전파과정에 미치는 영향을 정량적으로 평가하기 위한 수치모의를 수행하였다. 이 과정에서 비선형 응력-변형률 관계를 설명하기 위해 Newmark-β 방법과 수정 Newton-Raphson 방법을 차용하였다(Chopra, 1995). 모의결과 전단파가 지표면으로 전파되면서 상당한 확률 질량이 상대적으로 큰 진폭과 장주기 쪽으로 이동하는 것을 확연하게 확인할 수 있었다. In order to evaluate the seismic capacity of massive vertical type breakwaters which have intensively been deployed along the coast of South Korea over the last two decades, we carry out the preliminary numerical simulation against the PoHang, GyeongJu, Hachinohe 1, Hachinohe 2, Ofunato, and artificial seismic waves based on the measured time series of ground acceleration. Numerical result shows that significant sliding can be resulted in once non-negligible portion of seismic energy is shifted toward the longer period during its propagation process toward the ground surface in a form of shear wave. It is well known that during these propagation process, shear waves due to the seismic activity would be amplified, and non-negligible portion of seismic energy be shifted toward the longer period. Among these, the shift of seismic energy toward the longer period is induced by the viscosity and internal friction intrinsic in the soil. On the other hand, the amplification of shear waves can be attributed to the fact that the shear modulus is getting smaller toward the ground surface following the descending effective stress toward the ground surface. And the weakened intensity of soil as the number of attacking shear waves are accumulated can also contribute these phenomenon (Das, 1993). In this rationale, we constitute the numerical model using the model by Hardin and Drnevich (1972) for the weakened shear modulus as shear waves go on, and shear wave equation, in the numerical integration of which Newmark-β method and Modified Newton- Raphson method are evoked to take nonlinear stress-strain relationship into account. It is shown that the numerical model proposed in this study could duplicate the well known features of seismic shear waves such as that a great deal of probability mass is shifted toward the larger amplitude and longer period when shear waves propagate toward the ground surface.