[Physical Review Focus] AI가 초음파 이미징을 향상시키다 외

김민철,김민철 한국물리학회 2025 물리학과 첨단기술 Vol.34 No.5

지하수 모델을 이용한 제주도 지하수 유동특성 및 수리전도도 분석

김민철,양성기,Kim, Min-Chul,Yang, Sung-Kee 한국환경과학회 2019 한국환경과학회지 Vol.28 No.12

We used numerical models to reliably analyze the groundwater flow and hydraulic conductivity on Jeju Island. To increase reliability, improvements were made to model application factors such as hydraulic watershed classification, groundwater recharge calculation by precipitation, hydraulic conduction calculation using the pilot point method, and expansion of the observed groundwater level. Analysis of groundwater flow showed that the model-calculated water level was similar to the observed value. However, the Seogwi and West Jeju watersheds showed large differences in groundwater level. These areas need to be analyzed by segmenting the distribution of the hydraulic conductivity. Analyzing the groundwater flow in a sub watershed showed that groundwater flow was similar to values from equipotential lines; therefore, the reliability of the analysis results could be improved. Estimation of hydraulic conductivity distribution according to the results of the groundwater flow simulation for all areas of Jeju Island showed hydraulic conductivity > 100 m/d in the coastal area and 1 - 45 m/d in the upstream area. Notably, hydraulic conductivity was 500 m/d or above in the lowlands of the eastern area, and it was relatively high in some northern and southern areas. Such characteristics were found to be related to distribution of the equipotential lines and type of groundwater occurrence.

Coefficient Diagram Method를 적용한 브러쉬없는 선형 직류 전동기의 PI 전류 제어기의 게인 결정에 관한 연구

김민철 한국지식정보기술학회 2021 한국지식정보기술학회 논문지 Vol.16 No.2

In modern times, although many control theories have been developed, the classical control methods such as PID or Lead/Lag compensator control methods are still mainly applied in industrial. Classical control methods have a simple structure, are easy to implement, and show excellent performance in tracking target values, but there are also disadvantages that a lot of time and effort are consumed because the controller gain is empirically adjusted by a field expert. Therefore, in view of this background, CDM (Coefficient Diagram Method) systemized as a controller design technique in a coefficient space was announced to design a controller with simple, stability, time response, and robustness for any plant. The CDM technique is a method of designing an arbitrary order controller considering the characteristics of the plant from the logarithm scale after designing a coefficient diagram in which the coefficients of the polynomial are expressed on the vertical axis and the coefficient diagram in descending order of the polynomial order is designed on the horizontal axis. This CDM has the advantage of simultaneously considering several things such as system stability, settling time, response speed, and robustness. This paper proposes a method gain tuning of PI current controller for the BLLDCM(Brushless Linear DC motor) using a new algebraic control scheme, CDM. Based on the modeled BLLDCM, the simulation are performed under step-response and load condition using CDM comparing with the conventional gain tuning method(Cross-over angular frequency) of current PI controller for BLLDCM, the proposed CDM method shows improved characteristics for system response via some simulation results.

A study of bio-based elastomer/epoxidized natural rubber–silica filler interaction on tensile properties and dynamic properties

김민철,김진국 한국고분자학회 2014 한국고분자학회 학술대회 연구논문 초록집 Vol.2014 No.4

플립러닝 기법을 적용한 캡스톤디자인 수업 사례 연구

김민철 한국지식정보기술학회 2021 한국지식정보기술학회 논문지 Vol.16 No.4

In contrast to traditional classes, flipped learning is an educational method in which students take offline video lectures via the internet in advance, then discuss the subject and solve related problems in the classroom. In the case of flipped learning, it can be said that it is effective in improving the completeness of engineering works by shortening the work time in offline main class and by smoothing the flow of design and production through online prior knowledge learning, offline main course, and offline post-learning. On the other hand, the capstone design class is one of the automatic electrical engineering courses, and its purpose is to cultivate the comprehensive design capability of electrical engineering by deriving creative ideas based on engineering design, engineering design process, communication with engineering, engineering ethics, and experience of various prior design, and by designing, manufacturing, and implementing them. In this paper, the teaching method called flip learning is applied to the class characteristics of capstone design, which is the above-mentioned comprehensive design subject, to improve the completion of students' work. In addition, in order to verify the effect of flipped learning applied to the capstone design class, the operation was divided into a group that applied flipped learning and a group that did not. In the group to which flipped learning was applied, it proceeds as a process that can be applied to the realization of the work directly in the offline main class by watching a video about the required basic theory at home before class. As a result of operating the capstone design class to which flip learning was applied, it was confirmed that the group A to which the flip learning was applied showed higher overall class performance than group B to which the flip learning was not applied.

유기탄성체와 폐식물성 오일을 이용한 친환경성 Bio elastomer 제조

김민철,이혁,문병규,K. BoonKerd,김진국 한국고분자학회 2012 한국고분자학회 학술대회 연구논문 초록집 Vol.2012 No.4

기후변화 관련 법제 동향 분석

김민철,김현민 국가녹색기술연구소 2018 수시간행물 Vol.- No.-

기후변화적응 정책과 기술

김민철,김지환,김현민,송영일,심창섭,장훈,박제우,최한나,김세기,남궁윤,류호준,이명주,한지현 국가녹색기술연구소 2018 수시간행물 Vol.- No.-

1799년 11월 9일, 시에예스와 나폴레옹 보나파르트의 무월 18일 정변

김민철 한국프랑스사학회 2023 프랑스사연구 Vol.- No.48

On 9 and 10 November 1799, Sieyès and Bonaparte seized power in a planned coup. They overthrew the Directory and established the Consulate along with the Constitution of Year VIII. It was not long before Sieyès lost power and Bonaparte rose through the republican consulship to the imperial throne as Napoleon I. Commonly referred to as the “coup of the 18 brumaire,” this event has long been regarded as the expected downfall of an incompetent and chaotic government, but such a view is highly biased in that it accepts at face value the perspective of the victors. Therefore, this study aims to identify the nature of the coup by taking into consideration the development of the event itself and the evaluations of it by various political groups.

Look-Up Table을 이용한 부호화 기반 프라이버시 보장 행렬 곱 기법

김민철,양희철 한국통신학회 2023 韓國通信學會論文誌 Vol.48 No.10

Private Coded Matrix Multiplication (PCMM) is a technique that combines existing coded computation and Private Information Retrieval (PIR) methods, and it has been the subject of extensive research. Fully Private Coded Matrix Multiplication (FPCMM) is one of the derivative studies of PCMM, which considers the scenario where a master node in a distributed computing system composed of multiple worker nodes does not possess its own data. In this paper, we propose a method to enhance the efficiency of computation in such FPCMM scenarios by utilizing Look-up tables (LUTs).