전국공과대학 학장협의회 민동준 회장님

민동준 한국공학교육학회(구 한국공학교육기술학회) 2012 공학교육동향 Vol.19 No.3

2016년도 POSCO학술상 수상자 -민동준 교수

민동준 대한금속재료학회(구 대한금속학회) 2016 재료마당 Vol.29 No.3

전국공과대학 학장협의회 민동준 회장님

민동준 한국공학교육학회 2012 Ingenium(人材니움) Vol.19 No.3

고온에서의 BaO-B2O3 의 열역학적 연구

민동준 대한금속재료학회(대한금속학회) 1995 대한금속·재료학회지 Vol.33 No.9

Present study was carried out to understand the thermodynamic behavior of BaO-B₂O₃ slag system at high temperature by chemical equilibration technique. Also, thermodynamic properties of Ag-Ba binary system at high temperature was measured to carry out the above mentioned investigation by the same technique. Thermodynamic behavior of Ba in Ag melts shows negaive deviation from ideal solution and can be expressed quantitatively by using α function concept as follows : logγ_(Ra)=2.63(1-X_(Ba))² α=logγ_(Ba)/(1-X_(Ba))²=2.3-7700/T BaO activity was increased with increasing the mole fraction of BaO and shows the negative deviation from the ideal sloution model. Thermodynamic properties of BaO shows similar behavior with CaO system. The thermodynamic properties of BaO in BaO-B₂O₃ slag system could be related with the stability of BaO-B₂O₃ melts which was considered to be stable compound at high temperature as a 3BaO·B₂O₃ composition. also, comparison between BaO and CaO activity and optical basicity was carried out to confirm relative strength of BaO basicity to CaO. BaO system shows higher optical basicity than CaO system at the same activity of those basic oxide, This fact may imply that BaO was more effective oxide for the refining reagents because of strong basicity.

LaNi5-H계에서 화학적 이력현상의 온도 의존성

민동준,박충년 대한금속재료학회(대한금속학회) 1989 대한금속·재료학회지 Vol.27 No.9

A chemical hysteresis and its temperature dependence in the LaNi_5-H system have been investigated by using a Sievert-type apparatus. The initial hydrogenation rate was controlled by the valve opening and the initial hydrogen pressure of a hydrogen gas reservoir. The pressure-composition isothermss in LaNi_5-H measured at 10, 30, and 50℃ varied sensitively with the hydrogenation rate and the temperature, implying an existence of a chemical hysteresis and its temperature dependence in this alloy. The chemical hysteresis decreased with increasing the temperature. By an annealing treatment of the activated LaNi_5 the temperature dependence of the chemical hysteresis decreased remarkably.

경향성 변화에 대응하는 딥러닝 기반 초미세먼지 중기 예측 모델 개발

민동준,김혜림,이상근,Dong Jun Min,Hyerim Kim,Sangkyun Lee 한국정보처리학회 2024 정보처리학회논문지. 컴퓨터 및 통신시스템 Vol.13 No.6

초미세먼지, 특히 지름이 2.5㎛ 이하인 PM2.5는 인체 건강과 경제에 큰 피해를 주는 오염물질이다. 본 연구는 대한민국 서울 지역을 중심으로, 2017년부터 2022년까지 자료를 수집하여 PM2.5 데이터 분석 및 데이터 경향성 변화 추이를 분석하고, PM2.5 중기 예측 모델을 개발하는 것을 목표로 한다. 수집, 생산된 대기질 및 기상 데이터, 재분석 데이터, 수치모델 예측 데이터를 바탕으로, 모델을 학습하고 이를 통합한 경향성 변화에도 대응할 수 있는 앙상블 기법을 제안한다. 본 연구에서 제안하는 앙상블 기법은 PM2.5 농도 예측 성능 면에서 기존 모델 대비 미래 D+3~D+6 예측일 F1 Score 기준 평균 2019년 약 42.16%, 2021년 약 58.92%, 2022년 약 34.79% 높은 성능을 보였다. 제안한 모델은 변화하는 환경 조건에도 성능을 유지함으로써 안정적인 예측을 가능하게 하며, 기존 딥러닝 기반 PM2.5 단기 예측보다 먼 예측을 수행하는 중기 예측 모델을 제시한다. Fine particulate matter, especially PM2.5 with a diameter of less than 2.5 micrometers, poses significant health and economic risks. This study focuses on the Seoul region of South Korea, aiming to analyze PM2.5 data and trends from 2017 to 2022 and develop a mid-term prediction model for PM2.5 concentrations. Utilizing collected and produced air quality and weather data, reanalysis data, and numerical model prediction data, this research proposes an ensemble evaluation method capable of adapting to trend changes. The ensemble method proposed in this study demonstrated superior performance in predicting PM2.5 concentrations, outperforming existing models by an average F1 Score of approximately 42.16% in 2019, 58.92% in 2021, and 34.79% in 2022 for future 3 to 6-day predictions. The model maintains performance under changing environmental conditions, offering stable predictions and presenting a mid-term prediction model that extends beyond the capabilities of existing deep learning-based short-term PM2.5 forecasts.

Recent Advances in Understanding Physical Properties of Metallurgical Slags

민동준,Fumitaka Tsukihashi 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.1

Present-day knowledge of the structure and physical properties of metallurgical slags is summarized to address structure-property and inter-property relationships. Physical properties of slags including viscosity, electrical conductivity, and surface tension is reviewed focusing on the effect of slag structure, which is comprehensively evaluated using FT-IT, Raman, and MAS-NMR spectroscopy. The effect of the slag composition on slag structure and property is reviewed in detail: Compositional effect encompasses traditional concepts of basicity, network-forming behaviors of anions, and secondary impact of network-modifying cations. Secondary objective of this review is elucidating the mutual relationship between physical properties of slags. For instance, the relationship between slag viscosity and electrical conductivity is suggested by Walden’s rule and discussed based on the experimental results. Slag foaming index is also introduced as a comprehensive understanding method of physical properties of slags. The dimensional analysis was made to address the effect of viscosity, density, and surface tension on the foaming index of slags.

전로 슬래그의 용융환원 공정에 관한 물질 및 에너지수지

민동준,정원변,백종문 대한금속재료학회(대한금속학회) 1997 대한금속·재료학회지 Vol.35 No.2

The computer simulation model was established to verify the applicability of smelting reduction concepts to converter slag which becomes an issue on the environmental and recycling aspects. The computer simulation model provides the following results. The utilization of latent energy of converter slag after tap is a very effective and reasonable method for saving energy. Also, the increase of post combustion ratio and heat transfer efficiency are effective ways in saving energy. But in order to increase PCR, recovery efficiency of post combustion energy has to be higher than 85% HTC to satisfy both refractory life and energy efficiency. Coke is a most useful fuel source because it shows low dependence to post combustion ratio and low hydrogen content. In the present process, the quality of hot metal would be expected to be at a similar level with that of the blast furnace. The utilization of scrap was also possible to maximize the advantages of the present process which were high temperature and chemical dilution with hot metal. In the case of scrap, energy consumption increases slightly due to preheating of scrap. Consequently, the concept of the present process provides one possibility of integrating recyclable waste materials such as converter slag, coke oven dust, life terminated acidic refractory, scrap by smelting reduction process.

고온에서의 Fe-C-S 합금 중 Cu 의 열역학적 거동에 관한 연구

민동준,허기행,김대환,이창희 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.12

The thermodynamic behavior of copper in molten Fe-C-S alloy at high temperature was investigated by chemical equilibrating technique. The effects of copper, carbon, sulfur content and temperature on the activity coefficient of copper in molten pure iron and carbon saturated were was determined by measuring the distribution ratio between silver and Fe-C-S-Cu alloy. The activity coefficient of copper in molteniren and carbon saturated iron at infinite dilution of copper were measured 11.02 and 28.50 at 1823K respectively. The interaction parameter between copper and copper, sulfur and carbon in molten iron at 1823K, was estimated as follows; ε^(Cu)_(Cu) = -4.80, ε^S_(Cu) = -2.544, ε^C_(Cu) = -4.60 The dependence of the activity coefficient in molten Fe-C alloy on temperature was determined as follows; For molten pure iron : lnγ^(oFe)_(Cu) = 4370/T For Fe-2wt%C : lnγ^(oFe-2wt%C)_(Cu) = 0.72 + 3840/T For carbon saturated iron : lnγ^(oFe_C)_(Cu) = 1.11 + 4100/T Combining the effect of temperature and the alloying component, the activity coefficient of copper could be expressed as follows ; lnγ^(Fe-C-S)_(Cu) = 4370/T·(1-X_(Cu))² + (2.15 + 4600/T)·2.54·X_s The possibility of removal of copper from steel by slag refing and evaporating technique was discussed.

질소 용해반응기구에 미치는 슬래그 염기도의 영향에 관한 연구

민동준 대한금속재료학회(대한금속학회) 1995 대한금속·재료학회지 Vol.33 No.9

The nitrogen solubility and nitride capacity of the BaO-B₂O₃ and CaO-B₂O₃ slag systems at high temperatures were measured in order to understand the nitrogen solution mechanism of slag by using a chemical equilibration technique. The present slag systems were chosen because they have wide liquid regions at the temperature of interest and were expected to show two different types of nitride dissolution behaviors. The nitride capacities of both systems showed some minimum values with changing composition. This was explained by considering that nitrogen can dissolve into slag as "free nitride" at high basicities and "nitride incorporated" with the network for acidic slags. The change of nitride capacity with optical basicity and the activity of the basic component followed the predicted behavior for the proposed solution mechanism. The nitride capacity of the BaO-B₂O₃ system is considerably greater than that of the CaO-B₂O₃ system because BaO is a more basic oxide than CaO.