http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
논문 : 수치해석 ; 원형빌렛 DC주조몰드에서 이동자장에 의한 자기장, 유동장 및 온도장의 수치해석
정순효 ( S. H. Chung ),조영환 ( Y. W. Cho ),심재동 ( J. D. Shim ) 대한금속재료학회 ( 구 대한금속학회 ) 1998 대한금속·재료학회지 Vol.36 No.6
The electromagnetic stirring of molten metal in the continuous casting mold is one of the most effective tools to decrease various casting defects such as macrosegregation, center cracks, and to homogenize the grain structure of the ingots. For DC casting of large diameter aluminium billets, it is important to control molten metal flow and heat transfer in order to prevent the formation of center cracks and macrosegregation. A circular inductor with minimum height producing travelling magnetic field in vertical direction has been designed with the help of a 3D numerical simulation program. The electromagnetic field, fluid and heat flows have been analysed by the numerical calculation and physical model experiment. The results of calculation agreed very well with those of experiment. It has been found that the downward stirring near the mold wall seems more efficient to homogenize the melt than the upward stirring. An optimized inductor design for stirring aluminium melt in the DC casting mold of 240 mm inner diameter have been proposed based on the result of the numerical calculation.
Slag/Metal 향유유통 (向流流通) 에 의한 용선의 연속정련법 연구
현도빈,김경식,심재동,오영주,정형효 대한금속재료학회(대한금속학회) 1989 대한금속·재료학회지 Vol.27 No.6
The continuous refining process which enables to refine the molten iron in stream lined flow was studied the slag metal counter current operating method in runner type reactor. The simultaneous desiliconization and dephosphorization proceeded over 60% in spite of high Si content, while the decarburization was supressed. The simulation model based on the mass transfer in reaction zones with and without O₂ blowing expressed fairly the actual reaction in the reactor. The contributions of the slag/metal reaction zone with out O₂blowing were estimated to be 26-32% for desiliconization and 47-53% for dephosphorization. From the results obtained here, the continuous process for pre-treatment of molten pig iron was conformed to be possible technically.
Al 탈산강의 Ca 첨가에 의한 비금속개재물의 형태제어
이원재,김경식,심재동,윤종규 대한금속재료학회(대한금속학회) 1983 대한금속·재료학회지 Vol.21 No.6
In order to clarify the shape control mechanism of nonmetallic inclusions in molten steel, the morphology changes of oxide and sulfide inclusions were investigated by Ca treatment in Al-deoxidized steel at 1600℃. The Ca addition of suitableamount into Al-deoxidized steel considerably improved the degree of steel cleanliness because the alumina cluster formed after Al-deoxidization changed to liquid phase calcium-aluminates which float out rapidly from steel bath. And also, when total oxygen content in molten steel was less than about 20ppm, MnS sulfide and Al₂O₃oxide were modified to C type inclusions such as (Ca, Al, Mn) O-(Ca, Mn) S or CaO-Al₂O₃-CaS
고체철과 평형하는 FetO-CaO-CaF2 계 슬래그의 열력학
이응조,현도빈,심재동 대한금속재료학회(대한금속학회) 1987 대한금속·재료학회지 Vol.25 No.2
As a fundamental study on the physico-chemical properties of slags containing fluoride ion, a measurement has been made on the activity at the equilibrium of hydrogenwater vapor gas mixtures with the slags of Fe_tO-CaO-CaF₂ ternary system contained in solid iron crucible at 1400℃. From the results obtained, the activity of iron oxide and the ratio of ferrous to ferric iron (Λ=Fe^(3+)/Fe^(2+)) have been determined as a function of slag composition. The addition of F- anions increased the activity coefficient of iron oxide exponentially, but it seemed to be independent on Λ-values. The obtained results are as follows, lnγ_(Fe_tO)/lnγ^0_(Fe_tO) =1.78 N_F-
Fet O-Na2O-SiO2 계 슬라그의 열력학적 성질
이응조,현도빈,심재동,김성만 대한금속재료학회(대한금속학회) 1985 대한금속·재료학회지 Vol.23 No.3
As a fundamental study on the physicochemical properties of soda-bearing slags, an equilibrium measurement between hydrogen/water vapour mixtures and the soda-bearing stags of Fe_tO-Na₂O-SiO₂ternary system contained in solid iron crucible at 1400℃ has been made. From the results obtained, the activity of iron oxide and the ratio of Ferric to ferrous in (Fe^(3+)/Fe^(2+)) have been determined as a function of slag composition. The activity of iron oxide in this slag markedly deviated to the direction of N_(Na₂)O/N_(SiO₂)=⅔. In the view of ionic theory, the approximate validity of regular solution model for cations was examined to evaluate the thermodynamic properties of this ternary slag containing Na₂O. It was confirmed that the regular solution model was satisfied within experimental error except for extremely FeO rich region.
The Optimal feed-back Control of Delay Differential system with General Boundary Condition
Shim, J.D. 한국기술교육대학교 1998 論文集 Vol.5 No.1
본 연구에서는 일반적인 경계조건과 이차 비용 함수를 갖는 지연 미분 방정식의 시스템에 대한 최적 피드백 제어를 구하였다. 이 제어를 구체적으로 구하기 위하여 시스템의 기초 행렬과 지연 미분 연산자를 이용하여 최적제어를 얻었으며 이의 결과에 제2종의 프레드홈의 이론을 근거로 하여 최적 피드백 제어를 특성화 하였다.