Artificial Neural Network for Modeling the Tensile Properties of Ferrite-Pearlite Steels: Relative Importance of Alloying Elements and Microstructural Factors

Tae‑Woon Hong,Sang‑In Lee,Jae‑Hyeok Shim,Myoung‑Gyu Lee,Joonho Lee,Byoungchul Hwang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

An artificial neural network (ANN) model was developed to predict the tensile properties as a function of alloying elementand microstructural factor of ferrite-pearlite steels. The input parameters of the model were composed of alloying elements(Mn, Si, Al, Nb, Ti, and V) and microstructural factors (pearlite fraction, ferrite grain size, interlamellar spacing, and cementitethickness), while the output parameters of the model were yield strength and tensile strength. Although the ferrite-pearlitesteels have complex relationships among the alloying elements, microstructural factors, and tensile properties, the ANNmodel predictions were found to be more accurate with experimental results than the existing equation model. In the presentstudy the individual effect of input parameters on the tensile properties was quantitatively estimated with the help of theaverage index of the relative importance for alloying elements as well as microstructural factors. The ANN model attemptedfrom the metallurgical points of view is expected to be useful for designing new steels having required mechanical properties.

600W급 IPMSM의 구동특성 변화에 따른 온도 내력 분석

이원식(Wonsik_Lee),고덕화(Duk-Hwa Go),김용태(Yong-Tae Kim),조규원(Gyu-Won Cho),김규탁(Gyu Tak Kim) 대한전기학회 2016 대한전기학회 학술대회 논문집 Vol.2016 No.10

본 논문에서는 동일 출력에서 연기전력 증가 및 형상 변경을 통한 효율 향상 전동기와 기본모델 전동기를 열 등가회로망법을 사용한 열해석을 수행하여 온도 내력을 비교, 분석하였다.

부신피질 자극호르몬 단독결핍 1례

박경식,이승현,최석영,박태규,이동화,이찬우,정성복,이인규 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.3

부신피질 자극호르몬 단독결핍은 국내에서 7례만이 보고된 희귀 질환이며 병인 및 경과 등 아직 불분명한 측면이 많다. 이는 질환지체의 희귀성도 있지만 치료후 자연경과에 대한 장기적인 추적검사가 이루어진 경우가 드물기 때문이기도 하다. 저자들은 비특이적인 전신증상을 주소로 내원한 폐경기후의 56세 여자 환자에서 자가면역질환의 증거없이 고프로릭틴혈증을 보인 부신피질 자극호르몬 단독결핍 1례를 경험하고 1년간의 부신피질호르몬 대치요법후 추적검사를 실시하였기에 문헌 고찰과 함께 보고하는 바이다. Isolated ACTH deficiency is a rare disorder which shows secondary adrenal insufficiency with normal states of other pituitary hormones. A 56-year-old postmenopausal woman complaining general weakness and intermittent mental confusion presented negligible serum cortisol and ACTH level with hyperprolactinemia and mild hyponatremia. Rapid ACTH stimulation test did not show significant increase of serum cortisol level. Combined pituitary stimulation test showed negligible response of cortisol and ACTH, and slightly decreased response of prolactin and gonadotropin. But the responses of TSH and GH were normal. There was no evidence of organic pituitary of hypothalamic lesion in brain MRI and antithyroid autoantibody was not detected in serum. After receiving 12 months of glucocorticoid replacement therapy, she skipped the medicine for 3 weeks and we performed follow-up endocrinologic tests. Serum ACTH and cortisol level was also negligible and prolonged ACTH simulation test showed normal response of serum cortisol. CRF stimulation test showed no response of serum ACTH. Basal prolactin level was decreased to near normal and combined pituitary stimulation test showed normal response of prolactin with slightly blunted response of TSH and GH. We concluded that the case was nonautoimmune origined isolated ACTH deficiency which was accompanied by hyperprolactinemia and resultant deficiency of gonadotropin, so we report this case with review of literatures.

철근콘크리트 구조물의 휨 거동 해석

이태규 우송대학교 부설 산업연구원 1999 산업연구 Vol.1 No.2

To predict the entire load-deformation behaviors including the softening of reinforced concrete structures due to flexural failure, solution techniques are developed. the stiffness matrix of concrete elements considering the material onlinearity is derived. To demonstrate the validity of this algorithm, the analytical results are compared with the experimental results by others. This proposed method reduce greatly the computational time and needs the very small space of the computer main memory with comparison to the present method. The spurious sensitivity to the chosen element size in the result of analysis by finite element method for the materials with strain-softening can be overcome by modifying rigidities and curvatures for each element based on the concept of concentrated inelastic rotation at plastic hinge considering the applied axial load.

타원편광해석법에 의한 MOCVD-Nb₂O5 박막의 성장과정과 내식특성에 관한 연구

이찬규,윤재홍,김명호,박태곤,杉本克久,이성훈 國立 昌原大學校 産業技術硏究所 1994 産技硏論文集 Vol.8 No.-

Nb(OC₂H?)?를 원료로 하여 AP-MOCVD에 의한 N₂O?박막의 성장과정을 기판온도, carrier gas유량, 원료온도, 반응 O₂gas의 함수로 in-situ Ellipsometry에 의해서 조사하였다. 실험결과 얻어진 Δ-Ψ곡선은 투명균질막의 이론적 Δ-Ψ곡선에 잘 일치하였으며 성장과정은 473∼673K의 저온영역에서는 1단계적 직선 성장거동을 나타내었고 673∼753K의 고온영역에서는 2단계의 직선적 성장거동을 나타내었다. 석출된 박막의 밀도를 의미하는 굴절율은 기판온도 673K까지는 증가하나 그 이상의 온도에서는 감소하기 시작했다. 그리고 산소를 첨가하지 않았을 경우는 723K에서 석출된 박막이 가장 뛰어난 내식성을 나타내었는데 이것은 이 온도에서부터 석출박막이 δ-Nb₂O?로 결정화하기 때문이라 사려된다. By the Nb(OC₂H?)? source, Growth process of Nb₂O? films formed by AP-MOCVD has been examined by in-situ Ellipsometry as a function of the substrate temperature, carrier gas flow rate, source temperature and reactant O₂gas flow rate, Δ-Ψcurve obtained in experimental results corresponded to the theorical Δ-Ψcurve of transparant homogenious film, and showed a rectilineal growth behaviour of the one stage at a low temperature range of 473∼673K and indicated a rectilineal growth behaviour of the two stage at the high temperature of 673∼753K. A refractive index meaning density of the deposited film increased until 673K of the substrate temperature but decreased above 673K. In the absence of oxygen, The thin film deposited at 723K showed the most excellent corrosion resistance, because the deposited film was crystallized into the δ-Nb₂O? above 723K.

不確實性(3) : 재무이론응용의 한계 In its application into corporate finance

李泰奎 충남대학교 경상대학부설 경영경제연구소 1991 경영논집 Vol.7 No.2

열처리 개선을 통한 전동 공구 Gear류의 수명 향상에 관한 연구

이창순,임태환,박인규 선문대학교 중소기업기술지원연구소 1997 선문공대 연구/기술 논문집 Vol.2 No.1

폐허탈 및 농흉을 유발한 기관지 지방종 1예

이규진,이송주,옥철호,장태원,정만홍,김영옥,박성달 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

저자들은 객혈을 주소로 내원한 75세 남자 환자에서 기관지내시경 육안 소견상 양성 종양이 의심 되었으나 조직 검사상 지방종을 확진하지 못하였고 악성종양을 배제할 수 없는 상황에서 종괴에 의한 왼쪽 폐의 허탈과 농흉 때문에 수술적 치료를 시행 하였으며, 수술 결과 기관지 지방종에 의한 폐허탈, 농흉 및 기관지 확장증, 이로 인한 객혈이 발생한 예가 있어 보고하는 바이다. Lipoma is a common neoplasm on soft tissues. However, bronchial lipoma is rare benign tumor. Patients with bronchial lipoma might have a malignant potential, and there were case reports of lung cancer accompanied with lipoma. Therefore, it should initially be treated by fibrotic bronchoscopy or surgery. We encountered a 75 year-old male patients with bronchial lipoma, causing hemoptysis.

기관지 탄분 섬유화증 환자의 임상 경과와 고감도 C-반응 단백(high sensitivity C-reactive protein, hsCRP)과의 상관 관계 비교

이규원,옥철호,장태원,정만홍 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

Background: To investigate the association between bronchial anthracofibrosis(AF) and tuberculosis(TB). and the clinical utility of high sensitivity C-reactive protein(hsCRP) for diagnosis of active pulmonary TB in patients with bronchial AF. Method: Eighty three patients(62 women and 21 men ranging in age from 55 to 87), who were diagnosed with bronchial AF by a bronchoscopy, were enrolled in this study. The hsCRP was measured in patient's blood. The hsCRP results were compared with the bacteriological, and clinical finding. Results: The common respiratory symptoms were cough(70%), sputum(35%), dyspnea(20%), and hemoptysis(10%). The sputum AFB smear, culture were positive in 20(22.8%) and 37(44.5%) patients, respectively. The level of hsCRP in patients with postive culture was significantly higher than that of patients with negative culture.(4.67±7.5, 0.90±1.59, p=0.005). Of 63 patients with negative smear, the level of hsCRP in patients(n=18) with positive culture was higher than that of patients(n=45) with negative culture.(3.39±5.78, 0.92±1.50, p=0.013). Of 20 patients with negative smear and positive culture who were empirically treated with anti-TB medication, 11 patients showed radiologic response. and their level of hsCRP was higher than that of 9 patients who showed no radiologic response.(1.56±1.89, 0.81±0.10,p=0.03) Conclusion: hsCRP appears to be useful diagnostic tool for predicting active pulmonary tuberculosis. in patients with bronchial AF.

국제사법재판소의 역사적 배경에 관한 연구

이태규 안양대학교 사회과학연구소 1997 社會科學硏究 Vol.5 No.-

ABSTRACT Nowadays when the international relationship has been "renormalized" since the end of the Cold War era, among the means of peaceful settling international disputes, a judicial way of settlement, whIch embodies the pre-fixed judiciary procedures, and an independent and neutral judiciary organ free from any kinds of impacts and influences including the disputed states', has been treated as a favored means despite its most authoritative and final nature. This kind of new tendency in which the pursuit of international disputes settlement through the law rather than politics supported by power leads me in this article to discuss what the Interational Court of Justice is and what its historic backgrounds are really about.