제2이사야와 신명기 역사에 반영된 바벨론 제국의 상황

吳澤弦 연세대학교 신과대학 1999 신학논단 Vol.26 No.-

보이드 생성기구에 의한 복합조직강의 연성 파괴거동에 관한 연구

吳澤烈,崔明振,楡龍錫,金松正 慶熙大學校 材料科學技術硏究所 1993 材料科學技術硏究論集 Vol.6 No.-

Ductile Fracture of Dual Pase Steel begins with void nucleation, at Martensite-Ferrite interface or deformed Martensite particle. In this study void nucleation, void growth, void volume fraction and void coalescence at given strain were studied in dual phase steel. Therefore, by means of the heat treatment of low corbon steel the study deal with void nucleation and void growth for ferrite grain sizeof dual phase steel. Void nucleaton and void growth with increasing strain are shown depend upon the ferrit grain size. The number of voids and volume fraction of voids generary increase as ferrite grain size decrease. At the close to fracture the void coalescence in the direction of the applied tensile stress, but near the fracture surface they linked in direction transverse to the tensile axis.

신명기 역사에 나타난 바알종교

오택현 연세대학교 신과대학 2001 신학논단 Vol.29 No.-

유한요소법을 이용한 복합조직강의 경도비 변화에 따른 응력-변형거동에 관한연구

吳澤烈,張現貴 慶熙大學校 材料科學技術硏究所 1992 材料科學技術硏究論集 Vol.5 No.-

Mechanical properties of dual phase steel are affected by the microstructural factor, such as, martensite volume fraction, grain size of ferrite, hardeness ratio of ferrite-martensite, connectivity and chemical properties. In this study, the tensile test was carried out to analyze the tensile characteristic of the Ferrite-Martensite dual phase steel with the Hardeness Ratio of four kinds. The result obtained could be summarized as follow ; The calculated Stress-Strain curves for four hardeness ratios were compared with their corresponding experimental curves, and in general, good agreements were found. After tensile tests were done at various tempering temperatures, we had a result that the tensile strength at 200℃ was the largest. It was found that for a given hardeness ratio, the calculated stress-strain curve was higher than experimental curve. The more reduce the hardeness ratio, the more narrow the gaps between the experimental curve and the calculated curve. It is related with the plastic constraint factor K.

複合組織鋼의 衝擊擧動에 關한 實驗的 硏究

吳澤烈 慶熙大學校 1984 論文集 Vol.13 No.-

This study has been made of analysis on the influence of micro-structure which releates to impact behavior of dual-phase(D.P.) steel. Some important conclusions obtained from this study are summerized in the following 1. Martensite encapsulated islands of ferrite (MEF Microstructure) satisfied the Hall-Petch relation well. In the case of Ferrite encapsulated islands of ferrite (FEM Microstructure), it didn't satisfy the relation when Impact velocity was law. According to the increase of impact velocity, however, both materials became satisfied the Hall-Petch relation completely. 2. The more matrix grain size was minute, the more maximum load was increased. And maximum load of MEF structure was higher than FEM structure. 3. Loading time of FEM structure was longer than FEM structure, and large matrix grain size prolonged the loading time. 4. Fracture toughness increased when matrix grain size became minute and martensite came to more isolated. 5. The reason that strength of MEF structure is higher than FEM structure is due to the restraint effect of plastic deformation of MEF structure.

Martensite 체적분률에 따른 복합조직강의 인장강도 및 Void형성과 성장에 관한 연구

吳澤烈,金斗英 慶熙大學校 材料科學技術硏究所 1991 材料科學技術硏究論集 Vol.4 No.-

The mechanical properties of ferrite-martensite dual phase steel are affected by the microstuctural factors such as the martensite volume fraction, grain size of ferrite, strength ratio of ferrite-martensite, connectivity and chemical components, etc. Therefore, by means of the heat treatment of low carbon steel (SM20C), this study deals with the tensile strength and void formation, growth for martensite volume fraction of dual phase steel. The results obtained could be summarized as follow : ⅰ) The tensile strength increased by increasing martensite volume fraction in dual phase steel. And experimental strength made a differerence in theorectical strength in low martensite volume fractionm, but it accorded with that in high martensite volume fraction. ⅱ) The void formation, growth in dual phase steel occured in the onset of plastic deformation. Voids were observed more at martensite/martensite than at ferrite/martensite interface. The longest void was observed near at noting surface, the rate of increase for the longest void is much larger than that for average void size. According to strain, the number of voids increase in low strain, and then decrease in high strain(0.4 over) because of void coalescence. ⅲ) Under martensite volume fraction 60%, fraction mode of dual phase steel showed ductile fracture. Over martensite volume fraction 60%, there was shear fracture mode which had the rate of fast crack propagation. Therefore, beyond martensite volume fraction 60%, dual phase steel is not good for the use of Engineering.

複合組織鋼의 引張强度特性에 관한 硏究

吳澤烈 慶熙大學校 1986 論文集 Vol.15 No.-

A study has made of the tensile characteristics of dual phase(martensite plus ferrite) steels produced when a low carbon steel is quenched from either the austenite of austenite plus ferrite phase fields. The results can be summarized as follows; 1. The hardness ratio of second phase martensite to ferrite phase and reduction of area are decreased with increasing the martensite volume fraction when dual phase structures are made of a steel having the same composition. 2. Ductile fracture decreases when the intercritical temperature is increased and martensite hardness is decreased, because of the composite hardness increasing with increasing the intercritical temperature. 3. Tensile and yield strength of dual phase steel are function of martensite volume fraction, and the yield ratio showed relative low values. 4. The morphology of martensite in a low carbon steel through the step quenching is a lath type, and the true uniform strain is decreased according to the increase of martensite volume fraction, but it is higher than HSLA steel in the same strength level.

레이저를 이용한 Tailored Blank 용접 판재의 피로거동

오택열,권윤기,이종재,곽대순 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

For the Tailor Welded Blank sheet used for automobile body panel, the characteristics of fatigue strength and crack propagation behavior were studied. The thickness of specimen was joined to be same (0.9mm+0.9mm) and different (0.9mm+2.0mm). As a base test, mechanical properties around weld zone were examined. The results indicated that there were no significant decreases in mechanical properties, but hardness around weld bead was 2.3 times greater than base material. The fatigue strength was the highest when the loading direction was parallel to the welding direction, which was about 85% of tensile strength of base metal. It was decreased by 8.5% when the thickness of specimen and base metal was different, and it was increased by 25% when pre-strain was applied. The crack propagation rate was noticeably decreased around weld line and rapidly increased as it passed through weld line. Reviewing the shape of the crack propagation, crack width around weld line was wide around the weld zone due to retardation of crack growth, but it became narrow passing weld line due to decreased toughness.

Robert Browning의 시에 나타난 낙관주의

권오택 대구대학교 외국어교육연구소 1992 외국어교육연구 Vol.7 No.-

I researched on an optimism appered in Robert Browning's poetry through his artistic poetry, love poetry, and religious poetry. Browning did not study on art critically from the situation of the outside, but created art from the inner part of his heart. His love poetry is the expression of the optimistic view of life. He learned that love is the source of life and realized it in his love poetry. In his religious poetry, love is a nickname of God and power is love. He obeys God as long as God exists. As in his verse, "God's in His heaven― All's right with his world", he has freedom and optimistic life under the garantee of God. We can read his life and works in a verse, "On earth the broken arcs, in heaven the perfect round". Here are his love, faith and optimism.

硏究開發課題의 選定과 評價에 관한 硏究

李五範,李光澤,高德弼,金炳泰 청주대학교 경상대학 1985 經商論叢 Vol.26 No.-