파괴인성 JIC 와 파단면에서 측정한 미세조도와의 상관 관계

오태성 대한금속재료학회(대한금속학회) 1995 대한금속·재료학회지 Vol.33 No.4

Correlations of the critical fracture strain ε_f and the fracture toughness J_(lc) with the microroughness measured on the fracture surfaces have been investigated for HP9-4-20 steel and ASTM A710 steel with different strength level. The critical fracture strain ε_f was proportional to the local microroughness (1/3)·ln(M²/3f_p) measured on the fracture surfaces. Fracture toughness J_(lc) was in good agreement with (σ_o/3)·ln(M²/3f_p)·l_o and could be estimated using the microroughness parameter M, the characteristic distance l_o, and the effective yield stress σ_o.

데이터센터 정전 대비 버퍼탱크의 종류 및 성능보증

오태성 대한설비공학회 2024 설비저널 Vol.53 No.11

미세구조가 균열개시인성 J ic 와 균열성장인성 T r 에 미치는 영향

오태성,Ritchie, R O 대한금속재료학회(대한금속학회) 1993 대한금속·재료학회지 Vol.31 No.10

Microstructural effects on crack initiation toughness (J_(IC)) and crack growth toughness (T_R) have been examined for HP9-4-20 steel and ASTM A710 steel. Microstructural changes, which increased the fracture strain (ε_f) and decreased the yield strain (ε_o), improved both J_(IC) and T_R, and had the larger effect on T_R for ASTM A710 steel with law strength. Observation of crack profiles revealed a zig-zag fracture which propagated along the spiral slip lines emanating from the blunted crack tip for ASTM A710 steel, and along the straight slip lines characteristic of a non-blunted crack for HP9-4-20 steel.

RF 스퍼터 처리된 폴리이미드와 Cr박막간 계면 접착력과 계면 반응성

오태성,김동구,김정일 한국마이크로전자및패키징학회 1994 하이브리드마이크로일렉트로닉스 Vol.1 No.1

Effects of Ar ion RF sputtering of polyimide surface prior to metal deposition on the adhesion and interfacial reactions between Cr films and polyimides have been studied using 90℃ peel test, TEM, FTIR and XPS. With Ar pre-sputtering, the peel strength of Cr/polyimide interfaces increases remarkably from 1g/㎜ to 100g/㎜. Adhesion enhancement of Cr/polyimide interfaces by RF pre-sputtering has been found to be due to the chemical modification of polyimide surfacer facilitating bond formation with deposited Cr, which was confirmed by resistivity measurement, FTIR and XPS analyses.

생체활성 Ti-수산화 아파타이트 복합재료의 소결 특성

吳泰成 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

Sintering characteristics and mechanical properties of HAP/Ti composites have been investigated with variations of the powder processing method. Ti volume fraction, and sintering temperature. HAP/Ti composite powders were fabricated either by mechanical alloying, or mechanical milling and mixing processes of hydroxylapatite and Ti powders. With complete broadening of X-ray diffraction peaks of HAP/Ti powders by mechanical alloying for 10 hours, it could be suggested that reactions between HAP and Ti occurred during mechanical alloying process. For HAP/Ti composites processed by mechanical milling and sintered at 1100℃ for 4 hours, fracture toughness ??? and MOR decreased with Ti volume fraction in HAP/Ti composites due to the crack propagation along the poorly sintered Ti-rich phases. For HAP/Ti composites fabricated by mechanical alloying and sintered at 1300℃ for 4 hours, fracture toughness and MOR incerased with Ti volume fraction, and ??? of ??????????? and MOR of 50 MPa could be obtained for 80HAP/20Ti composite.

어머니의 스마트폰 과의존과 긍정적 · 부정적 양육태도 및 아동의 외현화 · 내재화 문제행동의 구조적 관계

오태성,최나야,장해진,최하영,송지언 한국아동학회 2020 한국아동학회 학술발표논문집 Vol.2020 No.6

Island-Bridge 구조의 강성도 경사형 신축 전자패키지의 유효 탄성계수 및 변형거동 분석

오태성 한국마이크로전자및패키징학회 2019 마이크로전자 및 패키징학회지 Vol.26 No.4

A stiffness-gradient soft PDMS/hard PDMS/FPCB stretchable package of the island-bridge structure was processed using the polydimethylsiloxane (PDMS) as the base substrate and the more stiff flexible printed circuit board (FPCB) as the island substrate, and its effective elastic modulus and stretchable deformation characteristics were analyzed. With the elastic moduli of the soft PDMS, hard PDMS, and FPCB to be 0.28 MPa, 1.74 MPa, and 1.85 GPa, respectively, the effective elastic modulus of the soft PDMS/hard PDMS/FPCB package was analyzed as 0.58 MPa. When the soft PDMS of the soft PDMS/hard PDMS/FPCB package was stretched to a tensile strain of 0.3, the strains occurring at hard PDMS and FPCB were found to be 0.1 and 0.003, respectively. Polydimethylsiloxane (PDMS)를 베이스 기판으로 사용하고 이보다 강성도가 높은 flexible printed circuit board (FPCB)를 island 기판으로 사용하여 island-bridge 구조의 soft PDMS/hard PDMS/FPCB 신축 패키지를 형성하고, 이의 유효 탄성계수와 변형거동을 분석하였다. 각기 탄성계수가 0.28 MPa, 1.74 MPa 및 1.85 GPa인 soft PDMS, hard PDMS, FPCB를 사용하여 형성한 soft PDMS/hard PDMS/FPCB 신축 패키지의 유효 탄성계수는 0.58 MPa로 분석되었다. Soft PDMS/hard PDMS/FPCB 신축 패키지에서 soft PDMS의 변형률이 0.3이 되도록 인장시 hard PDMS와 FPCB 의 변형률은 각기 0.1과 0.003이었다.

Sol-Gel법으로 제조된 Ta2O5 박막의 유전특성과 누설전류 특성

오태성,이창봉,이병찬,오영제,김윤호 한국세라믹학회 1992 한국세라믹학회지 Vol.29 No.1

Phase transition, dielectric properties, and leakage current characteristics of Ta2O5 thin film fabricated by sol-gel process with tantalum penta-n-butoxide were studied as a function of annealing temperature in O2 atmoshpere. Although Ta2O5 thin film annealed at temperatures below 700$^{\circ}C$ for 1 hr was amorphous, it was crystallized to ${\beta}$-Ta2O5 of orthorhombic phase by annealing at temperatures higher than 750$^{\circ}C$. With increasing annealing temperature from 500$^{\circ}C$ to 900$^{\circ}C$, dielectric constant of sol-gel processed Ta2O5 thin film was changed from 17.6 to 15.3 due to the increase of SiO2 thickness at Ta2O5/Si interface. For Ta2O5 thin film annealed at 500$^{\circ}C$ to 800$^{\circ}C$ for 1 hr in O2 atmosphere, leakage current was remarkably reduced and breakdown strength was increased with higher annealing temperature. For Ta2O5 film annealed at 800$^{\circ}C$, breakdown did not occur even at electric field strength of 30${\times}$105V/cm and leakage current was maintained lower than 10-8A/$\textrm{cm}^2$.

Conventional simulator를 이용한 Digital image capture system(DICS)의 구축

오태성,박종일,변영식,신현교,Oh Taesung,Park Jongil,Byun Youngsik,Shin HyunKyoh 대한방사선치료학회 2004 大韓放射線治療技術學會誌 Vol.16 No.2

Purpose : The simulator is used to determine patient field and ensure the treatment field, which encompasses the required anatomy during patient normal movement such as during breathing. The latest simulator provide real time display of still, flouroscopic and digitalized image, but conventional simulator is not yet. The purpose of this study is to introduce digital image capture system(DICS) using conventional simulator and clinical case using digital captured still and flouroscopic image. Methods and materials : We connect the video signal cable to the video terminal in the back up of simulator monitor, and connect the video jack to the A/D converter. After connection between the converter jack and computer, We can acquire still image and record flouroscopic image with operating image capture program. The data created with this system can be used in patient treatment, and modified for verification by using image processing software. (j.e. photoshop, paintshop) Result : DICS was able to establish easy and economical procedure. DCIS image was helpful for simulation. DICS imaging was powerful tool in the evaluation of the department specific patient positioning. Conclusion : Because the commercialized simulator based of digital capture is very expensive, it is not easily to establish DICS simulator in the most hospital. DICS using conventional simulator enable to utilize the practical use of image equal to high cost digitalized simulator and to research many clinical cases in case of using other software program.

Dopant 첨가가 (Bi,Sb)₂Te₃열전재료의 열전특성에 미치는 영향

吳泰成 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

Formation of (Bi??Sb??)₂Te₃alloy powders was completed by mechanical alloying of the as-mixed Bi, Sb, and Te powders for 5 hours at ball-to-material ratio of 5 : 1. Lattice parameters of mechanically alloyed (Bi??Sb??)₂Te₃powders, a = 0.4305 nm and c = 3.476 nm, were not changed with addition of AgI or SbI₃within the range of 0.2 wt%. When hot pressed at 500℃ for 1 hour in vacuum, figure of merit of (Bi??Sb??)₂Te₃ could be improved from 2.15 ×10??/K to 2.33 ×10??/K with addition of 0.05 wt% SbI₃.