http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이종대,이소정,방정환,윤길상,김목순,김준기,Lee, Jong-Dae,Lee, So-Jeong,Bang, Jung-Hwan,Yoon, Gil-Sang,Kim, Mok-Soon,Kim, Jun-Ki 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.6
For the resistance spot welds of CR1180 and GA1180 TRIP steels, the weld quality evaluation method using the digitalized X-ray transmission imaging apparatus was investigated in comparison with the crosssectional examination method. In the case of the resistance spot welding of CR1180, three circular regions, such as WZ(white zone), GZ(grey zone) and DZ(dark zone), appeared on X-ray image and they corresponded to the diameters of indentation mark, nugget and corona bond, respectively. The variation of X-ray transmission thickness due to the thickness variation of the weld seemed to be mainly responsible for the formation of those contrasts. The X-ray image contrast formed from the variation of transmission thickness at the outer border line of DZ could also enable the inspections of the notch shape, nonuniformity of the welding pressure and spatter from its sharpness, concentricity and the normal straight line, respectively. The X-ray image of the resistance spot weld of galvannealed GA1180 TRIP steel was very similar to that of CR1180 TRIP steel except the crown shaped outer border line of DZ which was considered to be due to the melting behavior of zinc having the boiling temperature even lower than the melting temperature of steel.
아래로부터 균일하게 가열되는 수평 유체층에서 자연대류 및 열전달에 대한 Prandtl 수의 영향
이종대,최창균 ( Jong Dae Lee,Chang Kyun Choi ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.3
The onset of natural convection in an initially quiescent fluid layer heated uniformly from below has been analysed by employing the propagation theory. The stability criteria for finite Prandtl numbers(0.01≤Pr≤100) have been obtained deterministically as a function of bath the Rayleigh number and the Prandtl number. A new heat transfer correlation connecting the theoretical critical condition has been suggested. It is found that this correlation agrees reasonably well with the extant experimental data.
이종대,최창균 ( Jong Dae Lee,Chang Kyun Choi ) 한국화학공학회 1992 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.30 No.6
In experimental electroplating copper ion on copper electrodes from CuSO₄-H₂SO₄solution, the limiting current technique was used in order to investigate the critical time of natural convection and characteristics of mass transfer. A correlation of the critical time vs. the Rayleigh number was depicted experimentally for 2000≤Sc≤3000 and 10^8≤Ra≤10^(12). It is found that experimental values of the critical time are about four times larger than theoretical values in the isothermal heating system. This trend is consistent with that of heat transfer. The present mass transfer correlation represents favorably not only the experimental data of this study but also the existing experimental data.
이종대,신치범 ( Jong Dae Lee,Chee Burm Shin ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.5
Thermal characteristics of optical recording media were investigated using the finite element method when a laser beam with a Gaussian distribution was incident on it. For a stationary media, it was found that the maximum temperature increased with increasing laser power and decreasing film thickness. Thermal equilibrium state was reached in 100 ns after the laser was turned on. In addition, in the recording media moving with a constant linear velocity, it was possible to predict the formation of teardrop-shaped pit.
등척성수축으로 근피로 유발 후 스트레칭과 마사지가 근수축력 회복에 미치는 영향
이종대,배준호,배성수,Lee, Jong-Dae,Bae, Jun-Ho,Bae, Sung-Soo 대한물리치료학회 2006 대한물리치료학회지 Vol.18 No.1
Purpose: The present study purposed to examine the effects of massage and stretching on the recovery of muscle contraction force for muscle fatigue caused by sustained isometric contraction. Methods: The subjects of this study Were 64 healthy men and women (women: 30, men: 34). They Were divided into massage group (23), stretching group (21) and rest group (20), and using Biodex System we observed the pattern of changes in maximal voluntary contraction force (MVC) after causing muscle fatigue in quadriceps femoris muscle through sustained isometric contraction. Results: We measured the point of fatigue occurrence by sustained isometric contraction with 50% MVC and changes in isometric contraction force at 0, 10, 20 and 30 minutes after fatigue and compared them according to gender and treatment group. Conclusion: 1. According to the result of measuring the point of time when fatigue occurred, a difference was observed in time to task failure between men and women. It was significantly longer in women. 2. By gender, MVC changed significantly in all time frames in women, but it showed significant increases only at 10 minutes after fatigue in men. 3. In the comparison of MVC among the treatment groups, it showed significant differences among the groups at 10 minutes after fatigue. 4. In the comparison of changes in MVC among the time frames for each group, the rest group showed significant differences in MVC between 0 and 10 minutes after fatigue and between 20 and 30 minutes after fatigue. The massage group showed significant differences in MVC between 0 and 10 minutes after fatigue and between 10 and 20 minutes after fatigue. The stretching group showed a significant difference in MVC between 10 and 20 minutes after fatigue and between 20 and 30 minutes after fatigue.
차체용 1.2GPa급 초고장력 TRIP강의 Weldbond 접합부의 기계적 거동
이종대,이소정,방정환,김동철,강문진,김목순,김준기,Lee, Jong-Dae,Lee, So-Jeong,Bang, Jung-Hwan,Kim, Dong-Cheol,Kang, Mun-Jin,Kim, Mok-Soon,Kim, Jun-Ki 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.5
The effect of weldbond hybrid joining process on the mechanical behavior of single lap and L-tensile joints was investigated for the newly developed 1.2GPa grade ultra high strength TRIP(transformation induced plasticity) steel. In the case of single lap shear behavior, the weldbond joint of 1.2GPa TRIP steel showed lower maximum tensile load and elongation than that of the adhesive bonding only. It was considered to be due to the reduction of real adhesion area, which was caused by the degradation of adhesive near the spot weld, and the brittle fracture behavior of the spot weld joint. In the case of L-tensile behavior, however, the maximum tensile load of the weldbond joint of 1.2GPa TRIP steel was dramatically increased and the fracture mode was change to the base metal fracture which is desirable for the spot weld joint. These synergic effect of the weldbond hybrid joining process in 1.2GPa TRIP steel was considered to be due to the stress dissipation around the spot weld joint by the presence of adhesive which resulted in the change of crack propagation path.
Bismuth 박막으로 된 추가기록형 디스크에 대한 광 기록특성
이종대,김창수,이동철 ( Jong Dae Lee,Chang Su Kim,Dong Chul Lee ) 한국화학공학회 1994 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.32 No.3
The deposition and optical recording characteristics of Bi thin film were investigated using the DC/RF magnetron sputtering unit and the semiconductor laser. It was found that the deposited film thickness increased with increasing power density, sputtering time, argon gas flow rate and decreasing distance between the polycarbonate substrate and Bi target. Before the laser marking, the reflectance of 47% was obtained for the film thickness ranging from 1000 to 3500 A˚. Also, in comparison with the standard pit length defined by the Red Book, it was shown that the measured pit length was somewhat small.