• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.89.1-89.8
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• 2018

Objective: Highly effective chemotherapy for patients with low-risk gestational trophoblastic neoplasia (GTN) is associated with almost a 100% cure rate. However, 20%-30% of patients treated with chemotherapy need to change their regimens due to severe adverse events (SAEs) or drug resistance. We examined the treatment outcomes of second-line chemotherapy for patients with low-risk GTN. Methods: Between 1980 and 2015, 281 patients with low-risk GTN were treated. Of these 281 patients, 178 patients were primarily treated with 5-day intramuscular methotrexate (MTX; n=114) or 5-day drip infusion etoposide (ETP; n=64). We examined the remission rates, the drug change rates, and the outcomes of second-line chemotherapy. Results: The primary remission rates and drug resistant rates of 5-day ETP were significantly higher (p<0.001) and significantly lower (p=0.002) than those of 5-day MTX, respectively. Forty-seven patients (26.4%) required a change in their chemotherapy regimen due to the SAEs (n=16) and drug resistance (n=31), respectively. Of these 47 patients failed the first-line regimen, 39 patients (39/47, 82.9%) were re-treated with single-agent chemotherapy, and 35 patients (35/39, 89.7%) achieved remission. Four patients failed second-line, single-agent chemotherapy and eight patients (17.0%) who failed first-line regimens were treated with combined or multi-agent chemotherapy and achieved remission. Conclusions: Patients with low-risk GTN were usually treated with single-agent chemotherapy, while 20%-30% patients had to change their chemotherapy regimen due to SAEs or drug resistance. The second-line regimens of single-agent chemotherapy were effective; however, there were several patients who needed multiple agents and combined chemotherapy to achieve remission.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.1
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• pp.71-80
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• 2003

Development of new ceramic and esthetic need of patient increased the use of ceramic restorations. The purpose of this study was to confirm the possibility of recycling for IPS Empress2 which has a lot of advantages in esthetics. 1st, 2nd and 3rd pressed disc-shaped($10{\times}1.5mm$) IPS Empress 2 specimens were made with IPS Empress ingot(shade 200, Ivoclar, Liechtenstein) and pressing furnace(IPS Empress EP 500, Ivoclar, Liechtenstein). Flexure strength was measured with universal testing machine(Zwick 145641, Zwick, Germany), and color change and staining resistance of specimens were evaluated with colorimeter (Model TC-6FX, Tokyo Denshoku Co., Japan). The followings were drawn from this study : 1. Flexure strength of the 1st, the 2nd, and the 3rd pressed specimens showed 236.78 MPa. 247.16MPa, and 220.72MPa, respectively. Flexure strength of the 2nd pressed specimens was higher than others, but there's no statistical difference between them. 2. The color difference between the 1st and the 2nd pressed specimens was 3.25, and that between the 1st and the 3rd pressed specimens was 3.63(P<0.05). 3. The color change after staining of the 1st, the 2nd. and the 3rd pressed specimens were 1.43, 2.64, and 1.45, respectively. In this study, reused IPS Empress 2 specimens showed insignificant change of flexure strength and stain resistance, but they showed some color change according to reuse. From this results, the limited possibility of reuse for IPS Empress 2 could be considered.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.381-386
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• 2014

In order to investigate the effect of contact load, which is one of the fretting corrosion factors affecting the electric connector, a coupled fretting corrosion specimens were prepared using a tin-plated brass coupon with a thickness of $3{\mu}m$. Electric resistance of the contact was measured during the fretting corrosion test period. There was increase in resistance with fretting cycles. The change in resistance can be classified by 3 stages. The first stage exhibited low and stable resistance. Second stage showed steady increment of the resistance and third stage showed very high and intermittent resistance. The relationship between the failure cycle (Nf) and contact force (P) can be drawn as; It is possible to draw the prediction equation for the failure cycle of the electric connector corresponding to the very high and intermittent resistance under various environment conditions through the fretting tests under various conditions such as load, displacement, temperature.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.3
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• pp.175-181
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• 2021

This study describes the model tests in ice according to the frictional coefficient of an ice-breaking ship and the change in ice resistance by the analysis method for each component of ice resistances. The target vessel is a 90K DWT ice-breaking tanker capable of operating in ARC7 ice conditions in the Arctic Ocean, and twin POD propellers are fitted. The hull was specially painted with four different frictional coefficients on the same ship model. The total ice resistance can be separated by ice breaking, ice buoyancy, ice clearing resistances through the tests in level ice, pre-sawn ice and creep test in pre-sawn ice under sea ice thickness of 1.2 m and 1.7 m. Ice resistance was analyzed by correcting the thickness and bending strength of model ice by the ITTC correction method. As the frictional coefficient between the hull and ice increases, ice buoyancy and clearing resistances increase significantly. When the surface of the hull is rough, it is considered that the broken ice pieces do not slip easily to the side, resulting in an increase in ice buoyancy resistance. Also, the frictional coefficient was found to have a great influence on the ice clearing resistance as the ice thickness became thicker.

• Information Systems Review
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• v.10 no.3
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• pp.257-287
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• 2008

Grounded in the prior literatures on acceptance and diffusion of IT and innovation in the level of organization research, 3 major constructional factors such as Motivation, IT resistance, and IT change management were investigated to suggest propositions from 15 multi-cases of PLM from 6 different companies in Automotive OEMs and suppliers, and we posited that the diffusion is continued only when motivation is stronger enough to overcome IT resistance as a fundamental finding and basis of this research on PLM acceptance and diffusion. The Motivation was found to be initiated and categorized from three different factors such as environmental factors, organizational factors, and technological factors, providing key propositions for further research: (1)The Automotive suppliers, contrary to OEM, are affected more by the demand of inter-connectivity as an environmental factor, while the other factors are similarly influencing to them, (2)The big organizations are influenced more by the champion, while the small organizations get influenced more by leader. (3)When the trend, inter-connectivity and complexity get stronger, the motivation gets more strongly influenced by the perceived benefit in the technological context. Regarding Change management we suggests IT change management is supportive to overcome IT resistance and also to enforce Motivation, and the critical mass exists differently according to the market maturity adopted, and more market matured technology has lower critical mass, implies less requirement of IT change management than less market matured technology.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.7
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• pp.799-804
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• 2011

A thermal cycling test was conducted on a chip resistor solder joint with real-time failure monitoring. In order to study the failure mechanism of the chip resistor solder joint during the test, the resistance between both ends of the resistor was monitored until the occurrence of failure. It was observed that the monitored resistance first fluctuated linearly according to the temperature change. The initial variation in the resistance occurred at the time during the cycle when there was a decrease in temperature. A more significant change in the resistance followed after a certain number of cycles, during the time when there was an increase in the temperature. In order to explain the failure patterns of the solder joint, a mechanism for the solder failure was suggested, and its validity was proved through FE simulations. Based on the explained failure mechanism, it was shown that prognostics for the solder failure can be implemented by monitoring the resistance change in a thermal cycle condition.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.232-238
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• 2021

The development of a low cost catalyst with high performance and small amount of carbon deposition on catalyst from toluene steam reforming were investigated by using coal ash as a support material. Ni-loaded coal ash catalyst showed similar catalytic activity for toluene steam reforming compared with the Ni/Al2O3. At 800 ℃, the toluene conversion was 77% for Ni/TAL, 68% for Ni/KPU and 78% for Ni/Al2O3. Ni/TAL showed similar toluene conversion to Ni/Al2O3. However, Ni/KPU produced higher hydrogen yield at relatively lower toluene conversion. Ni/KPU catalyst showed a remarkable ability of suppressing the carbon deposition. The difference in coke deposition and hydrogen yield is due to the composition of KPU ash (Ca and Fe) which increase coke resistance and water gas shift reaction. This study suggests that coal ash catalysts have great potential for the application in the steam reforming of biomass tar.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.2
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• pp.72-78
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• 2001

A compact size high voltage pulse generator with nanosecond rise time has been designed and investigated experimentally. The inductance of a pulse generator can be reduced by fixing the Marx generator and pulse forming network components into a single cylindrical unit. As a result, nanosecond rise time about $8{\sim}10[ns]$ and pulse width of several hundred [ns] can be obtained from a modified Marx pulse generator. And parametric studies showed that the rise time of the output pulse was depended little on the change of the load resistance and the charging capacitance while, the pulse width of the output pulse was depended greatly upon the change of the load resistance and the charging capacitance. The theoretical showed the possibility to design the laboratory-size pulse generator very fast rising time and a proper pulse width by minimizing stray inductance and varying resistance and capacitance.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.331-336
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• 1999

Permeable polymer concrete in this study is one of the environment conscious concrete that can be applied at road, side walks and river embankment, etc. The purpose of this study is to evaluate the effects of mix proportions such as resing content, filler-binder ratio and aggregate ratio on the freezing and thawing resistance of permeable polymer concrete. The permeable polymer concrete are prepared with the resin ratio of 5%, 6% and 7%, filler-binder ratio of 0, 0.5 and 1.0, and 2.5~5mm sized aggregate ratio to standard sand of 10:10, 10:20, 20:10 and 20:20. It is tested for freezing and thawing test according to ASTM C 666092, and then, weight change, length change, relative dynamic modulus, durability factor, and compressive and flexural strengths after test are measured. From the test results, the resistance to freezing and thawing of permeable polymer concrete increased with increase the resing content, filler-binder ratio and fine aggregate ratio.

• KIEAE Journal
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• v.7 no.4
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• pp.119-126
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• 2007

In this study, we processed two procedures of application test of filler for fire-resistance utility that are new application methods of aerated concrete and properties test of aerated concrete according to mixing ratio because we investigated the better use of aerated concrete as filler for fireproof safety and we proposed basic data about standardization of mixing of aerated concrete. We measured flow and volume change of aerated concrete. And if its volume doesn't change, we added measuring unit weight and compressive strength. To test application of aerated concrete as filler for fireproof safety, we filled up aerated concrete to fireproof safety according to suitable mixing ratio. Then we measured maximum temperature of inner part of fireproof safety in accordance with the standard test of fireproof. According to the results, aerated concrete as filler for fireproof safety could be possibly used. So when we make aerated concrete, we should consider using an adding agent as well as a foaming agent.