• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.800-805
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• 2017

The accelerated thermal ageing of CSPE (chlorosulfonated polyethylene) was carried out for 16.82, 50.45, and 84.09 days at $110^{\circ}C$, equivalent to 20, 60, and 100 years of ageing at $50^{\circ}C$ in nuclear power plants, respectively. As the accelerated thermally aged years increase, the insulation resistance and resistivity of the CSPE decrease, and the capacitance, relative permittivity and dissipation factor of those increase at the measured frequency, respectively. As the accelerated thermally aged years and the measured frequency increase, the phase degree of response voltage vs excitation voltage of the CSPE increase but the phase degree of response current vs excitation voltage decrease, respectively. As the accelerated thermally aged years increase, the apparent density, glass transition temperature and the melting temperature of the CSPE increase but the percent elongation and % crystallinity decrease, respectively. The differential temperatures of those are $0.013-0.037^{\circ}C$ and, $0.034-0.061^{\circ}C$ after the AC and DC voltages are applied to CSPE-0y and CSPE-20y, respectively; the differential temperatures of those are $0.011-0.038^{\circ}C$ and $0.002-0.028^{\circ}C$ after the AC and DC voltages are applied to CSPE-60y and CSPE-100y, respectively. The variations in temperature for the AC voltage are higher than those for the DC voltage when an AC voltage is applied to CSPE. It is found that the dielectric loss owing to the dissipation factor($tan{\delta}$) is related to the electric dipole conduction current. It is ascertained that the ionic (electron or hole) leakage current is increased by the partial separation of the branch chain of CSPE polymer as a result of thermal stress due to accelerated thermal ageing.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.139-142
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• 2003

In this paper, we consider the factors that affect a conversion loss performance in designing a single balanced diode mixer integrated with IRF(Image Reject Filter), based on the embedded electrical wavelength placed between the IRF and mixer, diode matching and LO drive amplifier. To evaluate the conversion loss performance, we suggest two types of a single balanced mixer using 90 degree branch line coupler, microstrip line and schottky diode. One is only mixer and the other is integrated with IRF and LO drive amplifier. The measured results of a single balance diode mixer integrated IRF show the conversion loss of 8.5 dB and the flatness of 1 dB p-p from 21.2 GHz to 22.6 GHz with 10 dBm LO. The measured input PI dB and IIP3 are 7 dBm and 15 dBm respectively under the nominal LO power level of 10dBm. The LO/RF and LO/IF isolation are 22 dB and 50 dB, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.73.1-73.1
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• 2013

It is believed that the current census of star clusters in the Milky Way is far from being complete, because of high extinction. Taking advantage of recent wide-field infrared surveys (the WISE as well as 2MASS, UKIDSS GPS, and VVV), we search for new star clusters in the central region of the Milky Way (720 $deg^2$-wide area at |1| < $30^{\circ}$ and |b| < $6^{\circ}$). We find 1840 candidates by visual inspection of the WISE images. The spatial distribution of these candidates show a strong concentration along the Milky Way, showing that most of them belong to the Milky Way. Among them, 26 are probably star clusters, considering their morphology, color-magnitude diagrams, and the degree of central concentration of stars. Eighteen of them appear to be very young in the embedded phase, and six of them are considered to be relatively old, showing a developed red giant branch. Implications of the primary results will be discussed.

• Design & Manufacturing
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• v.6 no.1
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• pp.52-57
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• 2012

Aspect of filling imbalance that is originated from imbalanced share rate in runner is changed by material property, runner layout that are factors of changing viscosity and by injection pressure, injection speed, melt temperature and mold temperature that are injection conditions. In this paper, we made a study of runner system that is one of factor of filling imbalance and Sharp Conner Effect and Groove Corner Effect that are recently released. The study are showed that filling rate of between inside and outside cavity was influenced on shape of runner. Also, we suggested runner system for filling imbalance by adapting the two effects at multi cavity of unary branch type and theoretical investigated flow in the Shrap Conner runner type.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.4
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• pp.125-141
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• 2011

There have been some research papers on financial services marketing, but there are only few exploratory studies that analyze characteristics of financial consumers in Korea. This study examines, based on FGI and web survey results, which factors consumers consider more important when choosing their financial services. I found that 'product profitability' is the most important factor when consumers choose their financial services, followed by 'relational benefits', 'convenience', 'product diversity', 'company stability', 'branch satisfaction', and 'social responsibility' in order of importance. The study also showed that there are differences in perception of these important factors depending on the types of consumers such as gender, age, size of financial assets, degree of risk-taking, and main financial company they are using. This study hopefully provide implications to marketing managers in financial services that they could decide which factors they have to focus on more when planning marketing strategies. Another objective of this study is to provide useful insights to the future researchers in financial services marketing.

• Journal of Chest Surgery
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• v.24 no.3
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• pp.296-302
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• 1991

Coronary artery involvement and myocardial ischemic symptom in Takayasu`s arteritis is uncommon Its presentation as coronary artery narrowing is a potentially lethal but correctable problem. In this case report, a 17-year-old woman of Takayasu`s arteritis with unstable anginal and moderate heart failure is presented. Her coronary angiogram showed that the main trunk of the left coronary artery was moderately narrowed and the proximal portion of the circumflex branch was severely obstructed and the right coronary artery was also narrowed diffusely. Simultaneously the patient had the moderate degree of mitral regurgitation. In order to save her life, the coronary bypass surgery using the saphenous veins and the modified Wooler`s mitral annuloplasty were done urgently, Immediate recovery was uneventful and the postoperative exercise capacity was markedly improved. But the long-term prognosis seems to be uncertain because of 3 reasons: 1] natural progress and complication of Takayasu`s arthritis; 2] fate of the saphenous vein grafts in a relatively young patient with aortitis; 3] residual mitral regurgitation. So long-term follow-up should be needed.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.71-74
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• 2002

Fluid flow in a rectangular duct system are measured by W laser doppler velocity meter, and also computed by commercial software of STAR-CD for comparison between then First, for a rectangular duct with 90 degree metered elbow, the fluid flow with Reynolds numbs's of 1,508 is predicted by assumption of both laminar and turbulent models. But, even though the Reynolds number is less than 2,300-3,000, the computation by turbulent model is close to the experimental data. Moeover, the computation by turbulent model for Reynolds number of 11,751 also predicts the experimental data satisfactorily. Second, for a rectangular duct with two branch ducts, the ratios between flow rates in the two branches are invariant to Reynolds number according to both of numerical and experimental results.

• Proceedings of the Korean Society for Quality Management Conference
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• 2009.10a
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• pp.176-181
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• 2009

Social networking service (SNS), which is based on the "six degree separation" theory, has gained its popularity in recent years. SNS creates a new way for maintaining relationship and sharing information over the virtual space. As a major branch, campus SNS provides a new platform for student to study as well as build and maintain inter-personal relationships. The highly realness of personal information and relatively strong group cohesion of campus SNS has turned it into an inevitable tool in students' daily life. The rapid growth of SNS in campus is creating huge academic and commercial benefits. However, little comprehensive research reveals what are determinant factors in driving students' intention to participate in campus SNS. In this paper, we conceptualize the participation of campus SNS as a social behavior and evaluate the impact made by social factors such as subjective norms and identity, as well as the impact of perceived reality and playfulness through an extended technology acceptance model.

• Macromolecular Research
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• v.8 no.2
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• pp.66-72
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• 2000

Cis-Polybutadiene (cis-PBD) and the three polyethylenes (PE's) having different branch content were mixed to investigate crystallinity, thermodynamic interaction parameter(c), and diluents effect. Crys-tallinty of PE's decreased with increasing content of amorphous cis-PBD because of a decrease in both the degree of annealing and kinetics of diffusion of the crystallizable polymer content. The thermodynamic interaction parameter(c) for the three blend systems approximately equals to zero near the melting point. These systems were determined to be miscible on a molecular scale near or above the crystalline melting point of the crystalline PE's. From the measurement of T$\sub$m/ vs. T$\sub$c/ behavior, all the three blends showed a straight line for a plot of T$\sub$m/ vs. T$\sub$c/. This result means that the melting behavior of PE is mainly due to a diluent effect of cis-PBD component.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.276-280
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• 2018

It is important to choose which approaches should be used to correct the fracture if the operation is indication for surgery in patients with orbital floor fracture. Transorbital, transantral, and endonasal approaches are methods for correcting the orbital floor fracture. The approach needs to be considered the location of the fracture, the degree, the severity of the fracture, the least remaining patient's disability, and preference of the surgeon. We report a case of orbital floor fracture using transorbital approach and endonasal catheter ballooning to resolve the limitations of transorbital approach alone.