• Korean Journal of Materials Research
• /
• v.24 no.2
• /
• pp.105-110
• /
• 2014

The aim of this work was to investigate the effects of electrodeposition conditions on the microstructural characteristics of copper thin films. The microstructure of electroplated Cu films was found to be highly dependent on electrodeposition conditions such as system current and current density, as well as the bath solution itself. The current density significantly changed the preferred orientation of electroplated Cu films in a DC system, while the solution itself had very significant effects on microstructural characteristics in a pulse-reverse pulse current system. In the DC system, polarization at high current above 30 mA, changed the preferred orientation of Cu films from (220) to (111). However, Cu films showed (220) preferred orientation for all ranges of current density in the pulse-reverse pulse current system. The grain size decreased with increasing current density in the DC system while it remained relatively constant in the pulse-reverse pulse current system. The sheet resistance increased with increasing current density in the DC system due to the decreased grain size.

• International Journal of Concrete Structures and Materials
• /
• v.10 no.3
• /
• pp.383-391
• /
• 2016

This paper reports the results of an experimental program involving several small-scale columns which were constructed to simulate corrosion damage in the field using two accelerated corrosion techniques namely, constant voltage and constant current. A total of six columns were cast for this experiment. For one pair of regular RC columns, corrosion was accelerated using constant voltage and for another pair, corrosion was accelerated using constant current. The remaining pair of regular RC columns was used as control. In the experiment, all the columns were subjected to cyclic wetting and drying using sodium chloride (NaCl) solution. The currents were monitored on an hourly interval and cracks were visually checked throughout the test program. After the specimens had suffered sufficient percentage steel loss, all the columns including the control were tested to failure in compression. The test results generated show that accelerated corrosion using impressed constant current produces more corrosion damage than that using constant voltage. The results suggest that the constant current approach can be better used to simulate corrosion damage of reinforced concrete structures and to assess the effectiveness of various materials, repair strategies and admixtures to resist corrosion damage.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.11
• /
• pp.1582-1587
• /
• 2014

In this paper, we perform a modeling for the AT Feeder system in AC electric railway and we utilize the power EMTDC program to implement about AT feeder system modeling. In addition, we study the impedance characteristics of the AT feeder system and calculated fault current and impedance according to the distance due to fault accident. Based on it's result, fault current are compared between calculating the value and simulation value in EMTDC modeling. Impedance of power system is Largest at the middle point of the system and is smallest near autotransformer, and then showed that the fault current is inversely proportional to impedance characteristics.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.693-694
• /
• 2006

In order to develop a high temperature superconducting(HTS) coil for the fault current limiter(FCL), the over-current characteristics in YBCO coated conductor(CC) with Ni-W alloy substrate are analyzed. The HTS wire is wound by bifilar winding method for resistive current limitation and it is operated in 65K sub-cooled nitrogen. In order to analyze the resistance and the temperature characteristics of the CC wire, an analysis program is developed considering all the composition materials except the buffer layer. Using this program, the temperature rise, the resistance development and the current limitation of CC are calculated depending on the applied voltage and the stabilizer materials. According to the analysis results, under the temperature restriction of 300K, the maximum voltage per meter is determined as 40V/m if the stabilizer is $25{\mu}m$ thick stainless steel at each side. Finally, the wire length needed for the distribution level HTS FCL is estimated.

• Journal of Korean Library and Information Science Society
• /
• v.34 no.4
• /
• pp.153-177
• /
• 2003

In order for public education to iud its balance, stronger arts education program is necessary. Successful delivery of arts education program is expected when it is implemented in cooperation with public library, which is at the heart of community culture and education. Under these assumptions, this study determined current status of arts education programs by investigating public library documents. The research also verified the prospect of facilitating the programs with public library support with survey. Based on the findings, problems in current public library were identified and alternatives for seamless collaboration with schools were recommended.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.2
• /
• pp.91-97
• /
• 2014

This paper presents the modeling and contingency analysis of Jeju power system. For the analysis of contingency with simulation, thermal power plants, current source type HVDC systems, wind farms, STATCOMs and Jeju power load are modeled by PSCAD/EMTDC program. And three kinds of simulation are carried out. Firstly, two STATCOMSs are in normal operation. Secondly, one STATCOM is in fault. Lastly, all of STATCOMs are in fault. These comparative studies will be useful for evaluating the effectiveness of STATCOM to stabilize for the Jeju power system.

• Health Policy and Management
• /
• v.28 no.3
• /
• pp.251-256
• /
• 2018

The origin of hospital accreditation in Korea is the Hospital Standardization Program of the Korea Hospital Association. Current accreditation program implemented by the Korea Institute for Healthcare Accreditation has succeeded in stimulating quality improvement activities of participating hospitals since its launching in 2010. However it has been criticized due to some unintended consequences of accreditation. In order to fully enjoy the benefit of the accreditation program in Korea, national efforts to expand accreditation scheme and coverage, upgrade accreditation standards, insure substantiality of accreditation process, provide consumers with more useful information, and strengthen the professional capacity of accreditation organization will be needed.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.340-342
• /
• 2001

This paper introduces the program of calculating the permissible current-carrying capability of underground power cables. Its program is developed the KEPCO's standard based on IEC 287.

• Journal of the Korean Society for Railway
• /
• v.8 no.1
• /
• pp.51-56
• /
• 2005

A dynamic simulation program of a catenary-pantograph system including tunnel section and transient section is developed in this study. The simulation program can accommodate for the pantograph of two panheads and three d.o.f model. Using the developed program, the dynamic characteristics with a SCHUNK'S WBL 85-PANTOGRAPH are analyzed at the conventional TAEBAEK line and its tunnel section when the catenary system is supported by a tunnel bracket. The simulation results show that the variation of contact force md uplift displacement is allowable in general section and the entrance and exit of a tunnel, but the uplift displacement and the separation ratio within tunnel section is difficult to allow.

• YAKHAK HOEJI
• /
• v.52 no.2
• /
• pp.160-164
• /
• 2008

This study investigated the current status and drug expenditure of the drug shortage prevention program in Korea. National health insurance claims data from 2001 to 2005 were analyzed for the drugs with inadequate supply, which were designated as shortage prevention drugs (SPDs). Drug use of SPDs have increased every year, but the average increase rate of drug expenditure for SPDs, 13.5% was lower than that for all the reimbursed drugs, 18.6%. Drugs with price increase based on production cost were more actively used than drugs with prescription incentives for doctors.