• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.2 s.120
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• pp.1-8
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• 2007

To examine the feasibility of dry forming technology for papermaking, a dry forming mold (DFM) was developed and evaluated. Main fanning section of DFM was a cylindrical tube, and at the top of the mold a stirring equipment was placed to disperse dry fibers. These fibers were screened using a hole type screen plate placed just under the stirring equipment and dropped freely on the fanning wire located 0.9 m below of the screen plate to form a dry fiber pad. The vertical and horizontal velocity of air flow in the forming cylinder were evaluated and analyzed to find the most effective method of air flow control in the cylinder. Humidification and pressing conditions to obtain a decent dry fanned papers were examined. Results showed dry fanned papers can be prepared with this dry forming mold. And this mold can be used to examine the effect of the papermaking process factors including pressing pressure, drying temperature, humidification on sheet quality of dry formed papers.

• ETRI Journal
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• v.44 no.5
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• pp.715-732
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• 2022

Despite the successful launch of Advanced Television Systems Committee (ATSC) 3.0 broadcasting worldwide, broadcasters are facing obstacles in constructing void-less large-scale single-frequency networks (SFNs). The bottleneck is the absence of decent on-channel repeater (OCR) solutions necessary for SFNs. In the real world, OCRs suffer from the maleficent feedback interference (FI) problem, which overwhelms the desired input signal. Moreover, the undesired multipaths between studio-linked transmitters and the OCR deteriorate the forward signals' quality as well. These problems crucially restrict the feasibility of conventional OCR systems, arousing the strong need for cost-worthy advanced OCR solutions. This paper presents an ATSC 3.0-specific solution of advanced OCR that solves the FI problem and refines the input signal. To this end, the FI canceler and channel equalizer functionalities are carefully implemented into the OCR system. The presented OCR system is designed to be fully compliant with the ATSC 3.0 specifications and performs a fast and efficient signal processing by exploiting the specific frame structure. The real product of ATSC 3.0 OCR is fabricated as well, and its feasibility is verified via field and laboratory experiments. The implemented solution is installed at a commercial on-air site and shown to provide substantial coverage gain in practice.

• Archives of design research
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• v.6 no.1
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• pp.73-86
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• 1993

The development of Korean textile industry has continued for the early industrialization. But a change in situation of circumstances, textile industry undergoes hard times. To overcome the barrier, therefore, technical development and design innovation are needed to make high value added product. This paper try to put to practical use of the silk weighting process technique(WPT). First, we investigate the technical trend of WPT to summarize the theory, and examine the feasibility of technical development. Second, the application of Graft process to silk textile is examined to know whether it is possible as an practical use. Next, we present the practical way of WPT using MAA monomer through experiment. The results are as follow. 1) Considering the lack of silk yarn. Graft process is appropriate new technique to make the value added product, and fine quality. 2) Studing textile goods, it need inter-displlinary co-work not only fiber engineering scope because textile goods is closely related with fashion industry. 3) MAA monomer used in this paper is more excellent then other monomer because it has good weighting effect and does not harm to the nature of textile. 4) MAA WPT is good for silk textiles of ladies jacket and neck-tie.

• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.118-121
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• 2005

In this paper, it has been proposed the simultaneous controller of electronic ballast and PFC(power factor corrector) for fluorescent lamp by one chip micro-controller. Boost DC-DC converter is adopted for PFC, and half bridge inverter for electronic ballast. It controls, simultaneously and independently, the boost DC-DC converter and the half bridge inverter. As electronic ballast and PFC are controlled by one chip micro-controller, it is possible to achieve the cheaper controller for fluorescent lamp. Experimental result has shown the feasibility of the proposed simultaneous controller of PFC and electronic ballast.

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.221-227
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• 2005

This paper evaluates minimum and maximum power exchange considering economic and technical characteristics between Russia and ROK. First, we evaluate minimum power exchange to assure the economic feasibility by comparison with the total cost and benefit of the interconnected line. For evaluating maximum exchange power, system constraints are considered, which are examined through load flow and dynamic analysis by using the PSS/E program. As a result of these evaluations, we suggest the reasonable range of power exchange between ROK and Russia considering economic and technical constraints with the interconnection scenario that power system interconnection between ROK and Russia will be realized in the year 2010.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.855-863
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• 2021

The purpose of this study is to suggest an improvement plan for the National Technical Qualification Practical Evaluation focusing on National Competency Standards. First, in order to strengthen practical techniques such as field abilities and expertise, practical evaluation methods were applied to the National Competency Standards, referring to a learning module focused on field performance. Second, an expert advisory committee in the field of organic agriculture was utilized to compare, analyze, and match the competency unit and competency unit elements of the National Competency Standards with the national technical qualification examination standards in field of organic agriculture. In addition, in order to identify work in progress in the industrial field, share professional practice skills, and analyze facilities and equipment, we visited an organic agriculture industry site. Through this, a practical evaluation exam was developed. Subsequently, in order to confirm the adequacy of the developed exam, the pilot test assessment was conducted for those majoring in organic agriculture. Finally, as a feasibility study, a survey was conducted. Based on the results, greater technical job competency in the field of organic agriculture will contribute to strengthening knowledge in this field by suggesting an improvement plan for the national technical qualifications practical evaluation method in the field of organic agriculture.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.347-352
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• 2001

Midtown redevelopment project is intended for restoration of city's declining function and promoting the utilization of land, but several factors such as participants of different nature in the project, different expectation level from them, high land value accompanied by geographical location as a city and the demand for high density development, nature of business that requires long duration to complete and vast amount of fund contribute to complication of feasibility study. Due to these characteristics of midtown redevelopment project, consideration of various factors involved with it and reliable analysis are required but suggested complication of feasibility study is causing halt in project, preventing from launching it and delaying it. So, this study was undertaken to be a help to feasibility study of midtown redevelopment project by suggesting main elements that need to be dealt with analysing questionnaire survey result attained from related expert in this area and arranging total 45 factors essential to feasibility study for midtown redevelopment project that can be classified into 5 main category such as economic/financial factors, legal/institutional factors, market related factors, technical factors and conflict related factors through documental investigation, case study and interview with specialist concerned.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.632-634
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• 2005

Korea takes part in overseas business by use of accumulated advanced technology through construction of the worlds first 765kV double circuit transmission system designed with pure local technology. 'Development Study on the Power System Network Analysis in Myanmar' was received in the year 2001 and was completed in the year 2002. The following project,'Feasibility Study and Basic Designs for the 500kV Transmission System in Myanmar' has been in progress since January, 2004. With regards to this project the master plan for the Myanmar long term power system was submitted in January 2005, and now the basic designs for the 500kV transmission system construction are in progress. Technical data for the design of the transmission line is calculated using a very complex numerical formula that is almost impossible to be completed by hand. So the transmission technical calculation system was developed to calculate and support Myanmar technical data for the design of transmission line with respect to factors such as wind prossure load, tower design data conductor design data and insulator design data on the basis of weather conditions for the Myamar transmission line design area of the Myanmar 500kV trans- mission line construction basic design.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.865-873
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• 2021

The purpose of this study is to suggest an improvement plan for the practical evaluation method used to determine the national technical qualification in field of flower design to improve its development. First, an advisory committee was formed, after which comparisons, an analyses and matching were conducted of the currently used national technical qualifications and competency units and the competency unit elements of the National Competency Standards in an effort to strength practical skills and industrial field abilities in the field of flower design. Second, we visited an industrial site to understand the practical and technical aspects as well as the facilities and equipment used in the flower design field. The status of workers in the industrial field in the field of flower design was then analyzed. Through this process, practical examination questions were developed for improve the evaluation method. In addition, to ensure a properly configured result, a pilot test was conducted involving those majoring in the field of flower design. To investigate the feasibility of the developed exam, a survey focusing on targets related to flower design was conducted. Based on the results, by suggesting an improvement plan for the practical evaluation method of national technical qualifications in the field of flower design, it is possible to improve knowledge, technical aspects, and literacy, allowing us to train outstanding technical professionals. In the end, this study can be expected to contribute to the improvement of the flower design industry.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.123-127
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• 2020

KEPCO has installed Frequency Regulation ESS (FR ESS) of 376 MW since 2015. Frequency Regulation is ancillary service to support stabilizing system frequency, which is divided into governor free and automatic generation control. KEPCO operates FR ESS as governor free application and leads FR ESS market with capability of diverse demonstration and operation experiences. To expand FR ESS role during transient states of power system, KEPCO has extended operating time of charging and discharging. KEPCO has also changed speed droop lower than before to improve contribution on frequency compensation, and acquired much experiences of differentiating bad cells from others. Based on these technologies and know-hows, KEPCO Research Institutes received request of feasibility study and technical cooperation for overseas FR ESS business. This paper suggests the simple and practical method for making technological feasibility study of FR ESS.