• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.211-212
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• 2007

There have three kinds of partial discharge diagnosis testing: online, offline and dismantled testing on high voltage rotating machine. Our lab testing is dismantled testing, taking off pieces into individual parts of stator coil of high voltage rotating machine in laboratory. We investigate internal discharge, slot discharge, corona discharge and normal state on pre-made stator winding by using spiral patch antenna sensor. In this lab test we compare the experimental results of our spiral patch antenna sensor and reference commercial HFCT sensor.

• Acta Via Serica
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• 제6권2호
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• pp.61-90
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• 2021

Recent excavations in Qinghai Province, China, have disclosed textiles and artworks from Tuyuhun-Tubo (Tibetan) tombs, dated to the 7^th-9^th centuries, that suggest artistic and cultural exchanges along an external southern branch of the main Silk Road, between Gansu and Sichuan Provinces, across the Qinghai-Tibetan plateau toward the Himalayas. Many similar textiles, possibly from this area, have appeared lately on the art market and ended in private collections. Although these textiles, dated to the early Tibetan period, follow a popular prototype established in Central Asia in the 6^th century, the technical features, colors, and other indigenous elements suggest that they were woven in workshops different from those established between Sogdiana and Gansu. The exhibition "Cultural Exchange Along the Silk Road - Masterpieces of the Tubo Period," organized by the Dunhuang Research Academy and the Pritzker Collaborative Art between July and October 2019 in Dunhuang, Gansu, was a groundbreaking event that gathered scholarly attention on early Tibetan material culture, but a relevant publication is still forthcoming. In my previous work, I briefly discussed a group of silk textiles, possibly from Qinghai or Sichuan, that I analyzed in 2014 in the China National Silk Museum in Hangzhou, Zhejiang. In light of the recent material excavated, published online, or displayed in Dunhuang, in this article, I reevaluate the data previously collected, and discuss in detail the technical and iconographic features of one of the fragments held in Hangzhou. Eventually, the piece was recognized as the ending part of a large panel, which is now in the Abegg Stiftung in Riggisberg, Switzerland.

• 한국초전도ㆍ저온공학회논문지
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• 제24권3호
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• pp.1-6
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• 2022

The Magnetic Force Control MFC technology is very useful because of its physical treatment process. Especially the Magnetic Separation MS technology is expected to contribute to SDGs 2030, Circular Economy and Carbon neutral 2050 realization. This paper describes the review of the IFMFC activity from 2010.The IFMFC is organized by three local committees of researchers in Japan, China and Korea. The IFMFC aims to exchange the information of the development results using the MFC technology and to educate the young researchers. The forum has been held in every year around three countries. In 2020 and 2021, the forum was organized by Zoom online due to the COVID-19. The 134 presentations were made up to 2020.The breakdown of these presentations are categorized to the environment remediation52%, material resource37% and fundamental research/technology11%. The Super Conducting Magnet SCM development promotes the MFC technologies. There are some impressive backgrounds as to the brilliant SM technology applications for many different magnetism ; SCM development, High Gradient Magnetic Separation HGMS, magnetic seeding method and magneto-Archimedes effect. This paper reviews the IFMFC activity according to those presented presentations.

• Journal of the Korean Wood Science and Technology
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• 제50권6호
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• pp.375-391
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• 2022

Improving public awareness of wood is crucial for expanding the use of wood and establishing a wood culture. In this study, the environment and trends of the public's wood utilization were analyzed using a questionnaire survey and online text mining at a time when eco-friendly practices are gaining popularity. As a result of reducing climatic and environmental concerns and its positive physical and psychological effects, the use of wood is predicted to rise in areas intimately connected to everyday living, such as wood furniture, wooden structures, and interior materials. Nonetheless, there was a negative awareness that wood was expensive, difficult to maintain, and associated with deforestation. The correlations between wood-related search terms on major Korean portal sites were analyzed and categorized into five groups: Wooden architecture, cultural education, woodworking, wood industry, and wood policy. As a building material, wood was seen as more traditional and friendly than reinforced concrete and stone. Eighty-six percent of respondents expected to utilize wood as a building material in the future, regardless of whether the wood is domestically produced or imported. Sixty-five percent responded favorably about the effects of wood on the health of wooden home inhabitants. It is believed that both active publicity and quantifiable value analysis of human and environmental friendliness are required to increase pro-environment awareness of wood utilization.

• 유통과학연구
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• 제22권1호
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• pp.115-125
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• 2024

Purpose: This study is to analyze the purchasing process and distribution management requirements for teaching materials that have important meaning in the practical field of preschool education. Research design, data and methodology: A structured questionnaire was used to survey 103 childcare staffs regarding the purchasing process and distribution managements. The collected data underwent Likert's 5-point scale analysis and keyword grouping. Additionally, ANOVA was conducted to examine the distribution management demands based on demographic characteristics. Results: The purchasing of teaching materials involved more offline channels than online, and the purchase decisions were predominantly made by principals rather than teachers. Although the purchasing process is similar to that of general businesses, there are difficulties in purchasing due to the disorganized distribution channels and limited accessibility to product information. Additionally, the management of inventory for teaching materials is challenging due to limited personnel and storage. Childcare staffs have requirements for classification systems, evaluation criteria, environments and policies related to teaching materials distribution. The need to introduce a teaching material evaluation and certification system to ensure quality was not high. Conclusions: Most of the respondents recognized that strict management and measures should be taken for the distribution of teaching materials. There were differences in the demand of teaching material distribution depending on the respondents' status, age, education, and experience.

• Design & Manufacturing
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• 제17권4호
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• pp.8-13
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• 2023

In this study, it was studied whether a new measurement factor "frictional vibration" that occurs due to the material flow of the die and sheet metal in the flange area during deep drawing process, could be measured using an vibration sensor. The blank holder force acting on the flange area during drawing processing acts as a friction force in the opposite direction into which the sheet material flows and causes friction vibration. As the blank holder force increases, the friction force increases, and as the blank holder force decreases, the friction force also decreases. Because of this, friction vibration also increases and decreases in proportion to the size of the blank holder force. According to this theory, whether frictional vibration occurs was measured using a flange simulator and a vibration sensor. The initial pressure was created using a torque wrench, and it was confirmed that the amplitude increased by about 4 times when torque 6 Nm was increased. When the forming velocity was rapidly changed to 300 mm/min, the amplitude increased approximately 4 times. It was confirmed that the amplitude of frictional vibration according to the measurement location was greater the further away from the specimen. It was verified that a new measurement factor "friction vibration" in the flange area can be measured and used for online monitoring.

• Transactions on Electrical and Electronic Materials
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• 제7권5호
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• pp.247-251
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• 2006

The traction DC feeder cable is one of the key devices for the safety operation of subway system, but for low voltage DC feeder cable (<3000 V) for subway, little attention has been paid by investigators on its online monitoring technology. With an introduction of cable laying and operation environment for the cable, this paper investigated the on-line monitoring technology of 1500 V DC feeder cable of subway. Firstly, in the text, the fault model of 1500 V DC cable was proposed based on the analysis of the fault type of the DC feeder cable, and then put forward synthetically on-line monitoring discharge signal and DC leakage current signal to assess DC feeder cable insulating state. The results of laboratory experiment prove that the proposed methods are feasible and can be implemented on-line monitor on DC feeder cable of subway.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.570-571
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• 2011

CTMS(Compact Tower Online Monitoring System), which deals with the polymer insulation arms of new material, is the on-line monitoring system for verifying stability and reliability of a new Compact Tower. CTMS measures real time data from the installed sensors in a Compact Tower and transmission line, air craft warning lights for detecting and determining the life time and the replace cycle of these facilities. This paper introduces how develop the CTMS and proposes how it will be use.

• Journal of Magnetics
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• 제18권2호
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• pp.105-110
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• 2013

The design model and key parameters of the material design for the control of induced magnetic flux at the near-field and efficient power transfer in a modified wireless power transfer (WPT) system with a large air gap of wireless electric vehicles were investigated through analytical simulations for magnetic vector and time-domain transient analysis. Higher saturation magnetic core with low core loss induced a stronger vertical magnetic field by the W-type primary coil in the WPT system with a gap of 20 cm at 20 kHz, which is shown from the vector potentials of the magnetic induction. The transient analysis shows that the higher magnetic fluxes through the pick-up cores lead to a linear increment of the alternating voltage with a sinusoidal waveform in the non-contact energy transfer system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권6호
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• pp.374-376
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• 2019

Last week, after our receiving online journal regarding Journal of the Korean Association of Oral and Maxillofacial Surgeons, we found a recently published original article by Alawode et al., entitled "A comparative study of immediate wound healing complications following cleft lip repair using either absorbable or non-absorbable skin sutures". Although this clinical article was well written and provided a great deal of information regarding the suture materials in the cleft lip repair, I would like to add a few additional comments based on the importance of skin suture during cheiloplasties in the primary cleft lip or secondary revision patients with representative figures.