• Title/Summary/Keyword: single core

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Current Limiting Characteristics of a Flux-Lock Type SFCL for a Single-Line-to-Ground Fault

  • Oh, Geum-Kon;Jun, Hyung-Seok;Lee, Na-Young;Choi, Hyo-Sang;Nam, Gueng-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.9
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    • pp.70-77
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    • 2006
  • We have fabricated an integrated three-phase flux-lock type SFCL, which consists of an YBCO($YB_a2Cu_3O_7$) thin film and a flux-lock reactor wound around an iron core of each phase. In order to apply the SFCL in a real power system, fault analyses for the three-phase system are essential. The short-circuit currents were effectively limited by adjusting the numbers of winding of each secondary coil and their winding directions. The flux flow generated in the iron core cancelled out under the normal operation due to the parallel connection between primary and secondary windings. However, the flux-lock type SFCL with same iron core was operated just after the fault due to the flux generating in the iron core. To analyze the current limiting characteristics, the additive polarity winding was compared with the subtractive one in the flux lock reactor. Whenever a single line-to-ground fault occurred in any phase, the peak value of the line current of the fault phase in the additive polarity winding increased up to about 12.87 times during the first-half cycle. On the other hand, the peak value in the subtractive polarity winding increased up to about 34.07 times under the same conditions. This is because the current flow between the primary and the secondary windings changed to additive or subtractive status according to the winding direction. We confirmed that the current limiting behavior in the additive polarity winding was more effective for a single-line-to-ground fault

Evaluation on the Marginal Fitness of Zirconia Core fabricated with CAD/CAM System (CAD/CAM 시스템으로 제작한 지로코니아 코어의 변연 적합도 평가)

  • Noh, Hyeongrok;Sun, Gumju;Joo, Kyuji
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.800-806
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    • 2013
  • The purpose of this study was to evaluate the marginal fitnesses on the effect of span length of bridge and the marginal gaps within the clinically allowed range. The samples were fabricated with zirconia core using CAD/CAM system. The test groups were divided by four groups, single crown, 2-units bridge, 3-units bridge and 4-units bridge and 10 zirconia cores per each group. The results of mean marginal gaps were $42.95{\pm}6.93{\mu}m$ in the single crown, $43.53{\pm}5.27{\mu}m$ in 2-unit, $53.43{\pm}13.38{\mu}m$ in 3-unit, and $50.85{\pm}8.25{\mu}m$ in 4-unit on each. The marginal gap of mesial and distal surfaces were statistically significant differences between single, 2-unit group and 3-unit, 4-unit group (p<.05) and this results was effected by the span length. The buccal and lingual surfaces were no statistically significant differences within all groups(p>.05). From this results the span length of the zirconia core may have influence on marginal fitness and the marginal gaps were within the clinically allowed range.

Preparation and Characterization of Stretch Fabric : Dyeing Properties of Core Yarn and Effect Yarn (신축성사 개발 및 물성평가 : 코어(core)사와 장식(effect)사간의 동색성 및 염색성 평가)

  • Kang, Ki-Hyuk;Kim, Young-Sung;Son, Young-A
    • Textile Coloration and Finishing
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    • v.22 no.2
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    • pp.140-144
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    • 2010
  • In this study, we investigated the clean appearance and good stretch properties. Usually, clean appearance concerned with the dyeing properties of core and effect yarns. The dyeing properties between core yarn (conjugate yarn) and effect yarn were determined by the build-up and the color differences using the four different yarns of SDY FD(spindraw yarn full dull), SDY CD(spindraw yarn cation dyeable), POY FD( partially-oriented yarn full dull) and POY CD(partially-oriented yarn cation dyeable). We used the single color dye of C. I. Disperse Blue 79 and mixed colors made by C. I. Disperse Red 60, C. I. Disperse Blue 56, and C. I. Disperse Yellow 54.

CORE $SHELL^{TM}$: THE LATEST INNOVATION IN POLYMER TECHNOLOGY FOR THE PAPER INDUSTRY (코어쉘 : 제지산업에 있어서 고분자 기술의 최근 혁신)

  • Gerli, Alessandra;Johnson, Gray
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2003.06a
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    • pp.87-105
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    • 2003
  • A new polymer technology commercialized with the name of Core Shell has been developed by Ondeo Nalco Company. Laboratory evaluations have demonstrated that Core Shell polymers produce a floc with high shear resistance, making them the flocculants of choice for modern high-speed paper machines. Core Shell polymers provide significant papermaking benefits, when used as single component or in combination with microparticles. At this time, the new program has been successfully applied on more than 60 paper and board machines across the world. Implementation of Core Shell polymers with or without a microparticle provided better and more stable retention values and improvements in paper quality, system cleanliness and machine runnability.

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A Study on Characteristics of Campus Core and Hierarchy of Exterior Space in University Campus Masterplan (대학 캠퍼스 마스터플랜의 중심공간의 성격과 외부공간의 위계에 관한 연구)

  • Choi, Jin-Hee;Kim, Jin-Mo;Cho, Sung-Yong
    • Journal of the Korean Institute of Educational Facilities
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    • v.16 no.3
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    • pp.59-67
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    • 2009
  • The intention of the study is to understand a characteristics of 'Campus core' in university campus and to verify the connection and hierarchy of exterior space in campus masterplan. This study concludes that 'Multi-nuclei structure', is where a single campus core was subdivided into several service cores, is an integral part of campus masterplan in process of expansion from campus core and the changing exterior space, by in-depth case analysis of Seoul Women's University Campus.

Highly sensitive temperature sensor based on etched fiber with thermally expanded core (식각된 열확산 코어 광섬유를 이용한 고감도 온도 센서)

  • Kim, Kwang-Taek;Song, Hyun-Suk;Shin, Eun-Soo;Hong, Ki-Bum
    • Journal of Sensor Science and Technology
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    • v.15 no.4
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    • pp.263-268
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    • 2006
  • We have demonstrated a highly sensitive temperature sensor using an etched single mode fiber with a thermally expanded core region. Large core size of thermally expanded core facilitates access to evanescent wave by the wet etching. The etched region was surrounded by a low dispersive external medium with high thermo-optic coefficient. Due to the large difference between the dispersion property of the fiber and that of the external medium, the device reveals a cut-off properties at spectral region. The cut-off wavelength was shifted by the variations of the environmental temperatures because of thermo-optic effect of the external medium. The sensitivity of the fabricated device was found to be $45nm/^{\circ}C$.

HiCORE: Hi-C Analysis for Identification of Core Chromatin Looping Regions with Higher Resolution

  • Lee, Hongwoo;Seo, Pil Joon
    • Molecules and Cells
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    • v.44 no.12
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    • pp.883-892
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    • 2021
  • Genome-wide chromosome conformation capture (3C)-based high-throughput sequencing (Hi-C) has enabled identification of genome-wide chromatin loops. Because the Hi-C map with restriction fragment resolution is intrinsically associated with sparsity and stochastic noise, Hi-C data are usually binned at particular intervals; however, the binning method has limited reliability, especially at high resolution. Here, we describe a new method called HiCORE, which provides simple pipelines and algorithms to overcome the limitations of single-layered binning and predict core chromatin regions with three-dimensional physical interactions. In this approach, multiple layers of binning with slightly shifted genome coverage are generated, and interacting bins at each layer are integrated to infer narrower regions of chromatin interactions. HiCORE predicts chromatin looping regions with higher resolution, both in human and Arabidopsis genomes, and contributes to the identification of the precise positions of potential genomic elements in an unbiased manner.

Electromotive Force Characteristics of Current Transformer According to the Magnetic Properties of Ferromagnetic Core

  • Kim, Young Sun
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.1
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    • pp.37-41
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    • 2015
  • The most common structure of the current transformer (CT) consists of a length of wire wrapped many times around a silicon steel ring passed over the circuit being measured. Therefore, the primary circuit of CT consists of a single turn of the conductor, with a secondary circuit of many tens or hundreds of turns. The primary winding may be a permanent part of the current transformer, with a heavy copper bar to carry the current through the magnetic core. However, when the large current flows into a wire, it is difficult to measure its magnitude of current because the core is saturated and the core shows magnetic nonlinear characteristics. Therefore, we proposed a newly designed CT which has an air gap in the core to decrease the generated magnetic flux. Adding the air gap in the magnetic path increases the total magnetic reluctance against the same magnetic motive force (MMF). Using a ferrite core instead of steel also causes the generation of low magnetic flux. These features can protect the magnetic saturation of the CT core compared with the steel core. This technique can help the design of the CT to obtain a special shape and size.