• Title/Summary/Keyword: Short Resistance

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A study on the effective fault current limiting characteristics of stacked coated conductors with stainless steel stabilizer (스테인리스 스틸 안정화재를 가진 coated conductor의 적층 유무에 따른 효과적인 사고전류 제한을 위한 연구)

  • Na, J.B.;Ahn, M.C.;Kim, M.J.;Kim, Y.J.;Yang, S.E.;Park, D.K.;Kim, H.M.;Seok, B.Y.;Ko, T.K.
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.1
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    • pp.9-13
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    • 2007
  • Coated conductor(CC) is recently in actively progress for the research and development, and its can be used various stabilizer lot the specific requirements for each application. Among various superconducting applications, coated conductor applied to superconducting fault current limiters(SFCLS) bypasses fault current to its stabilizer, where the surge is abruptly reduced ; thus, stainless steel, which has large resistivity can be a suitable stabilizer for SFCLS. Despite high n-value of the YBCO, CC stabilized with stainless steel did not effectively limit the first peak fault current. In the short circuit test results of AMSC's 344S, a half period delay was observed between the fault and the generation of resistance(60Hz). In this paper, we performed short-circuit experiments with stacked and unstacked CC and compared the test results to analyze effective fault current limiting characteristics. we compared time of the generated resistance as the fault current limiting characteristics and made the samples one is the stacked CC and the other is unstacked CC. These samples were used equal numbers of pieces of CC. In addition, comparison and analysis was made for the stacked structure by measuring fault current limiting characteristics with respect to thermal insulation by impregnating with epoxy resin.

Development of Automatic Fault Detection System for Chip-On-Film (칩 온 필름을 위한 자동 결함 검출 시스템 개발)

  • Ryu, Jee-Youl;Noh, Seok-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.2
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    • pp.313-318
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    • 2012
  • This paper presents an automatic system to detect variety of faults from fine pitch COF(chip-on-film) which is less than $30{\mu}m$. Developed system contains circuits and technique to detect fast various faults such as hard open, hard short, soft open and soft short from fine pattern. Basic principle for fault detection is to monitor fine differential voltage from pattern resistance differences between fault-free and faulty cases. The technique uses also radio frequency resonator arrays for easy detection to amplify fine differential voltage. We anticipate that proposed system is to be an alternative for conventional COF test systems since it can fast and accurately detect variety of faults from fine pattern COF test process.

Analysis and comparison of initial performance degradation for single crystalline silicon solar cell under open and short circuit (단결정 태양전지의 단락 및 개방 시 노광에 의한 초기 출력저하 비교 분석)

  • Jung, Tae-Hee;Kim, Tae-Bum;Shin, Jun-Oh;Yoon, Na-Ri;Woo, Sung-Cheol;Kang, Gi-Hwan;Ahn, Hyung-Keun;Han, Deuk-Young
    • Journal of the Korean Solar Energy Society
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    • v.30 no.6
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    • pp.16-21
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    • 2010
  • It is well-known that Boron-doped Cz Si solar cells suffer light-induced degradation due to boron-oxygen defect which is responsible of a reduction in lifetime and hence efficiency. In this paper, we assume that PV solar cell has been connected with variable load to account the real operating condition and it shows different light-induced degradation of Si solar cell. To evaluate the effect of light-induced degradation for solar cell with various load, Single crystalline solar cells are connected with open and short circuits during light exposure. Isc-Voc curve evaluate light induced degradation of solar cells and the reason is explained as a change for serial resistance. From the results, Electrical characteristics of solar cells show better performance under short circuit conditions, after light exposure.

A Study on the Determination System of Process Conditions for Moldability by Using Fuzzy Logic (퍼지논리에 의한 최적 성형조건 결정 시스템에 관한 연구)

  • 강성남;허용정
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.3 no.1
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    • pp.1-4
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    • 2002
  • A short shot is a molded part that is incomplete because insufficient material was injected into the mold. Any factors that increase the resistance of polymer melt to flow or prohibit delivery of sufficient material into the cavity can cause a short shot. Inappropriate injection pressure is one of the most common factors which cause a short shot. Conventionally, domain experts in injection molding decide and modify the pressure based on their experience. It is difficult for a non-expert to decide the pressure properly with the considerations such as a part dimension, shape, and other processing variables. In this study, fuzzy algorithm is proposed to standardize the empirical determination of the pressure so that not only the experts but also non-experts can find the appropriate injection pressure easily. To acquire the more accurate results. domain experts should be interviewed and then technical documents which are collected from the experts should be restored in the fuzzy rule base. But in this study, simulations have been done by using C-MOLD to settle the rule base because it takes much time and also it's difficult to meet and interview the experts.

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A report of six unrecorded radiation-resistant bacterial species isolated from soil in Korea in 2018

  • Maeng, Soohyun;Sathiyaraj, Srinivasan;Subramani, Gayathri;Kim, Ju-Young;Jang, Jun Hwee;Kang, Myung-Suk;Lee, Ki-Eun;Lee, Eun-young;Kim, Myung Kyum
    • Journal of Species Research
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    • v.7 no.3
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    • pp.222-230
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    • 2018
  • Six bacterial strains 18JY42-3, 18SH, 18JY76-11, 17J11-11, 18JY14-14, and 18JY15-11 assigned to the phylum Proteobacteria, Firmicutes, and Actinobacteria were isolated from soil samples in Korea. The Cohnella species, strain 18JY42-3 was Gram-stain-positive, short rod-shaped and beige-colored. The Methylobacterium species, strains 18SH and 18JY76-11 were Gram-stain-negative, short rod-shaped and pink-colored. The Microterricola species, strain 17J11-11 was Gram-stain-positive, short rod-shaped and yellow-colored. The Paenarthrobacter species, strains 18JY14-14 and 18JY15-11 were Gram-stain-positive, short rod-shaped and white-colored. Phylogenetic analysis based on 16S rRNA gene sequence showed that strains 18JY42-3, 18SH, 18JY76-11, 17J11-11, 18JY14-14, and 18JY15-11 were most closely related Cohnella rhizosphaerae (MH497628; 98.8%), Methylobacterium goesingense (MH497632; 99.1%), Methylobacterium populi (MH497635; 99.9%), Microterricolagilva (MH504108; 98.4%), Paenarthrobacter nicotinovorans (MH497641; 100%), and Paenarthrobacter nitroguajacolicus (MH497646; 99.2%), respectively. All the six unrecorded strains showed resistance to UV radiation. This is the first report of these six species in Korea.

An Analysis of Muscular Activity of Supination According to the Elbow Flexion Angle Excluding the Elbow Flexor Activity of the Long and Short Head of the Biceps Brachii Muscle (팔굽관절 굽힘근 활성을 배제한 위팔두갈래근의 긴갈래와 짧은갈래의 팔굽관절 각도에 따른 뒤침동작의 근활성도 분석)

  • Kim, Jeong-Wook;Park, Min-Chull
    • PNF and Movement
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    • v.19 no.1
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    • pp.147-152
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    • 2021
  • Purpose: This study was conducted to investigate the functional differences of the two heads of the biceps brachii by measuring the functions in supination according to pronation by the angle of the flexion of the elbow joint, except for the activities of the elbow flexors. Methods: This study was conducted with 25 healthy men in their 20s. At a glenohumeral-joint 0˚ flexion posture, angles of flexion of the elbow joint of 0˚, 30˚, 60˚, 90˚, and 120˚ were randomly provided, and they were asked to perform supination and pronation with an elastic band. Using an eight-channel surface electromyogram, the muscle activities of the long and short heads of the biceps brachii were measured. The activities of the short and long heads according to the angle were analyzed using a one-way ANOVA, and as a post-test, LSD was employed. Results: The analysis of the impact of the resistance of the elastic band in supination on the differences in the muscle activities in the short and long heads suggests there was a significant difference between 0˚ and 30˚ (p < 0.05). Conclusion: In supination according to forearm pronation, the long head had greater action in the early flexion posture of the elbow joint, and it is judged that the ratio of the flexion of the elbow joint according to the actions of the biceps brachii was considered small.

Laboratory Test and Evaluation to Characterize the Cracking Resistance of Asphalt Mixtures (아스팔트 혼합물의 균열 저항성 평가 연구)

  • Kim, Boo-Il
    • International Journal of Highway Engineering
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    • v.6 no.3 s.21
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    • pp.9-15
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    • 2004
  • The cracking resistance of asphalt mixtures is generally evaluated by measuring a single parameter (i.e., Tensile strength, Stiffness). However, the use of a single parameter has been questioned in the evaluation of asphalt mixture cracking performance. The focus of this study was to clearly identify the key properties and characteristics associated with the cracking resistance of asphalt mixtures. Results of fracture, creep, and strength tests at multiple loading rates performed on the modified and unmodified mixtures showed that the mixture cracking resistance was primarily affected by the rate of micro-damage accumulation. This was reflected in the m-value, without affecting the fracture energy limit. It was also observed that the short loading time (elastic) stiffness alone could not differentiate the mixture cracking resistance of the mixtures. It was concluded that the key to characterize the cracking resistance of asphalt mixture is in the evaluation of the combined effects of creep and failure limits. It was also found that a residual dissipated energy parameter measured from Superpave IDT strength test gave the quick and useful way to distinguish the difference of cracking resistance of asphalt mixtures. Failure strain in the longer-term creep test appeared to be a useful parameter for evaluating the combined effects of creep and failure limits of asphalt mixtures.

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Analysis of QTLs Related to Resistance to Brown Planthopper in Rice (DH 집단을 이용한 벼멸구 저항성 연관 QTLs 분석)

  • Kim, Suk-Man;Qin, Yang;Sohn, Jae-Keun
    • Korean Journal of Breeding Science
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    • v.41 no.3
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    • pp.236-243
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    • 2009
  • This study was conducted to develop a japonica-type rice cultivar with brown planthopper (BPH) resistance using DNA markers. A doubled haploid (DH) population consisting of 120 pure-lines was established by anther culture of $F_1$ hybrids between 'Samgang', a Tongil type BPH resistance cultivar, and 'Nagdong', a japonica cultivar. To determine the map position of genes responsible for BPH resistance in rice, a genetic map was constructed based on 120 DH lines. A total of 162 molecular markers were classified into 12 linkage groups, covering 1,884 Kosami centimorgan (cM) with an average of 11.6 cM. Five QTLs (qBPR3, qBPR6, qBPR7, qBPR8, and qBPR12) associated with BPH resistance were identified and mapped on chromosomes 3, 6, 7, 8, and 12, respectively, using the genetic map constructed in this study. To analyze the relationship between BPH resistance and agronomic traits, a total of eight QTLs related to the agronomic traits were detected on 12 rice chromosomes. In an analysis of relationships, three QTLs (qBPR3, qBPR7, and qBPR8) showed a linkage with tested agronomic traits. A QTL (qBPR3) located on chromosome 3 (RM282-3023) was closely linked to culm length (qCL3). The QTL (qBPR8) for BPH resistance on the short arm of chromosome 8 also overlapped the region detected in culm length (qCL8).

An Comparative Study on the Method of Determining Allowable Horizontal Bearing Capacity of Piles (말뚝의 허용횡방향지지력 결정법의 비교연구)

  • Lee, Seung-Hyun;Han, Jin-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.267-274
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    • 2021
  • Among several methods for determining the allowable lateral resistances of piles, the subgrade reaction method and ultimate lateral resistance method are generally used. To determine the effects of the soil conditions, pile head restraint conditions, and pile lengths on determining the allowable lateral resistances of piles, computations of the allowable lateral resistances of piles using the two methods were executed, and the computation results were compared. For piles in soft cohesive soil, the pile design is governed by the allowable lateral resistance of a pile from subgrade soil reaction method regardless of the pile head restraints conditions and pile lengths. The allowable lateral resistance of a pile from the ultimate lateral resistance governs the design as the undrained shear strength increases. Except for the case of a short pile, which is installed in loose granular soil, the allowable lateral resistance of a pile from ultimate lateral resistance governs the design of laterally loaded piles. According to this study, computation of the ultimate lateral resistance of a pile is needed, even though some opinions suggest that the design of a laterally loaded pile is satisfied only by the subgrade reaction method. The pile width barely influences the coefficient of horizontal subgrade reaction. Realistically, the effect of the pile width can be disregarded in the condition of common pile widths of 20~90cm.

Identification of a novel mutation in a patient with pseudohypoparathyroidism type Ia

  • Lee, Ye Seung;Kim, Hui Kwon;Kim, Hye Rim;Lee, Jong Yoon;Choi, Joong Wan;Bae, Eun Ju;Oh, Phil Soo;Park, Won Il;Ki, Chang Seok;Lee, Hong Jin
    • Clinical and Experimental Pediatrics
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    • v.57 no.5
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    • pp.240-244
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    • 2014
  • Pseudohypoparathyroidism type Ia (PHP Ia) is a disorder characterized by multiform hormonal resistance including parathyroid hormone (PTH) resistance and Albright hereditary osteodystrophy (AHO). It is caused by heterozygous inactivating mutations within the Gs alpha-encoding GNAS exons. A 9-year-old boy presented with clinical and laboratory abnormalities including hypocalcemia, hyperphosphatemia, PTH resistance, multihormone resistance and AHO (round face, short stature, obesity, brachydactyly and osteoma cutis) which were typical of PHP Ia. He had a history of repeated convulsive episodes that started from the age of 2 months. A cranial computed tomography scan showed bilateral calcifications in the basal ganglia and his intelligence quotient testing indicated mild mental retardation. Family history revealed that the patient's maternal relatives, including his grandmother and 2 of his mother's siblings, had features suggestive of AHO. Sequencing of the GNAS gene of the patient identified a heterozygous nonsense mutation within exon 11 (c.637 C>T). The C>T transversion results in an amino acid substitution from Gln to stop codon at codon 213 ($p.Gln213^*$). To our knowledge, this is a novel mutation in GNAS.