• The Plant Pathology Journal
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• 제35권4호
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• pp.372-380
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• 2019

Pseudomonas syringae pv. actinidiae (Psa) is by far the most important pathogen of kiwifruit. Sustainable expansion of the kiwifruit industry requires the use of Psa-tolerant or resistant genotypes for the breeding of tolerant cultivars. However, the resistance of most existing kiwifruit cultivars and wild genotypes is poorly understood, and suitable evaluation methods of Psa resistance in Actinidia have not been established. A unique in vitro method to evaluate Psa resistance has been developed with 18 selected Actinidia genotypes. The assay involved debarking and measuring the lesions of cane pieces inoculated with the bacterium in combination with the observation of symptoms such as callus formation, sprouting of buds, and the extent to which Psa invaded xylem. Relative Psa resistance or tolerance was divided into four categories. The division results were consistent with field observations. This is the first report of an in vitro assay capable of large-scale screening of Psa-resistance in Actinidia germplasm with high accuracy and reproducibility. The assay would considerably facilitate the breeding of Psa-resistant cultivars and provide a valuable reference and inspiration for the resistance evaluation of other plants to different pathogens.

• 한국지구과학회지
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• 제34권2호
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• pp.162-172
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• 2013

이 연구에서는 플래시 파노라마 기반 가상야외답사(VFT)를 활용한 야외 지질 답사 활동의 효과를 공간 시각화 능력, 개념 이해와 인식 측면에서 분석하고자 하였다. 17명의 강원도 소재 중학교 학생을 대상으로 Kim and Lee (2011)에 의해 제안된 플래시 파노라마 기반 VFT 활용을 위한 3단계 모형을 적용하여 제주도 일대에서 2박 3일간 실제 지질 답사 활동을 수행하였다. 전실험 연구 설계를 적용하여 단일 집단에 대하여 사전과 사후의 공간 시각화 능력과 화산 개념 이해 변화를 각각 분석하였으며, 사후 설문을 통해 VFT 활용 효과에 대한 학생들의 인식을 조사하였다. 플래시 파노라마 기반 VFT 활용 모형을 적용하여 야외 답사 활동을 수행한 결과, 공간 시각화 능력에서는 '공간 관계' 능력이, 화산 개념 이해에서는 '지식'과 '이해'에서 유의미한 증가를 나타내었다. 또한, 공간 시각화 능력과 화산 개념 이해에서 대부분의 학생들의 향상 지수가 양(+)으로 산출되었다. 한편, 참가 학생들은 플래시 파노라마 기반 VFT 활용에 대해서 높은 흥미와 만족도를 나타내었으며, 야외 답사 활동에서 플래시 파노라마 기반 VFT의 활용에 대해 매우 긍정적으로 인식하는 것으로 분석되었다. 또한 플래시 파노라마 기반 VFT 활용이 인지적, 지리적 요소에서 실제 야외 답사 활동에 많은 도움이 되는 것으로 인식하였다.

• 디지털융복합연구
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• 제13권10호
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• pp.51-58
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• 2015

교육 분야에서의 빅데이터 활용이 선진국을 중심으로 확산되고 있다. 그러나 국내의 경우 이와 관련된 실험적 접근만이 있을 뿐 관련 연구나 현장의 서비스는 아직 나타나지 않고 있는 실정이다. 따라서 이러닝 업계에서 빅데이터의 응용이 저조한 이유를 파악하고 이를 개선할 연구와 대안 모색이 시급한 상황이다. 연구 결과, 이러닝 산업계에서는 빅데이터의 이해 수준이 높으면 빅데이터가 이러닝에 미치는 영향이 크다고 인식하고 있으며, 매출 규모가 큰 업체일수록 영향이 크다고 인식하고 있는 것으로 종합되었다. 이에 본 연구는 매출규모에 따라 다른 빅데이터에 관한 교육 및 활용 지원 정책을 펼 것을 제언하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제13권1호
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• pp.27-30
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• 2011

A sub-cooled liquid nitrogen cooling system is known as a most promising method to develop large scale superconducting apparatuses such as superconducting fault current limiters and superconducting cables [1]. Gaseous helium (GHe), gaseous nitrogen ($GN_2$) and sulfur hexafluoride ($SF_6$) are commonly used for designing an high voltage applied superconducting device as an injection gaseous medium [2, 3]. In this paper, the analysis on the dielectric characteristics of GHe, $GN_2$ and $SF_6$ are conducted by designing and manufacturing sphere-to-plane electrode systems. The AC withstand voltage experiments on the various gaseous insulation media are carried out and the results are analyzed by using finite element method (FEM) considering field utilization factors (${\xi}$). It is found that the electric field intensity at sparkover ($E_{MAX}$) of insulation media exponentially decreases according to ${\xi}$ increases. Also, the empirical expressions of the functional relations between $E_{MAX}$ and ${\xi}$ of insulation media are deduced by dielectric experiments and computational analyses. It is expected that the electrical insulation design of applied superconducting devices could be performed by using the deduced empirical formulae without dielectric experiments.

• 전기학회논문지
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• 제61권10호
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• pp.1471-1476
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• 2012

A study on the dielectric characteristics of the Glass Fiber Reinforced Plastic (GFRP) is important for designing a reliable high voltage superconducting machines such as transmission superconducting fault current limiters, superconducting cables, and superconducting transformers. In this paper, dielectric experiments of the GFRP under lightning impulse voltage are conducted in liquid nitrogen($LN_2$) according to various experimental conditions such as the thicknesses of the GFRP, the diameters of electrode systems and the pressures. The dielectric characteristics of the GFRP are analyzed by using a Finite Elements Method(FEM) according to various field utilization factors. It has been reported that the electrical insulation design of the GFRP would be conducted by considering the mean electric field intensity($E_{mean}$) distributed inside the GFRP. In this study, it is found that the dielectric performance of the GFRP could be explained by not only $E_{mean}$ but also the maximum electric field intensity ($E_{max}$). Finally, the empirical formulae of the GFRP to estimate an electrical breakdown voltage at sparkover under the lightning impulse condition are deduced. It is expected that the presented experimental results in this paper are helpful to design electrically reliable high voltage superconducting machines using the GFRP as an insulation material.

• Journal of Construction Engineering and Project Management
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• 제5권2호
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• pp.44-52
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• 2015

Various approaches have been used in crack preparations and each of the approaches has advantages and disadvantages. Although the routing method has been widely used and seems to be the best approach among the approaches, it is not a complete solution for crack preparation. This paper compares and evaluates a pneumatic crack cleaning device (CCD) developed by Robotics and Intelligent Construction Automation group at Georgia Tech, over existing devices. Surveys were conducted to discover factors that affect the performance of crack/joint preparation work. Then, data for such information were collected via field tests for devices such as router, heat lancer, air blower and CCD. Performed field test results and follow-up interviews demonstrated that the utilization of CCD has potential to offer improvements in productivity, safety, and maintenance cost. An analytic hierarchical procedure (AHP) and economic analyses were conducted. The AHP analysis considered three factors including safety, quality and productivity while the economic analyses examined the alternatives in various ways. The results indicated that the CCD was ranked first and second for the AHP analysis and economic analysis, respectively. In conclusion, the field tests and results revealed that the utilization of CCD achieved satisfactorily in performance, quality, safety and control, and showed that it has high potential in crack cleaning practice.

• 대한안전경영과학회지
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• 제22권4호
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• pp.35-43
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• 2020

The National Competency Standards(NCS) has been developed a good curriculum to reflect the demand in the industry. NCS is defined as systemizing the knowledge, skill, and attitude required to perform a task in the industry. It is an effort to reduce the gap between educational requirements and occupational requirements. However, when NCS is applied, the task level is changed to the title of qualification according to the policy outcomes for the government project. And, the NCS has been emphasizing the purpose of license acquisition, rather than using the standard for tasks in the industry. It means that the misuse of NSC hinders utilizing it as the original purpose of standardizing a task. It requires the customer to study the required competency unit with a no-choice option. Moreover, it makes it hard for companies or industry autonomically run the NCS. Therefore, we define the operational range in terms of the education field, the qualification field, and the career field to diffuse and apply NCS, and suggest the effective utilization method.

• 디지털융복합연구
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• 제14권6호
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• pp.449-455
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• 2016

본 연구는 미용사 일반 국가자격증 7가지 실기과제 두피스켈프, 샴푸, 헤어커트, 블로우 드라이, 롤셋팅, 퍼머넌트웨이브, 컬러링실기과제와 현장 실무와의 연계성에 관하여 알아보고자 서울 소재 미용실에서 근무하는 현직 미용사 180명을 대상으로 설문 조사를 실시하였다. 7가지 실기과제 과목 대부분은 현장실무에 대한 활용정도가 평균 수준 정도로 나타났으며, 세부과제들 중 헤어컬러링의 경우만 유일하게 도포량, 도포방법 등의 항목에서 도움 정도가 높은 것을 알 수 있었다. 또 헤어커트와 컬러링 두 과제의 활용수준은 현장 실무에 긍정적인 영향을 미치는 것으로 나타나(p<0.05), 현직 미용사들에게 가장 중요한 과제 중 하나 인 헤어 커트에 대한 실전 응용과 고객 만족을 위한 수준 높은 교육이 요구되며, 상대적으로 현장실무에 영향을 미치지 못한 과제들에 대한 재점검이 필요할 것으로 판단된다.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권2호
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• pp.45-50
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• 2004

The field utilization factor (equation omitted) (the mean electric field / the maximum electric field) of standard sphere gaps was calculated by the charge simulation method, taking into account the ground plane and shanks. n changes mainly with g/r and slightly with 1$_1$, 1$_2$ and 1, where D=2r is the sphere diameter, g is the gap length, 1$_1$ and 1$_2$, respectively, are the lengths of the upper and lower shank, and t is the shank diameter. Generally, (equation omitted) increases as 1$_1$,1$_2$ and t each becomes larger. IEC standard 60052(2002) limits t$\leq$0.2D 1$_1$$\geq$1D and prescribes A=1$_2$＋D＋g where A is the height of the spark point on the upper sphere. Therefore, (equation omitted) is the largest when A=9D and the smallest when A=3D. The simple equation of a straight line, (equation omitted)=1- (g/3r), can generally be used as a representative value of (equation omitted) for a wide variety of sphere diameters that are permitted by the IEC standard. The maximum electric field E$_{m}$ at sparkover of standard air gaps has also been calculated by the relation E$_{m}$=V/(equation omitted)g). E$_{m}$ describes a U-curve for g/r, up to the sphere diameter of 1 m. Moreover, for 1.5-m and 2-m diameters and especially .for negative polarity, sparkover voltages have been calculated by integration of the ionization index.index.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.295-296
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• 2009

There are various application of liquid crystal materials to devices, especially, blue phase liquid crystal (BPLC) and nano-structured liquid crystal mixture have been studied recently because BPs existing temperature range has been expanded by polymer-stabilization and liquid crystal has been confined in room which has certain coherence length so that their particular characters, such as fast response time and optically isotropic state at no electric field, could apply to advanced liquid crystal display devices. However, there is an crucial problem which is high operating voltage from low Kerr constant and limited electric field utilization using in-plain electric field. In this paper, we will analyze cell structure in the way of using electric field and show effective electric field utilization to reduce operating voltage.