• 대한기계학회논문집B
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• 제26권4호
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• pp.570-577
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• 2002

Charged liquid particle's behavior in electric and flow field was simulated to define the effect of electric field on the contact area and its dispersion. For the simulation of flow and electric field finite volume method was applied. To find out the particle's moving path in that field lagrangian equation of motion was solved by Runge-Kutta methods. We assumed that the particle was charged 10% of Rayleigh limit while the particle passing through the electrode and the particle does not have an effect on the electric field. In case of 30[Kv] of voltage charging the particles injected from the central 60% of the nozzle injection area adhere to the grounded moving plate and no dispersion occurred. Increasing the charged voltage to 40[Kv], it brought about the same phenomena as that of 30[Kv] charging except the dispersion. Voltage increasing from 30[Kv] to 40 [Kv] caused higher Coulomb force acts on the particle and it made the particle dispersion.

• Current Optics and Photonics
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• 제4권3호
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• pp.193-199
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• 2020

In this paper we propose a dark-field digital holographic microscopy system based on 360-degree oblique illumination. This setup is constructed without using a dark-field objective. The principle of 360-degree oblique illumination of vortex beam and dark-field digital holographic microscopy are introduced theoretically and experimentally. By analyzing the reconstructed image of a dark-field digital hologram of a USAF 1951 target, it is proved that the imaging resolution can be improved by this method. And also, comparison and analysis are made on the reconstructed image of a bright-dark field digital hologram of a pumpkin stem slice, the result shows that the imaging contrast is also enhanced with this method, and it is effective for dark-field digital holographic microscopy imaging of large transparent biological samples.

• 전기학회논문지
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• 제64권12호
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• pp.1673-1678
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• 2015

This paper describes magnetic field on power cable in underground transmission systems. Based on specification which is being used in domestic power utility, magnetic field was analyzed in accordance with line arrangement, line burial depth and phase spacing. Magnetic field magnitude and its trend were understood in each circuit type such as double circuits, triple circuits and quadruple circuits of underground transmission systems. In addition, magnetic field was analyzed according to phase arrangement changing in each circuit. Finally, the proper phase arrangement configuration type was suggested by the evaluation of analysis result. Magnetic field was calculated by using Biot-Savart's law. According to the evaluated magnetic fields based on phase layout configuration in each circuit, it figured out that each of magnetic fields was different. As a result, this paper proposes a proper phase layout configuration for generating minimum magnetic field. It is evaluated that the phase layout configuration in each circuit proposed in this paper can be used at actual underground transmission systems.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.93-94
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• 2022

Although various studies about indoor positioning systems, such as beacon and Wifi, have been conducting for indoor positioning of workers at construction sites, these systems have limitations in terms of accuracy or economics. To overcome these limitations, geomagnetic field sequence-based indoor positioning technology can be a good alternative. However, it is necessary to correct the geomagnetic field near the construction material stocking area since the geomagnetic field can be distorted near construction materials such as rebars. Therefore, this study conducted an experiment for identifying correction range of geomagnetic field near the construction material stocking area. It was analyzed that the geomagnetic field should be corrected up to 60cm in the horizontal direction from the stocking point if the height of stocking area for rebars is 40cm or more. This study can be used for important reference for development of geomagnetic field sequence-based indoor positioning technology suitable for construction sites.

• Progress in Superconductivity
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• 제6권1호
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• pp.79-83
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• 2004

We fabricated Bi-2223/Ag superconductor tape with 55 filaments and estimated the magnetic field dependence of critical current (I$_{c}$) and index n (n) up to 30 T at 4.2 K. The I$_{c}$ and n were characterized as a function of external magnetic field parallel to the tape surface on increasing and decreasing field, using a 35 T hybrid magnet. The $I_{c}$ was estimated to be 325 A, and n was 32, 22, and 26 in the electric field range of $0.1 ∼1\mu$V/cm, 1∼10 $\mu$V/cm, and 0.1∼10 $\mu$V/cm, respectively, under self-field at 4.2 K. It was observed that $I_{c}$ was dependent on magnitude of magnetic field and it decreased exponentially as the field increased; in a parallel and increasing field, It was 128 A at 30 T which is approximately 40% of critical current in self-field. In addition, the $I_{c}$ was higher on decreasing field than that on increasing one. On the other hand, n did not significantly depend on field strength up to 30 T, nor varied on whether increasing or decreasing field; n value in 0.1∼1 $\mu$V/cm was 23.0$\pm$5.2 and 27.8$\pm$8.0 on increasing and decreasing field, respectively. The n value on decreasing magnetic field was slightly higher than that on increasing field. This hysteretic behavior of n was similar to that of$ I_{c}$, which is related to the trapped flux at the grain boundary.ary.

• 대한전기학회논문지:전력기술부문A
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• 제55권4호
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• pp.151-155
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• 2006

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environmental design software, TLCALC(Transmission Line CALCulation) for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC solved a few problems in use of the existing foreign tools and took several advantages as follows; (1) It is a common tool that solves calculating limitations of foreign formulas, (2) It has wide application ranges and enhances accuracy of prediction. (3) It can be applied to almost transmission line configurations in Korea. (4) Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC is easy and practical, this program will be usefully applied to the environmental friendly design and construction of transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC.

• 한국도서관정보학회지
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• 제47권2호
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• pp.27-50
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• 2016

이 연구는 미국과 일본의 독서과학의 학문적 체계와 우리나라 대학의 학부와 대학원의 독서학과와 독서교육전공의 교육과정을 살펴보고, 이를 기초로 독서과학의 학문적 체계에 대한 원칙을 수립하여 독서과학의 학문적 체계를 제안한 것이다. 미국의 독서과학 연구영역은 독서사회학, 독서생리학, 독서심리학, 독서교육학의 4가지로 구분하고 있다. 일본의 독서과학 연구는 미국의 영향을 받아 독서과학의 연구영역을 독서사회학, 독서생리학, 독서심리학, 독서교육학으로 구분하고 있다. 그러나 실복무(室伏武)는 독서과학 교육과정을 기초분야, 독서자료분야, 독서교육의 방법분야, 독서교육 관리분야, 독서과학 인접학문 분야로 구분하고 있다. 우리나라 대학에 개설되어 있는 독서과학 교육과정을 비교하고 분석한 결과 독서과학의 영역은 독서사회학, 독서심리학, 독서교육방법학, 독서자료학, 독서와 관련된 인접과학의 5가지로 구성되어 있다. 이상의 내용을 기초로 새로운 독서과학의 학문적 체계를 제시해 보면 독서과학의 기초, 독자 영역, 독서자료 영역, 독서지도자의 교육 영역, 독서과학의 인접학문으로 구분할 수 있다.

• 한국환경복원기술학회지
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• 제8권2호
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• pp.1-20
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• 2005

The purpose of this paper is to classify two study sites into the biotope types and investigate the landscape ecological characteristics of them. This will be available for the rural planning in the aspect of environmental preservation. The summaries of the result are as follows. 1) In the result of the area assessment in biotope groups, a dry field (32%) and a paddy field (28%) are more than 50%, but settlement space and water space are less than 10%. The result shows the land use condition of rural areas. 2) In the investigation result of elongation, running water spaces are higher than other biotope groups relatively, it is because they long shaped and 1-3m narrow. 3) In case of Fractal index analysis, residential spaces and cultivated lands are investigated to be lower in numerical value, it is because they have the definite borders and get simple in the border of landscape by human intervention. 4) In case of dispersion degree, the dry field has the highest value because they are located close by forests spread widely around study sites. It means that the land which is used by artificial purpose get more value rather than natural lands 5) In the connectivity analysis, a paddy field and a residential space appear the highest. It is because residence spaces spread intensively through roads and a paddy field, through streams. 6) In rural landscape, the diversity of landscape is investigated to be simple. A paddy field and a dry field contain small sized patches that have been divided by human intervention. Besides, there appear much different vegetation around waterways and farm-roads.

• 재활복지
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• 제17권4호
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• pp.267-289
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• 2013

본 연구는 장애영역별 학교기업의 설치와 운영에 대한 교사들의 인식의 자료를 알기 위하여 대구 지역에 있는 5개 학교 교사들을 대상으로 설문조사를 실시하였다. 연구결과 장애영역별 학교기업 설치에 있어서 필요성이 유의한 것으로 나타났으며, 운영에 있어서도 학생들의 전문 직업능력 개발 및 취업률 증대를 기대하였고. 그 방식도 산업체와 지역사회에서 의뢰한 물품을 생산하여 공급하는 방식을 선호하였다. 학생들의 교육활동 시간편성도 유연성 있게 운영하고 교과는 필요에 따라 통합교육과정으로 한다. 장애영역별 학교기업의 전담교사 및 직원도 학교 실정에 따라 지원 보조하도록 제안하였다. 본 연구 결과를 장애영역별 학교기업에 대한 실천적 함의와 후속연구의 방향을 논의하였다.

• 융합정보논문지
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• 제11권4호
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• pp.102-110
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• 2021

본 연구에서는 해외현장실습 및 해외취업 프로그램 현황을 진단하기 위해 관련 문헌 연구를 실시하였고 CIPP모형에 맞추어 설문을 구성하고 분석하여 향후 효과적인 해외진출 프로그램을 추진하기 위한 정책적 제안을 제시하였다. 주요결과로는 참여자들의 만족수준을 높이기 위해서는 본인의 참여의지가 강해야 하고 해외취업 프로그램의 목표를 명확히 설정해야 할 필요가 있다고 조사되었다. 또한, 해외취업 성사 후에도 담당자의 현지출장 및 업체와의 관계유지 등 지속적인 지원을 보장해 줄 수 있는 시스템이 구축되어야 할 것으로 분석되었다. 본 연구는 현행되고 있는 해외진출 프로그램들이 가지고 있는 긍정적인 효과와 문제점들을 확인함으로써 국가, 대학, 지자체의 해외현장실습 및 해외취업 관련 사업 정책 수립시 도움될 만한 시사점들을 제시하고 있다.