• Journal of Power Electronics
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• 제19권4호
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• pp.980-988
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• 2019

When compared with traditional power frequency generators, the frequency of a super high-speed permanent magnet generator (SHSPMG) is a lot higher. In order to study the influence of frequency on the electromagnetic field of SHSPMGs, a 60000rpm, 117kW SHSPMG was taken as a research object. The two-dimensional finite element model of the generator was established, and the two-dimensional transient field of the generator was simulated. In addition, a test platform of the generator was set up and tested. The reliability of the simulation was verified by comparing the experiment data with that of the simulation. Then the generator electromagnetic field under different frequencies was studied, and the influence mechanism of frequency on the generator electromagnetic field was revealed. The generator loss, voltage regulation rate, torque and torque ripple were analyzed under the rated active power load and different frequencies. The influences of frequency on the eddy current density, loss, voltage regulation rate and torque ripple of the generator were obtained. These conclusions can provide some reference for the design and optimization of SHSPMGs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1656-1662
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• 2010

Automatic train control systems are divided into ATC, ATP and ATS systems etc. The ATP and ATS systems offer discontinuous information for train control. While the ATC systems provide continueous information for train control. There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of ceramics, researches are required about variation of flux density by the ceramics. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity in the AF track circuit. Standard permeability of ceramics is proposed by analyzing the variation of magnetic field intensity. It is demonstrated by using Maxwell and Matlab program.

• 한국도서관정보학회지
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• 제42권2호
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• pp.171-191
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• 2011

본 연구는 문헌정보학 학술지의 최근 10년간 발표된 연구논문 2,165건에 대한 내용분석을 통해 현장연구의 현황 즉, 양적 변화, 주제, 연구자, 연구비 지원여부 등을 분석하였다. 연구결과, 전체 논문 중 현장연구는 691건으로 31.9%를 차지하는 것으로 조사되었다. 이들 현장연구의 주제를 도서관 유형별로 구분한 결과 공공도서관이 246편(35.6%)으로 가장 많았으며, 대학도서관이 238편(34.4%), 학교도서관 141편(20.4%), 그리고 기타 66편(9.6%)으로 조사되었다. 문헌정보학 관련 주제별로 구분한 결과는 도서관운영 관련 연구가 328편(47.5%)으로 가장 많았으며, 정보봉사, 정보시스템 및 전자도서관, 이용자교육, 독서교육 순으로 조사되었다. 저자별 구분의 경우 교수가 329편(47.6%)으로 가장 높게 조사되었으며, 사서, 교수/사서, 교수/학생, 강사 순으로 나타났다. 연구비지원 여부의 경우 대학으로부터 지원을 받는 경우가 145편으로 연구비 지원에 의해 수행된 논문 195편 중 74.4%로 절대적인 비중을 차지하였으며, 학술진흥재단 27편, 한국교육학술정보원 9편, 교육인적자원부 4편 순으로 조사되었다.

• Journal of electromagnetic engineering and science
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• 제12권1호
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• pp.115-121
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• 2012

This paper presents a scattering model and measurements of backscattering coefficients for soybean fields. The polarimetric radar backscatters of a soybean field were measured using the ground-based X-band polarimetric scatterometer in an angular range from $20^{\circ}$ to $60^{\circ}$. The backscattering coefficients were also obtained using the COSMO-SkyMed (Spotlight mode, HH-polarization) from July to October 2010. The backscattering coefficients of the soybean field were computed using the 1st-order radiative transfer model (RTM) with field-measured input parameters. The soybean layer is composed of the stems, branches, leaves, and soybean pods. The stems, branches, and pods are modeled with lossy dielectric cylinders, the leaves are modeled with lossy dielectric disks. The estimated backscattering coefficients agree quite well with the field-measured radar backscattering coefficients.

• Journal of Information Technology Applications and Management
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• 제19권4호
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• pp.153-169
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• 2012

In the rapidly changing field of Management Information Systems, the definition and educational programs must be continually reevaluated and revised. A study was conducted to find a way to which the modeling principle is applied for redefining the identity of Management Information Systems as an independent academic field and to develop a plausible MIS curriculum based on the modeling principle. Previous researches on the MIS frameworks, knowledge and technology requirements for IS professionals, and standard MIS curriculums were reviewed thoroughly. For this study, the Kantian cognitive model was adopted as a basis of modeling principle. The result shows that modeling ability has been the core competence of IS people in the field of MIS. The applicability of a modeling principle is also verified in establishing the identity of MIS and developing a normative MIS curriculum. For the MIS field to thrive as an independent academic field and research discipline, it is believed to be imperative for the discipline to have a unique educational goals distinguished from both other management areas, and sub-fields of computer science.

• 전자공학회논문지SC
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• 제47권1호
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• pp.42-46
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• 2010

정보보안을 위한 암호화는 종종 Galois Field 상에서 산술 연산의 형태로 이루어진다. 본 논문은 Galois Field 상에서 산술 정보의 지수 연산 처리를 효과적으로 수행하는 방법을 제안한다. 특히 기존의 비트별 병렬 처리 지수 연산기에서 게이트 카운트가 큰 요소를 제거하고, 시스템 상수를 효과적으로 사용하도록 개량함으로써, m 값이 큰 경우에도 고성능인 VLSI 시스템을 설계한다.

• Journal of information and communication convergence engineering
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• 제8권1호
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• pp.13-18
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• 2010

The composite stock cutting problem is defined as allocating rectangular and irregular patterns onto a large composite stock sheet of finite dimensions in such a way that the resulting scrap will be minimized. In this paper, we introduce a novel approach to hybrid optimization algorithm called MGA in MPI (Message Passing Interface) environments. The proposed MGA combines the benefit of rapid convergence property of Mean Field Annealing and the effective genetic operations. This paper also proposes the efficient data structures for pattern related information.

• 정보관리학회지
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• 제37권1호
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• pp.23-49
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• 2020

본 연구는 문헌정보학 정규교육과정에서 중점적으로 다뤄야 하는 정보조직분야의 주요 영역을 도출하고, 영역별 내용요소를 제안하였다. 이를 위해 문헌연구, 내용분석, 설문조사 및 전문가평가를 수행하였다. 이를 통해 정보조직분야를 정보조직일반, 분류, 목록, 실습이라는 4영역으로 구성하고, 총 31개의 영역별 내용요소를 제시하였다. 본 연구를 통해 영역별로 도출된 내용요소들은 정보조직분야 교과목에 대한 강의계획안이나 교수 요목을 설계할 때 도움이 될 수 있는 기초자료로 활용할 수 있다. 또한, 본 연구에서 사용한 연구방법을 적용하여 정보조직분야의 주요 영역별 내용요소를 확장할 수 있기 때문에, 정보조직분야 교육내용을 설계를 위한 기초자료로 활용될 수 있을 것이다.

• Agricultural and Biosystems Engineering
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• 제4권2호
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• pp.50-57
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• 2003

This study was conducted to develop software which provides automatic site-specific field data acquisition, data processing, data mapping and management for precision agriculture. The developed software supports acquisition and processing of both digital and analog data streams. The architecture was object-oriented and each component in the architecture was developed as a separate class. In precision agriculture research, the laborious task of manual ground-truth data collection will be avoided using the developed software. In addition, gathering high-density data eliminates the need for interpolation of values for un-sampled areas. This software shows good potential for expansion and compatibility for variable-rate-application (VRA). The FIM (Field Information Management) computer program provides the user with an easy-to-follow process for field information management for precision agriculture.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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• pp.280-284
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• 2004

안테나의 특성 중 지향성(Directivity)과 관계있는 방사 패턴을 측정하기 위한 저가의 근역장 측정 시스템을 설계한다. 근역장 측정방법은 평면주사법에 기반을 둔 개선된 원통형 주사법 공식을 이용한다. 고가의 측정 장비인 네트워크 분석기를 대체하기 위한 방법을 제시하고 필요한 장치 규격을 제안한다.