• Journal of information and communication convergence engineering
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• v.19 no.4
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• pp.205-213
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• 2021

The properties of a scale-free network are little known; its node degree following a power-law distribution is among its few known properties. By selecting real-field scale-free networks from a network dataset and comparing them to other networks, such as random and non-scale-free networks, the topology characteristics of scale-free networks are identified. The assortative coefficient is identified as a key metric of a scale-free network. It is also identified that most scale-free networks have negative assortative coefficients. Traditional generation models of scale-free networks are evaluated based on the identified topology characteristics. Most representative models, such as BA and Holme&Kim, are not effective in generating real-field scale-free networks. A link-rewiring method is suggested that can control the assortative coefficient while preserving the node degree sequence. Our analysis reveals that it is possible to effectively reproduce the assortative coefficients of real-field scale-free networks through link-rewiring.

• Journal of information and communication convergence engineering
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• v.18 no.4
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• pp.245-253
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• 2020

The human body and nervous system transmit information through electric charges. After the electric charge transmits information to the brain, we can feel pain, numbness, comfort, and other feelings. Electric therapy is currently used widely in clinical practice because the field of examination is more representative of electrocardiogram, and in the field of treatment is more representative of electrotherapy. In this study, we design a system for neurophysiological therapy and conduct parameter calculation and model selection for the components of the system. The system is based on a discontinuous conduction mode (DCM) boost circuit, and controlled and regulated by a single-chip microcomputer. The system does not only have a low cost but also fully considers the safety of use, convenience of the human-computer interface, adjustment sensitivity, and waveform diversity in the design. In future, it will have strong implications in the field of electrotherapy.

• The KIPS Transactions:PartB
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• v.12B no.1 s.97
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• pp.57-68
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• 2005

It is important to segment a text, which is independent upon any text-embedded auxiliary information. This paper presents a technique for dividing the text into field-coherent passages. The presented method is based upon extracting field-associated terms from the text measuring how the topics grow, shrink and shift from sentence to sentence. We propose measures of topic continuity and of topic transition and suggest how those could be used to find the boundaries among passages. After collecting 12,500 documents, we obtain $88{\%}$ for average precision and $78{\%}$ for recall in Korean training set.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.263-272
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• 2017

To design a wide-field optical system, the inverted telephoto configuration, which has a negative front group and a positive rear group, is popular. For a two-mirror system, the inverse Cassegrain system has the inverted telephoto configuration, but the inverse Cassegrain system with the conventional, axially symmetric configuration shows severe field screening and ray obstruction. To avoid these problems, we put the aperture stop on the secondary mirror of an inverse Cassegrain system to increase field of view, and designed a wide-field off-axis two-mirror system which only uses the off-axis field, without ray obstruction.

• Journal of Korean Library and Information Science Society
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• v.42 no.2
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• pp.277-297
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• 2011

This study aims to develop the journal feedback program, based on the ways of writing journal and abstract, for applying it to the course of library field experience in the university, to apply this program to the course of library field experience, and to explore the effects of this program after applying it to the course of the library field experience for pre-librarians and pre-teacher librarians. The results of this study are like these: (1) The thinking level was increased after some feedbacks. (2) Journal feedback program was regarded to be necessary in the library field experience. (3) The program helped them to solve their problems in the course of the library field experience.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.445-450
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• 2016

This paper studied on the influence of naval vessel shape on vertical magnetic field after the vessel was demagnetized. The triangular shape, the rectangular shape and circular shape were adaped from vessel's structual drawings. Magneto-static FEM analysis was performed to obtain the iduced magnetic field due to earth magnetic field for those shapes. During demagnetization process, magnetic field of residual magnetization was observed. The holizontal and vertical magnetic field were calculated depending on vertical bias magnetic field through magnetc component seperation. To demagnetize naval vessel ship, demagnetizing coils shoud be wound more finely in the vow and stern of the ship than it should be in the mid-part of the ship.

• Journal of the Korean Society for Library and Information Science
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• v.42 no.2
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• pp.147-170
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• 2008

Evaluation of an academic library is a key to its success. Library and Information Policy Bureau of the President of the Republic of Korea conducted a trial evaluation on academic libraries with a university evaluation index developed by KERIS in 2005. The committee decided to review its feasibility based on the feedbacks from the academic libraries after the trial. This study aims to address the indexing issues appeared during the trial and suggest a new evaluation index tailored to academic libraries. First, the evaluation field is condensed from 7 to 6 as "financing" and "infrastructure" are integrated into "budget and infrastructure." Secondly, both "user charter" and "planning" are removed from the "library management" field category. and "library self-assessment" is added instead. In "information resource" field, "non-books and etc." is added. Third, evaluation categories for "budget and infrastructure" field are altered to budget-related items and library equipment. Forth, "collection turnover rate" category is incorporated into "collection usage" in "information usage" field, and "library use rate" in "information service" field is moved to "information resource" field and renamed as "use rate."

• ETRI Journal
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• v.40 no.2
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• pp.237-245
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• 2018

The Distributed Modulated Wideband Converter (DMWC) is a networking system developed from the Modulated Wideband Converter, which converts all sampling channels into sensing nodes with number variables to implement signal undersampling. When the number of sparse subbands changes, the number of nodes can be adjusted flexibly to improve the reconstruction rate. Owing to the different attenuations of distributed nodes in different locations, it is worthwhile to find out how to select the optimal sensing node as the sampling channel. This paper proposes the spectrum sensing of DMWC based on a Markov random field (MRF) to select the ideal node, which is compared to the image edge segmentation. The attenuation of the candidate nodes is estimated based on the attenuation of the neighboring nodes that have participated in the DMWC system. Theoretical analysis and numerical simulations show that neighboring attenuation plays an important role in determining the node selection, and selecting the node using MRF can avoid serious transmission attenuation. Furthermore, DMWC can greatly improve recovery performance by using a Markov random field compared with random selection.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2158-2167
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• 2018

This paper analyzed the magnetic field produced by the cylindrical stator coils of permanent magnet spherical motor (PMSM). The elliptic equations about the vector magnetic potential were given. Given that the eddy current effects are neglected, the magnet field of the PMSM is regarded as irrotational field, which can be calculated by scalar magnetic potential. The current density of cylindrical stator coil was proposed based on the definition of current density. The expression of current density of stator coil was obtained according to the double Fourier series decomposition and spherical harmonic functions. Then the magnetic flux density for scalar magnetic potential was derived. Further, the influence of different parameters on radial flux density was also analyzed. Finally, the results by the analytical method in this paper were validated by finite element analysis (FEA).

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.309-312
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• 2002

Triode field emitters with planar-carbon-nanopaticle (CNP) cathodes were successfully fabricated using the conventional photolithography and the hotfilament chemical vapor deposition. Electron emission from a CNP triode emitter with a 12-${\mu}m$-diameter gate hole started at the gate voltage of 45 V, and the anode current reached the level of ${\sim}120$ nA at the gate voltage of 60 V, respectively. For the quantitative analysis of the Fowler-Nordheim (F-N) type emission from a CNP triode emitter, we carried out 2dimensional numerical calculation of electrostatic potential using the finite element method. As it turned out, a radial variation of electric field was very important to account for the emission from a planar emitting layer. By assuming the graphitic work function of 5 eV for CNPs, we were able to extract a consistent set of F-N parameters, together with the radial position of emitting sites.