• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.907-910
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• 2005

Although several artificial disc designs have been developed for the treatment of discogenic low back pain, biomechanical change with its implantation was rarely studied. To evaluate the effect of artificial disc implantation on the biomechanics of functional spinal unit, nonlinear three-dimensional finite element model of L4-L5 was developed with 1-mm CT scan data. Two models implanted with artificial discs, SB $Charit\acute{e}$ or Prodisc, via anterior approach were also developed. The implanted model predictions were compared with that of intact model. Angular motion of vertebral body, force on spinal ligaments and facet joint, and the stress distribution of vertebral endplate for flexion-extension, lateral bending, and axial rotation with a compressive preload of 400 N were compared. The implanted model showed increased flexion-extension range of motion and increased force in the vertically oriented ligaments, such as ligamentum flavum, supraspinous ligament and interspinous ligament. The increase of facet contact force on extension were greater in implanted models. The incresed stress distribution on vertebral endplate for implanted cases indicated that additinal bone growth around vertebral body and this is matched well with clinical observation. With axial rotation moment, relatively less axial rotation were observed in SB $Charit\acute{e}$ model than in ProDisc model.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.277-285
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• 2010

This paper describes an approach to analyze geometrical information of building images for understanding outdoor environment of autonomous navigation robot. Line segments and color information are used to classily a building with the other objects such as sky, trees, and roads. The line segments and their two neighboring regions are extracted from detected edges in image. The model of line segment (MLS) consists of color information of neighbor regions. This model rules out the line segments of non-building face. A building face converges into dominant vanishing points (DVPs) which include one vertical point and one of five horizontal points in maximum. The intersection of vertical and horizontal lines creates a facet of building. The geometrical characteristics such as the center coordinates, area, aspect ratio and aligned coexistence are used for extracting the windows in the building facet. In experiments, 150 building faces and 1607 windows were detected from the database of outdoor environment. We found that this result shows 94.46% detection rate. These experimental images were all taken in Ulsan metropolitan city in Korea under difference of viewpoints, daytime, camera system and weather condition.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.2
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• pp.99-118
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• 2020

The purpose of this study is to suggest the faceted classification scheme as a new classification scheme for 1,136 records (1950-1979) collected from UNESCO which are related to Korea. After extracting 1,601 nouns from the titles and index terms of the 1,136 records, they were classified and categorized based on the temporarily set fundamental categories. Through repeated classification and categorization, the last category names were derived as facets. As a result, the faceted classification scheme for Korea related records are structured into 10 basic facets and 38 sub-facets.

• Korean Journal of Materials Research
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• v.31 no.7
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• pp.397-402
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• 2021

In this study, binderless-WC, WC-6 wt%Co, WC-6wt% 1 and 2.5 B₄C materials are fabricated by spark plasma sintering process (SPS process). Each fabricated WC material is almost completely dense, with a relative density up to 99.5 % after the simultaneous application of pressure of 60 MPa. The WC added Co and Co-B₄C materials resulted in crystalline growth. The WC with HCP crystal structure has respective interfacial energy (basal facet direction: 1.07 ~ 1.34 J·m^-2, prismatic direction: 1.43 ~ 3.02 J·m^-2) that depends on the grain growth direction. It is confirmed that the continuous grain growth, biased by the basal facet, which has relatively low energy, is promoted at the WC/Co interface. As abnormal grain growth takes place, the grain size increases more than twice from 0.37 to 0.8 um. It is found through analysis that the hardness property also greatly decreases from about 2661.4 to 1721.4 kg/mm², along with the grain growth.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.3
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• pp.145-152
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• 2020

In this study, we evaluated spinal stability based on the change in the thoracolumbar fixation segment using finite element analysis (FEA). To accomplish this, a finite element (FE) model of a normal thoracolumbar spine (T10-L4), including intervertebral discs (IVD), ligaments, and facet joints, was constructed, and the material properties reported in previous studies were implemented. However, L1 was assumed as the lesion site, and three types of posterior fixation, namely, L1-L2, T12-L2, and T12-L1-L2, were implemented in the thoracolumbar FE model. In addition, the loading conditions for flexion, extension, lateral bending, and axial rotation were adopted. Through the series FEA, the deformation, equivalent stress, range of motion, and moment on the pedicle screws, vertebrae, and IVD were calculated, and the spinal stability was evaluated based on the FEA results.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.11
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• pp.48-53
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• 1997

Volume hologram was recorded using reference beam form optical fiber taper. A singel mode fiber was chemically etced to make a taper structure, and we showed experimentally that the referencing by the irregular beam pattern from this taper structure could increase the storage density of photorefractive volume hologram. The spatial selectivity of the volume hologram with this method was increased by two times compared to the normal single mode fiber referencing case. A theoretical analysis with randomly phased plane model also confirmed the results.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.3
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• pp.45-57
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• 1995

We derive analytic expressions for the spontaneous emission spectrum of a device using DFB structures including the effects of both facet reflections and the phase of a grating. In solution of coupled mode equations. Equations for the reations between the spontaneous emission spectrum and structure parameters of the device are derived to investigate the effect of structure parameters on the spontaneous emission spectrum and operating characteristics of possibility of evaluating the structure parameters of the device from its spontaneous emission spectrum.

• Journal of Korean Library and Information Science Society
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• v.50 no.1
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• pp.273-291
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• 2019

This study aims to extend fundamental categories from Clause 11, "facet analysis" in International Standards for thesaurus(ISO 25964-1) by analyzing fundamental categories of Clause 11 and concept and their scope in a thesaurus of Clause 5. For to do this, the fundamental categories were established by adjusting partially and adding mental entities explicitly referencing the highest concepts(YAMATO which is the upper ontology of Mizoguchi, and ISO 2788) and existing fundamental categories(PMEST, FRBR group 3 entities, 13 categories in CRG). Also, established fundamental categories were reorganized and structured based on concreteness/abstraction of PMEST in Ranganathan and independence/dependence of YAMATO in Mizoguchi. And the upper categories were divided into independent and dependent entities. Under these entities 28 criteria are included in the independent ones and 2 criteria in the dependent ones. In the further study, the result of this study can be expected to reuse and refer as controlled vocabulary in the field like classification, taxonomies and thesauri where expected to utilize fundamental categories and as the high-level concept when constructing an ontology for information retrieval.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.423-430
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• 2001

The facts of job satisfaction and their perceived importance among elementary school foodservice dietitians were assessed. The survey instrument consisted of three parts: the job satisfaction survey was used to measure facets of job satisfaction and the level of total satisfaction; perceived importance questions for corresponding job facets; and demographic items. A survey of school food service operations was undertaken and detailed information was collected from 170 dietitians. The collected data were processed using the SPSS package program for descriptive analysis and analysis of valiance. School foodservice dietitians' importance and satisfactions scores on their job and working environment were 4.25 and 2.83, respectively. The respondents rated the subscales of 'communication' and 'nature of work' the highest and the subscales of 'pay' and 'working environment' the lowest The results of facet satisfaction scores and corresponding perceived importance scores were paired to be plotted on the Importance-Performance Analysis Grid. IPA grid was used to provide a strategy for food service managers to counteract dietitian dissatisfaction.

• Archives of design research
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• v.20 no.2 s.70
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• pp.117-128
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• 2007

Design management has become a critical facet of corporate management for leveraging strategic and competitive advantages. In order to identify the pattern and the development of design management studies, we investigated contents of the periodical journals published by Design Management Institute (DMI): the Design Management Review and the Academic Review. An in-depth analysis was performed on 64 themes, 722 articles, and 704 authors of these two journals between 1989 and 2005, and the primary research topics and authorship patterns were identified. Based on these findings, several directions for advancing design management studies were suggested.