• Structural Engineering and Mechanics
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• v.85 no.2
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• pp.233-246
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• 2023

Bending and buckling analysis of multi-directional porous functionally graded sandwich plate has been performed for two cases namely: FG skin with homogeneous core and FG core with homogeneous skin. The principle of virtual displacements was employed and the solution was obtained using Navier's technique. This theory imposes traction-free boundary conditions on the surfaces and does not require shear correction factors. The validation of the present study has been performed with those available in the literature. The composition of metal-ceramic-based FGM changes in longitudinal and transverse directions according to the power law. Different porosity laws, such as uniform distribution, unevenly and logarithmically uneven distributions were used to mimic the imperfections in the functionally graded material that were introduced during the fabrication process. Several sandwich plates schemes were studied based on the plate's symmetry and the thickness of each layer. The effects of grading parameters and porosity laws on the bending and buckling of sandwich plates were examined.

• Steel and Composite Structures
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• v.46 no.2
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• pp.263-277
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• 2023

Free vibration analysis of multi-directional porous functionally graded (FG) sandwich plate has been performed for two cases namely: FG skin with homogeneous core and FG core with homogeneous skin. Hamilton's principle was employed and the solution was obtained using Navier's technique. This theory imposes traction-free boundary conditions on the surfaces and does not require shear correction factors. The results obtained are validated with those available in the literature. The composition of metal-ceramic-based functionally graded material (FGM) changes in longitudinal and transverse directions according to the power law. Imperfections in the functionally graded material introduced during the fabrication process were modeled with different porosity laws such as evenly, unevenly distributed, and logarithmic uneven distributions. The effect of porosity laws and geometry parameters on the natural frequency was investigated. On comparing the natural frequency of two cases for perfect and imperfect sandwich plates a reverse trend in natural frequency result was seen. The finding shows a multidirectional functionally graded structures perform better compared to uni-directional gradation. Hence, critical grading parameters and imperfection types have been identified which will guide experimentalists and researchers in selecting fabrication routes for improving the performance of such structures.

• Dementia and Neurocognitive Disorders
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• v.22 no.1
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• pp.1-15
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• 2023

The Seoul Neuropsychological Screening Battery (SNSB) is known as a representative comprehensive neuropsychological evaluation tool in Korea since its first standardization in 2003. It was the main neuropsychological evaluation tool in the Clinical Research Center for Dementia of South Korea, a large-scale multi-center cohort study in Korea that was started in 2005. Since then, it has been widely used by dementia clinicians, and further solidified its status as a representative dementia evaluation tool in Korea. Many research results related to the SNSB have been used as a basis for the diagnosis and evaluation of patients in various clinical settings, especially, in many areas of cognitive assessment, including dementia evaluation. The SNSB version that was updated in 2012 provides psychometrically improved norms and indicators through a model-based standardization procedure based on a theoretical probability distribution in the norm's development. By providing a score for each cognitive domain, it is easier to compare cognitive abilities between domains and to identify changes in cognitive domain functions over time. Through the development of the SNSB-Core, a short form composed of core tests, which also give a composite score was provided. The SNSB is a useful test battery that provides key information on the evaluation of early cognitive decline, analysis of cognitive decline patterns, judging the severity of dementia, and differential diagnosis of dementia. This review will provide a broad understanding of the SNSB by describing the test composition, contents of individual subtests, characteristics of standardization, analysis of the changed standard score, and related studies.

• Polymer(Korea)
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• v.31 no.2
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• pp.168-176
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• 2007

The sub-micron particles of poly ($\gamma-glutamic$ acid) (PGA) containing lysozyme have been prepared using supercritical antisolvent (SAS) precipitation process at various experimental conditions such as pressure, temperature, inner diameter of nozzle, and concentration. As overall results of the application of SAS process to this system, the smaller size powder has been produced as (i) increasing pressure, (ii) decreasing temperature, (iii) decreasing the inner diameter of nozzle, and (iv) decreasing the concentration of PGA and lysozyme. It is found by means of FT-IR analysis that during SAS process, the composition has changed from the original composition of PGA : lysozyme=50 : 50 into PGA : lysozyme=33 : 67 at final product powder. It means that PGA has higher solubility for the mixed solvent of carbon dioxide and dimethyl sulfoxide (DMSO). Due to such difference of solubility, this particle forms the core-shell structure of which the core consists mainly of lysozyme. It is also found that the residual DMSO amount of $7.8\times10^{-3}wt%$ exists inside the powder.

• Journal of Korean Home Economics Education Association
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• v.34 no.2
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• pp.1-19
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• 2022

The purpose of this study is to analyze the keywords of the middle school textbooks based on the 2015 revision of the technology and home economics curriculum to understand the core concepts and contents composition of the 'housing' unit. Using TEXTOM and UCINET programs, the frequencies and centralities of the keywords were analyzed, and CONCOR analysis was performed. The results are as follows. First, the content system of the 'housing' unit is divided into 'life culture' and 'safety' in the 'family life and safety' area. Second, in the 'safety' section, the frequencies of occurrence of the words were high in the order of indoor, occurrence, use, noise, and safety accidents, in the order of frequency of occurrence. It was confirmed that words related to daily life, safety accidents, and prevention were closely connected to each other. In the 'life culture' section, the frequencies of occurrence were high in the order of space, housing, family, and residential space, and the correlations between these keywords were also high. Third, the most influential core keywords were, indoor and occurrence in the 'safety' section, and space, family, and housing, in the 'life culture' section. Fourth, the 'safety' section were divided into two subunits, 'safe living environment' and 'comfortable living environment', and the 'life culture' section were divided into four subunits, 'living space composition', 'space utilization', 'housing value and lifestyle', and 'housing culture'.

• Journal of the Korean Regional Science Association
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• v.9 no.1
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• pp.3-23
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• 1993

In this paper the prevailing geography of the information sector, fousing on its occupatonal dimension, is examined. The purposes of this paper are to analyze the labor force share of information occupation workers at each special city and region, to compare the inter-regional distribution of information workforce and to analyze regional share of information occupations in manufacturing industry. Spatial pattern of size and occupational composition of information sector shows a core-periphery disparity. There is a clear evidence of Seoul's dominance of the information economy, particularly such as scientific and technical, consultative services, management and process control function. Also the distribution of information workers in manufacturing industry over space was polarized than is the case for total manufacturing employment and noninformation workers. Therefore Korean information economy is marked by a highly articulated spatial division of labor within individual industry, which can be attributed to the locational characteristics of information intensive industries and industrial composition of regional economy. From the results of this study, information employment prospects among regions of Korea would reinforce the unequal geography of job opportunity. In this light, regional policy efforts should be given to the improvement of information infrastructure to facilitate new computer-based service products and process in peripheral regions.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.299-310
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• 2004

Business process in e-government mostly embody as the flow of documents. Constructing a web-based document flow system becomes an critical task for today s digital government. But few of them use an off-the-shelf workflow product. Why? One of the reasons is that most of the workflow system are heavyweight, monolithic, and package a comprehensive set of features in an all-or-nothing manner. Another reason is that workflow technology lacks the constructs and modeling capability as programming language. It is incumbent on government IT organizations to transform their solution development to component-based computing model. Component technology isolates the computation and communication parts, but how to compose different software components is still a hard nut. An integrated development environment is necessary for CBSD. In this paper we propose a XML and component-based document flow-oriented integrated development environment (DFoIDE) for software developers. By writing some xml configure file, and operate on DFoIDE, developer can construct a workflow application quickly. This method divides system to several components and the activities in process are implemented as business component. Different components are discribed detailedly in this paper, especially one of the core component. Component Integrating Tool. Different perspectives in workflow application are seperated and depicted as different XML files. Correspondly, A component composition method for developing workflow application instead of workflow itself is proposed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.596-606
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• 1998

Thermophysical properties and the compressive strength of concrete used in nuclear power plants in Korea were measured. The chemical composition of the concrete was also analyzed. The measured thermophysical properties include the density, the thermal conductivity, the thermal diffusivity and the specific heat for a wide temperature range of 20.deg. C to 1100.deg. C. The chemical composition of Korean concrete is similar to that of US basaltic concrete and the thermophysical properties are strongly temperature dependent. The density, the conductivity and the diffusivity decrease with an increase in temperature, and particularly the conductivity and the diffusivity are a 50-perdent decrease at 900.deg. C as compared with these values at room temperature. The specific heat increases until 500.deg. C, decreases from 700.deg. C to 900 .deg. C, and then increases again when temperature is above 900.deg. C. The measurement beyond 1100.deg. C is not acceptably accurate because the concrete decomposes to a liquid phase from a solid phase at that temperature. The results of this study can be applied, for example, to an analysis of the molten core-concrete interaction (MCCI) phenomenon of concrete structures at high temperature will also require those property data, especially for high temperature ranges.

• Transactions on Electrical and Electronic Materials
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• v.12 no.5
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• pp.218-221
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• 2011

We modified the optical properties of the $CuInS_2$ nanocrystal (NC) by alloying. Nanocrystals (NCs) with alloyed cores were synthesized by refluxing the as-synthesized $CuInS_2$ NCs with a mixture of cadmium acetate, zinc acetate and palmitic acid. The shift in emission wavelength of the NCs after shell layer formation was minimized by alloying. The photoluminescence (PL) spectra showed significant reduction of emission intensity. A detailed study on the emission process of NCs implies that the formation of shell layers with small lattice mismatch minimized the mismatch strain generated from the shell layers in contrast to core alloyed NCs. In particular, time-resolved PL spectra of the NCs showed a significant increase in the lifetime of excited carriers by modifying the band alignment of the NCs by modifying the shell composition.

• Korean Institute of Interior Design Journal
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• v.18 no.2
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• pp.33-40
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• 2009

Reflecting the idea of benevolent royal government of King Jeongjo(鼎俎), the Buyongji(芙蓉池) and Juhamru(宙合樓) of Changdeokgung(昌德宮) are the traditional Korean architecture to represent the Joseon(朝鮮) period. The purposes of this study were to investigate how the Likiron(理氣論), one of the foremost theories of Joseon Confucianism, was applied to the principle of space composition by analyzing Buyongji and Juhamru with Jung's analytical psychology and to provide basic data to utilize the results in modem space planning. The research findings indicate that Buyongji is the space of Ki(氣) to reflect the reality, corresponds to conscious, and represents the Joseon land and people including Chiljeong(七情) And Juhamru is the space of Li(理) with the ideal of benevolent royal government inherited in it and represents unconscious. It also has each building placed which contained the nature of Sadan(四端) along with Gyujanggak and Jewolgwangpunggwak(齊月光風觀) to represent "Self Archetype" that's the core of human mind. Each representing Ki and Li, Buyongji and Juhamru must have worked as a major composition principle of Likilwonronjeokilwonron(理氣二元論的一元論) that could simultaneously satisfy the practice philosophy of reality and ideal among Likiron.