• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.114-122
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• 1995

In this paper a computational method is presented to solve the plane problem of wave propagation in linear-elastic plate with zones of different materials. An existing numerical scheme of bicharacteristics for rectangular plate is extended to plates with curvilinear boundaries. In order to show the validity of the employed concept, it is necessary to examine the numerical results whether they reproduce the well-known physical phenomena of stress waves. It seems also desirable to make a comparison between the numerical results and appropriate experimental results for plates with curvilinear boundaries. Also studied are the focusing phenomena induced by reflection and refraction at curved outer boundaries and material interfaces.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.150-156
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• 2023

In a recent study, the phenomena of attention being drawn to the media business, particularly over-the-top (OTT) services, was the focus. Particularly, after the Squid Game was broadcast in September 2021, the total number of Netflix users had topped 213.6 million since the company first entered the domestic market. Domestic companies have also introduced OTT services like 'Wave', 'Tving', and 'Watcha Play' to capitalize on this market trend. However, questions persist about how Korea's native OTT providers, both large and small, are being harmed by Netflix's strong financial position and massive content quantity. In order to offer realistic performance metrics, we analyze Coupang Play among domestic OTT service providers after reviewing the business model and management strategy of representative OTT service firms.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.13-29
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• 2022

Nonalcoholic fatty liver disease, characterized by excessive accumulation of fat in the liver, is the most common chronic liver disease worldwide. The current standard for the detection of hepatic steatosis is liver biopsy; however, it is limited by invasiveness and sampling errors. Accordingly, MR spectroscopy and proton density fat fraction obtained with MRI have been accepted as non-invasive modalities for quantifying hepatic steatosis. Recently, various quantitative ultrasonography techniques have been developed and validated for the quantification of hepatic steatosis. These techniques measure various acoustic parameters, including attenuation coefficient, backscatter coefficient and speckle statistics, speed of sound, and shear wave elastography metrics. In this article, we introduce several representative quantitative ultrasonography techniques and their diagnostic value for the detection of hepatic steatosis.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.308-320
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• 2021

An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

• Korean Journal of Social Welfare Studies
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• v.44 no.2
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• pp.169-199
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• 2013

This study has a purpose to analyze trajectories of life satisfaction of the elderly after their retirement and how the characteristics of individual, retirement and family relationship have an effect on the life satisfaction. This study has investigated the Korean elderly, who had been retired, using the data from three waves(1st wave(2005)~3rd wave(2009) of the Korean Retirement and Income Panel(KReIS). Data analysis has been used to identify the predictors of the intercept and slope related to the life satisfaction after retirement, focusing the trajectories of the life satisfaction after retirement and individual characteristics, retirement characteristics and family relationship with application of the growth curve model by Amos 20.0. First, the intercept of the life satisfaction after retirement was somewhat below average. Life satisfaction averagely increased little by little from 1st wave to 3rd wave. Second, by conducting the conditional growth curve model, the study revealed that the intercept of the life satisfaction after retirement is high on individual characteristics(sex, educational level, income, health status) and in retirement characteristics(voluntary retirement) and satisfaction with family relationship and married life). Furthermore, health status, voluntary retirement, and satisfaction with family relationship asserted the meaningful variables in the slope of life satisfaction after retirement.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.1
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• pp.11-19
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• 2013

The aim of this study is to analyze the research trend focusing on Yangseng(養生) studies in Korea. Through this study, the researchers attempt to explore the research trends of the Yangseng(養生) in Traditional Korean Medicine. Yangseng(養生) as a key word was searched on representative domestic databases of articles and the researchers and collected the articles of journals published from 1980 to 2012. Finally 350 articles of Yangseng(養生) were selected. After mid-2000s, Yangseng(養生) studies has been increased with the great interest in quality of life. Taoism and Traditional Korean Medicine were closely related with Yangseng(養生). Most of the Yangseng(養生) Studies in Medicine have been carried out by Traditional Korean Medicine and primarily focused in the literature. Yangseng(養生) has been defined as a sort of health-promoting behaviors. Therefore, Yangseng(養生) studies that mainly analyzed the variables associated with health-related quality of life and Yangseng(養生) and the main subjects were elderly and workers in this study. But every measuring instrument except Yangseng(養生) was adapted from western tools. In order to handle the new wave of society and medicine, new health concept and measuring instrument of Traditional Korean Medicine should be developed through Korean unique ideas of Yangseng(養生).

• Journal of the Korea Fashion and Costume Design Association
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• v.8 no.1
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• pp.155-168
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• 2006

The purpose of this study focusing on the gather decorations shown in the modern fashion was to review needlework techniques and design features of gather decorations and thereupon, analyze the aesthetic characteristics of gather decorations shown in designers' works to examine the gather decoration trend in today's fashion. First, the decorative features of gather decorations different from the conventional costumes are shirring, lace and trimming combined or shirring repeated. Second, in view of sensualism, the gather decorations seem to play a role of enhancing the exposure as a mode of expression, while the indirect exposure or beach is mixed with the materials to widen the range of gather decoration expressions. Third, in terms of history, the conventional decorative techniques are combined with new techniques and materials to create a fantastic and romantic mood different from the conventional costumes. Fourth, in view of rhythms, the wave line of the rim for gather decorations serves to express some vivid effects; on the human body, its monotonous plane repetition will turn into a new expression or a voluminous physical sense of motion. However, since expressions or meanings of the gather decorations are much diversified, they should not be regarded as simple decoration details. Our modern designers searching for new expression of creases use unique structural forms to explore the possibility of creative gather decorations. In all, since gather decorations seem to be significant as unique details conducive to a structural pragmatism and aesthetics, it is deemed necessary to continue to develop gather decorations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1378-1388
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• 2005

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

• Korean Journal of Child Education & Care
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• v.18 no.1
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• pp.53-76
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• 2018

The purpose of this study was to investigate the effect of child care type on infant's developmental outcomes assessed by K-ASQ, focusing on the child-centric role of nurture policy. For this, this study categorized child care type into types including home nurturing, child care center, and subtypes of each category. The findings of multiple regression analysis using the first-third wave data of Panel Study of Korean Children(PSKC) are as follows. First, the child care center experience had rather positive effect on the development of all abilities in the infants comparing to home nurturing. Second, the time of attending child care center was differently related to the development of motor, communication, and personal-social skill in infanthood. Finally, the accreditation of child care showed a difference only in terms of social development of infants. In conclusion, even if the experience of using child care center has positive impact on infant's developmental level, it is still in need of improving service quality such as reinforcing accreditation system.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.443-454
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• 2018

The purpose of this convergence study was to evaluate and to identify predictors of health-related quality of life(HRQoL) of families with cancer survivor(FCS) focusing on the comparison of families with cancer patient(FCP) receiving treatments. The research was conducted with the data for 153 FCS and 115 FCP taken from the 6th wave of the Korea National Health and Nutrition Examination Survey. The independent variables included socio-demographic, health related, psychological and social factors. The data were analyzed by hierarchical multiple regression analysis using SPSS/WIN 18.0. The results showed different patterns of predictors on the HRQoL of FCS and FCP. In FCS, the statistically significant factors were stress(${\beta}=-.192$, p<.05) and exclusion from economic activities(${\beta}=-.191$, p<.05). Therefore, families of cancer patients also need appropriate interventions for each stage of the disease.