• Journal of Families and Better Life
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• v.5 no.2
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• pp.83-97
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• 1987

The objected of this study were to investigate how social class system influences family life, especially, marital relationship through area of marital satisfaction and marital stability and to find out influences of variables related to marital stability, that is, marital satisfaction, marital alternatives and barriers to marital breakup. The study was performed in a viewpoint of social exchange approach. Major findings were as follows; First, husbands and wive's marital satisfaction and marital stability differed significantly by their level of SES. The marital satisfaction scores and the marital stability score of higher class were higher than those of lower class. second, the higher the marital satisfaction scores and the barriers to marital breakup scores were, the higher the marital stability scores were. And the higher the marital alternatives scores were, the loser the marital stability scores were. Third, the independent influences of variables related to marital stability were differed by level of SES. The last, the typology of marital satisfaction and marital stability differed by level of SES. In lower class, the marriage type of low satisfaction and low stability is more than other types. But in middle and upper class, the most marriage type is high satisfaction and high stability marriage.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.168-175
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• 1990

Pasquill stability class (PSC) was evaluated with Monin-Obukhov length (L) using the data observed at a height of 213m meteorological tower in Tsukuba, Japan. PSC was determined with wind speed and insolation (net radiation at night), and L was calculated with the heat flux and the friction velocity obtained at 25m by the eddy correlation method. To evaluate PSC with L, for every class of Pasquill stability (from A to F class), percentiles and median of L were used. Results show that for every class of Pasquill stability, L varies so widely that PSC does not adequately represent the atmospheric stability conditions. The scheme which estimates L using air temperature at two levels and wind speed at single level was developed. Comparison between estimated L by the scheme and observed L reveals that the scheme is better than PSC. Furthermore, the scheme is more advantageous than PSC because it uses air temperature at two levels instead of insolation which is more difficult to observe in the field than air temperature.

• Bulletin of the Korean Mathematical Society
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• v.40 no.2
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• pp.243-251
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• 2003

This note Presents sufficient conditions for Lyapunov's stability and instability of a class of nonlinear nonautonomous second-order ordinary differential equations. Such a class includes as particular cases a remarkably large number of differential equations with specific physical applications. Two successive nonlinear transformations are applied to the original differential equation in order to convert it into a more convenient form for stability analysis purposes. The obtained stability / instability conditions depend closely on the parameterization of the original differential equation.

• Communications of the Korean Mathematical Society
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• v.13 no.3
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• pp.525-538
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• 1998

Recently, a stability theorem for the Feynman integral as a bounded linear operator on$ L_2$($R^{d}$ /) with respect to measures whose positive and negative variations are in the generalized Kato class was proved. We study a stability theorem for the Feynman integral with respect to measures whose positive variations are in the class of $\sigma$-finite smooth measures and negative variations are in the generalized Kato class. This extends the recent result in the sense that the class of $\sigma$-finite smooth measures properly contains the generalized Kato class.

• The Journal of the Korean dental association
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• v.50 no.2
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• pp.64-71
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• 2012

Recently, the presurgical orthodontic duration tends to be shortened by virtue of the advancement of surgical and orthodontic techniques in class III orthognathic surgery cases. But the predictability of the surgical results should be secured by removing several uncertain factors in presurgical orthodontic treatment. The purpose of this study is to investigate the influence of immediate postsurgical occlusal stability on postsurgical mandibular change. The study includes 40 patients who underwent orthognathic surgery to correct skeletal class III malocclusion. The patients were divided into two groups based on the numbers of occlusal contact in surgical setup occlusion: group 1 (stable surgical occlusion, n=24) and group 2(unstable surgical occlusion, n=16). Changes of horizontal and vertical mandibular measurements during postsurgical follow up period(from 1 week postsurgery to 12month after debonding) were compared to examine the differences between two groups. The stability of surgical occlusion is one of the factors influencing postsurgical mandibular changes in class III malocclusion. The various class III malocclusion cases have specific prerequisites for the orthognathic surgery according to the skeletal patterns. The prerequisites should be obtained by minimum presurgical orthodontics to increase the predictability of the surgical results.

• Journal of Fashion Business
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• v.24 no.6
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• pp.135-147
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• 2020

This study explored students' online fashion studio class experiences, and investigated the factors affecting their class satisfaction. An online survey of college students who were enrolled in online studio classes within apparel and fashion-related departments during the spring of 2020 was conducted in June 2020. Responses from a total of 213 participants were included in the final data. Respondents rated lecture clips as the most useful, followed by teacher demonstration and feedback, PowerPoint (PPT) supplements, and Q&As. Frequently mentioned areas of improvement were online platform stability and video quality. Many respondents also stated that more streamlined teacher-student communication channels, immediate and meticulous teacher feedback, the adoption of course contents developed specifically for an online environment, and provisions for equipment usage would be desirable. Student satisfaction of an online fashion design studio class was significantly affected by teaching presence, social presence, online learning system stability, perceived usefulness of teacher's demonstration, and affective response toward COVID-19. Students satisfaction of an online garment construction studio class was significantly affected by teaching and social presence, online learning system stability, and perceived usefulness of teacher's demonstration. Based on these findings, we recommend developing teaching contents and methods that allow students to feel included in class and establish an online system with various functions to enhance the sense of social connection that can enable two-way communication.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.851-864
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• 2017

The problems of global and local exponential stability analysis of a class of nonlinear non-autonomous difference equations in Banach spaces are studied in this paper. By a novel comparison technique, new explicit exponential stability conditions are derived. Numerical examples are given to illustrate the effectiveness of the obtained results.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.22 no.4
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• pp.253-287
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• 2018

This paper studies the global stability of a class of discrete-time pathogen infection models with latently infected cells. The rate of pathogens infect the susceptible cells is taken as bilinear, saturation and general. The continuous-time models are discretized by using nonstandard finite difference scheme. The basic and global properties of the models are established. The global stability analysis of the equilibria is performed using Lyapunov method. The theoretical results are illustrated by numerical simulations.

• The Journal of the Korean dental association
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• v.57 no.6
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• pp.344-351
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• 2019

Skeletal Class III malocclusion is a relatively common form of malocclusion in Korea. In borderline cases where only mild skeletal discrepancy exists and if worsening of the facial profile is expected as a result of premolar extraction, mandibular full arch distalization with miniscrews is the treatment of choice. The purpose of this study was to investigate the pattern of tooth movement and evaluate the stability of mandibular full arch distalization and to identify correlation between stability and factors such as initial skeletal pattern, dental changes during treatment and alveolar bone in symphysis region using lateral cephalograms.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.1
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• pp.123-132
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• 2014

In this paper, we investigate the following form of a certain class of quadratic functional equations and its fuzzy stability. $$f(kx+y)+f(kx-y)=f(x+y)+f(x-y)-2(1-k^2)f(x)$$ where k is a fixed rational number with $k{\neq}1$, -1, 0.