• 대한가정학회지
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• 제37권9호
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• pp.39-56
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• 1999

Households have experienced economic instability since Korea economic crisis in 1997. This study attempts to explore the financial management behavior by the types of economic instability classified considering the two aspects of the employment and the income instability of the households. The specific objectives of this study are : 1) to classify households’economic instability in terms of employment and income instability. 2) to examine whether the financial management behavior is different between households experiencing the different types of the economic instability. The sample consisted of 792 married women living in Seoul. The statistical methods used for analysis included Reliability, Frequencies, Percent, Mean, Standard Deviation, Analysis of Covariance, one-way Anova, DMR-test. The major results can be summarized as following : 1) The economic instability experienced by houeholds can be classified into the 4 types employment-income instability, employment instability income stability, employment stability$.$income instability, and employment$.$income stability. 2) There are statistically significant differences in the levels of financial management behavior between households having the different types of economoc instability. The results of this study could be needed for development of the employment policies and the financial education programs.

• 가정과삶의질연구
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• 제25권1호
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• pp.45-58
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• 2007

This study explored the impact of couple interaction behaviors on the relationship between economic stress and marital instability. The study results showed that economic satisfaction and economic pressure greatly influenced the marital instability of married males and females. However, the interaction behaviors of couples tended to have a stronger impact on marital instability than economic stress. In other words, perceived spouse support and perceived spouse hostility had a significant impact on marital instability, with perceived spouse hostility being the more damaging of the two. The study also showed that there were sender differences regarding the impact of couple interaction behaviors on marital instability and economic stress. For married males, economic satisfaction as well as couple interactions influenced significantly on their marital instability. For females the impact of couple interactions on their marital instability tended to be more salient. On the whole, the results of the interaction effects between economic stress and couple interaction behaviors on marital instability did not appear significant, except in the case of females' perceived spouse hostility and its effect on marital instability.

• 대한족부족관절학회지
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• 제6권2호
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• pp.251-255
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• 2002

Purpose: Chronic subtalar instability is not common and similar to chronic ankle instability and the incidence and cause chronic subtalar instability are not well known. Recently we have experienced chronic subtalar instability without chronic ankle instability which was treated with modified Brostrom procedures. Materials and Methods: The patient is 46 year old man who has suffered from left ankle sprain for 30 years and recently aggravated more than twice a day. On subtalar stress view, 14 degree angulation of subtalar joint was noted and on anterior drawer view, 8 mm anterior displacement of left ankle was seen. Results: In operation, there was no anterior talofibular ligament abnormility but calcaneofibular ligament loosening was found. Ligament reconstruction was performed using modified Brostrom procedure. At 12 months after operation, the patient complains no pain and no limit of motion and no instability. Conclusion: We experienced chronic subtalar instability without ankle instability treated with modified Brostrom procedures. No instability was found after treatment without complication.

• 한국전문물리치료학회지
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• 제15권4호
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• pp.18-26
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• 2008

The present study was aimed at investigating the postural control ability of volleyball players with functional ankle instability. The subjects were 26 male volleyball players were divided into 2 groups (13 subjects with functional ankle instability and 13 subjects with ankle stability) who could evaluate Questionnaire. All the male participants were tested by a Balance Master System. This study were to measure of static balance ability, dynamic balance ability, motor function the difference between functional ankle instability group and control group. Ankle instability group and stable group in postural sway ($^{\circ}/sec$) on film surface with eye closed in modified clinical test sensory interaction on balance, and left unilateral stance with eye opened and closed were significantly different (p<.05). The ankle instability group and stable group in limit of stability were significantly different (p<.05). The ankle instability group and stable group in left/right rhythmic weight shirt were significantly different (p<.05). The ankle instability group and stable group in turn time (sec) & turn sway ($^{\circ}$) during step/quick turn and end sway ($^{\circ}/sec$) in tandem walk were significantly different (p<.05). This study showed that volleyball players with functional ankle in stability were effected postural control ability by static balance & dynamic balance ability. Further study is needed to measure various athletic with functional ankle instability for clinical application.

• 천문학회보
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• 제39권2호
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• pp.78.1-78.1
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• 2014

An ionization front (IF) surrounding an H II region is a sharp interface through which a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central massive stars. We investigate the structure and instability of a plane-parallel D-type IF threaded by magnetic fields parallel to the front. We find that magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor, defined as the density ratio of neutral to ionized phases. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow speed. The IF instability is stabilized by gas compressibility and becomes completely quenched when the front is D-critical. The instability is also stabilized by magnetic pressure when the perturbations propagate in the direction perpendicular to the fields. When the perturbations propagate in the direction parallel to the fields, on the other hand, it is magnetic tension that reduces the growth rate, completely suppressing the instability when ${\beta}$ < 1.5, with ${\beta}$ denoting the square of the ratio of the sound speed to the Alfven speed in the pre-IF region. When the front experiences an acceleration, the IF instability cooperates with the Rayleigh-Taylor instability to make the front more unstable. We discuss potential effects of IF instability on the evolution and dynamics of IFs in the interstellar medium.

• 대한전기학회논문지:전력기술부문A
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• 제52권6호
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• pp.295-300
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• 2003

Voltage instability has been studied for some decade now. But, There is not generally accepted definition of voltage instability because of the complex phenomenon and the variety of ways in which it can manifest itself. Both IEEE and CIGRE have the respective definitions. The areas of voltage instability research are the analysis, simulation and countermeasure of voltage instability. It needs to model the components of the power system to simulate the voltage instability and voltage collapse. At the beginning, the static simulation was used. This method provides the voltage stability indices and it requires less CPU resource and gives much insight into the voltage and power problem. However, it is less accurate than the dynamic simulation peformed in the time domain simulation. So, when it appears difficult to secure the voltage stability margin in a static stability, it is necessary to perform the dynamic simulation. To perform time-domain simulation, we have to model the dynamic component of the power system like a generator and a load. The dynamic simulation provides the accurate result of the voltage instability. But, it is not able to provide the sensitivity information or the degree of stability and it is time consuming and it needs much CPU resource. In this Paper, we perform a dynamic simulation of voltage instability and voltage collapse using EMTP MODELS. The exponential load model is designed with MODEIS and this load model is connected with test power system. The result shows the process of voltage change in time domain when the voltage instability or voltage collapse occurs.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.335-341
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• 1997

The generic analysis method for core flow instability is suggested to confirm that the core flow instability would not occur on PWR conditions. For the confirmation, the stability criteria of each fuel type are provided. Instability investigations in various accident conditions prove that the locked rotor accident is the most limiting case to instability. Parametric Effects are surveyed and in good agreement with available studies. The effects of heat flux distribution become negligible as the subcooling number is decreased. The power margin to instability is calculated quantitatively in various accident conditions.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.77-78
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• 2012

To predict combustion instability in actual full-scale combustion chamber of rocket engines, air-injection test is proposed with scaling techniques. From the data, damping factors have been obtained as a function of hydraulic parameter and the data give us instability map. Two instability regions are presented and it is found that they coincide reasonably with them from hot-fire test with full-scale flow rates. Accordingly, the proposed approach can be applied cost-effectively to stability rating of jet injectors when mixing of fuel and oxidizer jets is the dominant process in instability triggering.

• 대한가정학회지
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• 제40권9호
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• pp.17-33
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• 2002

This study was to investigate the relationships of personal resources, individual psychological variables, and relational characteristics with marital instability of wives who experienced physical and/or psychological abuse from their husbands, and to analyze the relative significance of related variables on marital instability. Self-administered questionnaire method was used to collect data from 500 wives residing in Chonbuk-do province, and data from 306 wives who reported to be psychologically and/or physically abused during last three years were used in the final analyses. Results showed that there were significant differences in the levels of marital instability according to wives' employment status, number of children, and occupational status of husbands. Correlational analyses indicated that wives' economic dependence, all individual psychological variables, and three relational variables were significantly correlated with marital instability of abused wives. Finally, multiple regression analyses showed that marital comparison level and degree of abuse from husband were the most powerful predictors on marital instability, and all these variables accounted for 61% of the total variance of abused wives' marital instability.

• 한국연소학회지
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• 제18권2호
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• pp.42-50
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• 2013

Linear stability analysis of radiating counterflow diffusion flames is numerically conducted to examine the instability characteristics of cellular patterns. Lewis number is assumed to be 0.5 to consider diffusional-thermal instability. Near kinetic limit extinction regime, growth rates of disturbances always have real eigen-values and neutral stability condition of planar disturbances perfectly falls into quasi-steady extinction. Cellular instability of disturbance with transverse direction occurs just before steady extinction. However, near radiative limit extinction regime, the eigenvalues are complex and pulsating instability of planar disturbances appears prior to steady extinction. Cellular instability occurs before the onset of planar pulsating instability, which means the extension of flammability.