• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.372-383
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• 2020

This study analyzed the influence of Korean adults sleep time on psychological symptoms, suicidal ideation and attempts considering gender differences. The data was collected from the community health survey in 2017 with 228,381 people. When categorizing them into male and female, logistic regression analysis was conducted and the main analysis results are as follows. First, there are more women with shorter or longer sleep time than men. Second, in case of shorter sleep time (5 hours and less), stress, depression, and the suicidal ideation rates were high while suicidal attempts were higher in case of sleep greater than 9 hours and more. Third, in case of men, based on 6~8 hours of sleep time, people with shorter sleep time showed higher stress (1.84 times), depression (1.98), suicidal ideation (1.88), and attempts (2.38). People with 9 hours and more sleep showed greater depression (1.79), suicidal ideation (1.96) and attempts (2.39). Fourth, in the case of women, people with shorter sleep time showed greater stress (2.09), depression (1.94), suicidal ideation (1.96), and attempts (2.90). People with longer sleep showed greater depression (1.39), suicidal ideation (1.45) and attempts (1.71). Fifth, people's stress with greater sleep for both genders was higher than that of people with normal sleep. but there was no significant difference. Further prospective studies are needed on specific sleep dysfunctions effects on suicidal ideation and attempts.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.33-41
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• 2014

This study conducted a survey 212 adolescents in multi-cultural family to measure the level of their discrimination experience and acculturation stress by comparing with social integration analysis frame of D. Heater and examined how it affects them to national identity. Followings are the main results of this study. First, after measuring the discrimination experience level of those surveyed, their average was a bit higher than the normal level, showing 2.63(SD=.72), and their acculturation stress was 2.48(SD=.65) which is average. Second, their level of national identity showed 2.16(SD=.57), which was lower than the normal level, and there was statistically a meaningful difference between the groups depending on their academic level, parents' marital status, mother's Korean ability. Third, the factors that affected in national identity were in the order of their discrimination experience(${\beta}$=-.305), parents' marital status(${\beta}$=.286), acculturation stress(${\beta}$=-.225), academic level(${\beta}$=.186), mother's Korean ability(${\beta}$=.173). Based on these results, several ways are suggested to improve national identity of adolescents in multi-cultural family.

• Fibers and Polymers
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• v.6 no.2
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• pp.131-138
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• 2005

A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases as Ca increases. The normal stress difference (NSD) under the simple shear has the largest value when Ca is around 1 and the ratio Of the first NSD to the second NSD has the value of 3/4 for large Ca but 2 for small Ca. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.25-35
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• 2015

This research analyzed the factors which have an effect on the turnover intention of 375 childcare teachers who work at child care center in the Chungnam, Chungbuk area as the subjects of research. The main results of this study are as follows; First, the level of turnover intention in childcare teachers appeared to be higher than the normal level in all groups and significant difference was evident in each of the groups. Second, the key factor which had an effect on the turnover intention was proven to be significantly different in each of the groups. Teachers who work in home and private the area of infant care in job stress, and director's leadership in organizational health were evident. Teachers who work in public the area of administrative work in job stress were evident. Teachers who work in corporation relationship with colleagues and student's parents in job stress were evident. This research lies in the point that it is the first to make a customized plan suggestion on how to decrease turnover intention in childcare teachers in accordance with types of child care centers for each of the groups.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.45-52
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• 2008

Purpose: The purpose of the study is to provide the clinical results of arthroscopic posterior cruciate ligament(PCL) reconstruction with preservation of the original PCL using transtibial tunnel and posterior transseptal portal. Materials and Methods: 36 patients underwent PCL reconstruction with achilles tendon allografts. We tried to preserve of the original PCL.At the final follow-up, patients were evaluated retrospectively by four measurements: Lysholm knee scores, IKDC grades, Telos stress radiography, and second look arthroscopy.Follow-up periods were from 12 months to 30 months. Results: The average Lysholm knee score improved from $66.0{\pm}8.67$ to $87.9{\pm}5.04$. Preoperative IKDC grades were abnormal in 15(41.7%) and severely abnormal in 21(58.3%), postoperative IKDC grades were normal in 6(16%),nearly normal in 24(66%), abnormal in 5(16%) and severely abnormal in 1(2%).The average side to side difference in Telos stress test decreased from $12.5{\pm}2.61(7{\sim}20)$ mm to $3.9{\pm}1.34(7{\sim}1)$ mm (paired sample T test, p=0.001) Conclusion: Arthroscopic posterior cruciate ligament(PCL) reconstruction with preservation of the original PCL using transtibial tunnel and posterior transseptal portal is useful surgical method.

• Korean Journal of Biological Psychiatry
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• v.12 no.1
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• pp.20-31
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• 2005

Objectives:This study was designed to investigate the characteristics of personality changes and emotional distress using the Personality Assessment Inventory (PAI) in patients with traumatic brain injury(TBI), divided into mild (MTBI) and severe (STBI) groups according to the severity of injury. Methods:The subjects were consisted of 25 patients with MTBI, 25 patients with STBI, and 25 normal controls. They were interviewed with the PAI. The data were analyzed by ${\chi}^2$ test, analysis of variance and Tukey test. Results:The results were the followings. First, Negative Impression in validity scales was elevated above cutoff point(T score 70) in both MTBI and STBI groups. Second, the clinical scales of which scores elevated above the cutoff point were Somatic Complaints, Anxiety, Anxiety-Related Disorders, Depression, and Schizophrenia in the MTBI, and Somatic Complaints and Depression in the STBI. Third, the clinical subscales above the cutoff point were Conversion, Somatization, Health Concerns, Affective Anxiety, Physiological Anxiety, Traumatic Stress, Cognitive Depression, Affective Depression, Physiological Depression, Thought Disorder, and Affective Instability in the MTBI, and Health Concerns, Cognitive Depression, Affective Depression, and Physiological Depression in the STBI. Fourth, Suicide Ideation in treatment scales was the only scale above the cutoff point in the MTBI and the others of the treatment and interpersonal scales in the MTBI and all of these scales of the STBI were not elevated above the cutoff point. Fifth, the scales of which scores showed significant difference between the MTBI and the STBI were Somatic Complaints, Anxiety, Depression, and Suicide Ideation, the subscales were Conversion, Somatization, Health Concerns, Affective Anxiety, Physiological Anxiety, Physiological Depression, and Psychotic Experiences. Conclusion:These results suggest that the patients with MTBI had more somatic and anxiety symptoms, depressed mood, and suicidal ideation than the patients with STBI. These characteristics are generally consistent with clinical observation and findings from previous studies of the patients with TBI, and the PAI seems to be a beneficial adjunctive assessment tool for the evaluation of patients with traumatic brain injury.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.350-363
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• 1999

The precision cyclic shear test system was established to investigate the mechanical characteristics of rough rock joints under cyclic loading conditions. Laboratory cyclic shear tests were conducted for saw-cut joints and artificial rough rock joints using Hwangdeung granite and Yeosan marble. Surface roughness and aperture characteristics of specimens were examined by measuring surface topography using the laser profilometer. Peak shear strength, phase difference during loading and unloading, and anisotropic shear behavior were investigated throughout the cyclic shear test results. These features and their subsequent variations in each loading cycle are significantly dependent upon the second order asperities and the strength of intact rock. It was observed that degradation of asperities for rough rock joints under cyclic shear loading followed the exponential degradation laws of asperity angle and that the mechanism for asperity degradation would be different depending upon the normal stress level, roughness of joint surface and the loading stage.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.153-170
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• 2007

Loading time and loading environment of the Dokdo seamounts were studied from flexure model and VGP(Virtual Geomagnetic Pole) determined by gravity and magnetic data. In spite of their similarity in size. a large difference about 50 mGal between gravity anomaly peaks of Dokdo and the Isabu Tablemount suggests different compensation degrees. Flexural modeling results show that the flexural rigidity(effective elastic thickness) of lithosphere for Dokdo is stronger(thicker) than that for the Isabu Tablemount. Also, it implies that the age of lithosphere at the time of loading of the Isabu Tablemount may be younger than that of Dokdo. Magnetic anomalies occur complicated over the Dokdo seamounts. Paleomagnetism was studied from VGP estimated by the least square and the seminorm magnetization methods with 1500 m upward continued magnetic anomalies. Age dating of Dokdo from previous study, flexural modeling, VGP, and geomagnetic polarity time scale suggest that after the cease of spreading in the Ulleung Basin, the Isabu Tablemount was formed first in normal polarity interval and followed by Dokdo. Also, they indicate that the fist large eruption of Dokdo was in normal polarity interval and the second large eruption in reversed polarity interval. The Simheungtaek Tablemount was formed in normal polarity interval between the formations of the Isabu Tablemount and Dokdo. These loading times for the Dokdo seamounts show a good coherence with the compressive stress period after the end of the opening of the East Sea. The Dokdo seamounts probably was caused by volcanism associated with the compressive stress.

• Journal of Korean Academy of Nursing
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• v.20 no.1
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• pp.88-117
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• 1990

The purposes of this study are to delineate a profile of the state of a stroke patient's adaptation at 3 months after hospitalization and to explore the relationship between the level of adaptation and the variables which influence the adaptation of hemiplegic patients. To these ends, theoretical framework was derived basically from the stress adaptation model. The basic assumption underlying the level of adaptation is influenced by the presenting focal, contextual and residual stimuli. This group of stimuli is further operationalized and represented by a perception of stress. which is the perceived effect of the disability and by the mediating variables such as sociodemographic factors as an external conditioning variables and perceived social support and hardiness personality characteristics as an internal intervening variables. The dependent varibales in this study is the level of physical, psychological and social adaptation and is hypothesized to be a function of the interaction between 3 sets of variables namely, the perceived disability effect, external conditioning variables and internal intevening varibles. A total of fourty three subjects from 3 general hospitals in Seoul were observed and interviewed with the aid of 7 structured instruments. The data were collected twice on each subject : first at the pre-discharge period arid at 3 months post-discharge from hospital for the second time. The study was carried out for the period from February to August, 1988. The instruments used for the study include 4 existing scales and 3 scales developed by the researcher for this study. They are : 1) The ADL dependency scale and the scale of the clinical physical functions for the assessment of physical adaptation. 2) the SDS(self report of depression) to measure the level of psychological adaptation. 3) The scale for the amount of social activities for the measurement of the level of social adaptation. 4) The scale for the perceived effect of disability for the measurement of the focal stimuli. 5) The health related hardiness scale and the perceived interpersonal support self evaluation list(ISEL) for the measurement of the hardiness personality character and the perceived social support. The data obtained were analyzed using percentage, oneway ANOVA, Pearson coefficients correlation and stepwise multiple regression. The findings provide valuable information about the present level of physical adaptation at 3 months after discharge. The patient revealed a decreased ADL dependency and lowered limitation of physical function as compared with pre - discharge state. Psycholcgically, the average degree of depression at follow up was within normal range of depression. Socially, the amount of social activities was very low. The one way ANOVA and the correlational analysis revealed the relationship between the 3 sets of variables and the adaptation level as follows : 1) The perceived disability effect was related to the degree of the depression and the amount of social activities but was not related to the physical adaptation. 2) Among the sociodemographic variables, sex and education were related to the difference of ADL dependency and the change of physical function. These factors indicate that women more than men and educated more than the less educated were found more independent. The education was also related to the degree of depression suggesting that the higher the educational level, the more well adapted the patients were both physically and psychologically. Age, marital status and job state were not found to be related to the patient's adaptation level. 3) Among the internal intervening variables, the health related hardiness characteristic was related to the differences of ADL dependency, physical functions and the social activities, indicating that the higher the hardiness character the higher the level of physical and social adaptation. 4) The perceived social support, another internal intervening variable, was related to the degree of depression and the social activities. This data suggest that the higher the perception of social support, the better adapted the patients were psychogically and socially. In summarizing the results of the correlational analysis, the level of physical adaptation was influenced by sex, the years of education and the hardiness character. The level of psychological adaptation was influenced by the years of education, the perceived disability effect and the perceived social support. And the level of social adaptation was influenced by the perceived disability effect, the hardiness character and the perceived social support. The stepwise multiple regression analysis shows findings as follows : 1) The most important factor to explain the difference of ADL dependency was sex, indicating females were more independent than males. 2) The most important factor to explain the difference of physical function and the degree of depression was the patient's education level. 3) The strongest explaining factor for the amount of social activities was perceived self esteem(one of the subconcepts of perceived social support). Thus the most important factors influencing the level of adaptation were found to be sex, education, the hardiness character and self esteem. From the above findings, the significance of this study can be delineated as follows : 1) Corroboration of the assumed relationship between the various variables and the adaptation level as suggested in the conceptual model. 2) Support for the feasibility of the cognitive approach for nursing intervention such as hardness character training, counselling and teaching for self-care in the chronic patients.

• Korea-Australia Rheology Journal
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• v.21 no.1
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• pp.59-69
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• 2009

The prediction of pressure drop for a droplet flow in a confined micro channel is presented using FE-FTM (Finite Element - Front Tracking Method). A single droplet is passing through 5:1:5 contraction - straight narrow channel - expansion flow domain. The pressure drop is investigated especially when the droplet flows in the straight narrow channel. We explore the effects of droplet size, capillary number (Ca), viscosity ratio ($\chi$) between droplet and medium, and fluid elasticity represented by the Oldroyd-B constitutive model on the excess pressure drop (${\Delta}p^+$) against single phase flow. The tightly fitted droplets in the narrow channel are mainly considered in the range of $0.001{\leq}Ca{\leq}1$ and $0.01{\leq}{\chi}{\leq}100$. In Newtonian droplet/Newtonian medium, two characteristic features are observed. First, an approximate relation ${\Delta}p^+{\sim}{\chi}$ observed for ${\chi}{\geq}1$. The excess pressure drop necessary for droplet flow is roughly proportional to $\chi$. Second, ${\Delta}p^+$ seems inversely proportional to Ca, which is represented as ${\Delta}p^+{\sim}Ca^m$ with negative m irrespective of $\chi$. In addition, we observe that the film thickness (${\delta}_f$) between droplet interface and channel wall decreases with decreasing Ca, showing ${\delta}_f{\sim}Ca^n$ Can with positive n independent of $\chi$. Consequently, the excess pressure drop (${\Delta}p^+$) is strongly dependent on the film thickness (${\delta}_f$). The droplets larger than the channel width show enhancement of ${\Delta}p^+$, whereas the smaller droplets show no significant change in ${\Delta}p^+$. Also, the droplet deformation in the narrow channel is affected by the flow history of the contraction flow at the entrance region, but rather surprisingly ${\Delta}p^+$ is not affected by this flow history. Instead, ${\Delta}p^+$ is more dependent on ${\delta}_f$ irrespective of the droplet shape. As for the effect of fluid elasticity, an increase in ${\delta}_f$ induced by the normal stress difference in viscoelastic medium results in a drastic reduction of ${\Delta}p^+$.