• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.3 no.1
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• pp.106-116
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• 1992

This study were purposed to find out parental perceptions of child adjustment associated with parenting stress with autistic children and differences of parenting stress between autistic children's parents and normal children's. Subjects were 27 autistic children's parents, 28 normal children's, 4 teachers with autistic children. 'Scales were Parenting Stress Index(PSI), Eyberg Child Behavior Index(ECBI), Childhood Autism Rating Scale(CARS), Social Maturing Scale(SMS). The results of this study were as follows. 1) In total parenting stress, parents with autistic children had significantly higher scores than normal's. 2) In child domain of parenting stress, fathers with autistic children had significantly higher than mothers on the other components except Mood and Demandingness. 3) In parent domain of parenting stress, parents with autistic children had significantly higher than nomal's on Restrict of role, Attachment, Sense of Competence. All mothers of normal and autistic children had significantly higher than fathers on the other components except Repression. 4) In parenting perceptions associated with parenting stress level of autistic children's parents. Low level group perceived their children as higher adaptibility than teacher's evaluation and high level group perceived them as equal to teacher's.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.407-415
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• 2019

A controlled low strength material (CLSM) is a highly flowable cementitious material used for trench backfilling. However, when applying vertical loads to backfilled trenches, shear failure or differential settlement may occur at the interface between the CLSM and natural soil. Hence, this study aims to evaluate the characteristics of the interface friction between the CLSM and soils based on curing time, gradation, and normal stress. The CLSM is composed of fly ash, calcium sulfoaluminate cement, sand, silt, water, and an accelerator. To investigate the engineering properties of the CLSM, flow and unconfined compressive strength tests are carried out. Poorly graded and well-graded sands are selected as the in-situ soil adjacent to the CLSM. The direct shear tests of the CLSM and soils are carried out under three normal stresses for four different curing times. The test results show that the shear strengths obtained within 1 day are higher than those obtained after 1 day. As the curing time increases, the maximum dilation of the poorly graded sand-CLSM specimens under lower normal stresses also generally increases. The maximum contraction increases with increasing normal stress, but it decreases with increasing curing time. The shear strengths of the well-graded sand-CLSM interface are greater than those of the poorly graded sand-CLSM interface. Moreover, the friction angle for the CLSM-soil interface decreases with increasing curing time, and the friction angles of the well-graded sand-CLSM interface are greater than those of the poorly graded sand-CLSM interface. The results suggest that the CLSM may be effectively used for trench backfilling owing to a better understanding of the interface shear strength and behavior between the CLSM and soils.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.93-103
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• 2000

Objective: Stress is assumed to have many effects on menstruation of highschool senior female students, and it is expected to cause many problems and low efficiency during their studies. Therefore, through analyzing the menstruation state of highschool senior female students, the effects of stress on their menstruation and their education were studied. Methods: We made a survey of 583 senior female students of 'N' highschool located in Taegu. The survey was composed of the degrees of stress they were undergoing, menstrual problems caused by stress. Results: The survey results showed that 96.7% of the candidates were experiencing stress. 51.6% of them experienced an altered menstrual cycle, and menstrual irregularity was brought out in 32.1 % among them. 18.1 % of them were experiencing dysfunctional uterine bleeding. In sustaining period of menstruation, 17.5% of them had a shortened menstruation period, and 8.9% had a prolonged period. In case of menstrual quantity, less than normal quantity was reported by 26.9% of respondents and more than normal quantity was reported by 8.8%. 26.6% of respondents reported their menstrual blood was impure and the color was dark. Blood clots were increased in 27.5% of respondents. 86.6% went through premenstrual syndrome, and 34.3% had worsened menstrual pain. Studying was affected by menstrual pain in 83.9% of respondents. Of treating the disorder, 66.2% of them said they just waited till the pain went away, and 26.9% of them said they went to a pharmacy, and 2.4% of them said they went to an oriental medical clinic. Conclusions: From the above results, it is concluded that stress has a close connection with menstrual disorders. And it affects senior highschool female students' education, while they don't take proper treatments. Hence we think that we must have a lot of concern about senior female students and they must receive proper treatments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.65-67
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• 2003

Flounder (Paralichthys olivaceus) fish goes through metamorphosis in the larvae phase. In this phase, it secretes much thyroid hormone to control metamorphosis. Sharp change in the environment and nutrition deficiency may cause stress in the metamorphosis phase. It leads to interfering with the development of thyroid hormone and finally inhibits the normal growth of larvae. In this study, the correlation between the change in thyroid hormones and the albinism appearance was examined by growing them with low temperature ($13^{\circ}C$) stress over the premetamorphosis stages (stage $D\~F$) of flounder metamorphosis. Albinism rate was $15\%$ in the low temperature group and $25\%$ in the control goup. $T_{4}\;and\;T_{3}$ of the control group tended to increase from stage F as larvae grew. $T_{4}$ increased 2 times compared to the control group as 72 ng/g at stage H, the increasing phae of water temperature, in the low temperature group. $T_{3}$ increased 8 times compared to the control group as 2.9 ng/g at stage E, the decreasing phase of water temperature. Therefore, it is judged that the albinism appearance of flouner is caused from the sharp increase in $T_{3}$ by the inappropriate secretion of thyroid hormone.

• Tribology and Lubricants
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• v.13 no.4
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• pp.66-70
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• 1997

Thin films and coating technologies are used for an enormous and diverse set of application including mechanical and automotive components. Many of these applications require the various properties which can be used for decreasing wear, friction and cost, and increasing the long life. The relationship between the load and the stress is usually nonlinear. The material is often apt to deform plastically under the low loads. Numerical method may be used for some simple problems of the coating. If the property of coating and base materials are inhomogeneous and the geometry is complex, the numerical method may be recommended. In this paper, the contact normal stress of the coating layer has been solved using finite element method.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.57-63
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• 2009

Objectives : Since the Front Points are treated as response zone, it can be used for the diagnosis and treatment of disease in viscera and bowels. Jeonjung($CV_{17}$) is the Front Point of SIMPO, it is related with cardiovascular, neuro-psychiatrical disease in aspect of Oriental Medicine. This research is for clarifying relations with palpation of the Jeonjung($CV_{17}$) and autonomic nerve system by comparing HRV and SRI(Stress Reaction Index). Methods : This study was proceeded for three months, from June 2009 to September 2009. Among 31 healthy volunteers, 13 subjects who complained the pressure pain around Jeonjung($CV_{17}$) are classified pressure pain group and 18 subjects who had no pain around Jeonjung($CV_{17}$) as normal group. All subjects had their HRV(SA-2000E: Medicore Co..Ltd. Korea) and SRI measured at visit. We studied the difference of HRV between two groups.(Statistics by Student t-test, p<0.05) Results : LF normalization of the pressure pain group were significantly higher than those of the normal group. HF normalization of the pressure pain group were significantly lower than those of the normal group. Compared with those of the normal group, total SRI of the pressure pain group were low but it's not significant. Conclusions : The results of HRV of the pressure pain group show that pressure pain around Jeonjung($CV_{17}$) is related to mental stress and autonomic disturbance.

• Korean Journal of Biological Psychiatry
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• v.15 no.3
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• pp.186-193
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• 2008

Objectives : The authors tried to investigate the characteristics of Heart Rate Variability(HRV) among the subjects with metabolic syndrome for testing the possibility of clinical application of HRV in evaluating metabolic syndrome. Methods : We examined the difference of the means of HRV between 122 subjects of metabolic syndrome and 1057 healthy controls using T-test, and the change of means in HRV according to increasing risk factors of metabolic syndrome. Using multiple regression analysis, we examined the association of HRV with the risk factors of metabolic syndrome. Results : The HRV indices including SDNN(Standard Deviation of all normal NN intervals), RMSSD(the square Root of the Mean Squared Differences of successive all normal NN interval), TP(Total Power), LF(Low Freuency), and HF(High Frequency) were significantly lower in the metabolic syndrome group than in the normal control group, and the means of all HRV indices except LF/HF were decreased consistently according to increasing risk factors of metabolic syndrome. The fasting glucose, triglyceride, and waist circumference were dependent factors that contributed significantly to the change of HRV. Conclusion : These findings suggest metabolic syndrome adversely affects cardiac autonomic system and HRV could be a useful method for evaluating metabolic syndrome.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.356-363
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• 2004

In this research, the shear behavior of four different interfaces consisting of 4 types of geosynthetics was examined, and both static and dynamic tests for the geosynthetic interface were conducted. The monotonic shear experiments were performed by using an inclined board apparatus and large direct shear device. The interface shear strength obtained from the inclined board tests were compared with those calculated from large direct shear tests. The comparison results indicated that direct shear tests are likely to overestimate the shear strength in low normal stress range where direct shear tests were not performed. Curved failure envelopes were also obtained for interface cases where two static shear tests were conducted. By comparing the friction angles measured from three tests, i.e. direct shear, inclined board, and shaking table tests, it was found that the friction angle might be different depending on the test method and normal stresses applied in this research. Therefore, it was concluded that the testing method should be determined carefully by considering the type of loads and the normal stress expected in the field.

• Wind and Structures
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• v.22 no.6
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• pp.685-701
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• 2016

Downbursts are of great harm to transmission lines and many towers can even be destroyed. The downburst wind field model by Chen and Letchford was applied, and the wind loads of two typical transmission towers in inland areas and littoral areas were calculated separately. Spatial finite element models of the transmission towers were established by elastic beam and link elements. The wind loads as well as the dead loads of conductors and insulators were simplified and applied on the suspension points by concentrated form. Structural analysis on two typical transmission towers under normal wind and downburst was completed. The bearing characteristics and the failure modes of the transmission towers under downburst were determined. The failure state of tower members can be judged by the calculated stress ratios. It shows that stress states of the tower members were mainly controlled by 45 degree wind load. For the inland areas with low deign wind velocity, though the structural height is not in the highest wind velocity zone of downburst, the wind load under downburst is much higher than that under normal wind. The main members above the transverse separator of the legs will be firstly destroyed. For the littoral areas with high deign wind velocity, the wind load under downburst is lower than under normal wind. Transmission towers are not controlled by the wind loads from downbursts in design process.

• Journal of Plant Biology
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• v.36 no.1
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• pp.35-42
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• 1993

This study deals with the effect of dwarf growth for the wood and the structural changes of cambium in Pinus koraiensis subjected to water stress. The length and wall thickness of tracheary elements in dwarf trees was shorter and thicker than that in normal trees. The redial width and cell number of the annual rings are narrower and smaller in dwarf trees than those in normal trees. In serial tangential sections, the frequency of anticlinal division is low and loss of cambial initials is small in dwarf trees. The length of cambial initials in water deficit, trees are slightly shorter than that in normal trees, and the instructive growth of cambial initials during differentiation of xylem mother cells is inactive in dwarf trees. Thus, it is interpreted that the shortening of tracheary elements in dwarf trees is due to the fact that the length of cambial initials are shortened and the intrusive growth of those during differentiation of xylem mother cells is inactive. The structural variations in the wood of naturally occurring dwarf trees are similar to those of trees subjected to artificial water stress. Therefore, it is suggested that the variation of xylem element in dwarf trees are related to water conditions.