• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 1998년도 가을 학술발표회 논문집
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• pp.81-88
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• 1998

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.34-41
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• 2006

A 3-dimensional stress measurement system based on the bore hole bottom deformation method, which is one of the stress relief methods, was developed. A pilot bore hole is drilled from the bottom of a bore hole and the stress meter is inserted into the pilot bore hole in the method. The bore hole is advanced as an over coring and the deformations in seven directions are measured by cantilever type-sensors. Using the cantilever type-sensors saves time for hardening of glue. No cable connection between the stress meter and a data logger is necessary since a compact data logger is installed in the stress meter. The accuracy of the stress meter was confirmed by a biaxial test for a Shikotsu welded tuff block although in-situ tests have not been carried out yet.

• Journal of the Korea Society of Computer and Information
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• 제27권6호
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• pp.109-116
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• 2022

Before examining stress and physiological variables (immunity, inflammation), this study conducted a pilot test to provide basic data by analyzing depression and anxiety symptoms by age group for stress coping and coping methods. As a non-face-to-face method, BDI and STAI by age group (20s to 70s) and face-to-face survey were conducted concurrently and as follow-up surveys. In 20s to 60s, according to the coping method, there was a significant decrease after stress relief, and in all age groups, anxiety decreased significantly after stress relief, and in the 50s, stress coping with exercise was the lowest after stress relief. Based on the results of this study, through basic research according to psychological variables, physiological variables according to actual stress coping methods were further verified, and subjects with high stress levels were treated with long-term exercise therapy for depression and anxiety symptoms by exercise therapy. It will be necessary to additionally verify the appropriate stress coping method for each age group and subject, such as the correlation between improvement and immunity and inflammatory response.

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.1125-1132
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• 2009

The theory and a probe of the pilot hole wall deformation method, which is a 3-dimensional stress measurement method based on the stress relief principle, were developed. A pilot hole is drilled from the bottom of a borehole and the stress measurement probe is inserted into the pilot hole. The borehole is advanced as the overcoring and the changes in the radius of the pilot hole in three directions and in the axial lengths between the borehole bottom and the pilot hole wall along four axial lines are measured by cantilever type-displacement sensors. The differences between the displacements by the elastic stress analysis and those measured by using the probe were within 3% in the uniaxial compression test of an acrylic resin plate having a hole.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권12호
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• pp.3943-3959
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• 2022

People are constantly exposed to stress and anxiety environment, which could contribute to a variety of psychological and physical health problems. Therefore, it is particularly important to identify psychological stress in time and to find a feasible and universal method of stress reduction. This research investigated the influence of different music, such as relaxation music and natural rhythm music, on stress relief based on Electroencephalogram signals. Mental arithmetic test was implemented to create a stressful environment. 23 participants performed the mental arithmetic test with and without music respectively, while their Electroencephalogram signal was recorded. The effect of music on stress relief was verified through stress test questionnaires, including Trait Anxiety Inventory (STAI-6) and Self-Stress Assessment. There was a significant change in the stress test questionnaire values with and without music according to paired t-test (p<0.01). Furthermore, a model based on Transformer for stress level classification from Electroencephalogram signal was proposed. Experimental results showed that the method of listening to relaxation music and natural rhythm music achieved the effect of reducing psychological stress and the proposed model yielded a promising accuracy in classifying the Electroencephalogram signal of mental stress.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제22권5호
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• pp.859-864
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• 2013

Creation of a stress relief groove is a fairly simple yet high-performance method. During the application of this method, it is important to consider the location and size of the groove in order to achieve better performance. Consequently, this research proposes an approach for optimizing the application of the stress relief groove method to a press-fitted assembly. In a boss design, the position and diameter of the groove are configured as design variables and the design of experiments is applied. Based on this information, a 3D model is built and analyzed using the finite element analysis software ABAQUS. Meta-models are created using back-propagation neural networks. Then, deterministic optimization results obtained from a genetic algorithm are compared with the results of the finite element analysis. The temperature sensitivity of the optimized model is analyzed, and finally, reliability-based design optimization is conducted for enhancing the design quality.

• Journal of the Korean Society of Propulsion Engineers
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• 제1권1호
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• pp.104-110
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• 1997

To predict the effect of ring expansion and ring compression on residual stress relief of Al 7175 ring rot]s, 2-D axisymmetric thermal analysis and elastoplastic analysis were performed. The residual stress distributions along the thickness of T73, T7351 and T7352 treated rings were measured using three step sectioning method. The measured results were compared to numerical ones for quenched and stress relieved rings. After quenching, calculated hoop and axial residual stresses were similar to measured ones for T73 treated rings. The residual stresses of T7351 and T7352 treated rings were decreased remarkably compared to T73 treated rings. The effect of axial residual stress relief was superior to that of hoop one, and also ring compression to ring expansion. It was concluded that ring compression is advantageous over ring expansion in view of stress relief effect and practicality, and vice versa in view of dimensional control and press power.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.482-487
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• 1993

A prediction method for determining the welding residual stress by artificial neural network is proposed. A three-dimensional transient thermomechanical analysis has been performed for the CO $_{2}$ Arc Welding using the finite element method. The validity of the above results is demonstrated by experimental elastic stress relief method which is called Holl Drilling Method. The first part of numarical analysis performs a three-dimensional transient heat transfer anslysis, and the second part then uses results of the first part and performs a three-dimensional transient thermo-clasto-plastic analysis to compute transient and residual stresses in the weld. Data from the finite element method were used to train a backpropagation neural network to predict residual stress. Architecturally, the finite element method were used to train a backpropagation voltage and the current, a hidden layer to accommodate failure mechanism mapping, and an output layer for residual stress. The trained network was then applied to the prediction of residual stress in the four specimens. The results of predicted residual stress have been very encouraging.

• Women's Health Nursing
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• 제18권3호
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• pp.170-179
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• 2012

Purpose: The purpose of this study was to identify menstrual distress, coping method and relief of symptoms among female nurses who worked with 3-shift. Methods: A total of 185 participants were recruited from November 18, 2011 to January 30, 2012. The measurement included menstrual distress and coping method questionnaire and relief of symptoms. The data were analyzed using t-test, ANOVA, Pearson's correlation coefficients with SPSS 19.0 Results: The level of menstrual distress was moderate (mean 3.0), and there were significant differences in menstrual distress by age, education, stress, regularity of menstrual cycle. Among the coping methods, coping according to menstrual cycle specific was the most frequently used, followed by active recognizing coping, active behavioral coping, and avoidance coping. Among the degree of symptom relief, symptom relief score was the highest when used coping according to menstrual cycle specific. Menstrual distress was associated with stress, adequate amount of sleep, dysmenorrhea and number of coping method total. Conclusion: Nurses experienced moderate levels of menstrual distress and used various types of coping to relieve it. There is a need for hospital nurses to develop an effective nursing intervention to relieve the menstrual distress and utilize active coping methods.

• Journal of Korean Society of Steel Construction
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• 제25권5호
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• pp.451-461
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• 2013

In steel bridges, there are several details that constrain the deformation such as buckling by external forces. Most of these details which are composed of the intersection members have scallops in order to exclude the weld defects inherently and to get the ease of fabrication and also to decrease the stress concentration. In this study, stress relief hole (SRH) near stress concentration zone with detail category D or under is proposed as a method to improve the resistance on the fatigue crack initiation to detail category C. And the effects of the appropriate size and location of SRH were examined and the applicability to improve the fatigue resistance of the floorbeam web and the rib wall at rib/floorbeam intersection in the orthotropic steel deck bridge was evaluated.