• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.97-106
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• 1993

This is the study on fracture life under the interaction of creep and fatigue. It is difficult to explain the interaction of the creep and fatigue with indication of frequency but the dependency of the time should be considered. The formulation of material varieties causing by interaction of creep and fatigue is required in the accumulative damage method. The strain range partition method requires some of modification corresponding to the changes in temperature and load. All of other method also comprehended with above mentioned problems. Generally, in this field, the variety of stress-strain and suitable parameter is required and connective study between the macro and micro results seems to be insufficient. The linear damage rule is acquiring the support generally but it requires modification in the hgigh temperature instruments. The variety of stress effecting on crack and variety of stress on the metallurgical side are considered to be problems in the future days.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.4
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• pp.33-39
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• 2023

Purpose: The purpose of this study is that the college age is an important transition period from youth to adulthood. Nursing students are unfamiliar with their field of study and need to adapt to a large amount of academic and practical training, so that they can have a better college life. An attempt was made to determine the effect of exam anxiety, academic stress, and alcohol dependence on the academic achievement of nursing students. Research design, data, and methodology: The subjects of the study were 130 students from all grades who agreed to participate in the study after expressing convenience among students attending the Department of Nursing at a university in Gyeongnam. The data collection period was from August 15 to September 15, 2023. It was about a month. The data investigation was conducted through a self-report survey. Results: Results showed that significant variables included exam anxiety, academic stress, alcohol dependency, parent relationships, peer relationships, and major satisfaction, explaining a total variance of 31.9%. Among these, the most influential factor was academic stress (β=-.352). Conclusions: This study identify factors influencing the academic achievement of nursing college students and hopes to contribute to formulating strategies for their growth and competence development.

• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.139-153
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• 2010

Nitrosative stress is defined as pathophysiological conditions that are related to covalent modifications of proteins by nitration/nitrosylation by forms of nitrogen oxide ($NO_x$), leading to DNA damage, ultimately, cell death. This type of stress condition appears to be associated with a number of disease states, including diabetes, inflammation and neurodegenerative diseases. Since these pathological conditions are frequently chronic in nature and, thus, require long-term treatment, changes in pharmacokinetics are likely to affect the therapy. Transporters are membrane proteins that facilitate the movement of substrates, including drugs, across plasma membranes of epithelial / endothelial cells. Since it is now increasingly evident that transporters are pharmacokinetically significant, functional alteration of transporters by this stress condition may have therapeutic relevance. In this review, experimental techniques that are used to study both in vivo and in vitro nitrosative stress are summarized and discussed, along with available literature information on the functional implication of transporters under conditions of nitrosative stress conditions. In the literature, both functional induction and impa irment were apparently present for both drug transporter families [i.e., ATP-binding cassette (ABC) and solute carrier families (SLC)]. Furthermore, a change in the function of a certain transporter appears to have temporal dependency by impairment in the early phase of nitrosative stress and induction thereafter, suggesting that the role of nitrosative stress is complex in terms of functional implications of the transporters. Although the underlying mechanisms for these alterations are not fully understood, protein nitration/nitrosylation appears to be involved in the functional impairment whereas transcript factor(s) activated by nitrosative stress may play a role, at least in part, in functional induction. Interestingly, functional induction under conditions of nitrosative stress has not been observed for SLC transporters while such impairment has been documented for both ABC and SLC transporters. Further investigations appear to be necessary to fully delineate the underlying reasons for these differences on the impact and importance of nitrosative stress conditions.

• Tunnel and Underground Space
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• v.23 no.3
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• pp.219-227
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• 2013

Although Mohr-Coulomb failure criterion has limitations in that it is a linear criterion and the effect of the intermediate principal stress on failure is ignored, this criterion has been widely accepted in rock mechanics design. In order to overcome these shortcomings, the Hoek-Brown failure criterion was introduced and recently a number of 3-D failure criteria incorporating the effect of the intermediate principal stress on failure have been proposed. However, in many rock mechanics designs, the possible failure of rock mass is still evaluated based on Mohr-Coulomb criterion and most of practitioners are accustomed to understanding the strength of rock mass in terms of the internal friction angle and cohesion. Therefore, if the equivalent Mohr-Coulomb strength parameters of the advanced failure criteria are calculated, it is possible to take advantage of the advanced failure criteria in the framework of the Mohr-Coulomb criterion. In this study, a method expressing the tangential Mohr-Coulomb strength parameters in terms of the stress invariant is proposed and it is applied to the generalized Hoek-Brown criterion and the HB-WW criterion. In addition, a new approach describing the geometric meaning of the ${\sigma}_2$-dependency of failure criteria in 3-D principal stress space is proposed. Implementation examples of the proposed method show that the influence of the intermediate principal stress on the tangential friction angle and cohesion of the HB-WW criterion is considerable, which is not the case for the 2-D failure criterion.

• Korean Journal of Metals and Materials
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• v.48 no.3
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• pp.203-209
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• 2010

An application of the instrumented indentation technique has been expanded from the measurements of hardness and elastic modulus to the analysis of residual stress. A slope of the indentation loading curve increases (or decreases) according to compressive (or tensile) residual stress. A theoretical equation has been established for quantifying residual stress from the slope change. However, a precise observation of the remnant indents is indispensible because the theoretical approach needs actual contact information. In addition, the conventional hardness test is still used for predicting the residual stress distribution of welded joints. Thus, we observed the three-dimensional morphologies of the remnant indents formed on artificial stress states and analyzed stress effects on morphological recovery of the indents. First, a depth recovery ratio, which has been regarded as a sensitive stress indicator, did not show a clear dependency with the residual stress. Thus an analysis on volumetric recovery was tried in this study and yielded a inverse proportional behavior with the residual stress. In addition, an elastic to plastic volume recovery ratio showed more significant correlation with the residual stress.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.5
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• pp.480-487
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• 2003

To improve environmental control in various plants, signal characteristics of plants have been studied by a nondestructive technique. In this paper, the acoustic emission (AE) from plants was analyzed for water stress dependency. AE signals were taken from gymnosperm and angiosperm. AE sensor detected AE signals from the plant stem underneath the plant surface below the sensor. AE hit-event counts in daytime were more than those in night time, and it was found that the daily hit counts pattern was strongly affected by the water stress in the plant. frequency bands of AE signals from the angiosperm was different from those from the gymnosperm. Frequency bands of AE in outdoor condition were in accord with those in indoor having similar conditions.

• Geotechnical Engineering
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• v.2 no.1
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• pp.55-66
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• 1986

Considering the effects of confining pressure, initial shear stress, cyclic stress ratio and number of loading cycles, cyclic triaxial tests are carried out to clarify the soil dynamic properties such as shear modulus and value of material damping of clay under undrained cyclic loading conditions. The results show that no obvious dependency on initial shear stress and effective confining stress are recognized in the shear modulus and damping ratio plotted versus strain. However, the shear modulus decreases and the damping ratio increases with increasing axial strain. When compared with others, it is also revealed that the shear moduli are distributed within the range curves obtained using empirical equations derived by Marcuson et al. (3) and Kokusho et al. (4), and damping ratios are distributed between the curves obtained by Kokusho et al. (4) and Ishihara et al. (9).

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.465-476
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• 2019

This study was convergence study to determine sleep and its factors in university students on the basis of Spielman's 3P model. The participants were 191 graduate and undergraduate students who were scheduled to take the exam after 1~2 weeks. The related variables of quality of sleep were self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Chi-square test and t-test were used to make a comparison of the quality of sleep between the good and the bad sleep quality group. Pearson's coefficient correlation analysis was performed for correlation between the quality of sleep and the general characteristics, self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Stress and test anxiety as precipitating factors for sleep disturbance, smartphone dependency as a perpetuating factor for sleep disorder, and daytime sleepiness as a sleep-related factor were correlated with the quality of sleep; no statistically significant correlation was found with self-control as a predisposing factor in the biopsychological area. It is necessary to solve such problems with mental health as stress and test anxiety, which are factors for sleep disturbance, and smartphone dependency as a perpetuating factor for sleep disorder, in pursuit of higher quality of sleep for university students.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.215-226
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• 2021

The purpose of this study was to analyze the alcohol volume consumed and alcohol dependancy according to multiple rounds of drinking. Sectional data collected in 2012 as part of an International Alcohol Control Study were used, and 855 of 1,789 drinker aged 19 to 64 were conducted. The proportion of multiple rounds drinking were significantly higher in males(χ²=37.607, p<.001), students(χ²=52.466, p<.001), single(χ²=34.205, p<.001), smoking experience and stressed(χ²=40,09, p<.001; χ²=21.66, p<.001) among drinkers. In particular, the alcohol volume consumed of unmarried people, smokers, and stress groups were significantly higher than married people, non-smokers and no-stress group. The highest alcohol intake in the first, 2nd and third rounds was found in bars in the liquor trade (F=67.8g, p<0.001). The total alcohol intake increased as the number of rounds increased (F=209.993, p=0.001) and the number of drinkers who tested positive for alcohol dependency increased, using the tests RAPS4 and DSM-IV(F=129.836, p<0.001; F=94.669, p<0.001). The OR of alcohol dependancy in males was 2.3(95% CI: 1.745-3.057), unemployed was 3.2(95% CI: 1.053-9.838), smokers was 3.9(95% CI: 1.230-12.292), and stress group was 2.1(95% CI: 1.561-2.768) compared to females, employed, non-smokers, and no-stress group respectively. In conclusion, it suggests that those consuming multiple rounds drinking can become more vulnerable to alcohol harms due to its relation to smoking, stress and increased dependence on alcohol.

• English Language & Literature Teaching
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• v.15 no.2
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• pp.261-280
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• 2009

This study focuses on providing the pedagogical implications of stress in English pronunciation teaching since stress is one the most important characteristic factors in English pronunciation (Bolinger, 1976; Brown, 1994; Celce-Murcia, Brinton & Goodwin, 1996; Kreidler, 1989). The author investigated stress production regarding in terms of duration, pitch, and intensity by a group of native speakers of English and a group of low-proficiency South Kyungsang Korean college students for their pre-test. For both of the pre- and post-test, the same stimuli, which consisted of a one-syllable word, two two-syllable words, three three-syllable words, and three four-syllable words, were used along with the various sentence positions: isolation, initial, medial, and final. Soft ware programs, ALVIN and Praat, were used to record and analyze the data. Since Celce-Murcia et al. (1996), Klatt (1975), and Ladefoged (2001) treat duration of the stressed syllable more significantly than other factors, pitch and intensity, with respect to the listener's point of view, the author developed a special method of teaching English stress using a traditional Korean drum to emphasize duration. In addition, the results from the native speakers' production showed that their main strategy to realize stress was through lengthening stressed syllables. After six weeks of stress instruction using the drum, the production of the native speakers and the SK Korean participants from the pre- and post-test were compared. The results from the post-test indicated that the participants showed great improvement not only in duration but also in pitch after the stress instruction. Pitch improvement was unexpected but well-explained by the statement that long vowels receive accent in loan word adaptation in North Kyungsang Korean. The results also showed that the Korean participants' pitch values became more even in their duration values for each syllable as the structure of the word or the sentence became more complex, due to their dependency upon their L1.