• Tribology and Lubricants
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• v.36 no.3
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• pp.117-123
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• 2020

In this study, the effect of the pre-mild wear mode test condition on the subsequent severe wear behavior of carbon steel has been investigated when the wear mode is varied according to the sliding speed change during sliding contact. Two sliding speeds of 0.3 m/s and 3 m/s for the mild wear mode test have been chosen and a sliding speed of 1 m/s for the severe wear mode test. A mild wear mode test at two different sliding speeds has been carried out during the severe wear mode test and total sliding distance of the mild wear mode test has been changed at this time. As a result, it could be found that the wear rate of carbon steel under the severe wear mode test after performing a pre-mild wear mode test is significantly reduced, compared with that before performing. However, its wear rate was slightly higher than that under the mild wear mode test. Oxides produced during the pre-mild wear mode test have been found to play a significant role in reducing the wear rate under the subsequent severe wear mode test. In particular, it was found that the effect of a pre-mild wear mode test performed at the sliding speed of 3 m/s has more rapid and the reduction in the wear rate was greater than thst at the sliding speed of 0.3 m/s.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.4
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• pp.383-391
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• 1999

This study was carried out to determine whether the effects of an ${\alpha}_2-adrenoceptor$ agonist, clonidine, on mean arterial pressure (MAP) and heart rate (HR) are influenced by mild hypothermia. Experiments were performed in respiration-controlled and spontaneously breathing pentobarbital-anesthetized rats. Rectal temperature was maintained at $37.5{\pm}0.3^{circ}C$ for normothermic groups or at $35.2{\pm}0.3^{circ}C$ for mild hypothermic groups. Intravenous injection of clonidine (1 and 2 ${\mu}g/kg)$ produced depressor and bradycardic responses in spontaneously breathing rats under both normothermic and mild hypothermic condition: a decrease in MAP was not altered but bradycardic response was significantly augmented in the mild hypothermic group as compared with the normothermic group. Under the respiration-controlled condition, the hypotensive effect of clonidine $(2\;{\mu}g/kg)$ was reduced, whereas the bradycardic effect was increased in mild hypothermic rats as compared with normothermic rats. Both hypotensive and bradycardic effects of clondine $(2\;{\mu}g/kg)$ were blocked by pretreatment with an ${\alpha}_2-adrenoceptor$ antagonist, yohimbine (0.5 mg/kg), in both thermal conditions. Yohimbine (0.5 mg/kg, i.v.) alone produced signifcantly an increase in heart rate in the mild hypothermic group than in the normothermic group. Pretreatment with a muscarinic receptor antagonist, atropine methylnitrate (1 mg/kg, i.v.), attenuated the bradycardic effect of clonidine in the mild hypothermic group but not in the normothermic group. These results suggest that clonidine- induced bradycardia is amplified by mild hypothermia probably through an increased parasympathetic activity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1191-1194
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• 2005

The aim of this study was to investigate the change of Heart Rate Variability(HRV) that mild cold stimulus on the forehead of healthy men induces. 34 healthy male subjects participated in the experiments. On the first test series, 15 subjects were applied to the mild cold stimulus by the devise for cold stimulation. In the second test series, 10 subjects With heat Syndrome and 5 subjects With cold Syndrome were applied to the mild cold Stimulus. Aa a additional test, 4 subjects with cold syndrome were applied to the warm stimulus in the last test series. We analyzed the HRV through measuring electrocardiogram.(ECG). The result of this study is comparatively clear. In the first test series, mild cold stimulus made parasympathetic nervous system be activated. In the second test series, mild cold stimulus made parasympathetic nervous system be activated both in subjects with heat syndrome and subjects with cold syndrome, and heat syndrome shows more active parasympathetic nervous system rather than cold syndrome subjects do. In the last test series, 2 subjects with cold syndrome respond the mild cold stimulus. That means warm stimulus of cold condition subjects made parasympathetic nervous system active in 2 of 4 subjects. We found out that mild cold stimulus on forehead makes parasympathetic nervous system be activated in healthy male, and it can be interpreted that mild cold stimulus make healthy human be relaxed. Also, subjects have different fondness of thermal stimulus according to their Cold or Heat condition Preferences. Last test series shows that we need to investigate effect of the warm stimulus heat syndrome subjects.

• Journal of Welding and Joining
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• v.14 no.4
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• pp.99-108
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• 1996

The microstructure and bond strength are examined on the SiC/SiC and SiC/mild steel joints brazed by the Ag-Ti based alloys with different Ti contents. In the SiC/SiC brazed joints, the thickness of the reaction layers at the bond interface and the Ti particles in the brazing alloy matrices increase with Ti contents. When Ti is added up to 9 at% in the brazing alloy. $Ti_3SiC_2$ phase in addition to TiC and $Ti_5Si_3$ phase is newly created at the bond interface and TiAg phase is produced from peritectic reaction in the brazing alloy matrix. In the SiC/mild steel joints brazed with different Ti contents, the microstructure at the bond interface and in the brazing alloy matrix near SiC varies similarly to the case of SiC/SiC brazed joints. But, in the brazing alloy matrix near the mild steel, Fe-Ti intermetallic compounds are produced and increased with Ti contents. The bond strengths of the SiC/SiC and SiC/mild steel brazed joints are independent on Ti contents in the brazing alloy. There are no large differences of the bond strength between SiC/SiC and SiC/mild steel brazed joints. In the SiC/mild steel brazed joints, Fe dissolved from the mild steel does not affect on the bond strength of the joints. Thermal contraction of the mild steel has nearly no effects on the bond strength due to the wide brazing gap of specimens used in the four-point bend test. The brazed joints has the average bond strength of about 200 MPa independently on Ti contents, Fe dissolution and joint type. Fracture in four-point bend test initiates at the interface between SiC and TiC reaction layer and propagates through SiC bulk. The adhesive strength between SiC and TiC reaction layer seems to mainly control the bond strength of the brazed joints.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.3
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• pp.261-270
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• 1998

This study was conducted in order to investigate the effect of diet therapy on over weight and obese humans in Korea Subseng Research Institute from January 1, 1994 to August 31, 1997. The constitutions of subjects were classified mild negative, strong negative, mild positive and strong positive respectively by ecology and O-ring test. These results were obtained from the subjects who practiced at least 75% diet therapy recommended for over weight and obese human for 14~400days. The constitutions of over weight and obese human by Relative Body Weight (RBW$\geq$110%) were 89 mild negative humans, 62 strong negative humans, 56 mild positive humans and 30 strong positive humans. The constitutions of over weight and obese human by Body Mass Index(BMI$\geq$25) were 77 mild negative humans, 50 strong negative humans 46 mild positive humans and 23 strong positive humans. The negative subjects were higher than the positive subjects on over weight and obese humans. The diet therapy related to constitiution on over weight and obese humans showed RBW reduction of 6.73$\pm$0.53 on mild negative human, 7.78$\pm$1.69 on strong negative human, 6.94$\pm$0.76 on mild positive human, and 7.80$\pm$1.15 on strong positive human at p<0.001 by student paired t-test. The diet therapy related to constitution on over weight and obese humans showed BMI reduction of 1.47$\pm$0.12 on mild negative humans, 1.24$\pm$0.11 on strong negative humans, 1.59$\pm$0.17 on mild positive humans, and 1.66$\pm$0.30 on strong positive humans at p<0.001 by student paired t-test.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.153-158
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• 2020

The present study identify the predictive power of confrontational naming and generative naming as screening tests for normal and early cognitive impairment. The subjects were analyzed for 203 healthy elderly, 106 mild cognitive impairment (MCI), 31 mild dementia. The confrontational naming was measured by the short-term Korean Boston Name Waiting Test, and the generative naming was measured by the Control Associative Word Test. As a result of polynomial logistic regression, both confrontational naming and generative naming had a significant effect on discriminating cognitive impairment (MCI, mild dementia) in general elderly (p<0.05). On the other hand, when distinguishing mild dementia from mild cognitive impairment, the generative naming-phonetic test had no significant odds ratio. The results of this study suggest that when discriminating mild dementia in mild cognitive impairment group, it is not meaningful to look only at the total score of generative naming test.

• Dementia and Neurocognitive Disorders
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• v.17 no.3
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• pp.100-109
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• 2018

Background and Purpose: Although the clock drawing test (CDT) is a widely used cognitive screening instrument, there have been inconsistent findings regarding its utility with various scoring systems in patients with mild cognitive impairment (MCI) or dementia. The present study aimed to identify whether patients with MCI or dementia exhibited impairment on the CDT using three different scoring systems, and to determine which scoring system is more useful for detecting MCI and mild dementia. Methods: Patients with amnestic mild cognitive impairment (aMCI), vascular mild cognitive impairment (VaMCI), mild Alzheimer's disease (AD), mild vascular dementia (VaD), and cognitively normal older adults (CN) were included. All participants were administered the CDT, the Korean-Mini Mental State Examination (K-MMSE), and the Clinical Dementia Rating scale. The CDT was scored using the 3-, 5-, and 15-point scoring systems. Results: On all three scoring systems, all patient groups demonstrated significantly lower scores than the CN. However, while there were no significant differences among patients with aMCI, VaMCI, and AD, those with VaD exhibited the lowest scores. Area under the Receiver Operating Characteristic curves revealed that the three CDT scoring systems were comparable with the K-MMSE in differentiating aMCI, VaMCI, and VaD from CN. In differentiating AD from CN, however, the CDT using the 15-point scoring system demonstrated the most comparable discriminability with K-MMSE. Conclusions: The results demonstrated that the CDT is a useful cognitive screening tool that is comparable with the Mini-Mental State Examination, and that simple CDT scoring systems are sufficient for differentiating patients with MCI and mild dementia from CN.

• Physical Therapy Korea
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• v.25 no.4
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• pp.9-18
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• 2018

Background: Leg length discrepancy (LLD) leads to many musculoskeletal disorders and affects daily activities such as walking. In the majority of the population, mild LLD is a common condition. Nevertheless, it is still controversy among researchers and clinicians on the effects of mild LLD during gait, and available studies have largely overlooked this issue. Objects: The purpose of the present study is to investigate the effects of mild LLD on the gait parameters and trunk acceleration. Methods: A total of 15 female and male participants with no evidence of LLD of >.5 ㎝ participated in the present study. All participants walked under the following two conditions: (1) The non-LLD condition, where the participants walked in shoes of the same heel height; (2) A mild LLD condition induced by wearing a 1.5 ㎝ higher heel on the right shoe. The GAITRite system and tri-axial accelerometer were used to measure gait parameters and trunk acceleration. To compare the variation of each variable, a paired t-test was performed. Results: Compared to the non-LLD condition, step time and swing phase were significantly increased in the mild LLD condition, while stance phase, single support phase, and double support phase significantly decreased in the short limb (p<.05). In the long limb of the mild LLD condition, single support phase significantly increased, while swing phase significantly decreased (p<.05). Furthermore, significant decrease in the gait velocity and cadence in the mild LLD condition were observed (p<.05). In the comparison between both limbs in the mild LLD condition, the step time and swing phase of the short limb significantly increased compared with the long limb, while step length, stance phase, and single support phase of the long limb significantly increased compared with the short limb (p<.05). Additionally, trunk acceleration of all directions (anterior-posterior, medial-lateral, vertical) significantly increased in the mild LLD condition (p<.05). Conclusion: The results of the present study demonstrate that mild LLD causes altered and asymmetrical gait patterns and affects the trunk, resulting in inefficient gait. Therefore, mild LLD should not be overlooked and requires adequate treatment.

• Applied Science and Convergence Technology
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• v.24 no.4
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• pp.84-89
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• 2015

The base pressure and outgassing rate of a mild steel chamber were measured and compared to those of a stainless steel chamber. A combined sputter-ion and non-evaporable getter pump with a nominal pumping speed of 490 l/s generated the base pressure of $2.7{\times}10^{-11}$ mbar in the mild steel chamber and $1.2{\times}10^{-10}$ mbar in the stainless steel chamber. The rate-of-rise measurements show that the mild steel has an extremely low outgassing rate of $2.6{\times}10^{-13}$ mbar $ls^{-1}cm^{-2}$, which is about one-order of magnitude smaller than the outgassing rate of the stainless steels. Vacuum annealing of the mild steel at $850^{\circ}C$ reduced the outgassing rate further to $8.8{\times}10^{-14}$ mbar $ls^{-1}cm^{-2}$, which was comparable to the outgassing rate of a heat treated stainless steel for extreme-high vacuum use.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.458-461
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• 2016

In this study, a finite element analysis for high-speed blanking of mild steel is performed. A thermomechanically coupled simulation model of a blanking process was developed using ABAQUS/Explicit. Through a simulation of the high-speed blanking process of mild steel, the influence of the punch speed, tool edge radius, and work material thickness on the development of the plastic heat and punch load were studied. The results of the study revealed that a higher punch speed caused thermal softening of the work material and decreased the punch load. Decreasing tool edge radius could help reduce the punch load. In addition, the results of the study revealed that the thermal softening effect was more dominant in the blanking of a mild steel sheet with a greater thickness as compared to that in the blanking of a mild steel sheet with a lower thickness.