• Journal of the Korean Society for Heat Treatment
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• v.33 no.4
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• pp.161-172
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• 2020

The tensile property of A5082 and A6060 aluminium wrought alloys was investigated, in terms of the strain rate sensitivity on alloy conditions by heat treatment and bake hardenability on pre-strain prior to strain ageing. The tensile test was carried out in a range of strain rate of 4.17 × 10^-5 s^-1 ~ 4.17 × 10^-5 s^-1 in room temperature and the nominal range of pre-strain was 3.0 ~ 10.5%. The tensile deformation of A5082 alloys is characterized as typical case of dynamic strain ageing with negative strain rate sensitivity for all conditions, and the tensile strength indicates a similar level regardless of alloy conditions, except only in full annealed condition. The stress-relief annealing on A6060 alloys can induce practical decrease in strength level of over approximately 100 MPa without any ductility loss, compared to as-rolled condition, while a full annealed and aged condition leads remarkable strengthening effect with the decrease of tensile elongation. Additionally, the bake hardenability of A5082 alloy by strain ageing indicates a negative dependence upon the increase of pre-strain, while A6060 alloy exhibits a positive sign even in low level relatively compared with conventional SPCC.

• Korean Journal of Materials Research
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• v.26 no.5
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• pp.281-286
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• 2016

In the present study, the tensile properties and dynamic strain aging of an Fe-24.5Mn-4Cr-0.45C alloy were investigated in terms of strain rate. During tensile testing at room temperature, all the stress-strain curves exhibited serrated plastic flows related to dynamic strain aging, regardless of the strain rate. Serration appeared right after yield stress at lower strain rates, while it was hardly observed at high strain rates. On the other hand, strain-rate sensitivity, indicating a general relationship between flow stress and strain rate at constant strain and temperature, changed from positive to negative as the strain increased. The negative strain-rate sensitivity can be explained by the Portevin Le Chatelier effect, which is associated with dynamic strain aging and is dependent on the strain rate because it is very likely that the dynamic strain aging phenomenon in high-manganese steels is involved in the interaction between moving dislocations and point-defect complexes.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.351-354
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• 2013

Objective: To assess the practical utility of pleural fluid carbonic anhydrase XII (CAXII) quantification for differential diagnosis of effusions. Materials and Methods: Fluid was collected prospectively from fifty patients presenting with lymphocytic pleural effusions for investigation and CAXII was quantified by ELISA. Results: Pleural fluid CAXII concentrations were significantly higher in lung cancer patients (n=30) than in tuberculous controls (n=20). The sensitivity and specificity of this biomarker were 60%and 75%, respectively. CAXII measurement was not inferior to cytological examination in the diagnosis and exclusion of pleural effusions from lung cancer patitents (sensitivity 60% vs. 57%; specificity 75% vs. 100%; positive predictive value 77%; negative predictive value 54%). In patients with negative cytology, it offered a sensitivity of 54%. Conclusions: Pleural fluid CAXII is elevated in pleural effusions from lung cancer patients. Measurement of CAXII may be used in the future as a valuable adjunct to cytology in the diagnostic assessment of patients with pleural effusions related to lung cancer, especially when cytological examination is inconclusive.

• Journal of IKEEE
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• v.28 no.2
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• pp.131-135
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• 2024

In this study, the sensor such as current transformer type was developed for measuring non-contact partial discharge in power electrical facilities, and the results of the characteristic evaluation were discussed. The frequency response characteristics of the HFCT sensor were shown to be measurable from 20 [kHz] to 20 [MHz]. The average sensitivity for the positive direction was 0.308 [mV/pC], and the negative direction was 0.459 [mV/pC]. Which showed that the sensitivity for the negative direction was better than that for the positive direction. The developed HFCT sensor is possible to measure very small partial discharge pulse signals and can be measured various types of partial discharge that may occur at power electrical facilities.

• Advances in nano research
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• v.1 no.2
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• pp.105-109
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• 2013

We report dry thermal development of negative resist polystyrene with low molecular weight. When developed on a hotplate at $350^{\circ}C$ for 30 min, polystyrene showed reasonable high contrast and resolution (30 nm half-pitch), but low sensitivity. Resist sensitivity was greatly improved at lower development temperatures, though at the cost of reduced contrast. In addition, we observed the thickness reduction due to thermal development was higher for larger remaining film thickness, implying the thermal development process is not just a surface process and the more volatile chains below the top surface may diffuse to the surface and get evaporated.

• Korean Journal of Child Studies
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• v.28 no.6
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• pp.183-199
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• 2007

This longitudinal study investigated developmental changes in temperament and examined social adjustment problems by early temperamental characteristics and developmental patterns of temperamental change during infancy. Subjects were 153 six-month-old infants and their mothers. Infant temperament and toddler's problem behavior were measured by the Infant Behavior Questionnaire-Revised (Garstein & Rothbart, 2003) and the Toddler Behavior Checklist (Larzelere et al., 1989), respectively. Results showed that distress to limitations, high pleasure, perceptual sensitivity, and approach increased with age, while activity level, cuddliness, and vocal reactivity decreased. Infants with high scores in activity level, fear, sadness, and approach at 6 months showed more problem behaviors at 18 months. Infants showing abrupt developmental change of high pleasure and perceptual sensitivity developed more negative behavior.

• Journal of Chest Surgery
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• v.28 no.1
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• pp.37-41
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• 1995

To determine the role of mediastinoscopy in the preoperative staging of the primary lung cancer, we studied 23 patients from January 1993 to December 1993 and compared the results of mediastinoscopy and computed tomographic scanning with the findings at thoracotomy. Mediastinoscopy was performed in 14 patients when they had larger than 10mm mediastinal nodes at computed tomographic scanning. Six of them were found to have metastatic nodes. Nine patients, who had negative computed tomographic scanning and negative mediastinoscopic results,underwent thoracotomy. One of them was found to have a metastatic mediastinal lymph node. When results from both series of patients were compared, the sensitivity and specificity of computed tomographic scanning showed 83.3% and 47.1% respectively with an accuracy of 56.5%. The results of mediastinoscopy showed that the sensitivity was 85.7%, the specificity was 100% and the accuracy was 95.7%.Because of the low accuracy rate of computed tomographic scanning, a more routine use of mediastinoscopy seems to be justified.

• Korean Journal of Child Studies
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• v.18 no.2
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• pp.191-211
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• 1997

This study investigated the characteristics of children perceived as difficult by their mothers and compared these characteristics with the "difficult temperament" from the NYLS. The subjects were 36 mothers who have more than one child between 3 and 6 years of age. The descriptions from in-depth interviews were analyzed qualitatively. The results showed that (1) Korean mothers perceived the difficult temperament of their child as low adaptability, low rhythmicity in sleep habits, negative mood, and high activity. High response sensitivity was perceived as both a positive and a difficult characteristic. (2) The temperament of their children mothers perceived as most difficult for child rearing were negative mood and low manageability. (3) The activity, adaptability, rhythmicity, response sensitivity, mood and manageability characteristics of Korean children's difficult temperament was different from the difficult temperament of the Nyls.

• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.211-224
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• 2020

Sensitivity and specificity are popular measures described by the receiver operating characteristic (ROC) curve. There are also two other measures such as the positive predictive value (PPV) and negative predictive value (NPV); however, the PPV and NPV cannot be represented by the ROC curve. Based on the total operating characteristic (TOC) curve suggested by Pontius and Si (International Journal of Geographical Information Science, 97, 570-583, 2014), explanatory methods are proposed to geometrically describe the PPV and NPV by the TOC curve. It is found that the PPV can be regarded as the slope of the right-angled triangle connecting the origin to a certain point on the TOC curve, while 1 - NPV can be represented as the slope of the right-angled triangle connecting a certain point to the top right corner of the TOC curve. When the neutral zone exists, the PPV and 1-NPV can be described as the slopes of two other right-angled triangles of the TOC curve. Therefore, both the PPV and NPV can be estimated using the TOC curve, whether or not the neutral zone is present.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.9
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• pp.55-66
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• 2018

This study aims to propose color affective model of indoor space by evaluating subjects' physiological responses according to the types of behavioral and affective system. 99 subjects(44 females, 55 males) in their 20s, who had no disorders in visual perception, participated in the experiment. To categorize the subjects based on behavioral and affective system, BAS/BIS scale and Affective scale were used. Color stimuli were composed of five basic colors and three tones: vivid, pale and dull tone of R, Y, G, B, P. For physiological experiment, right and left prefrontal alpha activity was measured to analyze prefrontal EEG asymmetry. Participants were exposed to fifteen color stimuli for 20 seconds each other under the positive and negative emotional condition in a research room with the natural light blocked. The results and conclusion of this study are as follows. Along with factors of behavioral and affective system, cluster analysis was carried out and four types were classified. Type A had high BAS sensitivity, especially high 'drive' trait, and showed high levels of 'anxiety' and 'anger'. Type B had low BAS sensitivity, especially low 'fun seeking' and low 'drive' trait, and showed low levels of 'anxiety' as well as low levels of 'happiness'. Type C had low BIS sensitivity and showed high levels of 'happiness' and low levels of 'sadness'. Type D had high BIS sensitivity and showed high levels of 'lethargy' and 'sadness'. As a result of EEG signal analysis of color stimuli, Type B, Type C, and Type D showed significant differences in prefrontal alpha asymmetry under the negative emotional stimuli. Type B showed more left prefrontal activation in the spaces with pale R and dull G. Type C showed more left prefrontal activation in the spaces with vivid Y and B, pale R, and dull R, G, P. Type D showed more left prefrontal activation in the spaces with vivid Y and P, pale R, Y, P, and dull R, Y, G, B, P. The group of high BAS sensitivity was not influenced by color stimuli under the emotional conditions, whereas the group of high BIS sensitivity was affected by color stimuli under the negative emotional conditions. They showed left prefrontal activation when they were exposed the spaces with vivid, pale, dull tones of Y and P wall.