• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.714-719
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• 2017

The contaminated engine oil by fuel can intimidate driver safety due to vehicle problems such as engine abrasion, fire and sudden unintended acceleration. In this study, we investigate various functional properties of the engine oil contaminated with fuel. The test results indicated that the engine oil contaminated with fuel had relatively low values of the flash point, pour point, density, kinematic viscosity and cold cranking simulator. Furthermore, a four ball test suggested that the contaminated engine oil increased wear scar due to the poor lubricity. Moreover, SIMDIST (simulated distillation) using ASTM D2887 was applied to analyze fuel characteristics in an engine oil. The SIMDIST analysis result showed a lower carbon number, and the fuel was detected at an earlier retention time than that of using engine oil in chromatogram. Also, it is possible to quantitatively analyze for fuel contents in the engine oil. The SIMDIST method for the diagnosis of oil conditions can be used whether the fuel was involved or not, instead of analyzing other physical properties that require various analytical instruments, large volumes of oil samples, and long analysis time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.379-388
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• 2016

There are various system defects from weapons manufacturing due to the numerous production processes and various production environments. The first kind of defect is patent defects, which can be detected by visual inspection, functional testing, and existing quality control procedures during the manufacturing process. The second kind is latent defects, which cannot be detected though existing quality management approaches because of the complexity of the system and manufacturing process. To minimize the initial defect problems, environmental stress screening (ESS) is needed to detect the defects, remove them, and improve the product conditions based on the environmental stress conditions of temperature and vibration. We implemented a tool for quantitative ESS effectiveness analysis and profile design automation based on MIL-HDBK-344 and verified it using six scenarios with different temperature stress, vibration stress, and test designs.

• Journal of KIISE:Software and Applications
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• v.41 no.8
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• pp.533-544
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• 2014

The hardware-based software has been loaded in almost all industrial fields including the embedded system field. As it is increasingly important to control product quality, the more businesses are expending great quality cost. However, most domestic corporations in Korea are bent on spending more money solving problems caused by poor quality rather than prevention of quality loss cost. Therefore, it's time to improve to use quality prevention cost efficiently. As for this, there has been a growing interest in controlling quantitative quality, but the managing activities for quantitative quality require a high maturity process, belonging to Level 4 and 5. So it is necessary that statistical quality control activities should be fulfilled. This study introduces various measures to build up quality control among the process areas of TMMi Level 5 to help establish the high maturity test processes of statistical quality control.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.301-306
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• 2016

Objectives: Direct-reading instrument(Photoionization detectors, PID) and quantitative analysis using active type air sampling (Gas chromatography-flame ionization detector, GC-FID) were tested to evaluate their ability to detect volatile organic compounds(VOCs) in a semiconductor manufacturing plant. Methods: The organic compounds used were acetone and ethanol which are normally used as cleaning solutions in the semiconductor manufacturing. The evaluation was based on the preparation of test solutions of known acetone and ethanol concentration in a chamber($600{\times}600{\times}1150mm$). Samples were prepared that would be equivalent to 5~100 ppm for acetone and 10~ 200 ppm ethanol. GC-FID and PID were evaluated simultaneously. Quantitative analysis was performed after sampling and the direct-reading instrument was checked using real-time data logging. Results: Positive correlations between PID and GC-FID were found for acetone and ethanol at 0.04~2.4% for acetone(TLV: 500 ppm) and 0.1~8.3% for ethanol(TLV: 1000 ppm). When the sampling time was 15 min, concentration of test solution was the most similar between measurement methods. However, the longer the sampling time, the less similar the results. PID and GC-FID had similar exposure patterns. Conclusions: The results indicate that PID and GC-FID have similar exposure pattern and positive correlation for detection of acetone and ethanol. Therefore, PID can be used for exposure monitoring for VOCs in the semiconductor manufacturing industry. This study has significance in that it validates measuring occupational exposure using a portable device.

• Mass Spectrometry Letters
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• v.1 no.1
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• pp.25-28
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• 2010

The high-throughput identification and accurate quantification of proteins are essential strategies for exploring cellular functions and processes in quantitative proteomics. Stable isotope tagging is a key technique in quantitative proteomic research, accompanied by automated tandem mass spectrometry. For the differential proteome analysis of mouse neuronal cell lines, we used a multiplexed isobaric tagging method, in which a four-plex set of amine-reactive isobaric tags are available for peptide derivatization. Using the four-plex set of isobaric tag for relative and absolute quantitation (iTRAQ) reagents, we analyzed the differential proteome in several stroke time pathways (0, 4, and 8 h) after the mouse neuronal cells have been stressed using a glutamate oxidant. In order to obtain a list of the differentially expressed proteins, we selected those proteins which had apparently changed significantly during the stress test. With 95% of the peptides showing only a small variation in quantity before and after the test, we obtained a list of eight up-regulated and four down-regulated proteins for the stroke time pathways. To validate the iTRAQ approach, we studied the use of oxidant stresses for mouse neuronal cell samples that have shown differential proteome in several stroke time pathways (0, 4, and 8 h). Results suggest that histone H1 might be the key protein in the oxidative injury caused by glutamate-induced cytotoxicity in HT22 cells.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.21-25
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• 2004

People in tropics have the ability to tolerate heat by residential permanence in the tropics. Previously, we have shown that African and Thai subjects who lived for whole their lives in only their respective countries sweat less under hot conditions than South Koreans who also lived whole their lives in Korea. The difference in sweating responses was attributed to the dissimilar central and peripheral sweating mechanisms operating in people from both groups. In the present study, acetylcholine (ACh), the primary transmitter for the sudomotor functions, was iontophoretically administered to South Koreans and Africans to determine the characteristic sudorific responses of their acclimatized biologic make-up to their respective environments. Using quantitative sudomotor axon reflex test (QSART), direct (DIR) and axon reflex (AXR) responses were evaluated. The findings revealed that the sweat onset-time among South Koreans was 0.91 min earlier than among Africans (P<0.01). The axon reflex sweat volume of nicotine receptor activity AXR(1) and sweat volume of muscarinic receptor activity DIR(2) among South Koreans were 79% and 53% greater (P<0.01), respectively. These results indicate that the reduced thermal sweating among Africans is at least in part attributed to the diminished sensitivity of sweat glands to ACh.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.4
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• pp.231-240
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• 2009

Purpose：The aim of this study was to determine the effect of active sling exercise on shoulder subluxation in hemiplegic patients. Methods：Twenty persons with shoulder subluxation were randomly divided into two groups; the experimental group(10 persons) and the control group(10 persons). Usual physical therapy and occupational therapy were applied in all groups in a day for 4 weeks. Additionally the experimental group was received 30 minutes sling active exercise (flexion, extention, adduction, abduction, intenal rotation, external rotation, horizontal adduction, horizontal abduction) for shoulder joint in a day for 4 weeks. I investigated the therapeutic effect of sling exercise through the Wolf motor function test (WMFT), Quantitative radiographic measurements and range of motion test at pre and post intervention period. Results：The passive range of motion was significantly increased in the experimental group compare with the control group. However, the active range of motion was no statistically significantly difference in both of the experimental and the control group. The level of WMFT was significantly decreased in the experimental group compared with control group. Although, there was no significantly difference the degree of the shoulder subluxation was more decreased in experimental group than control group. Conclusion：Taken together, these results suggest that sling exercise could be beneficial therapeutic method for hemiplegic shoulder. But to generalize it, more study and exercise program might be needed to confirm its availability.

• Journal of Cancer Prevention
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• v.23 no.4
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• pp.176-182
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• 2018

Background: Family physicians (FPs) play an important role in cancer control. The aim of this study was to understand the functions of FPs in cancer control and to explore FPs' perceptions of their own roles and the difficulties they face in cancer control in Karabuk province, Turkey. Methods: The study consisted of two methodological parts. The qualitative part included a descriptive study in which data were collected from 87.5% (n=56) out of all FPs in Karabuk using a questionnaire. In the quantitative part, in-depth interviews with 15 FPs were conducted and analyzed through content analysis. Results: Half of the FPs (50.0%) provided cancer prevention information for their registered people, focusing on especially smoking cessation. In the last three months, the proportion of FPs who had not invited anyone to screenings was 37.5% for the pap test, 26.8% for the mammography, 19.0% for the fecal occult blood test and 34.5% for the colonoscopy. Only 16.1% of them reported that they made home visits for cancer patients. In the qualitative part of study, the following themes were highlighted: the perceived responsibilities of FPs regarding cancer control; the effect of geographically undefined working area of FPs; the issues with coordination between FPs and specialists; the effect of the number of primary care team members. Conclusions: Cancer control services provided by FPs have significant problems in terms of the FPs' approach to the services and their content, continuity and coordination.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.11-20
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• 2019

The purpose of this study was to propose a new approach for quantifying in situ rock mass damage, which would include a degree-of-damage and the degraded strength of a rock mass, along with its prediction based on real-time Acoustic Emission (AE) observations. The basic approach for quantifying in-situ rock mass damage is to derive the normalized value of measured AE energy with the maximum AE energy, called the degree-of-damage in this study. With regard to estimation of the AE energy, an AE crack source location algorithm of the Wigner-Ville Distribution combined with Biot's wave dispersion model, was applied for more reliable AE crack source localization in a rock mass. In situ AE wave attenuation was also taken into account for AE energy correction in accordance with the propagation distance of an AE wave. To infer the maximum AE energy, fractal theory was used for scale-independent AE energy estimation. In addition, the Weibull model was also applied to determine statistically the AE crack size under a jointed rock mass. Subsequently, the proposed methodology was calibrated using an in situ test carried out in the Underground Research Tunnel at the Korea Atomic Energy Research Institute. This was done under a condition of controlled incremental cyclic loading, which had been performed as part of a preceding study. It was found that the inferred degree-of-damage agreed quite well with the results from the in situ test. The methodology proposed in this study can be regarded as a reasonable approach for quantifying rock mass damage.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.3
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• pp.227-239
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• 2021

Purpose: This study used an exploratory sequential approach (mixed methods) design to explore essential meaning through comparing and analyzing the experiences of nursing students in virtual simulation practice and high fidelity simulation practice education in parallel. Methods: The study participants were 20 nursing students, and data were collected through focus group meetings from July 17 to August 5, 2020, and via online quantitative data from November 10 to November 15, 2020. The qualitative data were analyzed using Giorgi's phenomenological method, and the quantitative data were analyzed using descriptive statistics, the Mann-Whitney U test, Kruskal-Wallis H test analysis of variance and Spearman's ρ correlation. Results: The comparison between the two simulation training experiences was shown in five contextual structures, as follows: (1) reflection of the clinical field, (2) thinking theorem vs. thinking expansion, (3) individual-centered learning vs. team-centered learning, (4) attitudes toward participating in practical training, (5) metacognition of personal competency as a prospective nurse, and (6) revisiting the method of practice training. There was a positive correlation between satisfaction with the practice and the clinical judgment ability of high fidelity simulation, which was statistically significant (r=.47, p=.036). Conclusion: Comparing the experiences between virtual simulation practice training and high fidelity simulation practice training, which has increased in demand due to the Coronavirus Disease-2019 pandemic, is meaningful as it provides practical data for introspection and reflection on in-campus clinical education.