• Steel and Composite Structures
• /
• 제19권6호
• /
• pp.1549-1560
• /
• 2015

This paper presents the characterization of fatigue crack in the A283 Grade C steel using the MMM method by identifying the effects of magnetic flux leakage towards the crack growth rate, da/dN, and crack length. The previous and current research on the relation between MMM parameters and fatigue crack effect is still unclear and requires specific analysis to validate that. This method is considered to be a passive magnetic method among other Non-Destructive Testing (NDT) methods. The tension-tension fatigue test was conducted with a testing frequency of 10 Hz with 4 kN loaded, meanwhile the MMM response signals were captured using a MMM instrument. A correlation between the crack growth rate and magnetic flux leakage produces a sigmoid shape curve with a constant values which present the gradient, m value is in the ranges of 1.4357 to 4.0506, and the y-intercept, log C in the ranges of $4{\times}10^{-7}$ to 0.0303. Moreover, a linear relation was obtained between the crack length and magnetic flux leakage which present the R-Squared values is at 0.830 to 0.978. Therefore, MMM method has their own capability to investigate and characterize the fatigue crack effects as a main source of fracture mechanism for ferrous-based materials.

• Safety and Health at Work
• /
• 제2권2호
• /
• pp.169-175
• /
• 2011

Objectives: The questionnaire of occupational stress index (OSI) has been popular in the workplace, and it has been tailored for bus drivers in Taiwan. Nevertheless, its outcomes for participants are based on self-evaluations, thus validation by their physiological stress biomarker is warranted and this is the main goal of this study. Methods: A cross-sectional study of sixty-three city bus drivers and fifty-four supporting staffs for comparison was conducted. Questionnaire surveys, 24-hour urine cortisol testing, and blood draws for dehydroepiandrosterone-sulfate (DHEA-S) testing were performed. The measured concentrations of these biological measures were logarithmically transformed before the statistical analysis where various scores of stressor factors, moderators, and stress effects of each OSI domain were analyzed by applying multiple linear regression models. Results: For drivers, the elevated 24-hour urine cortisol level was associated with a worker's relationship with their supervisor and any life change events in the most recent 3 months. The DHEA-S level was higher in drivers of younger age as well as drivers with more concerns relating to their salary and bonuses. Non-drivers showed no association between any stressor or satisfaction and urine cortisol and blood DHEA-S levels. Conclusion: Measurements of biomarkers may offer additional stress evaluations with OSI questionnaires for bus drivers. Increased DHEA-S and cortisol levels may result from stressors like income security. Prevention efforts towards occupational stress and life events and health promotional efforts for aged driver were important anti-stress remedies.

• Annals of Laboratory Medicine
• /
• 제38권6호
• /
• pp.569-577
• /
• 2018

Background: The increasing prevalence of drug-resistant tuberculosis (TB) infection represents a global public health emergency. We evaluated the usefulness of a newly developed multiplexed, bead-based bioassay (Quantamatrix Multiplexed Assay Platform [QMAP], QuantaMatrix, Seoul, Korea) to rapidly identify the Mycobacterium tuberculosis complex (MTBC) and detect rifampicin (RIF) and isoniazid (INH) resistance-associated mutations. Methods: A total of 200 clinical isolates from respiratory samples were used. Phenotypic anti-TB drug susceptibility testing (DST) results were compared with those of the QMAP system, reverse blot hybridization (REBA) MTB-MDR assay, and gene sequencing analysis. Results: Compared with the phenotypic DST results, the sensitivity and specificity of the QMAP system were 96.4% (106/110; 95% confidence interval [CI] 0.9072-0.9888) and 80.0% (72/90; 95% CI 0.7052-0.8705), respectively, for RIF resistance and 75.0% (108/144; 95% CI 0.6731-0.8139) and 96.4% (54/56; 95% CI 0.8718-0.9972), respectively, for INH resistance. The agreement rates between the QMAP system and REBA MTB-MDR assay for RIF and INH resistance detection were 97.6% (121/124; 95% CI 0.9282-0.9949) and 99.1% (109/110; 95% CI 0.9453-1.0000), respectively. Comparison between the QMAP system and gene sequencing analysis showed an overall agreement of 100% for RIF resistance (110/110; 95% CI 0.9711-1.0000) and INH resistance (124/124; 95% CI 0.9743-1.0000). Conclusions: The QMAP system may serve as a useful screening method for identifying and accurately discriminating MTBC from non-tuberculous mycobacteria, as well as determining RIF- and INH-resistant MTB strains.

• Asian Journal for Public Opinion Research
• /
• 제9권2호
• /
• pp.188-211
• /
• 2021

Decreasing response rates to traditional survey methods, like face-to-face and telephone interviews, have led survey practitioners around the world to seek new ways of conducting surveys in recent years." The COVID-19 pandemic exacerbated this problem because it made conducting face-to-face interviews even more difficult than before. For example, it made conducting face-to-face surveys infeasible in 2020 in South Korea, and so the Korean Academic Multimode Open Survey (KAMOS) was unable to conduct a planned face-to-face survey to recruit new panel members. The entire 8,514-member panel, established via two-stage probability-based sampling from 2016 to 2019, was invited to take three online/telephone surveys in 2020. Of these panel members, 1,352 responded to at least one survey in 2020. To test to what extent the panel remained representative of the adult South Korean population, we compared the two groups of panel members: those who responded to at least one survey in 2020 and those who did not. After weighting both groups on the basis of age, sex, and geographical area, we analyzed their responses to some of the questions that were asked during multiple rounds of the face-to-face panel-recruiting interviews. Using Cohen's d for survey items that could be analyzed numerically and Cramér's V for categorical items, we were able to conclude that the respondents to the 2020 surveys were equivalent to the non-respondents in terms of both demographics and in the answers they originally gave to substantive questions on a variety of topics related to social science or public opinion research, including questions about quality of life, societal issue, and politics (Cohen's d items <0.2, 95% CI; Cramér's V items <0.1, 95% CI). This analysis may provide a model for others who wish to test the continued representativeness of their panel or who would like to use a different survey mode or change some other aspect of their methodology and test whether it is equivalent to their former methodology. Our success in building a panel that retained its representativeness may be useful to those in other countries where face-to-face surveys had previously been the norm but are becoming increasingly difficult to conduct.

• 구강회복응용과학지
• /
• 제30권2호
• /
• pp.112-120
• /
• 2014

목적: 이 논문의 목적은 열가압법을 이용한 도재의 축성이 금속과 어떠한 결합력을 나타내는지 알아보는 것이다. 연구 재료 및 방법: 90개의 비귀금속 시편($4{\times}4{\times}8mm$)을 제작하여 세 개의 군으로 나누었다. 모든 시편은 군에 따라 2종류의 다른 방법으로 포세린 축성($4{\times}4{\times}3mm$)하였다: Group I : $Inspiration^{(R)}$, Group II : Ivoclar, IPS $Inline^{(R)}PoM$, Group III: GC Initial IQ-One $Body^{(R)}PoM$. 각 군의 시편의 반은 열순환시켰다. 모든 시편의 전단 결합 강도는 Instron universal testing machine을 이용하여 측정하였다. 통계학적 분석을 위해, 2-way ANOVA가 사용되었다. 결과: 열순환을 하지 않은 시편의 전단결합강도는 모든 실험군에서 유사한 값으로 나타나 통계적 유의성이 없었다(P > 0.05). 각 실험군에서 열순환 처리 한 시편에서는 전단결합강도의 감소가 나타났으나 통계적 유의성은 없었다(P > 0.05). 열순환 처리한 시편의 실험군간 전단결합강도 비교에서 실험 III군에서 높게 나타났으나 유의한 차이는 없었다(P > 0.05). 결론: 전단결합력의 관점에서 보았을 때 열가압성형 도재는 임상적으로 유의한 것으로 사료된다.

• 한국환경농학회지
• /
• 제32권3호
• /
• pp.231-239
• /
• 2013

본 연구는 병저항성 OsCK1 유전자와 제초제저항성 PAT 유전자가 도입된 병저항성 GM벼에서 도입 유전자의 발현 검증과 수서환경의 비표적 생물체인 잉어와 미꾸리에 미치는 영향을 확인하기 위해 수행되었다. 병저항성 GM벼에 도입된 OsCK1와 PAT 유전자의 PCR 분석 결과, 병저항성 GM벼에서만 특이적인 밴드가 검출되었으며, PAT 단백질 발현량을 ELISA 분석한 결과, 병저항성 GM벼에서만 $45.44{\pm}2.23{\mu}g/g$ 수준으로 검출되었고, 모품종인 낙동벼에서는 검출되지 않았다. 병저항성 GM벼와 낙동벼의 미꾸리(Misgurnus anguillicaudatus)와 잉어(Cyprinus carpio)에 대한 급성독성시험을 실시한 결과, 48시간 및 96시간-$LC_{50}$ 은 5,000 mg/L 이상으로 나타났다. 48시간 및 96시간 무영향농도 NOEC)는 5,000 mg/L이었다. 급성독성 시험기간 중 병저항성 GM벼와 낙동벼간의 pH, DO, 수온, 체중 및 전장에 대한 유의적인 결과는 나타나지 않았다.

• 대한통합의학회지
• /
• 제12권2호
• /
• pp.47-53
• /
• 2024

Purpose : This study investigated the effects of concentric and eccentric contractions on muscle strength using an isokinetic dynamometer (ID) in college students in their 20s. It aimed to understand the impact of differences between the dominant and non-dominant sides on strength asymmetry and to elucidate the clinical implications of these differences to establish an appropriate posture and environment for patients. Methods : The experiment was conducted with 30 healthy adult participants. Prior to the experiment, participants underwent a warm-up targeting the shoulders, and efforts were made to eliminate factors that could potentially influence the measurement results. Subsequently, the maximum safe range of motion of shoulder joint abduction, extension, and flexion was measured using an isokinetic muscle function testing device. Muscle strength was assessed using concentric and eccentric contractions alternating between the dominant and non-dominant sides, and paired sample t-tests were used for the analysis. Results : There was no significant difference between bilateral peak torques for eccentric contraction in shoulder joint abduction, extension, and flexion (p>0.05). There was also no significant difference between bilateral peak torques for concentric contraction in shoulder joint abduction, extension and flexion (p>0.05). Conclusion : This study found no statistically significant difference in muscle strength between the dominant and non-dominant sides during concentric and eccentric contractions. However, previous studies have shown significant differences between the dominant and non-dominant sides during eccentric and concentric contractions during internal shoulder rotation in the general population, as well as significant differences in the upper trapezius muscle. Therefore, further research is needed to support the application of different intensities for bilateral muscle strengthening exercises in clinical practice.

• Clinical and Experimental Reproductive Medicine
• /
• 제39권4호
• /
• pp.172-175
• /
• 2012

Objective: The aim of this study is to investigate the various causes of male infertility using multiple approaches. Methods: Nine-hundred-twenty infertile male patients were analyzed at their first visit with one physician between January 1 and December 31, 2009. All patients were subjected to physical examination and semen analysis and azoospermic patients underwent hormonal testing, chromosomal tests, and testicular biopsy. Semen analysis was based on the definition of the World Health Organization. Results: Among the 920 patients, 555 patients (60.3%) had semen results within the normal range, 269 patients (29.2%) within the abnormal range, and 96 (10.5%) were diagnosed with azoospermia. Varicoceles were diagnosed in 84 of the 555 normal-range patients (15.1%) and in 113 of the 269 abnormal-range patients (42.0%). Of the 96 patients with azoospermia, 24 patients (25%) were diagnosed with obstructive azoospermia, 68 patients (71%) with non-obstructive azoospermia, and 4 patients (4%) with retrograde ejaculation. Conclusion: Various causes of male infertility have been reported and diverse treatment methods can be adopted for each cause. In this regard, research must be conducted on a larger number of patients to accurately assess the various causes of infertility in Korean patients and to investigate various infertility treatment methods.

• 대한간호학회지
• /
• 제45권3호
• /
• pp.357-366
• /
• 2015

Purpose: This study was done to develop an evidence-based incontinence care protocol through an adaptation process and to evaluate the effects of the protocol. Methods: The protocol was developed according to the guideline of adaptation. A non-randomized controlled trial was used for testing the effects of the new Incontinence Care Protocol. A total of 120 patients having bowel incontinence with Bristol stool type 5, 6, and 7 and admitted to intensive care units were recruited to this study. The newly developed incontinence care protocol was used with patients in the experimental group and conventional skin care was given to patients in the control group. Outcome variables were incontinence-associated dermatitis (IAD) severity, pressure ulcer occurrence and severity. Results: The experimental group had significantly less severe IAD (t=6.69, p <.001), lower occurrence of pressure ulcers (${\chi}^2=7.35$, p =.007), and less severity of pressure ulcers (Mann-Whitney=86.00, p =.009) than the control group. Conclusion: Use of this incontinence care protocol has the effects of preventing pressure ulcers and inhibiting worsening of IAD and pressure ulcers. Therefore, this incontinence care protocol is expected to contribute to managing IAD and pressure ulcers.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.120-125
• /
• 2007

Put Abstract text here The strain distribution measurement for wall thinned pipe bends by ESPI is presented. Defect types observed in the steel piping in the nuclear power plants (NPP) are the crack at the weld part and the wall thinning defect in the pipe bends. Especially, the wall thinning defects in the pipe bends due to the flow-accelerated corrosion (FAC) is a main type of defects observed in the carbon steel piping system. ESPI is one of the optical non-destructive testing methods and can measure the stress and the strain distribution of the object subjected by the tensile loading or the internal pressure. In this paper, the strain distribution of the wall thinned pipe bends due to the internal pressure will be measured by ESPI technique and the results are discussed. From the results, the size of the wall thinning defect can also be measured approximately.