• Journal of Mechanical Science and Technology
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• 제20권3호
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• pp.319-328
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• 2006

A simple approximation method for the stress intensity factor at the tip of the axial semielliptical cracks on the cylindrical vessel is developed. The approximation methods, incorporated in VINTIN (Vessel INTegrity analysis-INner flaws), utilizes the influence coefficients to calculate the stress intensity factor at the crack tip. This method has been compared with other solution methods including 3-D finite element analysis for internal pressure, cooldown, and pressurized thermal shock loading conditions. For these, 3-D finite-element analyses are performed to obtain the stress intensity factors for various surface cracks with t/R=0.1. The approximation solutions are within $\pm2.5%$ of the those of finite element analysis using symmetric model of one-forth of a vessel under pressure loading, and 1-3% higher under pressurized thermal shock condition. The analysis results confirm that the approximation method provides sufficiently accurate stress intensity factor values for the axial semi-elliptical flaws on the surface of the reactor pressure vessel.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.355-356
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• 2000

Three 'stress probe' plasmids were constructed and characterized which utilize a green fluorescent protein (CFP) as a non-invasive reporter to elucidate Escherichia coli cellular stress responses in quiescent or 'resting' cells. Facile detection of cellular stress levels was achieved by fusion of three heat shock stress protein promoter elements, those of the heat shock transcription factor ${\sigma}^{32}$, pretense subunit ClpB, and chaperone DnaK, to the reporter gene $gfp_{uv}$. When perturbed by chemical or physical stress (such as heat shock, nutrient (amino acid) limitation, addition of IPTG, acetic acid, ethanol, phenol, antifoam, and salt (osmotic shock), the E. coli cells produced GFPuv which was easily detected from within the cells as emitted green fluorescence. A temporal and amplitudinal mapping of these responses was performed, demonstrating regions where quantitative delineation of cell stress was afforded.

• 대한기계학회논문집
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• 제18권12호
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• pp.3136-3148
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• 1994

This paper proposed the method of fracture integrity evaluation for semi-elliptical crack. Plane strain fracture toughnesses are used to compare with the thermal shock stress intensity factors for semi-elliptical crack obtained by Vainshtok weight function method. The method is applied to the finite Cr Mo V and 2.25Cr Mo steel plates with semi-elliptical crack under the thermal shock. For the purpose, tensile property and fracture toughness with respect to the temperature are measured. To verify the method, thermal shock experiments are carried. The theoretical predictions are in good agreement with the experiments.

• 한국정밀공학회지
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• 제17권12호
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• pp.76-81
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• 2000

Analysis on failure of the panel glass under mechanical shock is the main topic of this study. Since the glass for the LCD panel is thin, it needs to be designed to have enough toughness against mechanical shock. In this paper, a process of estimating fracture of the panel glass is proposed to guarantee reliability of the product. The fracture toughness of the panel glass is used as a criterion of the fracture based on an experimental approach. The stress intensity factor was calculated considering a model with the largest initial crack size on a cut surface and with the boundary force obtained from a dynamic finite element analysis. Critical surface roughness on the cut surface of a typical glass panel, to prevent fracture in case of bending mode, is obtained.

• Clinics in Shoulder and Elbow
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• 제7권1호
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• pp.35-40
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• 2004

Purpose: The aim of this study was to investigate effects of calcific lesion on shockwave therapy of the tennis elbow. Materials and Methods: twenty-four patients with refractory tennis elbow were treated with shock waves. The patients were evaluated by assessment of pain using visual analog scale (VAS) and simple elbow test (SET). Comparision of clinical outcomes for the patients with and without calcification in the extensor tendon and/or cortical irregularity of lateral condyle was tried to determine if this could be a possible prognostic factor in clinical settings. Overall clinical outcomes were evaluated by Roles and Maudsley score at 12 months after ESWT. Results: Significant improvement of symptoms were observed in 20 (83 %) patients at 12 months follow up according to Roles and Maudesley scores. The patients with calcification and/or cortical irregularity improved significantly better, when compared to the patients without calcification and/or cortical irregularity at follow up. Conclusion: This study suggests that shock waves therapy could be considered as effective and noninvasive treatment modality for refractory tennis elbow. Also calcific deposit in extensor tendon and/or cortical irregularity of the lateral epicondyle was seem to be good prognostic factor for shock wave therapy for tennis elbow

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.406-411
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• 2003

One of the trends on information storage device is focused on the development of micro-optical devices with OFH (Optical Flying Head). Many different types of sliders for OFH and optical component systems have been introduced in the literature. However, the important issue on the mechanical system, which consists of suspension, swing arm and VCM (Voice Coil Motor) part has not been discussed up to date. In this research, we analyses the suspension, which is used for the small form factor MO drive. The analysis is in process two ways. One is probabilistic analysis, another is dynamic shock analysis. Probabilistic analysis is a technique you can use to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can and out how much the results of a finite elements analysis are affected by uncertainties in the model. Dynamic shock analysis is used for the mobile applications. The mechanical robustness of the suspension simulating the shock responses of a disk-suspension is proposed in this paper.

• Animal cells and systems
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• 제4권2호
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• pp.181-186
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• 2000

The expression of $p21^{WAF1/ClP1/SDl1}$, one of the cyclin-dependent kinase inhibitors, is regulated by a variety of transcription factors including p53 and STAT. Heat shock induces the expression of p21 in a temperature- and time-dependent manner. Although the p21 induction by heat shock has been reported to be controlled by p53, a p53-independent mechanism Is also involved. To understand the p53-independent regulation of heat shock-induced p21 expression, we searched the promoter region of p21 gene and found one or two heat shock element (HSE)-like sequences in human, rat, and mouse. Electromobility shift assay (EMSA) showed that heat shock factor (HSF) could bind to these HSE-like sequences In response to heat shock, even though to a lesser extent than to HSE. In addition, p21 promoter deletion analysis revealed that heat shock activated a p21 deletion promoter construct containing the HSE-like sequences but lacking p53-binding sites, but not a promoter construct containing neither HSE-like sequences nor the p53-responsive element. Furthermore, the p21 induction by heat shook was significantly inhibited in confluent cells in which heat shock-induced HSF activation was reduced. These results suggest that the transcriptional regulation of p21 by heat shock may be mediated through activation and binding to HSE-like sequences of HSF.

• 산경연구논집
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• 제11권3호
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• pp.7-17
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• 2020

Purpose: This study reexamines the test on the pricing of accruals quality. Theory suggests that information risk is a priced risk factor. Using accruals quality as the proxy for information risk, researchers have tested the pricing of information risk. The results are inconsistent potentially because of the information shock in the realized returns that are used as the proxy for expected returns. Based on this argument, this study revisits this issue excluding information-shock-free measure of expected returns. Research design, data and methodology: This study estimates expected returns using the vector autoregression model. This method extracts information shocks more thoroughly than the methods in prior studies; therefore, the concern regarding information shock is minimized. As risk premiums are larger in recession periods than in expansion periods, recession and expansion subsamples were used to confirm the robustness of the main findings. For the pricing test, this study uses two-stage cross-sectional regression. Results: Empirical results find evidence that accruals quality is a priced risk factor. Furthermore, this study finds that the pricing of accruals quality is observed only in recession periods. Conclusions: This study supports the argument that accruals quality, as well as the pricing of information risk, is a priced risk factor.

• 대한간호학회지
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• 제47권5호
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• pp.589-599
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• 2017

Purpose: The purpose of this study was to develop a scale to assess the transition shock experienced by newly graduated nurses, and test the validity and reliability of the scale. Methods: The initial items were identified through a review of literature and in-depth interviews with nine newly graduated nurses. Content validation of the items was evaluated by five nurse professors and three nurses. Participants were 269 newly graduated nurses who worked at six acute care hospitals in Busan, Ulsan, and Yangsan, South Korea. Data were analyzed using item analysis, exploratory and confirmatory factor analysis, criterion related validity, and internal consistency. Results: The final scale consisted of 18 items and six factors (conflict between theory and practice, overwhelming workload, loss of social support, shrinking relationship with co-workers, confusion in professional nursing values, and incongruity in work and personal life), which explained 71.3% of the total variance. The six subscale model was validated by confirmatory factor analysis. Cronbach's alpha for the total items was. 89. Convergent validity was evaluated by analyzing total correlation with burnout (r=.71, p<.001) and turnover intention (t=5.84, p<.001). Conclusion: This scale can be used in the development of nursing interventions to reduce the transition shock experienced by newly graduated nurses.

• 천문학회보
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• 제37권1호
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• pp.96.2-96.2
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• 2012

We statistically examined ULF Pc 3-5 wave power in the regions of undisturbed upstream solar wind, quasi-parallel shock (and foreshock), quasi-perpendicular shock, and the magnetosheath to understand how and to what extent the wave power changes as the solar wind propagates to the magnetosheath. For this study, we used the magnetic field data from the THEMIS spacecraft and Wind (as shifted to the bow shock nose) for May-November in 2008 and 2009. The statistical results show that, in the case of the Pc5 wave power, the sheath power is roughly proportional to the upstream power for both quasi-parallel (and foreshock) and quasi-perpendicular shock regions. Also we identified undisturbed upstream condition from WIND as being well away from foreshock region, and found that the sheath power can be larger for quasi-parallel shock region by a factor of 5-15 than for quasi-perpendicular shock region. In the cases of Pc 3 and Pc4 waves, we found the higher sheath power when associated with the foreshock than with the quasi-perpendicular shock region.