• Journal of Information Processing Systems
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• v.19 no.2
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• pp.173-188
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• 2023

To improve the shock-resistance of piezoresistive high-g accelerometer, we propose a design of piezoresistive high-g accelerometer. The accelerometer employs special-shaped proof masses system with a cross gap. Four tiny sensing beams are bonded above the cross gap. The expression of the deformation, natural frequency and damping is deduced, and the structural parameters are optimized. The accelerometer structure is simulated and verified by finite element method (FEM) simulation. The results show that the range of the accelerometer can reach 200,000 g, the natural frequency is 453.6 kHz, and the cross-axis sensitivity of X-axis and Y-axis is 0.25% and 0.11%, respectively, which can apply to the measurement of high shock. Contrastively, the cross-axis sensitivity of X-axis and Y-axis is respectively, reduced by 93.2% and 96.9%. The sensitivity of our accelerometer is 0.88 μV/g. It is of great value for the application of piezoresistive high-g accelerometer with high shock-resistance.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.169-175
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• 2012

The sensitivity of the performance measures such as the mean and the standard deviation of the queue length and the blocking probability with respect to the moments of the service time are numerically investigated. The service time distribution is fitted with phase type(PH) distribution by matching the first three moments of service time and the M/G/c retrial queue is approximated by the M/PH/c retrial queue. Approximations are compared with the simulation results.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1870-1877
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• 1990

The electromagnetic properties of P- and n-channel split drain magnetic sensitive MOSFET fabricated using 2\ulcorner design rules and CMOS process technology has been investigated. The achieved output voltage in the double drain MOSFET was 160mV at 10\ulcorner drain current and magnetic flux density of 10kG, and the sensitivity was 1.6x10**3 V/A\ulcornerG. A further higher sensitivity was obtained by introducing a third drain in the split region. In this case, the triple drain MOSFET showed a much higher sensitivity of 2x10**3 V/A\ulcornerG under the same condition. Also, the linearity of output voltage vs. magnetic flux density was excellent.

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.945-949
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• 1995

In order to investigate the performance of compression-type accelerometer on piezoelectric properties, PZT materials have been studied. The ring-shaped piezoelectric elements were prepared using commercial PZT powders by conventional ceramic process. Their estimated relative dielectric constant, piezoelectric charge constant (d33) and voltage constant (g33) values showed 390∼3400, (90∼593)×10-12 C/N and (19.5∼40.5)×10-3 V-m/N, respectively. The charge sensitivity of accelerometer is proportional to the piezoelectric charge constant value (d33) of PZT, but its voltage sensitivity is related with the piezoelectric voltage constant (g33). Since the mounted resonance frequency and sensitivity are dependent on the seismic mass as well as physical charateristics and size of PZT elements, the suitable considerations between two components are required for accelerometer's design.

• Earthquakes and Structures
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• v.1 no.1
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• pp.109-127
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• 2010

This work aims at introducing structural sensitivity analysis capabilities into existing commercial finite element software codes for the purpose of mapping retrofit strategies for a broad group of structures including heritage-type buildings. More specifically, the first stage sensitivity analysis is implemented for the standard deterministic environment, followed by stochastic structural sensitivity analysis defined for the probabilistic environment in a subsequent, second phase. It is believed that this new generation of software that will be released by the industrial partner will address the needs of a rapidly developing specialty within the engineering design profession, namely commercial retrofit and rehabilitation activities. In congested urban areas, these activities are carried out in reference to a certain percentage of the contemporary building stock that can no longer be demolished to give room for new construction because of economical, historical or cultural reasons. Furthermore, such analysis tools are becoming essential in reference to a new generation of national codes that spell out in detail how retrofit strategies ought to be implemented. More specifically, our work focuses on identifying the minimum-cost intervention on a given structure undergoing retrofit. Finally, an additional factor that arises in earthquake-prone regions across the world is the random nature of seismic activity that further complicates the task of determining the dynamic overstress that is being induced in the building stock and the additional demands placed on the supporting structural system.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.143-147
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• 2003

Sensitivity of Phytophthora infestans isolates to fungicides metalaxyl and ethaboxam in Korea was examined with 260 isolates for 3 years (9 isolates in 2000,93 isolates in 2001, and 158 isolates in 2002). Both Al and A2 mating types were found from the isolates collected for 3 years. Al mating type was dominant in the population with 8 isolates (88.9%) in 2000, 84 isolates (89.4%) in 2001, and 138 isolates (87.3%) in 2002. Only some isolates from diseased tomatoes in Buyergun and diseased potatoes in Pyeongchanggun were of the A2 mating type. As for metalaxyl sensitivity, 77.0% of the isolates were moderately resistant with 8 isolates (88.9%) in 2000, 73 isolates (77.7%) in 2001, and 120 isolates (75.9%) in 2002. Meanwhile, those found resistant were 1 isolate (11.1%) in 2000, 16 isolates (17.0%) in 2001, and 33 isolates (20.9%) in 2002. Only 5 isolates (3.2%) were sensitive to metalaxyl in 2002. There was no significant difference in the sensitivity among years. As for ethaboxam, no isolate was able to grow at 5.0 $\mu\textrm{g}$ /ml, and only four isolates (1.5 %) grew at 1.0 $\mu\textrm{g}$ /ml with heavy retardation compared with the untreated control. Based on these 3-year results, the minimum inhibitory concentration (MIC) of ethaboxam to p. infestans was determined to be 0.2-1.0 $\mu\textrm{g}$ /ml. Results indicate that resistance development by p. infestans to ethaboxam is not likely to occur in the natural condition. furthermore, there was no indication of cross resistance between metalaxyl and ethaboxam because all the isolates, regardless of classification for their sensitivity to metalaxyl, were not able to grow at 5.0 $\mu\textrm{g}$ /ml of ethaboxam.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.69-75
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• 2012

In response of fungicides for control of gray snow mold, isolates of Typhula incarnata were collected from three golf courses in 2012 Yongpyeong, Korea and tested for sensitivity to propiconazole, tebuconazole and azoxystrobin fungicides. Four discriminatory concentrations were used to detect in vitro sensitivity of 50 isolates. Mean 50% effective concentration inhibiting mycelial growth ($EC_{50}$) values for tebuconazole was the lowest among the three fungicides. The $EC_{50}$ value of tebuconazole ranged from 0.0005 ${\mu}g\;ml^{-1}$ to 0.014 ${\mu}g\;ml^{-1}$ with a mean of 0.0048 ${\mu}g\;ml^{-1}$. The mean $EC_{50}$ values of propiconazole in triazole family was 0.5825 (0.78-1.651) ${\mu}g\;ml^{-1}$. $EC_{50}$ value of azoxystrobin ranged from 0.0017 ${\mu}g\;ml^{-1}$ to 0.131 ${\mu}g\;ml^{-1}$ with a mean of 0.0278 ${\mu}g\;ml^{-1}$. There was no correlation among $EC_{50}$ values for propiconazole, azoxystrobin and tebuconazole indicating no cross-resistance relationships with each other. Results of this study were confirmed no resistance isolates in vitro sensitivity of T. incarnata of three fungicides in Yongpyeong.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.4
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• pp.312-320
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• 2022

Purpose: Screening serologic tests are important tools for the diagnosis of celiac disease (CD). Immunoglobulin (Ig)G anti-deamidated gliadin peptide (anti-DGP) is a relatively new autoantibody thought to have good diagnostic accuracy, comparable to that of anti-tissue transglutaminase (anti-tTG) antibody. Methods: Pediatric patients (n=86) with a clinical suspicion of CD were included. Duodenal biopsy, anti-tTG, and IgG anti-DGP antibody tests were performed. The patients were divided into CD and control groups based on the pathological evaluation of duodenal biopsies. The diagnostic accuracy of serological tests was determined. Results: IgA anti-tTG and IgG anti-DGP antibodies were positive in 86.3% and 95.4% of patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the IgA anti-tTG test were 86.3%, 50.0%, and 68.6%, respectively, and those of the IgG anti-DGP test were 95.4%, 85.7%, and 90.7%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.84 (95% confidence interval [CI], 0.74-0.91) for IgA anti-tTG test and 0.93 (95% CI, 0.86-0.97) for IgG anti-DGP test. The comparison of IgA anti-tTG and IgG anti-DGP ROC curves showed a higher sensitivity and specificity of the IgG anti-DGP test. Conclusion: IgG anti-DGP is a reliable serological test for CD diagnosis in children. High tTG and DGP titers in the serum are suggestive of severe duodenal atrophy. The combined use of IgA anti-tTG and IgG anti-DGP tests for the initial screening of CD can improve diagnostic sensitivity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.464-469
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• 2005

Optimum sensitivity analysis (OSA) is the process to find the sensitivity of optimum solution with respect to the parameter in the optimization problem. The prevalent OSA methods calculate the optimum sensitivity as a post-processing. In this research, a simple technique is proposed to obtain optimum sensitivity as a result of the original optimization problem, provided that the optimum sensitivity of objective function is required. The parameters are considered as additional design variables in the original optimization problem. And then, it is endowed with equality constraints to penalize the additional variables. When the optimization problem is solved, the optimum sensitivity of objective function is simultaneously obtained as Lagrange multiplier. Several mathematical and engineering examples are solved to show the applicability and efficiency of the method compared to other OSA ones.

• Tuberculosis and Respiratory Diseases
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• v.67 no.4
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• pp.331-337
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• 2009

Background: The whole-blood interferon-gamma release assay (QuantiFERON-TB Gold [QFT-G]: Cellestis, Carnegie, Victoria, Australia) has been studied primarily for the use of diagnosing active pulmonary tuberculosis (TB) or latent TB. In the present study, the usefulness of QFT-G was evaluated for the diagnosis of extra-pulmonary tuberculosis (EP-TB). Methods: From June 2006 to February 2009, we evaluated the usefulness of QFT-G in patients (n=65) suspected with EP-TB, retrospectively. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the QFT-G assay were analyzed. Results: EP-TB was diagnosed in 33 (51%) participants. The overall sensitivity, specificity, PPV, and NPV of the QFT-G assay for EP-TB were 78%, 79%, 81%, and 77%, respectively. Of the 33 with EP-TB, 14 (42%) were diagnosed with TB pleurisy, 7 (21%) with TB lymphadenitis, 7 (21%) with intestinal TB, and 5 (15%) with EP-TB in other sites. In subgroup analyses according by site of infection, the QFT-G showed 86% sensitivity, 64% specificity, and 78% NPV in TB pleurisy. On the other hand, the sensitivity, specificity, and NPV of the assay were 71%, 83% and 71%, respectively in TB lymphadenitis, and 86%, 100% and 88%, respectively in intestinal TB. Among the patients with suspected alternative site EP-TB, the sensitivity, specificity, and NPV of the assay were 50%, 80% and 67%, respectively. Conclusion: The QFT-G assay showed moderate diagnostic accuracy in EP-TB. However, negative QFT-G assay does not exclude EP-TB because of the low NPV of this assay.