• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.4
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• pp.270-277
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• 1997

Plastic anisotropy is one of important factors which determine the drawability of a steel sheet. It has been mainly measured by mechanical tensile test. From the ultrasonic velocities propagating along the relative directions to the rolling direction, CODF(crystallite orientation distribution function) can be measured and ODC's(orientation distribution coefficients) has some correlations with the plastic anisotropy. In this study the correlations between the plastic anisotropy and ODC's of the cold rolled steel sheet were measured. From the results of ultrasonic velocity measurements the average normal anisotropy, $\bar{\gamma}$ and the average planar anisotropy, ${\Delta}r$ could be predicted within the accuracy of ${\pm}0.082$ and ${\pm}0.096$, respectively. Acoustic resonance method was applied to measure the ultrasonic velocities and EMAT's were used for generating and detecting the ultrasonic waves.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1879-1883
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• 2014

Background: The relationship between obesity and prostate cancer aggressiveness is controversial in recent studies, partly because BMI is the only generally applied marker of obesity. Our study aimed at evaluating the correlation of periprostatic fat (PF) on magnatic resonance imaging (MRI) and adipocytokines with prostate cancer aggressiveness. Patients and method: A total of 184 patients who underwent radical retropubic prostatectomy (RRP) were analyzed retrospectively; different fat measurements on MRI slices and levels of adipocytokines were compared with the clinical and pathologic factors using SSPS ver.13.0. Result: The PF rates showed a statistically significant variation (p=0.019, 0.025) among groups, that is to say, more adipose tissue was distributed in periprostatic areas of high risk patients. Logistic regression analysis adjusted for age revealed a statistically association between the PF, the ratio and the risk of having high-risk disease (p=0.031, 0.024). The levels of IL-6, leptin and c-reactive protein (CRP) significantly increased with the aggressiveness of prostate cancer, and also with PF and its ratio. The strongest correlation was seen between IL-6 and PF (Pearson r coefficient=0.67, P<0.001). No association was observed between adipocytokines and BMI. Conclusion: Periprostatic adiposity not only affects prostate cancer aggressiveness, but also influences the secretion of adipocytokines. IL-6, PF and CRP have promoting effects on progression of prostate cancer.

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.86-99
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• 2001

Vortex lock-on or resonance in the flow behind a circular cylinder is investigated from a time-resolved PIV when a single frequency oscillation is superimposed on the mean incident velocity. Measurements are made of the $K\acute{a}rm\acute{a}n$ and streamwise vortices in the wake-transition regime at the Reynolds number 360. Streamwise vortices at the lock-on and natural shedding states are observed, as well as the changes in the wake region with the change of the shedding frequency of lock-on state. When lock-on occurs, the vortex shedding frequency is found to be half the oscillation frequency as expected from previous experiments. At the lock-on state, the $K\acute{a}rm\acute{a}n$ vortices are observed to be more disordered by the increased strength and spanwise wavelength of the streamwise vortices, which leads to a strong three-dimensional motion. Recirculation and vortex formation region at the lock-on state is reduced as the oscillating frequency is increased. By comparing the Reynolds stresses at the lock-on and natural shedding states, $\bar{u'u'}\;and \;\bar{u'u'}$ at the lock-on state are concentrated on the shear layer around the cylinder. The $\bar{u'u'}\;at\;f_o/f_n=2.0$ has a large value near the centerline, compared with that of other cases. Considering the traces of maximum of u', in the wake region near the cylinder, wake width at the lock-on state is wider than that at the natural shedding state.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.675-682
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• 2011

This paper presents two ground plane effects due to the size of two rectangular apertures for two-wire transmission line with equal line length crossing the changeable rectangular apertures in infinite ground planes. The CST MWS is used to determine the characteristics of the insertion loss of the transmission line from the load section in accordance with the ground plane aperture size. The results show that the insertion gain and the insertion loss are periodically observed for the multiple frequency of the half wavelength resonance by the wire length when the transmission line is nearby to horizontal side or vertical side of the aperture. The measurements of the insertion loss are performed to verify the theoretical analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6135-6140
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• 2015

Background: The aim of this meta-analysis was to assess the efficacy of the apparent diffusion coefficient (ADC) value of diffusion-weighted MRI (DWI) for differentiating biliary tract cancer (BTC) from benign biliary tract diseases in Asians. Materials and Methods: We systematically searched Embase and PubMed prior to December 2014. Eight studies conducted in Asians met our predetermined inclusion criteria. Results: Our meta-analysis results showed that ADC values in BTC tissues were significantly lower than in benign biliary tract tissues (SMD = -1.54, 95%CI: -1.75~-1.33, P<0.001). Subgroup analysis based on the MRI machine type showed that the ADC values were consistent, accurate and reliable in the diagnosis of BTC when comparing cancer tissue vs. benign tissue under the Siemens 1.5 T/3.0 T, Philips 1.5 T/3.0 T, GE 1.5 T, and Toshiba 1.5 T types, respectively (all P<0.05). Further, ADC values were still consistent and accurate in the differential diagnosis of BTC under the b value of 800 and $1000s/mm^2$ (all P<0.05). Conclusions: Our findings supported potential clinical applications of DWI ADC values in differentiating BTC from benign biliary tract diseases in Asians.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.10
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• pp.1327-1336
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• 2001

The structural modes driven by the low wave-number components of smooth elastic wall pressure provide a relatively weak coupling between the flow and the wall motion. If the elastic thin plate has any resonant mode whose wave-number of resonance coincides with $\omega$/U$\sub$c/, the power will be transmitted to those modes of vibration by the flows. We examine the problem in which the elastic thin plate is subject to pressure fluctuations under turbulent boundary layer. Measurements are presented of the frequency spectra of the near- and far-field pressures and radiated sound contributed by the various wave modes of the thin elastic plate. Dispersion equation for wave motions of elastic plate is used to investigate the effect of bending waves of relatively low wave number on radiated sound. The low wave-number motion of elastic plate is observed to have much less influence on the low-frequency energy of wall pressure fluctuations than that of the rediated sound. High amplitude events of the wall pressure are observed to weakly couple with high-frequency energy of radiated sound for case of low tension applied to the plate. The sound source localization is applied to the measurement of radiated sound by using acoustic mirror system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.185-192
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• 1993

A numerical model has been used for the prediction of wave agitations in a harbor which are induced by the intrusion and transformation of incident waves. Based on linear wave theory a mild-slope equation has been used. A partial absorbing boundary condition has been used on solid boundary. Functional has been derived following Chen and Mei(l974)'s technique based on Hybrid Element Method which uses finite discretisation in the inner region and analytical solution of Helmholtz equation in the outer region. Final simultaneous equation has been solved using the Gaussian Elimination Method. Helmholtz natural period and second peak period of seiche in Donghae Harbor coincide very well with the results from numerical calculation. Computed amplification factors show good agreement, especially when the reflection coefficient on solid boundary is 0.99, with those of measurements.

• Korean Journal of Acupuncture
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• v.21 no.2
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• pp.1-28
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• 2004

Objectives : Human physiological changes in the state of qigong has been measured using EEG(Electroencephalography), functional MRI(functional Magnetic Resonance Image), EAV(Electro-Acupuncture according to Voll) and SQUID(Superconducting Quantum Interference Device) measurements. Methods & Results : EEGs were measured to study the differences between Qigong masters and Qi receiver on the changes of EEG. During Qigong, an alpha waves were increased. The power spectra indicate that the peak frequency of alpha waves increased during Qigong. Qi receiver's EEG signals seemed to affected by the state of himself. Brain activation did not observed when qigong master concentrates the Qi at Laogong(P8). But a localization of fMRI signal in the sensory cortex was observed by electric acupuncture stimulation at Laogong(P8). Five phase deviation of EAV were clearly changed in the both cases of Qigong master and Qi receiver. When a Qigong master concentrates the Qi at Yintang, Laogong(P8), Qihai(CV6) meridian points during Qigong state, the change of magnetic field around acupoints Yintang, Laogong points has been measured using 40-Channel DROS-SQUID apparatus. After smoothing process of the continuously measured magnetic signal around acupoints for a few minutes, we could observe that a series of peaks, magnitude of -1.0~2.5pT appeared. But there was no significant difference in changes of magnetic signal around acupoints. Physical signals of magnetocardiogram has been measured by using 2-Channel DROS SQUID(Magnetocardiogram). Physical signals of magnetocardiogram were clealy changed at the ST segments after S-wave when qigong master concentrates the Qi.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.94-99
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• 2005

Electrocardiogram-gated single photon omission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.571-580
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• 2009

Biochip sensing technologies offering in-situ, fast and real-time measurements in addition to portability can be powerfully utilized in a wide spectrum of research areas including environmental science, food science, medical diagnostics and drug development. In this article, we introduce current research trends and economic aspects of the development of various optical biochip technologies for the analysis of organophosphorus/carbamate pesticides in environmental samples, which is of global importance with serious consequences for both current and future generations. In particular, we will highlight recent efforts made in the creation of highly sensitive and selective optical biochip sensors in conjunction with nanobiotechnologies and microfabrication for the rapid detection of organophosphorus/carbamate pesticides.