• Radiation Oncology Journal
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• v.32 no.1
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• pp.23-30
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• 2014

Purpose: The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum ($Rectum_{overlap}$) or PTV and bladder ($Bladder_{overlap}$) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met. Materials and Methods: Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters. Results: The percentage $Rectum_{overlap}$ and $Bladder_{overlap}$ correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum $V_{45}$ and bladder $V_{50}$ with $R^2$ = 0.78 and $R^2$ = 0.83, respectively, and predicted the boost plan rectum $V_{30}$ and bladder $V_{30}$ with $R^2$ = 0.53 and $R^2$ = 0.81, respectively. The optimal cutoff value of boost $Rectum_{overlap}$ to predict rectum $V_{75}$ >15% was 3.5% (sensitivity 100%, specificity 94%, p < 0.01), and the optimal cutoff value of boost $Bladder_{overlap}$ to predict bladder $V_{80}$ >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01). Conclusion: The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.287-296
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• 2000

It is well known that oral appliance could improve respiratory difficulty in patients with obstructive sleep apnea (OSA). To evaluate the effect of oral appliance, polysomnography and cephalometry were performed in OSA patients before and after oral appliance was used. Twenty four OSA patients were included in this study. Respiratory difficulty index (RDI) was obtained from polysomnography and the movement of soft palate, tongue, posterior pharygeal wall, hyoid bone, and mandible and the variables of the facial pattern were measured on the cephalogram. The changes of cephalometric parameters were compared to the RDI changes and the correlation was tested. After oral appliance was used, RDI decreased from 46.8 to 13.3. There was significant relationship between RDI improvement and the anterior movement of the mandible and superior movement of the hyoid bone. In 8 patients whose RDI was most improved, RDI improvement rate was correlated with the anterior movement of the tongue and anterior-posterior (AP) diameter of the airway at the levels between the lower portion of the soft palate and epiglottis. These results could conclude that anterior movement of the tongue and superior movement of the hyoid bone would be favorable cephalometric parameters for the improvement of OSA.

• Investigative Magnetic Resonance Imaging
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• v.20 no.3
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• pp.158-166
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• 2016

Purpose: To understand clinical significance of irregular interface between meningioma and adjacent brain parenchyma in predicting histological grading of tumor, focusing on brain parenchymal invasion. Materials and Methods: Pathologically confirmed 79 cases with meningiomas with pathological reports about the presence of parenchymal invasion were included. We defined the presence of interface irregularity as either spiculations or fuzzy margins between the tumor and brain parenchyma. We counted number of spiculations and measured ratio of fuzzy margin length to whole length of mass with consensus of two neuroradiologists. We classified the patients into Present group and Absent group, and the two groups were compared by using the Mann-Whitney U test. Statistical correlations between the presence of an interface irregularity and brain parenchymal invasion by the tumor as well as meningioma histological grade were tested with chi-square test. The optimal cutoff values of spiculation numbers and the ratio of fuzzy margins were determined. The sensitivity and specificity of number of spiculations, ratio of fuzzy margin and the presence of irregular interface as combined parameters for predicting the parenchymal invasion were calculated using ROC curve analysis. Results: Statistically significant differences were noted between the Present and Absent groups for number of spiculations and ratio of fuzzy margin (P = 0.038 and P = 0.028, respectively). The optimal cutoff value for number of spiculations (> 4.5 with 61.1% sensitivity and 68.9% specificity) and the ratio of fuzzy margin (> 0.24 with 66.7% sensitivity and 65.6% specificity) were determined. The sensitivity and specificity of interface irregularity as the combined parameters were 72% and 59%, respectively. The interface irregularity between tumor and brain parenchyma significantly correlated with not only brain parenchymal invasion (P = 0.001) and but also histological grade (P < 0.001). Conclusion: The interface irregularity between tumor and brain parenchyma in MRI can be a strong predictive factor for brain parenchymal invasion and high grade meningioma.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.3
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• pp.237-245
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• 1999

Rates of photosynthesis and respiration of Laminaria japonica sporophytes cultivated on the southeastern coast of Korea were monthly measured in situ and under constant temperature and nitrogen concentration in laboratory from February to July 1996 in order to understand the seasonal photosynthetic performance of this alga. P-I (the relationship between photosynthsis and irradiance) parameters measured in situ varied seasonally. Photosynthetic capacity ($P_{max}$) reached its maximum in March (6.64 mg $O_2{\cdot}gdw^{-1}{\cdot}h^{-1}$) and gradually decreased thereafter. Photosynthetic efficiency (${\alpha}$), which ranged from 0.026 to 0.106, generally showed a similar pattern with the $P_{max}$, curve. Correlation between respiration and $P_{max}$, was not significant (Spearman's rank correlation, p>0.05); respiration rate, which varied between 0.25 and 0.83 mg $O_2{\cdot}gdw^{-1}{\cdot}h^{-1}$, showed no gradual decline from March. $P_{max}$ in situ significantly correlated with the relative growth rate of frond weight (Spearman's rank correlation, p<0.01) and this result means that the amount of accumulated materials in body increased with the increment of $P_{max}$. Compared $P_{max}$, in situ with that in the laboratory. The lower $P_{max}$ in February was probably caused by the effect of lower seawater temperature at this time. The decrease in $P_{max}$ after March, however, was primarily attributable to the thickness of blade as the plants got old. Comparison of P-I parameters measured for different size groups in April, explained the negative relationship between $P_{max}$ and frond thickness.

• Journal of The Korean Astronomical Society
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• v.31 no.1
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• pp.1-17
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• 1998

To understand the basic physics underlying large spatial fluctuations of intensity and Doppler shift, we have investigated the dynamical charctersitics of the transition region of the quiet sun by analyzing a raster scan of high resolution UV spectral band containing H Lyman lines and a S VI line. The spectra were taken from a quiet area of $100'\times100'$ located near the disk center by SUMER on board SOHO. The spectral band ranges from 906 A to 950 A with spatial and spectral resolution of 1v and $0.044 {\AA}$, respectively. The parameters of individual spectral lines were determined from a single Gaussian fit to each spectral line. Then, spatial correlation analyses have been made among the line parameters. Important findings emerged from the present analysis are as follows. (1) The integrated intensity maps of the observed area of H I 931 line $(1\times10^4 K)$ and S VI 933 line $(2\times10^5 K)$ look very smilar to each other with the same characterstic size of 5". An important difference, however, is that the intensity ratio of brighter network regions to darker cell regions is much larger in S VI 933 line than that in H I 931 line. (2) Dynamical features represented by Doppler shifts and line widths are smaller than those features seen in intensity maps. The features are found to be changing rapidly with time within a time scale shorter than the integration time, 110 seconds, while the intensity structure remains nearly unchanged during the same time interval. (3) The line intensity of S VI is quite strongly correlated with that of H I lines, but the Doppler shift correlation between the two lines is not as strong as the intensity correlation. The correlation length of the intensity structure is found to be about 5.7' (4100 km), which is at least 3 times larger than that of the velocity structure. These findings support the notion that the basic unit of the transition region of the quiet sun is a loop-like structure with a size of a few $10^3 km$, within which a number of unresolved smaller velocity structures are present.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.2
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• pp.109-120
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• 2007

Auxiliary support systems such as the reinforced protective umbrella method have been applied before tunnel excavation to increase ground stiffness and to prevent the large deformation. However, determination procedure of geotechnical parameters along the construction sequence contains various errors. This study suggests a method to characterize the time-dependent behavior of pre-reinforced zones around the tunnel using elastic waves. Experimental results show that shear strength as well as elastic wave velocities increase with the curing time. Shear strength and strength parameters can be uniquely correlated to elastic wave velocities. Obtained results from the laboratory tests are applied to numerical simulation of tunnel considering its construction sequences. Based on numerical analysis, initial installation part of pre-reinforcement and portal of tunnel are critical for tunnel stability. Result of the time-dependent condition is similar to the results of for $1{\sim}2$ days of the constant time conditions. Finally, suggested simple analysis method combining experimental and numerical procedure which considering time-dependent behavior of pre-reinforced zone on tunnel would provide reliable and reasonable design and analysis for tunnel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.503-516
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• 2012

Rock mass rating (RMR) is the key factor when designing the appropriate support pattern of tunnel projects. Borehole drilling is usually performed along the tunnel route in order to determine the rock mass rating to be used for tunnel design. The rock mass rating at the non-boring region between boreholes is usually assessed through geophysical surveys such as electrical prospecting, seismic prospecting, etc. Many studies were carried out to find out the correlation between electrical resistivity and rock mass rating. However, most researches were aimed at obtaining the relationship between the two parameters utilizing experimental results obtained from laboratory tests or electrical prospectings. In this paper, efforts were made to analyze and obtain relationships between the electrical resistivity obtained from in-situ electrical resistivity logging data and the rock mass rating. Correlation studies using field data showed that the electrical resistivity is highly correlated with the rock mass rating with the determination coefficient more than 90%. The correlation analysis was also carried out between RMR classification parameters and the electrical resistivity. It was shown that the correlation between the condition of discontinuities and the electrical resistivity was very high with the determination coefficient more than 80%; that between the groundwater condition and the electrical resistivity was very low with the determination coefficient less than 57%.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2717-2722
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• 2013

Background: The objective of this research is the computed axial tomography (CT) imaging grading of radiation induced pneumonitis (RP) and its correlation with clinical and radiotherapeutic parameters. Materials and Methods: The chest CT films of 20 patients with non-small cell lung cancer who have undergone threedimensional conformal radiation therapy were reviewed. The proposed CT grading of RP is supported on solely radiological diagnosis criteria and distinguishes five grades. The manifestation of RP was also correlated with any positive pre-existing chronic obstructive pulmonary disease (COPD) history, smoking history, the FEV1 value, and the dosimetric variable V20. Results: The CT grading of RP was as follows: 3 patients (15%) presented with ground glass opacity (grade 1), 9 patients (45%) were classified as grade 2, 7 patients (35%) presented with focal consolidation, with or without elements of fibrosis (grade 3), and only one patient (5%) presented with opacity with accompanying atelectasis and loss of pulmonary volume (grade 4). Both univariate and multivariate analysis revealed as prognostic factors for the radiological grading of RP the reduction of FEV1 and the V20 (P=0.026 and P=0.003, respectively). There was also a significant (P<0.001) correlation of radiological grading of RP with FEV1 and V20 (spearman rho 0.92 and 0.93, respectively). Conclusions: The high correlation of the proposed radiological grading with the FEV1 and the V20 is giving a satisfactory clinical validity. Although the proposed grading scale seems relevant to clinical practice, further studies are needed for the confirmation of its validity and reliability.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.370-375
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• 2009

Purpose : The risk of metabolic syndrome (MS) and cardiovascular disease in Turner syndrome (TS) patients is high. We analyzed metabolic factors in adults with TS and evaluated the metabolic risk of insulin resistance. Methods : Forty-three adults with TS were enrolled. The frequency of MS and the values of the metabolic factors were analyzed. Patients were divided into insulin resistant and non-resistant groups according to values of homeostasis model assessment of insulin resistance (HOMA-IR). The correlations of HOMA-IR with metabolic parameters were analyzed. Results : The frequency of MS was 7% and those of each metabolic parameter were as follows: insulin resistance, 16.3%; central obesity, 15.4%; hypertriglyceridemia, 2.3%; low HDL cholesterol, 9.3%; hypertension, 36.8%. The insulin-resistant group had significantly higher values of body mass index (BMI), waist circumference (WC), fasting plasma glucose (FPG), HOMA-IR, and systolic blood pressure (SBP) than the non-resistant group (P<0.05). HOMA-IR showed a significantly positive correlation with BMI, WC, FPG, and SBP and showed a negative correlation with HDL cholesterol. Conclusion : This study suggests that adults with TS have a high risk of metabolic syndrome, and insulin resistance is correlated with metabolic factors. Therefore, TS patients should have their metabolic parameters monitored regularly to minimize metabolic complications and prevent cardiovascular diseases.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.25-33
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• 2014

Purpose : To investigate whether quantitative parameters derived from Diffusion-weighted magnetic resonance imaging (DW-MRI) correlate with those of Dynamic contrast-enhanced MRI (DCE-MRI). Materials and Methods: Thirteen patients with pathologically or clinically proven bony metastasis who had undergone MRI prior to treatment were included. The voxel size was $1.367{\times}1.367{\times}5mm$. A dominant tumor was selected and the apparent diffusion coefficient (ADC) value and DCE-MRI parameters were obtained by matching voxels. DCE-MRI data were analyzed yielding estimates of $K^{trans}$ (volume transfer constant) and $v_e$. (extravascular extracellular volume fraction). Statistical analysis of ADC, $K^{trans}$, and $v_e$ value was conducted using Pearson correlation analyses. Results: Fifteen lesions in pelvic bones were evaluated. Of these, 11 showed a statistically significant correlation (P<0.05) between ADC and $K^{trans}$. The ADC and $K^{trans}$ were inversely related in 7 lesions and positively related in 4 lesions. This did not depend on the primary cancer or site of metastasis. The ADC and $v_e$ of 9 lesions correlated significantly. Of these, 4 lesions were inversely related and 5 lesions were positively related. Conclusion: Unlike our theoretic hypothesis, there was no consistent correlation between ADC values and $K^{trans}$ or between ADC values and $v_e$ in metastatic bone tumors.