• Korean Journal of Radiology
• /
• v.20 no.4
• /
• pp.683-692
• /
• 2019

Objective: We aimed to evaluate correlations between computed tomography (CT) parameters and pulmonary function test (PFT) parameters according to disease severity in patients with chronic obstructive pulmonary disease (COPD), and to determine whether CT parameters can be used to predict PFT indices. Materials and Methods: A total of 370 patients with COPD were grouped based on disease severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) I-IV criteria. Emphysema index (EI), air-trapping index, and airway parameters such as the square root of wall area of a hypothetical airway with an internal perimeter of 10 mm (Pi10) were measured using automatic segmentation software. Clinical characteristics including PFT results and quantitative CT parameters according to GOLD criteria were compared using ANOVA. The correlations between CT parameters and PFT indices, including the ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC) and FEV₁, were assessed. To evaluate whether CT parameters can be used to predict PFT indices, multiple linear regression analyses were performed for all patients, Group 1 (GOLD I and II), and Group 2 (GOLD III and IV). Results: Pulmonary function deteriorated with increase in disease severity according to the GOLD criteria (p < 0.001). Parenchymal attenuation parameters were significantly worse in patients with higher GOLD stages (P < 0.001), and Pi10 was highest for patients with GOLD III (4.41 ± 0.94 mm). Airway parameters were nonlinearly correlated with PFT results, and Pi10 demonstrated mild correlation with FEV1/FVC in patients with GOLD II and III (r = 0.16, p = 0.06 and r = 0.21, p = 0.04, respectively). Parenchymal attenuation parameters, airway parameters, EI, and Pi10 were identified as predictors of FEV₁/FVC for the entire study sample and for Group 1 (R² = 0.38 and 0.22, respectively; p < 0.001). However, only parenchymal attenuation parameter, EI, was identified as a predictor of FEV₁/FVC for Group 2 (R² = 0.37, p < 0.001). Similar results were obtained for FEV₁. Conclusion: Airway and parenchymal attenuation parameters are independent predictors of pulmonary function in patients with mild COPD, whereas parenchymal attenuation parameters are dominant independent predictors of pulmonary function in patients with severe COPD.

• Korean Journal of Radiology
• /
• v.23 no.1
• /
• pp.13-29
• /
• 2022

Nonalcoholic fatty liver disease, characterized by excessive accumulation of fat in the liver, is the most common chronic liver disease worldwide. The current standard for the detection of hepatic steatosis is liver biopsy; however, it is limited by invasiveness and sampling errors. Accordingly, MR spectroscopy and proton density fat fraction obtained with MRI have been accepted as non-invasive modalities for quantifying hepatic steatosis. Recently, various quantitative ultrasonography techniques have been developed and validated for the quantification of hepatic steatosis. These techniques measure various acoustic parameters, including attenuation coefficient, backscatter coefficient and speckle statistics, speed of sound, and shear wave elastography metrics. In this article, we introduce several representative quantitative ultrasonography techniques and their diagnostic value for the detection of hepatic steatosis.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.6
• /
• pp.885-888
• /
• 2000

Electroantennogram(EAG) can be applied to detect odorants since insects have highly specialized olfactory receptors inside their antennae. The characteristics of EAG parameters were investigated for the quantitative measurement of a general odorant using ammonia as a model odorant. The antennae of male silkworm moth, Bombyx mori, were used for the EAG. The electical signal curves generated from a pair of antennae originating from the same silkworm moth were never identical; however, they exhibited a typical type I or type II characteristic curve pattern for every pair of antennae. The correlation between the EAG parameters and the ammonia concentration was analyzed for the type I and type II antennae. The stability of each parameter was also investigated for each type of antenna. The results show the possibility of the quantitative measurement of general odorants using the EAG technique.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.2
• /
• pp.147-152
• /
• 1996

To see the quantitative relationship between the structures of the C-7 substituted quinolones and their antibacterial activities, theoretical parameters such as the molecular van der Waals volume, surface area and some electrostatic parameters based on the molecular electrostatic potential, which represent lipophilicity, and some quantum mechanical parameters are introduced as descriptors. The sixteen substituted quinolone derivatives and twenty bacteria are used for the study. It is found that the QSARs of C-7 substituted quinolones are obtained for eleven bacteria and our descriptors are more useful for Gram positive organisms than negative ones. It is also shown that molecular surface area (or molecular Waals volume) of the C-7 substituent and net charge of C-7 atom of the quinolones are the descriptors of utmost importance.

• Journal of Biomedical Engineering Research
• /
• v.22 no.1
• /
• pp.49-58
• /
• 2001

A new scale named LCL(Logically Classified Level) has been developed to judge the status of the spasticity quantitatively implementing a pcndulum test in this study. Total 30 parameters have been used to develop the new scale. One representative parameter that can represent the dominant characteristics of spasticity has been chosen through statistical analysis. 20 parameters among 30 parameters uscd in the statistical analysis were newly developed and 10 parameters were from previous studies. The new 20 parametcrs were developed using combinations of pcndulum test characteristics. ie anglc, angular velocity. musclo midel. and EMG. 11 parameters among 30 parameters have showed strong correlations each other, Finally. L11 that showed consistency at every case has been chosen to be a representative parameter among the 11 parameters. 28 patients data were separated into 4 groups. A regression equation to predict the trend of patients of L11 has been made. The paramcter L11 was tested to prove its usabilitics for various cases of patients. The new LCL scale is expected to be a quantitative scale, and to replace the MAS(Modified Ashworth Scale) that is not a quantitative scale. Especially it is also expected that the new scale could be used to plan a treatmcnt period. methods, and intensity. as it can evaluate the status of patient's in detail.

• Explosives and Blasting
• /
• v.25 no.1
• /
• pp.67-77
• /
• 2007

The drill monitoring data are useful for the detection of abrupt and unexpected changes in ground renditions. This paper introduces a new approach to how drill performance parameters can be used for the prediction of quantitative rock mass properties ahead of tunnel face and the blasting design. The drill monitoring parameters available for the predictions include the instantaneous advance speed, thrust force, torque, tool pressure and penetration rate. The assessment of the drill monitoring parameters will be able to build a database provided that in-situ drill monitoring informations are accumulated and enable us to make a reasonable blast design based on quantitative assessment of rock mass.

• Biomolecules & Therapeutics
• /
• v.8 no.1
• /
• pp.63-72
• /
• 2000

We intended to show some basic requirements for spectrum analysis of electroencephalogram (EEG) by visualizing the differences of the results according to different values of some parameters for analysis. Spectrum analysis is the most popular technique applied for the quantitative analysis of the electroen- cephalographic signals. Each step from signal acquisition through spectrum analysis to presentation of parameters was examined with providing some different values of parameters. The steps are:(1) signal acquisition; (2) spectrum analysis; (3) parameter extractions; and (4) presentation of results. In the step of signal acquisition, filtering and amplification of signal should be considered and sampling rate for analog-to-digital conversion is two-time faster than highest frequency component of signal. For the spectrum analysis, the length of signal or epoch size transformed to a function on frequency domain by courier transform is important. Win dowing method applied for the pre-processing before the analysis should be considered for reducing leakage problem. In the step of parameter extraction, data reduction has to be considered so that statistical comparison can be used in appropriate number of parameters. Generally, the log of power of all bands is derived from the spectrum. For good visualization and quantitative evaluation of time course of the parameters are presented in chronospectrogram.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.88.3-88.3
• /
• 2015

Kepler mission is performing the quantitative and qualitative observations. Hence, it is possible to statistically study, which is called 'Ensemble asteroseismology', about seismic properties. They investigated about global oscillation parameters. In this study, we performed statistically study about global seismic parameters with Kepler data. Relation between global oscillation parameters (${\Delta}{\nu}$ and ${\nu}max$) are approximately confirmed. We investigated newly about distribution of Full-With-at-Half-Maximum (FWHM) and relation between FWHM and other global oscillation parameters.

• Korean Journal of Radiology
• /
• v.21 no.7
• /
• pp.859-868
• /
• 2020

Objective: To investigate the value of initial CT quantitative analysis of ground-glass opacity (GGO), consolidation, and total lesion volume and its relationship with clinical features for assessing the severity of coronavirus disease 2019 (COVID-19). Materials and Methods: A total of 84 patients with COVID-19 were retrospectively reviewed from January 23, 2020 to February 19, 2020. Patients were divided into two groups: severe group (n = 23) and non-severe group (n = 61). Clinical symptoms, laboratory data, and CT findings on admission were analyzed. CT quantitative parameters, including GGO, consolidation, total lesion score, percentage GGO, and percentage consolidation (both relative to total lesion volume) were calculated. Relationships between the CT findings and laboratory data were estimated. Finally, a discrimination model was established to assess the severity of COVID-19. Results: Patients in the severe group had higher baseline neutrophil percentage, increased high-sensitivity C-reactive protein (hs-CRP) and procalcitonin levels, and lower baseline lymphocyte count and lymphocyte percentage (p < 0.001). The severe group also had higher GGO score (p < 0.001), consolidation score (p < 0.001), total lesion score (p < 0.001), and percentage consolidation (p = 0.002), but had a lower percentage GGO (p = 0.008). These CT quantitative parameters were significantly correlated with laboratory inflammatory marker levels, including neutrophil percentage, lymphocyte count, lymphocyte percentage, hs-CRP level, and procalcitonin level (p < 0.05). The total lesion score demonstrated the best performance when the data cut-off was 8.2%. Furthermore, the area under the curve, sensitivity, and specificity were 93.8% (confidence interval [CI]: 86.8-100%), 91.3% (CI: 69.6-100%), and 91.8% (CI: 23.0-98.4%), respectively. Conclusion: CT quantitative parameters showed strong correlations with laboratory inflammatory markers, suggesting that CT quantitative analysis might be an effective and important method for assessing the severity of COVID-19, and may provide additional guidance for planning clinical treatment strategies.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.13 no.1
• /
• pp.5-17
• /
• 2002

Objectives : Videostrobokymography(VSK) has been recently developed and reported by Sung et at. We aimed to analyze vibratory patterns and objective parameters in various benign vocal fold lesions using VSK, and examine the efficacy of VSK in clinical application. Materials and Methods : Using VSK, we analyzed the vibration pattern of normal vocal fold and various benign lesions, such as nodules, polyps, cysts, Reinke's edema and unilateral vocal fold paralysis. We also calculated objective parameters, open quotient and asymmetric index, and compared them with mean values of parameters in normal controls. Results : In nodules, polyps, and cysts, the open quotient on the site of the lesion was similar to the mean value in normal controls, however, on the other part of the vocal folds it was much larger than normal mean value. In Reinke's edema, irregular and asymmetric vibration was observed. The posterior portion of the vocal folds showed larger open quotients than the anterior portion. In the unilateral vocal fold paralysis, irregular vocal folds vibration and incomplete closure of the vocal folds were documented. Much larger asymmetric indices were calculated in the unilateral vocal fold paralysis than in normal controls and other lesions. The asymmetric index could be a good quantitative parameter of vibration from a patient with vocal fold paralysis. Conclusion : This study demonstrated that VSK could generate clear quantitative documentations of fine vibrations of vocal folds in many different benign lesions. VSK has a potential as an effective tool for quantitative analysis of vibratory patterns of the vocal folds iii clinical settings.