• Tuberculosis and Respiratory Diseases
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• v.61 no.2
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• pp.129-136
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• 2006

Background: To interpret lung function tests, it is necessary to determine the lower limits of normal (LLN) and to derive a consensus on the interpretative algorithm. '0.7 of LLN for the $FEV_1$/FVC' was suggested by the COPD International Guideline (GOLD) for defining obstructive disease. A consensus on a new interpretative algorithm was recently achieved by ATS/ERS in 2005. We evaluated the accuracy of '0.7 of LLN for the $FEV_1$/FVC' for diagnosing obstructive diseases, and we also determined the effect of the new algorithm on diagnosing ventilatory defects. Methods: We obtained the age, gender, height, weight, $FEV_1$, FVC, and $FEV_1$/FVC from 7362 subjects who underwent spirometry in 2005 at the Asan Medical Center, Korea. For diagnosing obstructive diseases, the accuracy of '0.7 of LLN for the $FEV_1$/FVC' was evaluated in reference to the $5^{th}$ percentile of the LLN. By applying the new algorithm, we determined how many more subjects should have lung volumes testing performed. Evaluation of 1611 patients who had lung volumes testing performed as well as spirometry during the period showed how many more subjects were diagnosed with obstructive diseases according to the new algorithm. Results: 1) The sensitivity of '0.7 of LLN for the $FEV_1$/FVC' for diagnosing obstructive diseases increased according to age, but the specificity was decreased according to age; the positive predictive value decreased, but the negative predictive value increased. 2) By applying the new algorithm, 34.5% (2540/7362) more subjects should have lung volumes testing performed. 3) By applying the new algorithm, 13% (205/1611) more subjects were diagnosed with obstructive diseases; these subjects corresponded to 30% (205/681) of the subjects who had been diagnosed with restrictive diseases by the old interpretative algorithm. Conclusion: The sensitivity and specificity of '0.7 of LLN for the $FEV_1$/FVC' for diagnosing obstructive diseases changes according to age. By applying the new interpretative algorithm, it was shown that more subjects should have lung volumes testing performed, and there was a higher probability of being diagnosed with obstructive diseases.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.42-51
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• 2001

Background : Recently, cardiopulmonary exercise testing (CPX) has become a popular diagnostic method for differentiating the main cause of exertional dyspnea or exercise limitation. We evaluated the difference in the CPX results according to interpretative algorithms and the methals of exercise in Korea. Method : Sixty-six patients with chronic lung disease and 48 adults with dyspneic symptoms, but with no abnormalities in a spirometry performed symptom limited CPX, were included in this study. The results were interpreted using both Wasserman's(WA) and Eschenbacher's algorithm (EA), and a comparison between both algorithms was made. Thirty-three healthy medical students performed the CPX with a cycle ergometer and treadmill. The results were interpreted with EA and the concurrence in interpretations was evaluated accord ing to the methods of exercise. Results : 1. In patients with chronic lung disease, the overall concordance rate between the two algorithms was 63.6%. The concordance rates waw 69.8% in patients with obstructive, 25.0% in those with restrictive, and 66.7% in those with mixed pulmonary insufficiency. In patients with dyspneic symptoms but normal findings in resting spirometry, the concordance rate was 60.4%. 2. In healthy medical students, in results inter preted with EA, the concordance rate between the cycle ergometer and treadmill exercise was 25.0%. Conclusion : Both interpretative algorithms and methods of exercise may affect the CPX results. In using CPX as a diagnostic test for the causes of dyspnea in the Korean population. the interpretative algorithms and method of exercise need to be standardized, and a predictive $VO_2$max equation needs to be established.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.275-278
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• 2007

Dissolved gases analysis (DGA) is one of the most useful techniques to detect incipient faults in power transformers. Criteria interpreting DGA result is the most important. Because of difference of operation environment, construction type, oil volume, and etc, the interpretative criteria of DGA at KEPCO must be different with other standard like IEC-60599, Rogers and Doernenburg. In this paper, we collected the DGA data of the normal condition transformers and the incipient fault transformer to suggest the most appropriate criteria. Using these data, this paper suggests appropriate condition classification algorithm. Suggested algorithm can help to detect incipient fault earlier without unnecessary sampling.

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.163-176
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• 1999

Hydrology-based topographical informations generated by GIS techniques could be changed according to the selection of base map, algorithm of extraction, and so on. The purpose of this paper is to investigate the variation of SCS CN extracted by GIS technique and to propose the effective strategy for applying GIS to the rainfall-runoff simulation in ungaged basin. For experimental implementation, GIS spatial data, such as reconnaissance soil map, detailed interpretative soil map, landuse planning map and remotely sensed data(Landsat TM), were collected and generated to calculate the amount of effective rainfall in Pyungchang river basin. In applying SCS Runoff Curve Number to the test basin, the hydrological attribute data were analyzed. In addition, the characteristics of runoff responses according to the selection of GIS spatial data for SCS CN were reviewed. This study shows the applicability of GIS techniques to runoff simulation in ungaged basin by comparing with the measured flood hydrograph. It has been found that the detained interpretative soil map and remote sensing data are appropriate for calculating of SCS CN.