• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.317-324
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• 2020

Plastic wastes generated from domestic waste are separated by mixed discharge with foreign substances, and the cost of the separation and screening process increases, so recycling is relatively low. In this study, as a fundamental study for recycling mixed plastic wastes generated from domestic waste into concrete aggregates, changes in concrete properties according to the plastic waste types and the substitution rate were evaluated experimentally. The mixed plastic waste aggregate(MPWA) was found to have a lower density and a higher absorption rate compared to the coarse aggregate with good particle size distribution. On the other hand, the single plastic waste aggregate(SPWA) was composed of particles of uniform size, and both the density and the absorption rate were lower than that of the fin e aggregate. It was found that the MPWA substitution concrete did not cause a material separation phenomenon due to a relatively good particle size distribution even with the largest amount of plastic waste substitution, and the amount of air flow increased little. The compressive strength and flexural strength of the PWA substitution concrete decreased as the amount of substitution of the PWA increased due to the low strength of the PWA, the suppression of the cement hydration reaction due to hydrophobicity, and the low adhesion between the PWA and the cement paste. It was found that the degree of deterioration in compressive strength and flexural strength of concrete substituted with MPWA having good particle size distribution was relatively small.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.173-181
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• 2012

The aim of this study is to compare the geometric characteristics of the lung tumor, such as tumor centroid, HU change relative to breath phase, depending on tumor location and adhesion using 4DCT and deformable image registration program (MIMVista). The Y axis change was most significant and the mean Y axis centroid fluctuation was $7.32{\pm}6.88mm$ in lower lung tumor. The mean HU variation in lower lung mass has changed more than other locations, and its mean HU variation was $7.7{\pm}4.97%$ and non-adhered mass was more changed. Correlation for the mass volume between 3DCT and MIP was very high and its coefficient was 0.998. The effect of tumor location, adhesion and diaphragm excursion to geometric uncertainties was analyzed by linear regression model, it was influenced to mass deformation and geometrical variation so much except diaphragm excursion. but intra-fractional and inter-patient's uncertainties were great, so it couldn't find any exact deformation trend.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.77-82
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• 1967

The normal lung volumes were determined and subdivided under sitting position in 48 middle school girls, 49 high school girls and 44 house wives. All subjects were free of pulmonary and vascular diseases. The vital capacity was measured by Mckessons spirometer and the residual volume was determined by Rahn's three breathing method. 1. The lung volumes (BTPS) of middle school girls determined were: $RV\;0.59{\pm}0.11l\;FRC\;1.45{\pm}2.22l\;VC\;2.68{\pm}0.29l$ 2. The lung volumes (BTPS) of high school girls determined were: $RV\;0.83{\pm}0.19l\;FRC\;1.9{\pm}0.25l\;VC\;3.15{\pm}0.24l$ 3. The lung volumes (BTPS) of house wives determind were: $RV\;0.95{\pm}0.61{\ell}\;FRC\;2.1{\pm}0.25{\ell}\;VC\;3.06{\pm}0.29l$ 4. The calculated residual ratio $(RV/TLC{\times}100)$ were: $17.7{\pm}2.57%$ in middle school girls and $20.6{\pm}3.65%$ in high school girls and $24.0{\pm}2.31%$ in house wives 5. The functional residual ratio $(FRC/TLC{\times}100)$ were: $43.7{\pm}5.98%$ in middle school girls and $48.8{\pm}4.41%4 in high school girls and $52.6{\pm}5.38%$ in house wives. 6. The correlation coefficients between vital capacity and total lung capacity were r=0.96 in middle school girls and r=0.986 in high school girls and r=0.856 in house wives. 7. The regression equations were obtained follows: $TLC(l) =1.105{\times}VC+0.304$ (in middle school girls) $TLC(l) =1.551{\times}VC-0.902$ (in high school girls) $TLC(l) =0.999{\times}VC+0.954$ (in house wives)

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.34-34
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• 2003

목적 : 폐암 환자 세기변조방사선치료 과정을 소개하고, 방사선치료계획의 최적화를 위한 빔 수와 방향, 가상장기 설정 (virtual organ delineation, VOD) 및 선량 제한 인자들의 이용에 대해 평가함으로써 폐, 심장 등에 조사되는 선량을 최소화하는데 사용하는 세기변조방사선치료 (intensity modulated radiotherapy, IMRT) 기술의 유용성을 평가하고자한다. 대상 및 방법 : 종양이 종격동을 침범하여 상대적으로 장기움직임에 의한 오차가 적은 폐암환자 5 명을 대상으로 하였다. 환자고정장치는 상반신을 편안하게 유지함과 동시에 팔의 위치를 고정시킴으로써 기대할 수 있는 환자고정효과와 벨트를 이용하여 환자 상복부를 압박해줌으로써 호흡운동에 의한 장기 움직임을 감소시킬 수 있는 형태로 고안하였다. 치료계획시 빔 수와 방향은 5,7,9 문 (from 200 to 160, equispaced field, arbitrary field), 4 문 (anterior, posterior, bilateral posterior oblique field) 과 비등방 7, 9 문 (non-equispaced field, arbitrary field) 등을 사용하였다. 선량제한 ($V_{20}V_{25}$)은 문헌에 기초하여 설정하였으며, 가상장기를 적절히 사용하여 최적화된 치료계획 결과를 얻었다. 방사선치료계획 평가는 선량-체적간 히스토그람 (DVH), 등선량곡선 및 선량통계 등을 이용하여 수행하였다. 특히 가상장기 설정 전, 후의 결과 값을 분석함으로써 그 유용성을 확인하였다. 결과 : 9문 등방-IMRT와 7문 비등방-IMRT 방법이 치료계획용적의 선량균질성 (PTV dose homogeneity), 평균 폐선량 (mean lung dose) 및 $V_{20}V_{25}$ 모두에서 20% 이내의 좋은 결과를 얻을 수 있었고, 가상 장기를 설정함으로써 같은 결과를 가져옴을 알 수 있었다. 또한 폐암 세기변조방사선치료 프로토콜을 작성하여 임상에 사용함으로써 치료과정 중 발생할 수 있는 오류를 보완할 수 있음을 알 수 있었다. 결론 : 폐암 세기변조방사선치료 시 사용할 수 있는 프로토콜을 작성하였고, 적절한 가상 장기 및 조사계획 설정으로 치료계획의 최적화를 얻을 수 있음을 알 수 있었다.

• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.74-81
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• 2004

Purpose: To evaluate the computed tomography (CT) findings of pulmonary cryptococcosis in immunocompetent patients. Materials and Methods: CT scans of 25 patients with biopsy-proven cryptococcosis [surgery (n=3), percutaneous needle biopsy (n=21), and bronchoscopic biopsy (n=1)] were analyzed. Thirteen patients were men and 12 patients were women, with a mean age of 53.7 years. Presenting symptoms were cough, sputum, and dyspnea and 12 patients presented with incidentally found chest radiographic abnormalities. Results: Nodule or multiple conglomerate nodules (n=10, 40%) and segmental or lobular consolidation (n=9, 36%) were most common, followed by mixed patterns (n=5, 20%). Predilection sites were lower lobe (n=21/37, 57%) and subpleural areas (n=23, 92%). Air bronchograms within consolidations (n=11/14, 79%) with mild volume loss (n=10/14, 71%) were common. While interlobular septal thickening (n=11, 44%) and cavitation or central low-attenuations (n=11, 44%) were relatively common, lymphadenopathy (n=2, 8%) or free pleural effusions (n=1, 4%) were uncommon. Conclusion: Nodules or airspace consolidation with a predilection of lower lobe and subpleural area are the most common appearances of pulmonary cryptococcosis in immunocompetent patients.

• 한국산학경영학회:학술대회논문집
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• 2004.11a
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• pp.101-123
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• 2004

This study examines empirically the significant changes in tax payments when the consolidated tax return is introduced in the future. We estimate the consolidated tax payments under the eight cases which are classified as such : whether only 100% ownership subsidiaries should be included or 80% and over, whether all subsidiaries should be included or only subsidiaries with loss, and whether unrealized profits from intercompany transactions should be excluded or not. After estimating the consolidated tax payments, we test the difference between the consolidated tax payments and the sum of the individual tax payments of the subsidiaries. The results of the test show that the consolidated tax payments are significantly less than the sum of the individual tax payments of the subsidiaries. We interpret that the inclusion of the losses of the subsidiaries in the consolidated tax base makes the tax payment decrease. Based on our analysis about 3.8 billion Won per each parent company would decrease due to the introduction of the consolidated tax return. And we find that under the mandatory consolidated tax return system the significant difference between the consolidated and individual tax payment exists except that the only 100% ownership subsidiaries are included and unrealized profits from intercompany transactions are not excluded. However, when the parent companies have the discretion to select the consolidated subsidiaries, the consolidated tax payments are significantly less than the sum of the individual tax payments of the subsidiaries regardless of the ownership percentage, inclusion of the loss of the subsidiaries and exclusion of the unrealized profits.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.480-485
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• 2007

Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. COPD has systemic effects, such as skeletal muscle dysfunction and abnormal weight loss. It also has been suggested that COPD is related to other chronic disease, such as cardiovascular disease, osteoporosis, and anemia. The aim of this study was to evaluate a symptom questionnaire and laboratory findings in subjects with air flow limitation. Methods: We evaluated a symptom questionnaire and laboratory findings in subjects with airflow limitation detected by spirometry in conjunction with the Second Korean National Health and Nutrition Examination Survey. A total of 9,243 adults over the age of 18 were recruited. Among the adults, we finally analyzed 2,217 subjects who met the acceptability and repeatability criteria of spirometry, showed normal findings on chest radiography, and were older than 40 years of age. Results: There were 288 subjects with airflow limitation as determined by spirometry. The frequency of respiratory symptoms such as cough, sputum and wheezing were significantly higher in subjects with airflow limitation (p <0.01). Hemoglobin and hematocrit levels were higher in subjects with airflow limitation (hemoglobin level 13.98 mg/dL vs. 13.62 mg/dL, hematocrit 42.10% vs. 40.89%; p<0.01). The HDL cholesterol level was lower in subjects with airflow limitation (44.95 mg/dL vs. 45.60 mg/dL; p<0.01). There was no significant difference in the total cholesterol, triglyceride, blood urea nitrogen, creatinine, and fasting glucose levels. Conclusion: In subjects with airflow limitation, prevalence of respiratory symptoms was higher than in normal spirometry subjects and the levels of hemoglobin and the hematocrit were higher. The HDL cholesterol level was lower in subjects with airflow limitation.

• The Korean Journal of Physiology
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• v.15 no.1
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• pp.37-43
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• 1981

In the present study, an effort was directed to elucidate the effect of the physical training on the pulmonary function. Twenty-four male athletics major students who have undergone regular physical training for more than five years were randomly chosen as the athletic subjects, and 12 regular male students who have not been engaged in any form of regular physical exercise or training were chosen as the non-athletic subjects, and a comparison was made between the two groups. The following were mainly observed by spirometry for the study; respiratory rate, tidal volume, vital capacity, maximum voluntary ventilation(MVV), forced expiratory volume for 1 second$(FEV_1)$, percent $FEV_1$ to forced vital capacity$(FEV_1%)$, forced expiratory flow for initial 1 liter$(FEF_{0.2-1.2}L)$, and forced mid-expiratory flow$(FEF_{\;25-75}%)$. The results obtained are summarized as follow. 1) The respiratory rate, tidal volume, and vital capacity showed no significant difference between athletes and non-athletes. The MVV in athletes was significantly (p<0.01) increased to $148.1{\pm}3.1\;L/min$ comparing with $118.3{\pm}9.1\;L/min$ in non-athletes. 2) $FEV_1$ was $3.310{\pm}0.070\;L$ in athletes and $2.779{\pm}0.104$ in non-athletes; $FEV_1%\;83.63{\pm}1.29%$ in athletes and $75.33{\pm}1.75%$ in non-athletes, both showing significant(p<0.01) increase in athletes. 3) $FEF_{0.2-1.2}L$ was $297.1{\pm}13.5\;L/min in athletes and $222.7{\pm}15.0\;L/min$ in non-athletes; $FEF_{\;25-75}%$ was $3.543{\pm}0.109\;L/sec$ in non-athletes, both showing significant(p<0.01) increase in athletes. 4) Some discussions were made on these results. The lung volumes showed no significant difference between the two groups. But MVV, $FEV_1$, $FEV_1%$, $FEF_{0.2-1.2}L$ and $FEF_{25-75}%$ in athletes were significantly(p<0.01) higher than in non-athletes. It is therefore concluded that the athletes have more powerful respiratory muscles, or higher compliance of the lung and thorax than the non-athletes.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.31-40
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• 2003

Background : A CT scan is a useful modality for the diagnosis and evaluation of disease activity in patients with pulmonary tuberculosis. However, the CT diagnosis of pulmonary tuberculosis is sometimes difficult in patients with an atypical CT pattern, especially with lobar consolidation mimicking pneumonia. The aim of this study was to evaluate the clinical and CT features of pulmonary tuberculosis, simulating pneumonia, from a CT scan. Materials and Methods : The clinical and CT features in 21 patients, where the CT diagnosis was pneumonia, or the CT differential diagnosis included pneumonia, were retrospectively analyzed. Results : Of the 21 patients, 6 were immunocompromised, 15 presented with fever or leukocytosis and 15 showed positive sputum smear test for acid fast bacilli. Also, 17 of the 21 patients showed a positive sputum culture test. On the CT scan, consolidation was noted in all patients (100%), volume loss of the involved lobe or segment in 12 (57%), bronchogenic spread in 15 (71%), a cavity in 7 (33%) and bronchial wall thickening also in 7 (33%). The location of the consolidation revealed a relatively even distribution, with no specific predilection site. The other associated pulmonary diseases included ARDS, bronchiectasis, severe pulmonary emphysema, idiopathic pulmonary fibrosis and pulmonary alveolar proteinosis. Conclusion : In the immunocompromised patients, or patients with an underlying pulmonary disease, whose CT scans showed pulmonary consolidation, especially in association with findings of bronchogenic spread, a cavity or bronchial wall thickening, meticulous examination for pulmonary tuberculosis is recommended.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.201-209
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• 1996

Background : Auto-PEEP which develops when expiratory lung emptying is not finished until the beginning of next inspiration is frequently found in patients on mechanical ventilation. Its presence imposes increased risk of barotrauma and hypotension, as well as increased work of breathing (WOB) by adding inspiratory threshold load and/or adversely affecting to inspiratory trigger sensitivity. The aim of this study is to evaluate the relationship of auto-PEEP with WOB and to evaluate the effect of PEEP applied by ventilator (external PEEP) on WOB in patients with auto-PEEP. Method : 15 patients, who required mechanical ventilation for management of acute respiratory failure, were studied. First, the differences in WOB and other indices of respiratory mechanics were examined between 7 patients with auto-PEEP and 8 patients without auto-PEEP. Then, we applied the 3 cm $H_2O$ of external PEEP to patients with auto-PEEP and evaluated its effects on lung mechanics as well as WOB. Indices of respiratory mechanics including tidal volume ($V_T$), repiratory rate, minute ventilation ($V_E$), peak inspiratory flow rate (PIFR), peak expiratory flow rate (PEFR), peak inspiratory pressure (PIP), $T_I/T_{TOT}$, auto-PEEP, dynamic compliance of lung (Cdyn), expiratory airway resistance (RAWe), mean airway resistance (RAWm), $p_{0.1}$, work of breathing performed by patient (WOB), and pressure-time product (PTP) were obtained by CP-100 Pulmonary Monitor (Bicore, USA). The values were expressed as mean $\pm$ SEM (standard error of mean). Results : 1) Comparison of WOB and other indices of respiratory mechanics in patients with and without auto-PEEP : There was significant increase in WOB ($l.71{\pm}0.24$ vs $0.50{\pm}0.19\;J/L$, p=0.007), PTP ($317{\pm}70$ vs $98{\pm}36\;cm$ $H_2O{\cdot}sec/min$, p=0.023), RAWe ($35.6{\pm}5.7$ vs $18.2{\pm}2.3\;cm$ H2O/L/sec, p=0.023), RAWm ($28.8{\pm}2.5$ vs $11.9{\pm}2.0cm$ H2O/L/sec, p=0.001) and $P_{0.1}$ ($6.2{\pm}1.0$ vs 2.9+0.6 cm H2O, p=0.021) in patients with auto-PEEP compared to patients without auto-PEEP. The differences of other indices including $V_T$, PEFR, $V_E$ and $T_I/T_{TOT}$ showed no significance. 2) Effect of 3 cm $H_2O$ external PEEP on respiratory mechanics in patients with auto-PEEP : When 3 cm $H_2O$ of external PEEP was applied, there were significant decrease in WOB ($1.71{\pm}0.24$ vs $1.20{\pm}0.21\;J/L$, p=0.021) and PTP ($317{\pm}70$ vs $231{\pm}55\;cm$ $H_2O{\cdot}sec/min$, p=0.038). RAWm showed a tendency to decrease ($28.8{\pm}2.5$ vs $23.9{\pm}2.1\;cm$ $H_2O$, p=0.051). But PIP was increased with application of 3 cm $H_2O$ of external PEEP ($16{\pm}2$ vs $22{\pm}3\;cm$ $H_2O$, p=0.008). $V_T$, $V_E$, PEFR, $T_I/T_{TOT}$ and Cdyn did not change significantly. Conclusion : The presence of auto-PEEP in mechanically ventilated patients was accompanied with increased WOB performed by patient, and this WOB was decreased by 3 cm $H_2O$ of externally applied PEEP. But, with 3 cm $H_2O$ of external PEEP, increased PIP was noted, implying the importance of close monitoring of the airway pressure during application of external PEEP.