• Title/Summary/Keyword: Pack Analysis

Search Result 350, Processing Time 0.035 seconds

Case Study on the Bogie Arrangement of the Load-out System for On-ground Shipbuilding (선박 육상건조를 위한 로드-아웃 시스템의 보기 배치 사례 연구)

  • Hwang, John-Kyu;Ko, Jae-Yong
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.1
    • /
    • pp.153-160
    • /
    • 2022
  • This study presents the bogie arrangement of the load-out system for on-ground shipbuilding. The load-out system is one of the most important systems to perform the bogie arrangement of the on-ground shipbuilding technique without dry dock facilities, and this system is composed of four pieces of equipment: bogies, driving bogie with motors, trestles, and power packs. Also, the bogie arrangement analysis (BAA) is employed to simply calculate the reaction forces at the trestle for structural safety. In this context, the purpose of this study is to propose an optimal design method to perform the bogie arrangement satisfying structural safety requirements with minimal cost. It is expected that the proposed methodology will contribute to the effective practice as well as to the improvement of competitive capability for shipbuilding companies at the on-ground shipbuilding stage. Furthermore, we describe some problems and their solutions of the deformation that may occur in the bottom of the hull during the load-out process. As a result, it is shown that we applied it to the 114K crude oil tanker (Minimum bogie 54EA) and the 174K CBM LNG carrier (Minimum bogie 88EA), it can minimize the number of bogie and critical risks (Safety rate 1.61) during the load-out of on-ground shipbuilding. Through this study, the reader will be able to learn successful load-out operation and economic shipbuilding in the future.

The Effect on Attention of College Students by Epidermal Cooling in Posterior and Lateral of Upper Cervix (경추부 후면 및 측면 피부 냉각 작용이 대학생의 주의력에 미치는 영향)

  • Chang, Ji Hong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.15 no.5
    • /
    • pp.328-334
    • /
    • 2022
  • The process that one may consciously focuses on necessary stimulation among tremendous amount of stimulation through human sensory systems is called attention in psychology. It is known that the attention can be affected by many factors such as room temperatures, humidity level, etc. In the field of sports science, ice packs are widely used for recovery from exercise fatigue providing fast heat transfer by conduction. However, the effect on attention by so-called iced-pack-cooling has not been tested. This research focuses on the attention levels when one is provided with a special cooling pad on their dorsal and lateral cervices. 40 subjects were divided into four groups and their attention level was evaluated based on the exposure conditions of combinations in reading and light walking with and without the cooling pad. The Frankfruter Aufmerksamkeits-Inventar, FAIR was used to evaluate the attention levels; the performance index, quality index, and continuity index consist of the FAIR test indicating the selectiveness of the attention, correctness of the attention, and maintaining term of the attention, respectively. Analysis of variance was carried out for those variables and post-hoc if applicable. When visual attention is constantly used for reading and studying, application of conductive heat transfer by the cooling pads is significantly helpful for improvement in selectiveness of the attention and maintaining terms of the attention levels. Also, light walking yielded improvement in selectiveness of the attention and maintaining terms of the attention levels; however one should presupposedly consider the loss of reading time.

Analysis of Rollover Angle According to Arrangement of Main Parts of Electric Tractor Using Dynamic Simulation (시뮬레이션을 이용한 전기 트랙터 주요 부품 배치에 따른 전도각 분석)

  • Jin Ho Son;Yeong Su Kim;Yu Shin Ha
    • Journal of the Korea Society for Simulation
    • /
    • v.32 no.4
    • /
    • pp.77-84
    • /
    • 2023
  • In the agricultural sector, power sources are being developed that use alternative energy sources such as electric tractors and hydrogen tractors, away from internal combustion engine tractors. As parts such as engines and transmissions used in conventional internal combustion engine tractors are replaced with motors and batteries, the center of gravity changes, and thus the risk of rollover should be considered. The purpose of this study is to analyze the overturn angle of the main parts of the electric tractor through dynamic simulation to minimize the overturn accident and to derive the optimal arrangement of parts to improve stability. A total of nine dynamics simulations were conducted by designing three components of the PTO motor, drive motor and the battery pack, and three factors of the arrangement method. As a result of the experiment, it was confirmed that Type3 Level3, in which the drive motor and the PTO motor are located at the front and rear of the tractor, and two battery packs are located in the middle of the tractor, has a high rollover angle. As a result of this study, the stability increased as the center of gravity was placed backward and located below. Future research needs to be done to find the optimal location of parts considering their performance and placement efficiency.

Relationship between Physical Health Status and Life style(Health Practices) (건강상태(健康狀態)와 생활양식(生活樣式)(건강습관(健康習慣))과의 관계(關係))

  • Choi, In-Sook;Roh, Pyong-Ui;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
    • /
    • v.3
    • /
    • pp.111-140
    • /
    • 2002
  • This study was conducted from April 1 through April 30, 2002 in order to figure out the relationship between physical health status and life style and the factors influencing physical health. Subjects were selected from among the residents older than 20 years old by probability scheme of one out of 2000. Three thousand people were interviewed by questionnaires, and 2,742(91.4%) respondents were used for analysis, and the results are as follows: 1. Ridit(Relatives to an identified distribution it) of category one by sex was 0.26 in man, and 0.25 in woman. Ridit of category two was 0.57 in man and 0.53 in woman, those of category three was 0.72 in man and 0.65 in woman. That of category four was 0.86 in man and 0.85 in woman, that of category five was 0.95 in man and 0.97 in woman, and that of category six was 0.98 in man and 0.99 in woman. The ridits and health related categories by sex were r=.954 in man and r=.966 in woman(p<0.01) 2. Ridits of healthy behavior 2-1. The ridit of males who slept for less than 6 hrs was 0.71, that of those who slept for $7{\sim}8$ hrs was 0.24, and that of those who slept for more than 9 hours was 0.96. The ridit of females who slept for less than 6 was 0.80, that of those who slept for $7{\sim}8$ hrs was 0.32, and that of those who slept for more than 9 hrs was 0.97. 2-2. The ridit of male, who ate breakfast everyday was 0.30, that of those who ate one to four breakfast per week was 0.87, and that of those who never ate breakfasts was 0.96. The ridit of females who ate breakfast everyday was 0.32, that of those who ate breakfast one to four times a week was 0.75, and that of those who never ate breakfast was 0.99. 2-3. The ridit of males whose body weights were 10% lower than normal body weight was 0.45, that of those with $5{\sim}9.9%$ less than normal body weight was 0.28, that of those with ${\pm}4.9%$ of normal body weight was 0.12, that of those whose body weights were $5{\sim}9.9%$ heavier than normal was 0.40, that of those whose body weights were $10{\sim}19.9%$ heavier than normal was 0.74, that of those with $20{\sim}29.9%$ heavier than normal body weights was 0.78 and that of those with 30% heavier than normal body weight was 0.87. That of females with 10% less than normal body weight was 0.53, that of those with $5{\sim}99%$ less than normal body weight was 0.32, that of 4.9% those with ${\pm}f$ normal body weight was 0.14, that of those with 5.0 to 9.9% heavier body weights was 0.43, that of those with 10 to 19.9% heavier body weight was 0.65, that of those with $20{\sim}29.9%$ heavier body weight was 0.94 and that of those with more than 30% of normal body weight was 0.94. 2-4. The ridit of males who exercised everyday was 0.11, that of those who exercised three to four times a week was 0.25, that of those exercising once or twice a week was 0.48, and that of those who never exercised was 0.80. The ridit of females exercising everyday was 0.08, that of those exercising three to four times a week was 0.21, that of those exercising one to two times was 0.35 and that of those who never exercised was 0.72. 2-5. The ridit of males who did not drink at all was 0.14, that of those who drank one or two cups of hard liquor(Soju) was 0.39, that of those who drank a half bottle of Soju was 0.56, that of those who darnk a bottle of Soju was 0.73 and that of those who drank two bottles of Soju was 0.96. The ridit of females who did not drink at all was 0.30, that of those who drank one or two cups of Soju was 0.70, that of those who drank a half bottle of Soju was 0.84, that of those who drank a bottle of Soju was 0.97 and that of those who drank more than two bottles of Soju was 0.99. 2-6 The ridit of males who did not smoke was 0.20, that of those who smoked one or two cigarettes was 0.44, that of those who smoked about ten cigarettes was 0.58, and that of those who smoked more than a pack of cigarettes was 0.85. The ridit of females who did not smoke at all was 0.90, that of those who smokes one or two cigarettes was 0.91, that of those who smoked about the cigarettes was 0.93 and that of those who smoked more than a pack of cigarettes was 0.96 3. The ridit of males who had healthy behavior in six categories was 0.43 and the average age of them was 45, that of those who had healthy behavior in five categories was 0.47 and the average age was 45, that of those who had healthy behavior in three categories was 0.50 and the average age was 43, that of those who had heathy behavior in two categories was 0.60 and the average age was 40, that of those who had healthy behavior in one category was 0.68 and the average age was 38, and that of those who did not have healthy behavior at all in six categories was 0.79 and the average age was 41. The ridit of females who had heathy behavior in six categories was 0.38 and the average age was 45, that of those who had healthy behavior in five categories was 0.40 and the average age was 44, that of those who had healthy behavior in four categories was 0.46 and the average age was 43, that of those who had healthy behavior in three categories was 0.52 and the average age was 44, that of those who had healthy behavior in two categories was 0.57 and the average age was 41, that of those who the healthy behavior in one category was 0.62 and the average age was 40, and that those who did not have healthy behavior in six categories was 0.79 and the average age was 43. 4. The health statues of the persons who the healthy behavior were better than those who did not have healthy behavior. If the people have healthy behavior in young age and they have healthy education continuously, they can live healthier lives.

  • PDF

The Influence of Stress on Smoking and Drinking of High School Students (스트레스가 고등학생의 흡연.음주에 미치는 영향)

  • Kim, Jong-Mun;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
    • /
    • v.3
    • /
    • pp.35-58
    • /
    • 2002
  • This research attempted to investigate the real state of adolescent smoking and drinking, and to study how stress influences on smoking and drinking of high school students. This data was collected from 837 first and second grade students in a vocational high school in Go-yang city, Gyeonggi province. Data analysis consisted of frequency, percentage, Chi-square, T-test, step-wise regression analysis, using SPSSWIN. The results of analysis were as follows: First, 51.7% of the students have never smoked, while 48.3% have experienced smoking. Most students started smoking in the second year of the middle school, though 17.6% of the smokers already started in the elementary school. The strongest motive of initial smoking was curiosity, next the inducement of friends, and 10.9% of them smoked to get rid of stress. Their favorite place for smoking was in the order of the entertainment centers, schools, and private academies. They personally purchased cigarettes mostly at the store. Most of them smoked less than 5 cigarettes a day, but 3.7% smoked more than a pack of cigarettes a day, usually with friends rather than alone. Second, the ratio of drinking was relatively high 78.1%, and their initial drinking experience was most frequent at the third year of the middle school. The initial motive of drinking was mostly curiosity and the inducement of friends, but 10.7% of them started drinking to reduce stress and anxiety. The places for buying alcohol and drinking were bars or restaurants. The ratio of habitual drinking was 45.1%, and the ratio of irregular drinking was 53.3%. 1.8% of the drinking students enjoyed drinking everyday. The amount of drinking varied from half a bottle to two bottles of Soju, and the drinking problem was serious to see that 11% of them drank more than two bottles at a time. Because 84.4% drank in groups with friends, a thorough and systematic supervision and education of the peer group drinking is essential. Third, as for the relationship between personal matters and smoking, it was found that there was a positive relation between smoking and sex, but there was no correlation between smoking and school years. Adolescent smoking was also related with scholastic achievement, the number of friends, and the existence of parents. Fourth, as for the relationship between personal matters and drinking, it was found that there was no correlation between drinking and sex, but there was a positive relation between drinking and school years. Fifth, the average index of stress was students themselves(2.58), school life(2.53), family life(2.19), friends(2.00), and the total index of stress was 2.33. Sixth, there appeared a marginal negative correlation between stress and 'drinking and smoking' in Pearson coefficient of correlation r to see the influence of stress on smoking and drinking. The difference of the average index of stress according to smoking and drinking bears meaningful difference for all students, smokers and non-smokers, drinkers and abstainers in students themselves, school life, family life, friends, and total stress. Smoking has an effect on family life most, school life next, and drinking has an effect on school life most, family life next, with the explanation power of 11% and 9% respectively, in a regression analysis to analyze the factors influencing on smoking and drinking among the factors of stress.

  • PDF

The Brassica rapa Tissue-specific EST Database (배추의 조직 특이적 발현유전자 데이터베이스)

  • Yu, Hee-Ju;Park, Sin-Gi;Oh, Mi-Jin;Hwang, Hyun-Ju;Kim, Nam-Shin;Chung, Hee;Sohn, Seong-Han;Park, Beom-Seok;Mun, Jeong-Hwan
    • Horticultural Science & Technology
    • /
    • v.29 no.6
    • /
    • pp.633-640
    • /
    • 2011
  • Brassica rapa is an A genome model species for Brassica crop genetics, genomics, and breeding. With the completion of sequencing the B. rapa genome, functional analysis of the genome is forthcoming issue. The expressed sequence tags are fundamental resources supporting annotation and functional analysis of the genome including identification of tissue-specific genes and promoters. As of July 2011, 147,217 ESTs from 39 cDNA libraries of B. rapa are reported in the public database. However, little information can be retrieved from the sequences due to lack of organized databases. To leverage the sequence information and to maximize the use of publicly-available EST collections, the Brassica rapa tissue-specific EST database (BrTED) is developed. BrTED includes sequence information of 23,962 unigenes assembled by StackPack program. The unigene set is used as a query unit for various analyses such as BLAST against TAIR gene model, functional annotation using MIPS and UniProt, gene ontology analysis, and prediction of tissue-specific unigene sets based on statistics test. The database is composed of two main units, EST sequence processing and information retrieving unit and tissue-specific expression profile analysis unit. Information and data in both units are tightly inter-connected to each other using a web based browsing system. RT-PCR evaluation of 29 selected unigene sets successfully amplified amplicons from the target tissues of B. rapa. BrTED provided here allows the user to identify and analyze the expression of genes of interest and aid efforts to interpret the B. rapa genome through functional genomics. In addition, it can be used as a public resource in providing reference information to study the genus Brassica and other closely related crop crucifer plants.

Detection of Apoptosis by M30 Monoclonal Antibody in Non-small Cell Lung Carcinomas (비소세포 폐암에서 단클론항체 M30를 이용한 세포자멸사 측정)

  • Kim, Gwang-Il;Lee, Gun;Lim, Chang-Young;Lee, Hyeon-Jae
    • Journal of Chest Surgery
    • /
    • v.40 no.2 s.271
    • /
    • pp.114-121
    • /
    • 2007
  • Background: Apoptosis plays a crucial role in carcinogenesis, as well as in development and tissue homeostasis. Terminal deoxyribonucleotidyl transferase mediated neck end labelling (TUNEL) and in situ nick end labelling (ISEL) have been used to investigate the apoptosis in tissues. Since the introduction of the M30 monoclonal antibody to overcome drawbacks of TUNEL and ISEL, the apoptosis in various tumors, with the exception of pulmonary carcinomas, has been studied. In this study, attempts were made to examine the correlation of apoptosis in non-small cell carcinomas, using both M30 and the expression of p53 protein, with the clinicopathological factors. Material and Method: Forty five patients with surgically resected non-small cell carcinomas were included. Immunohistochemical staining with M30 and p53 monoclonal antibody were peformed, and their expressions compared with the clinicopathological features. The overall survival time and recurrence-free survival time were calculated, and the factors influencing the survival time analyzed using a univariate analysis. The effects of the expression stati of M30 and p53 on the risks of cancer related to both death and recurrence were evaluated using a multivariate analysis. Result: The p53 positive group had many more M30 positive cells than the p53 negative group (p53 positive group; $61.7{\pm}26.8$ cells vs. p53 negative group; $45.6{\pm}29.6$ cells, p=0.005) and significantly more p53 positive patients showing at least 10 positive cells (apoptotic index, $Al{\ge}1$) on M30 staining (p53 positive group; 52.4% (11/21) vs. p53 negative group 16,7% (4/24), p=0.025). In the univariate analysis, the survival times in relation to smoking (pack-year), performance status (PS) and Al showed significant differences. The multivariate analysis demonstrated the relative risk (R.R) of cancer death increased almost 7.5-fold (R.R 7.482; 95% Cl $1.886{\sim}29.678$; p=0.004) and the risk of recurrence almost 3,8-fold (R.R 3.795; 95% Cl: $1.184{\sim}12.158$; p=0.025) in the high Al (${\ge}1$) compared to the low Al (<1) group. There was no prognostic effect of p53 expression on the survival time or risk of cancer death and recurrence. Conclusion: In non-small cell lung carcinomas, M30 immunohistochemistry was an excellent method for analyzing apoptosis; the high apoptotic index could be an adverse prognostic predictive factor.

Diagnostic Approach to the Solitary Pulmonary Nodule : Reappraisal of the Traditional Clinical Parameters for Differentiating Malignant Nodule from Benign Nodule (고립성 폐결절에 대한 진단적 접근 : 악성결절과 양성결절의 감별 지표에 대한 재검토)

  • Kho, Won Jung;Kim, Cheol Hyeon;Jang, Seung Hun;Lee, Jae Ho;Yoo, Chul Gyu;Chung, Hee Soon;Kim, Young Whan;Han, Sung Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
    • /
    • v.43 no.4
    • /
    • pp.500-518
    • /
    • 1996
  • Background : The solitary pulmonary nodule(SPN) presents a diagnostic dilemma to the physician and the patient. Many clinical characteristics(i.e. age, smoking history, prior history of malignancy) and radiological characteristics( i.e. size, calcification, growth rate, several findings of computed tomography) have been proposed to help to determine whether the SPN was benign or malignant. However, most of these diagnostic guidelines are based on the data collected before computed tomography(CT) has been introduced and lung cancer was not as common as these days. Moreover, it is not well established whether these guidelines from western populations could be applicable to Korean patients. Methods : We had a retrospective analysis of the case records and radiographic findings in 114 patients presenting with SPN from Jan. 1994 to Feb. 1995 in Seoul National University Hospital, a tertiary referral hospital. Results : We observed the following results ; (1) Out of 113 SPNs, the etiology was documented in 94 SP IS. There were 34 benign SP s and 60 malignant SPNs. Among which, 49 SPNs were primary lung cancers and the most common hi stologic type was adenocarcinoma. (2) The average age of patients with benign and malignant SPNs was $49.7{\pm}12.0$ and $58.1{\pm}10.0$ years, respectively( p=0.0004), and the malignant SPNs had a striking linear propensity to increase with age. (3) No significant difference in the hi story of smoking was noted between the patients with benign SPNs($13.0{\pm}17.6$ pack- year) and those with malignant SPNs($18.6{\pm}25.1$ pack-year) (p=0.2108). (4) 9 out of 10 patients with prior history of malignancy had malignant SPNs. 5 were new primary lung cancers with no relation to prior malignancy. (5) The average size of benign SPNs($3.01{\pm}1.20cm$) and malignant SPNs($2.98{\pm}0.97cm$) was not significantly different(p=0.8937). (6) The volume doubling time could be calculated in 22 SPNs. 9 SPNs had the volume doubling time longer than 400 days. Out of these, 6 were malignant SPNs. (7) The CT findings suggesting malignancy included the lobulated or spiculated border, air- bronchogram, pleural tail, and lymphadenopathy. In contrast, calcification, central low attenuation, cavity with even thickness, well-marginated border, and peri nodular micronodules were more suggestive for benign nodule. (8) The diagnostic yield of percutaneous needle aspiration and biopsy was 57.6%(19/33) of benign SPNs and 81.0%(47/58) of malignant SPNs. The diagnostic value of sputum analysis and bronchoscopic evaluations were relatively very low. (9) 42.3%(11/26) of SPNs of undetermined etiology preoperatively turned out to be malignant after surgical resection. Overall, 75.4%(46/61) of surgically resected SPNs were malignant. Conclusions : We conclude that the likelihood of malignant SPN correlates the age of patient, prior history of malignancy, some CT findings including lobulated or spiculated border, air-bronchogram, pleural tail and lymphadenopathy. However, the history of smoking, the size of the nodule, and the volume doubling time are not helpful to determent whether the SPN is benign or malignant, which have been regarded as valuable clinical parameters previously. We suggest that aggressive diagnostic approach including surgical resection is necessary in patient with SPNs.

  • PDF

Prognostic Value of p53 Overexpression in Patients with Pathologic Stage I Non-small Cell Lung Cancer (제 1기 비소세포폐암 환자에서 p53 과발현과 예후의 관계)

  • Um, Sang-Won;Kim, Hojoong;Kwon, O Jung;Han, Joungho;Shim, Young Mog
    • Tuberculosis and Respiratory Diseases
    • /
    • v.65 no.6
    • /
    • pp.487-494
    • /
    • 2008
  • Background: Chromosome 17p allele losses and mutations of p53 gene are the most common genetic abnormalities in lung cancer. The purposes of this study were to evaluate the factors associated with p53 protein overexpression and to evaluate its prognostic value in patients with pathologic stage I non-small cell lung cancer (NSCLC). Methods: This is a retrospective review for the patients who underwent surgical resection at Samsung Medical Center between Jan 2003 and Jun 2004. Immunohistochemical staining for p53 protein was performed on tumor tissues from patients with lung cancer. The p53 overexpression was evaluated in relation to age, sex, smoking history, histology and pathologic stage by univariate and multivariate analyses. The disease-free survival (DFS), disease-specific survival (DSS) and overall survival (OS) were analyzed using the Kaplan-Meier methods and the differences in DFS, DSS and OS were assessed by using the log-rank tests. Results: A total of 125 patients were included in the analysis and a median frequency of p53 expression in tumor tissue was 10%. The p53 overexpression (${\geq}10%$) was more common in squamous cell carcinoma (66%) than in adenocarcinoma (38%, p=0.002). The p53 overexpression was more common in pathologic stage IB (59%) than in IA (38%, p=0.002). Patients with p53-overexpressing tumor (27 years) smoked more years compared with those without it (20 years, p=0.032). Smoking history ${\geq}25$ pack-years was more common in patients with p53 overexpression (58%) than in those without it (38%, p=0.024). In the multivariate analysis, only histology was significantly associated with p53 overexpression. However, there were no significant differences of DFS, DSS and OS in relation to p53 status. Conclusion: The p53 overexpression was associated with histology, pathologic stage and smoking history in patients with pathologic stage I NSCLC. However, the p53 overexpression was not associated with patient's survival.

Contributors of the Severity of Airflow Limitation in COPD Patients

  • Hong, Yoon-Ki;Chae, Eun-Jin;Seo, Joon-Beom;Lee, Ji-Hyun;Kim, Eun-Kyung;Lee, Young-Kyung;Kim, Tae-Hyung;Kim, Woo-Jin;Lee, Jin-Hwa;Lee, Sang-Min;Lee, Sang-Yeub;Lim, Seong-Yong;Shin, Tae-Rim;Yoon, Ho-Il;Sheen, Seung-Soo;Ra, Seung-Won;Lee, Jae-Seung;Huh, Jin-Won;Lee, Sang-Do;Oh, Yeon-Mok
    • Tuberculosis and Respiratory Diseases
    • /
    • v.72 no.1
    • /
    • pp.8-14
    • /
    • 2012
  • Background: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. Methods: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second ($FEV_1$)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with $FEV_1$ - the index of the severity of airflow limitation. Results: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient ${\beta}$=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; ${\beta}$=-0.24; p<0.001), and airway wall thickness (mean wall area %; ${\beta}$=-0.19, p=0.001), as well as current smoking status (${\beta}$=-0.14; p=0.009) were independent contributors to $FEV_1$. Conclusion: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.