• Journal of Korea Multimedia Society
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• v.23 no.5
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• pp.625-632
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• 2020

In the diagnosis of lung cancer, the tumor size is measured by the longest diameter of the tumor in the entire slice of the CT. In order to accurately estimate the size of the tumor, it is better to measure the volume, but there are some limitations in calculating the volume in the clinic. In this study, we propose an algorithm to segment lung cancer by applying a custom loss function that combines focal loss and dice loss to a U-Net model that shows high performance in segmentation problems in chest CT images. The combination of values of the various parameters in custom loss function was compared to the results of the model learned. The purposed loss function showed F1 score of 88.77%, precision of 87.31%, recall of 90.30% and average precision of 0.827 at α=0.25, γ=4, β=0.7. The performance of the proposed custom loss function showed good performance in lung cancer segmentation.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.4
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• pp.437-445
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• 2011

Purpose : The purpose of this study was to analysis on diaphragm thickness and lung function of stroke patients by walking ability. Methods : We recruited thirty-five adults after stroke(20 male, 15 female) for our study. The subjects were divided into two groups; independent walking group(11 male, 9 female) and non-independent walking group(9 male, 6 female). Assessment of diaphragm thickness was performed using ultrasound in B-mode with a 7.5 MHz linea probe. During the experiment, the subject was seated in the chair. All subjects performed maximal expiratory flow maneuvers using a spirometer in order to determine the forced expiratory volume in 1 second ($FEV_1$), forced vital capacity(FVC), peak expiratory flow(PEF) and $FEV_1$/FVC. Chest expansion was measured with a tape-measure placed circumferentially around the chest wall at the xiphoid process. The collected data analyzed by independent t-test. Results : The diaphragm thickness were significant differences between the independent walking and nonindependent walking group. Values of forced vital capacity, forced expiratory volume at one second, peak expiratory flow in pulmonary function tests were significant differences between the independent walking and non-independent walking group. However, chest expansion were not significant differences in both of the group. Conclusion : This study showed that walking ability of stroke patients have influenced on diaphragm thickness and pulmonary function.

• Journal of International Academy of Physical Therapy Research
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• v.8 no.2
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• pp.1146-1151
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• 2017

The purpose of this study was to compare the effects of respiratory exercise on cardiopulmonary function and muscle activity of rectus abdominis in smokers and non-smokers with elderly people. All the participants were older than 65 years, and twenty non-smokers, and twenty smokers participated. Non-smokers and smokers were randomly divined into 10 feedback breathing exercises (FBE) and a balloon-blowing exercise (BBE) group. The FBE and the BBE were performed three times a week for four weeks. Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), forced expiratory volume at one second/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and vital capacity (VC) were measured as pulmonary function. EMG was used to measure the activity of the rectus abdominis. In the FBE and BBE groups, $FEV_1$ was significantly lower in non-smokers compared to smokers at two and four weeks (p<.05), $FEV_1/FVC$, PEF and VC were significantly lower in non-smokers compared to smokers to pre-test, two weeks, four weeks and six weeks (p<.05). Muscle activity of rectus abdominis was significantly difference in the BBE group at pre-test, two weeks, four weeks, and six weeks (p<.05). These results suggest that respiratory exercise was effective in improving pulmonary function and rectus muscle activity.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.17-24
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• 2018

Purpose: This study aimed to investigate the relationship between forward head posture and pulmonary function in young women. Methods: Thirty-three young women participated in this study. The participants were grouped into non-forward head posture, mild forward head posture, and moderate-severe forward head posture groups. The craniovertebral angle (CVA) and pulmonary function were measured using ImageJ and a spirometer, respectively. Results: Statistically significant differences in the participants' forced expiratory volume for one second (FEV1) and predicted forced expiratory volume for one second (predicted FEV1) were found among the three groups. No statistically significant differences in the participants' forced vital capacity (FVC), predicted forced vital capacity (predicted FVC), FEV1/FVC, and peak expiratory flow (PEF) were found among the three groups. Furthermore, a significant positive correlation was found between CVA and FVC and among the predicted FVC, FEV1, and predicted FEV1. Conclusions: The results of this study demonstrate that severe forward head posture has a negative effect on pulmonary function in young women.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.31-37
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• 2023

PURPOSE: This study aimed to investigate the relationship between being underweight and respiratory function indicators such as pulmonary function, respiratory muscle strength, and diaphragm thickness in normal adults without lung disease. METHODS: The participants in this experiment were thirty young adults. To compare the respiratory function between the underweight and normal weight individuals, 15 participants were selected from each of the underweight and normal weight groups based on body mass index. Respiratory function tests were conducted through pulmonary function tests and respiratory muscle strength tests. Diaphragm thickness was measure with ultrasonography, and physical characteristics were obtained from grip strength and waist circumference. An independent t-test was used to compare the averages of the parameters measured in the two groups. RESULTS: In the respiratory function tests between the two groups, statistically significant differences (p < .05) emerged in the ratio of the predicted forced vital capacity (%FVC), the ratio of the predicted forced expiratory volume in one second (%FEV1), maximal expiratory pressure (MEP), and diaphragm thickness at the functional residual capacity (FRC). There was no statistically significant difference in the forced vital capacity, forced expiratory volume in one second, maximal inspiratory pressure, diaphragm thickness at the total lung capacity, and thickening ratio (p > .05). CONCLUSION: Decreases in some variables of respiratory function, such as the %FVC, %FEV1, MEP, and diaphragm thickness at the FRC were observed in underweight subjects. However, it is difficult to determine whether it affected the overall respiratory function. Future studies are needed to clearly identify the relationship between being underweight and respiratory function.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.221-230
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• 2023

Purpose : This study was performed to evaluate the effects of virtual reality combined robot assist gait training (VRG) on improvement of balance and respiratory function in chronic stroke patients. Methods : A single-blind, randomized controlled trial (RCT) was conducted with 35 chronic stroke patients. They were randomly allocated 2 groups; VRG group (n=18) and conservative treatment group (CG; n=17). The VRG group received 30 minutes robot assisted gait training combined virtual reality training, robot assisted gait training was conducted in parallel using a virtual reality device (2 sessions of 15 minutes in a 3D-recorded walking environment and 15 minutes in a downtown walking environment). In the conservative treatment group, neurodevelopmental therapy and exercise therapy were performed according to the function of stroke patients. Each group performed 30 minutes a day 3 times a week for 8 weeks. The primary outcome balance and respiratory function were measured by a balance measurement system (BioRescue, Marseille, France), Berg balance scale, functional reach test for balance, Spirometry (Cosmed Micro Quark, Cosmed, Italy) for respiratory function Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and maximum expiratory volume (PEF) were measured according to the protocol. The measurement were performed before and after the 8 weeks intervention period. Results : Both groups demonstrated significant improvement of outcome in balance and respiratory function during intervention period. VRG revealed significant differences in balance and respiratory function as compared to the CG groups (p<.05). Our results showed that VRG was more effective on balance and respiratory function in patients with chronic stroke. Conclusion : Our findings indicate that VRG can improve balance and respiratory function, highlight the benefits of VRG. This study will be able to be used as an intervention data for recovering balance and respiratory function in chronic stroke patients.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.3
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• pp.279-286
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• 2017

This study suggests design criteria to evaluate the availability of anchorage in Korea to contribute to ship safety by presenting necessary design criteria for anchorage volume according to port development. Accordingly, the concept of "necessary volume of anchorage" is introduced to evaluate the volume of anchorage available in Korea's major ports, and classify these ports into three types according to the characteristics of incoming ship. Numerical simulations designed using MATLAB-SIMULINK have been carried out to track the irregularly of arrival and, waiting times along with the environmental conditions that affect anchorage and necessary volume of anchorage have been suggested based on these tests. Finally, in order to complete a function equation analysis, the necessary volume of anchorage with reference to cargo volume is addressed using regression analysis as follows. Group $A-Y_{NA}=0.0002X_{HA}-3.67$, Group $B-Y_{NB}=0.0002X_{HB}-6.82$, Group $C-Y_{NC}=0.0001X_{HC}+9.02$. This study contributes to a review of anchorage volume from the perspective of harbor development.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.4
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• pp.495-503
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• 2001

In a functionally graded materials(FGM), two constituent material particles are mixed up according to a specific volume fraction distribution so that its thermoelastic behavior is definitely characterized by such a material composition distribution. Therefore, the designer should determine the most suitable volume fraction distribution in order to design a FGM that optimally meets the desired performance against the given constraints. In this paper, we address a numerical optimization procedure, with employing interior penalty function method(IPFM) and FDM, for optimizing 2D volume fractions of heat-resisting FGMs composed of metal and ceramic. We discretize a FGM domain into finite number of homogenized rectangular cells of single design variable in order for the optimization efficiency. However, after the optimization process, we interpolate the discontinuous volume fraction with globally continuous bilinear function in order to enforce the continuity of volume fraction distributions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.32-38
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• 2018

Studies on classification of national roads have been continued, but there is little research on the classification of urban arterial roads. Due to the increase of traffic volume, urban arterial roads do not perform well as main roads. In this paper, the function of urban arterial road was established by using cluster analysis using traffic characteristics. Traffic characteristics such as traffic volume, weekend coefficient and speed coefficient were used to establish the functions of 55 main arterial roads in Seoul. The results of this paper are compared with those of the method using AADT. The method using AADT classifies the characteristics according to the traffic volume of the whole lane. In this paper, however, the results are derived using the traffic volume per lane reflecting the actual traffic volume. In addition, the functional classification of the arterial roads in Seoul was compared with the results of this paper to verify that the traffic characteristics were reflected. As a result, the method presented in this paper is more effective in showing traffic characteristics than the current highway functional classification method, and the functional classification system will be helpful for road extension and planning design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.4
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• pp.468-480
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• 1998

The temporal and spatial distributions of soot volume fractions were measured for single toluene droplet flames as a function of pressure under the normal-gravity condition. In order to characterize the transient nature of the flame and sooting regions, a full-field light extinction and subsequent tomographic inversion technique was used. The reduction in sooting as a function of pressure was assessed by comparison of the maximum soot volume fractions at several vertical positions along the axis above the droplet. The maximum soot volume fraction was reduced by 70% when the pressure was reduced by 60% from 1 atm to 0.4 atm. The reduction in sooting is attributed to variation of the geometric configuration of flame which reduces the system Grashof number as well as only the change in the adiabatic flame temperature as the pressure decreases. The gravimetrically-measured total soot yield was also compared to the optically-measured soot volume fraction to obtain a correlation between the two measurements. As a result, the total soot yield was linearly proportional to the optically-measured maximum soot volume fraction and linearly reduced as the pressure decreased. Accordingly, the non-intrusive full-field light extinction-measurements were able to be calibrated not only to measure soot volume fraction, but to simultaneously evaluate the total soot yield emitted from the toluene droplet flame (which is useful in the practical application).