• Journal of Biomedical Engineering Research
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• v.40 no.2
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• pp.62-67
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• 2019

The purpose of this study was to evaluate the performance of deep neural network model in order to determine whether there is a risk factor for coronary artery disease based on the cardiac variation parameter. The study used unidentifiable 297 data to evaluate the performance of the model. Input data consists of heart rate parameters, which are SDNN (standard deviation of the N-N intervals), PSI (physical stress index), TP (total power), VLF (very low frequency), LF (low frequency), HF (high frequency), RMSSD (root mean square of successive difference) APEN (approximate entropy) and SRD (successive R-R interval difference), the age group and sex. Output data are divided into normal and patient groups, and the patient group consists of those diagnosed with diabetes, high blood pressure, and hyperlipidemia among the various risk factors that can cause coronary artery disease. Based on this, a binary classification model was applied using Deep Neural Network of deep learning techniques to classify normal and patient groups efficiently. To evaluate the effectiveness of the model used in this study, Kernel SVM (support vector machine), one of the classification models in machine learning, was compared and evaluated using same data. The results showed that the accuracy of the proposed deep neural network was train set 91.79% and test set 85.56% and the specificity was 87.04% and the sensitivity was 83.33% from the point of diagnosis. These results suggest that deep learning is more efficient when classifying these medical data because the train set accuracy in the deep neural network was 7.73% higher than the comparative model Kernel SVM.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.81-89
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• 2022

Purpose : Kegel exercises reported that it is effective in managing stress-related or complex urinary incontinence through contraction and relaxation of the pelvic floor muscles. In many previous studies, it was confirmed that Kegel exercise is involved in respiration as well as urinary system diseases. However, there is a lack of research on the effect of pelvic setting when performing Kegel exercises. Therefore, this study was conducted to investigate the effect on maximum voluntary ventilation (MVV) and abdominal muscle thickness through Kegel exercise after lumbar-pelvic motor control using pressure biofeedback unit (PBU). Methods : The subjects of this study were 10 healthy female students in their 20s. Subjects measured MVV with a spirometer. In hooklying, external oblique, internal oblique, and transverse abdominis of the dominant hand were measured using ultrasound. The measured value was an average of three times. After one week of intervention, measurements were made in the same manner. Before Kegel exercise, pelvic setting training was performed using PBU. In hooklying, PBU was placed in the waist and set to 40 mmHg, and it was adjusted to 60 mmHg through pelvic muscle contraction. For Kegel exercise, the pelvis was first set using PBU, and then the pelvic floor muscles were contracted for 8 seconds and relaxed for 8 seconds, 10 times, 1 set, and 3 sets. Results : In MVV, a significant difference was confirmed after exercise than before exercise (p<.05). There was also a significant difference in abdominal muscle thickness before and after exercise (p<.05). Conclusion : Based on the results of this study, Kegel exercise using PBU had an effect on MVV and abdominal muscle thickness. However, since this study was conducted without a control group as a preliminary study, additional research should be conducted to supplement this.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.48-57
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• 2008

The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.

• Speech Sciences
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• v.10 no.4
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• pp.189-200
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• 2003

The objective of this study was to examine two new parameters by which we could screen people with malignant vocal folds. The new parameters were the difference sums and Pearson correlation coefficients between adjacent pairs of intensity level matrices of narrow-band spectra. Audio files from the Korean Disordered Speech Database were analyzed by Praat, a speech analysis software, to obtain matrices of 400 intensity levels at 16 time points of each sustained vowel spectra. We limited our study to 12 normal subjects and 20 patients with malignant vocal folds who recorded at least three Korean vowels at a sound-proofed booth in Busan National University Hospital. Results indicated that the average coefficients of the abnormal subjects were much lower than those of the normal subjects while the average difference sums of the patients were much higher than those of the normal ones. Also, we found that the degree of the malignancy of the vocal folds was related to the coefficients and sums. However, some subjects at the initial stages of cancerous vocal folds yielded almost comparable coefficients and difference sums to those of the normal speakers. Further studies on larger databases will be desirable to set certain criteria or threshold levels for screening people with vocal fold diseases.

• Journal of Applied and Pure Mathematics
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• v.5 no.1_2
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• pp.41-53
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• 2023

Let G = (V, E) be a (p, q) graph. Define $${\rho}=\{{\frac{2}{p}},\;{\text{{\qquad} if p is even}}\\{\frac{2}{p-1}},\;{{\text{if p is odd}}$$ and L = {±1, ±2, ±3, … , ±ρ} called the set of labels. Consider a mapping f : V ⟶ L by assigning different labels in L to the different elements of V when p is even and different labels in L to p-1 elements of V and repeating a label for the remaining one vertex when p is odd.The labeling as defined above is said to be a pair difference cordial labeling if for each edge uv of G there exists a labeling |f(u) - f(v)| such that ${\mid}{\Delta}_{f_1}-{\Delta}_{f^c_1}{\mid}{\leq}1$, where ${\Delta}_{f_1}$ and ${\Delta}_{f^c_1}$ respectively denote the number of edges labeled with 1 and number of edges not labeled with 1. A graph G for which there exists a pair difference cordial labeling is called a pair difference cordial graph. In this paper we investigate pair difference cordial labeling behaviour of Petersen graphs P(n, k) like P(n, 2), P(n, 3), P(n, 4).

• Journal of applied mathematics & informatics
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• v.42 no.1
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• pp.1-14
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• 2024

Let G = (V, E) be a (p, q) graph. Define $$\begin{cases}\frac{p}{2},\:if\:p\:is\:even\\\frac{p-1}{2},\:if\:p\:is\:odd\end{cases}$$ and L = {±1, ±2, ±3, ···, ±ρ} called the set of labels. Consider a mapping f : V → L by assigning different labels in L to the different elements of V when p is even and different labels in L to p - 1 elements of V and repeating a label for the remaining one vertex when p is odd.The labeling as defined above is said to be a pair difference cordial labeling if for each edge uv of G there exists a labeling |f(u) - f(v)| such that |Δ_f1 - Δ_f^c1| ≤ 1, where Δ_f1 and Δ_f^c1 respectively denote the number of edges labeled with 1 and number of edges not labeled with 1. A graph G for which there exists a pair difference cordial labeling is called a pair difference cordial graph. In this paper we investigate the pair difference cordial labeling behavior of subdivision of some graphs.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.263-286
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• 2022

This study acquires NBA statistical information for a total of 32 years from 1990 to 2022 using web crawling, observes variables of interest through exploratory data analysis, and generates related derived variables. Unused variables were removed through a purification process on the input data, and correlation analysis, t-test, and ANOVA were performed on the remaining variables. For the variable of interest, the difference in the mean between the groups that advanced to the playoffs and did not advance to the playoffs was tested, and then to compensate for this, the average difference between the three groups (higher/middle/lower) based on ranking was reconfirmed. Of the input data, only this year's season data was used as a test set, and 5-fold cross-validation was performed by dividing the training set and the validation set for model training. The overfitting problem was solved by comparing the cross-validation result and the final analysis result using the test set to confirm that there was no difference in the performance matrix. Because the quality level of the raw data is high and the statistical assumptions are satisfied, most of the models showed good results despite the small data set. This study not only predicts NBA game results or classifies whether or not to advance to the playoffs using machine learning, but also examines whether the variables of interest are included in the major variables with high importance by understanding the importance of input attribute. Through the visualization of SHAP value, it was possible to overcome the limitation that could not be interpreted only with the result of feature importance, and to compensate for the lack of consistency in the importance calculation in the process of entering/removing variables. It was found that a number of variables related to three points and errors classified as subjects of interest in this study were included in the major variables affecting advancing to the playoffs in the NBA. Although this study is similar in that it includes topics such as match results, playoffs, and championship predictions, which have been dealt with in the existing sports data analysis field, and comparatively analyzed several machine learning models for analysis, there is a difference in that the interest features are set in advance and statistically verified, so that it is compared with the machine learning analysis result. Also, it was differentiated from existing studies by presenting explanatory visualization results using SHAP, one of the XAI models.

• Journal of Families and Better Life
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• v.20 no.6
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• pp.49-60
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• 2002

This study focused on family stresses and coping strategies among commuting couples. The participants of this study consisted of a national samples of 134 couples(268 individuals), who had been commuting for at least six months. The major findings obtained from the study are summarized in the following: First, the degree of family stresses among commuting couples was 2.98, when the maximal stress value was set to 5.0. No difference in the level of stress was detected from the roles of the wife and those of the husband. The most stressful aspect for the commuting couples came from the role of parents who care for their children. The second stressful aspect was their responsibility for their own parents, and finally the stress from the housework and maintenance of their marital lives followed next. There was no difference between the wives and husbands on the stressors. Secondly, the level of the coping strategies developed by the commuting couples themselves against their stresses was 3.37, when the maximal stress coping value was set to 5.0. Again, there was no difference in this level between wives and husbands. Among the strategies, they used ‘cognitive restructuring’the most frequently; sharing their responsibilities with other members in family life came next; and developing their own techniques to manage their stresses followed. Thirdly, the ages of the couple, the age of the first child, type of jobs, duration of the marriage and commute, and frequency of meeting affected the level of family stress among commuting couples. Finally, commuting couples developed quite different strategies to cope with their family stresses, and religion and family type affected significantly the type of coping strategies.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.429-434
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• 2007

This study was conducted to estimate site productivity of Quercus acutissima and Quercus mongolica by four forest climatic zones. We used site environmental variables (28 geographical and pedological factors) and site index as a site productivity indicator from nation-wide 23,315 stands. Based on multiple regression analysis between site index and major environmental variables, the best-fit multivaliate models were made by each species and forest climatic zone. Most of site index prediction models by species were regressed with seven to eight factors, including altitude, relief, soil depth, and soil moisture etc. For those models, three evaluation statistics such as mean difference, standard deviation of difference, and standard error of difference were applied to the test data set for the validation of the results. According to the evaluation statistics, it was found that the models by climatic zones and species fitted well to the test data set with relatively low bias and variation. Also having above middle of site index range, total area of productive sites for the two Quercus spp. estimated by those models would be about 6% of total forest area. Northern temperate forest zone and central temperate forest zone had more productive area than southern temperate forest zone and warm temperate forest zone. As a result, it was concluded that the regressive prediction with site environmental variables by climatic zones and species had enough estimation capability of forest site productivity.

• Journal of Oral Medicine and Pain
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• v.43 no.4
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• pp.125-130
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• 2018

Purpose: The etiology of temporomandibular disorders (TMDs) is complex and multifactorial including trauma, anatomical, pathophysiological, social and psychological factors. Psychological factors can induce or sustain TMDs in various ways. And psychological problems, such as anxiety and depression can be occurred due to TMDs. Therefore, evaluation of psychological factors in patients with TMDs is important. Although disc displacement (DD) is crucial in clinical situation, most of studies have focused on the relationship of psychosocial factors and myofascial pain. And also, Subtypes of DD can cause different degrees of discomfort, it is necessary to evaluate the psychological states of the patients according to the subtype. The Hospital Anxiety Depression Scale (HADS) is one of the self-report questionnaire to evaluate the psychological factors. HADS-Anxiety (HADS-A) and HADS-Depression (HADS-D) are assessed through 14 questions. The purpose of this study was to evaluate anxiety and depression assessed by HADS in patients diagnosed with subtypes of DD according to diagnostic criteria for TMDs. Methods: Four hundred thirty nine patients were diagnosed as one of the subtypes of DD. One hundred fourty nine subjects with no symptoms were set as control groups. All of them answered the HADS for Koreans. The cut-off score for anxiety and depression was set a score of 8. The chi-square test was performed to evaluate association between DD and anxiety/depression. Results: There was a significant difference in HADS-D between five groups (p<0.01). However, there was no significant difference in HADS-A. All the DD groups showed a significant difference in HADS-D compared with the control group except the DD without reduction without limited opening group. The DD without reduction with limited opening group showed the highest rates in HADS-D (40.4%). Conclusions: Based on the above results, it is necessary to consider the depression in treatment of the patients with DDs.