Relationship between Self-Compassion and Uneasiness about the Professional Future among Dental Hygiene Students: A Cross-Sectional Study

Izumi, Maya; Akifusa, Sumio

doi:https://doi.org/10.1155/2023/8880952

International Journal of Dentistry

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Abstract Introduction Materials and Methods Results Discussion Conclusion Data Availability Conflicts of Interest Authors’ Contributions References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 8880952 | https://doi.org/10.1155/2023/8880952

Relationship between Self-Compassion and Uneasiness about the Professional Future among Dental Hygiene Students: A Cross-Sectional Study

Maya Izumi¹and Sumio Akifusa¹

Academic Editor: Mario Dioguardi

Received17 May 2023

Revised10 Aug 2023

Accepted09 Sept 2023

Published27 Sept 2023

Abstract

Purpose. To examine the self-compassion of dental hygiene students in Japan and the correlation between their self-compassion and uneasiness about their professional future. Methods. This study was conducted from May to September 2021. Students were invited from three colleges and one university in Fukuoka Prefecture to take the survey. Participants provided information regarding demographic variables (e.g., gender and year of study) and answered six questions regarding feeling uneasy about one’s future, matters of learning, and what might happen after graduation. Self-compassion was assessed using the Japanese short version of the self-compassion scale (SCS), with the positive- and negative-SCS subdomains. Resilience was measured using the bidimensional resilience scale with the subdomains of innate and acquired resilience. For the statistical analysis, participants were divided into the “yes” group, where members felt uneasy and the “no” group, where members did not feel uneasy. Results. Data were obtained from 464 participants (response rate: 96.3%). The scores of total-, positive-, and negative-SCS were 36 (12–56), 18 (6–29), and 19 (6–30), respectively; 55.2% of students felt uneasy about their professional future. There was a statistically significant difference in scores for positive- and negative-SCS and innate resilience between the “yes” and “no” groups. Binomial logistic regression analysis revealed that when negative-SCS increased by one point, the risk of feeling uneasy about one’s professional future was 1.12 times higher (95% confidence interval: 1.07–1.17) after adjusting for resilience and the answers to the remaining five questions. Conclusion. Our findings suggest that the negative factor of self-compassion is related to increasing the risk of feeling uneasy about one’s professional future as a dental hygienist.

1. Introduction

Along with advances in dentistry, such as newly developed dental materials and changes in disease structure (e.g., an increase in lifestyles related to disease through the progression of aging), the diversity of knowledge and skills required for dental hygienists is expanding every year. Students in undergraduate dental hygiene programs experience high levels of stress and anxiety in terms of miscellaneous content in the educational curriculum [1]. Students attend classes and practical training simultaneously and are expected to meet the requirements of the curriculum for the dental hygiene profession over the course of 3 years.

Perceived stress negatively impacts nursing students’ physical and mental health [2] and hinders academic performance and course completion rates [3, 4]. Moreover, perceived stress is tied to overexhaustion and burnout among dental hygiene students [5–10]. As important psychological characteristics to cope with mental stress, we previously examined the relationship between innate (but not acquired) resilience and self-perceived health in dental hygiene students [11]. Regarding the reasons for dropping out of dental hygienist training schools in Japan, economic reasons comprised 4.9%–6.9% of all reasons, but changing career paths accounted for half [12]. Further, implementing initial-year education and promoting awareness of learning support systems can paradoxically lead to higher dropout rates [13]. Thus, simply enhancing and strengthening educational content and quality alone will not resolve anxiety about the future, and it is necessary to examine the psychological characteristics of dental hygiene students in Japan.

As for new ways of understanding mental well-being, Eastern philosophical thought, especially Buddhism, has often been compared with Western psychology [14]. Unlike Western culture, in Buddhist psychology, it is as essential to feel compassion for oneself as it is for others. Neff defined self-compassion as follows: When we experience pain or anxiety, we have compassion for ourselves (self-kindness); we recognize negative experiences as being shared by humanity (a sense of shared humanity), and we maintain a state of balance by avoiding painful thoughts and feelings (mindfulness) [15]. Many researchers have used the self-compassion scale (SCS), developed by Neff, to explore the relationship between self-compassion and perceived health [16], mental well-being [17], aggression in adolescents [18], and job burnout [19]. We posited that coping with stress would cause dental hygiene students to feel anguish in relation to self-compassion. Thus, we aimed to investigate the relationship between dental hygiene students’ anguish (in particular, feeling uneasy about their professional future) and self-compassion.

2. Materials and Methods

This study was approved by the Medical Ethics Committee of Kyushu Dental University (No. 21–52). We considered informed consent to have been obtained when the participants agreed to answer the survey following an oral agreement.

The participants were 482 students from four dental hygiene programs in Fukuoka Prefecture. Three schools offer 3-year dental hygiene programs; one university (our affiliated institution) has a 4-year program. Each school’s program aligns with the criteria for the national dental hygienist exam. We mailed the survey to each school (except for the university); after checking the returned survey, we remailed responses with incomplete sections to each school. At the university, we collected the survey directly from the participants.

We conducted the survey for this cross-sectional study from May to September 2021. The survey included items regarding demographic variables such as gender, the student’s year of study, and six questions about learning issues or what might happen after graduation:(Q1)I want to work as a dental hygienist in the future.(Q2)I will make a good dental hygienist.(Q3)Practical training will be useful in the future.(Q4)The lecture content will be useful in the future.(Q5)I feel uneasy about my professional future as a dental hygienist.(Q6)It is hard for me to learn at school.

The participants could choose from the responses of not at all, not much, neither, frequent, or always.

To assess psychological resilience, we employed the bidimensional resilience scale (BRS), which was developed to measure innate and acquired resilience [11, 20]. The BRS consists of 21 questions. Questions 1–12 test innate resilience, and questions 13–21 test acquired resilience. Each question is rated on a 5-point Likert scale, where higher scores imply greater resilience. The total possible score ranges from 21 to 105.

To assess self-compassion, we used the short form of the Japanese version of the SCS [21–23]. The SCS consists of 12 questions. Each question is rated on a 5-point Likert scale. The SCS is divided into two subdomains: positive- and negative-SCS. Positive-SCS contains six questions on self-kindness, a shared sense of humanity, and mindfulness. Negative-SCS is composed of six questions regarding self-judgment, isolation, and over-identification. The total possible score for each subdomain ranges from 6 to 30. When calculating the total score of the SCS, the score of positive-SCS was summed up with the remainder of 36 minus negative-SCS (total SCS = positive-SCS + (36 – negative-SCS)). The total possible score ranges from 12 to 60.

The primary outcome was to evaluate the self-compassion of dental hygiene students in Japan. The secondary outcome was to examine the correlation between self-compassion and uneasiness about one’s professional future.

We calculated Cronbach’s α to determine the internal consistency regarding the reliability of each scale. Values are represented as the median (minimum–maximum) for continuous variables and as the number (%) for categorized variables. To analyze the statistical differences of scores for each scale (e.g., SCS and BRS) based on the answers given to each question (e.g., Q1–Q6), we divided the participants into two groups: the “no” group (options for answers: not at all, not much, neither) and the “yes” group (options for answers: frequent, always). We evaluated the significance of the differences between the groups using the Mann–Whitney U test. We appraised the correlation between the two factors using Spearman’s rank correlation coefficient. To establish which variables were related to feeling uneasy about one’s professional future, we employed Q5. We also performed binomial logistic regression analysis by allowing dichotomized answers for Q1–Q4 and Q6 (positive-SCS, negative-SCS, innate resilience, acquired resilience). To analyze the collinearity of the explanatory variables for binomial logistic regression analysis, we assessed the variance inflation factor. We performed all analyses using SPSS v28 (IBM, Inc.). All statistical comparisons were two-sided, and we considered a <5% error to be statistically significant.

3. Results

We recruited 464 students (response rate: 96.3%). Values of Cronbach’s α for the SCS, positive-SCS, negative-SCS, BRS, innate resilience, and acquired resilience were 0.627, 0.721, 0.853, 0.833, 0.760, and 0.855, respectively. Table 1 shows the participants’ characteristics. All participants were women with a median age of 19 (18–50) years. Table 2 presents the numbers of each answer for Q1–Q6. Unexpectedly, the proportion of students who answered neither for Q2 was 51.1%, and for the “yes” group, it was 28.5%, suggesting that only one out of four students felt they would make a good dental hygienist. Likewise, the responses of the “yes” group (55.2%) to Q5 dominated that of the “no” group (44.8%), indicating that more than half of the students felt uneasy about their professional future. Table 3 presents the correlation between each subdomain of the SCS and BRS. Positive-SCS was positively correlated with innate and acquired resilience. Negative-SCS was inversely correlated with all other subdomains with statistical significance; however, there was a poor correlation efficiency between negative-SCS and positive-SCS at −0.256. Similarly, the correlation between negative-SCS and acquired resilience was poor because it was −0.168, below 0.3.

Next, to investigate which psychological features were associated with learning issues and self-recognition (assessed by Q1–Q6), we compared the scores of the SCS (Table 4) and BRS (Table 5) between the “yes” and “no” groups for each question. For Q1 (the desire to work as a dental hygienist) and Q3 (the meaning of practical training), only acquired resilience had a statistically significant difference. For Q4 (the meaning of the lecture), negative-SCS and acquired resilience had a statistically significant difference. For Q2 (thinking one will make a good dental hygienist), the scores of all scales of the “yes” group were higher than those of the “no” group, except for negative-SCS. For Q5 (feeling uneasy about one’s professional future), the scores of SCS and innate resilience for the “no” group were higher than those of the “yes” group. For Q6 (difficulty learning at school), SCS and its subdomains had a statistically significant difference. Since almost half of the students felt uneasy about their professional future, we performed binomial logistic regression analysis to assess the correlated factors for feeling uneasy about one’s professional future. As outlined in Table 6, together with Q2, Q4, and Q6, negative-SCS was correlated with feeling uneasy about one’s professional future (B ± SE: 0.11 ± 0.02, odds ratio: 1.12 (95% confidence interval: 1.07–1.17), ).

4. Discussion

The binomial regression analysis indicated that feeling uneasy about one’s professional future was statistically significantly correlated with negative-SCS but not positive-SCS or resilience. In the present study, when negative-SCS increased by one point, feeling uneasy about one’s professional future was 1.12 times higher. Given that the scores of negative-SCS ranged from 6 to 30 among the participants, negative-SCS could have a significant impact on feeling uneasy about one’s professional future. Negative-SCS is reflected in aspects related to self-judgment, isolation, and overidentification. Previous research has demonstrated that self-compassion increases one’s perceived competence and intrinsic motivation to learn [24]. Conversely, negative-SCS is correlated with anxiety and depression [14]. To address the issue of anxiety and depression among college students, intervention studies on mindfulness and compassion literacy have been implemented [25–27]. In one study, attending a seminar on compassion improved mindfulness, (self-)compassion, and salivary alpha-amylase as a stress indicator [27]. Another 8-week mindfulness meditation intervention delivered via a consumer-based mobile app called Calm significantly changed perceived stress, mindfulness, and self-compassion [25]. A recent narrative review showed that mindfulness meditation reduced anxiety in 82% of studies and stress in 74% of studies [28]. Interestingly, many studies have examined the effect of yoga on self-compassion [29–32]. A brief 1-hr yoga intervention improved mindfulness in dental and dental hygiene students [32]. An 11-week program of yoga and meditation with a neuroscience didactics intervention enhanced self-regulation and self-compassion among first- and second-year medical students with statistical significance [33]. Thus, the evidence described above suggests that boosting self-compassion literacy and yoga practice may increase mental well-being by enhancing self-compassion.

Neff [21], who developed the original and short form of the SCS, recommended analyzing the total sum, positive-, or negative-SCS, when using the short form. In the present study, Cronbach’s α for the total score of the SCS was 0.627, indicating possibly insufficient internal consistency in terms of reliability. Thus, we adopted the subdomains of the SCS but not the total SCS to conduct binomial logistic regression. Positive-SCS can be divided into self-kindness, a shared sense of humanity, and mindfulness, while negative-SCS can be divided into self-judgment, isolation, and over-identification. However, it is not recommended to analyze each factor because of the limited number of items that comprise each factor [21].

The proportion of the “no” group regarding one’s perceived aptitude as a dental hygienist (assessed by Q2) was 71.6% because the “no” group included participants who selected neither, accounting for 51.1%. The “yes” group had greater positive self-compassion, less negative self-compassion, and greater innate and acquired resilience compared to the “no” group (Tables 3 and 4). Academic motivation, assessed using the Academic Motivation Scale, was significantly related to self-compassion and resilience among UK nursing students [34] and Indonesian university students [35], thereby supporting our results. To maintain and improve academic motivation, teaching staff should pay attention to students’ self-compassion and resilience.

This study has some limitations. First, because it is a cross-sectional study, the causal link between psychiatric features and the answers for Q1–Q6 is inconclusive. To investigate the influence of self-compassion on emotions or mental well-being, further research on educational interventions, such as attending a mindfulness course, should be conducted. Second, all participants were Japanese women. Importantly, there are cultural differences in the rating scale values of the SCS [36]. The rating scale values of the SCS in Thailand, a Buddhist country, dominate those of the United States, and those of Taiwan are the lowest compared to other countries. A study involving the SCS in Japan revealed that the rating scale values of Japan are similar to those of Taiwan [23]. In Japan, similar to Taiwan, the proportion of the Buddhist population is not dominant. In addition, Japanese people tend to accept self-criticism as a feature leading to self-improvement. Their characteristics are similar to those of the Taiwanese [23]. Third, we did not collect religious information. In Japan, 31% of the participants stated that they believed in Buddhism, while 53% said they followed a certain faith or were religious [37]. Future research on the effect of religion on self-compassion is necessary. Fourth, this study mixed university students following a 4-year curriculum and vocational students in a 3-year curriculum. Most vocational school graduates work for dental clinics. In contrast, while half of university graduates work for dental clinics, the other half work in hospitals, and a few are employed by companies. We cannot deny that these differences in employment choices may impact anxiety about the future. Fifth, we did not collect data related to participants’ work experience. This omission constitutes a limitation of our study as these factors could influence the outcomes and interpretations of our findings. In future research, it will be essential to gather such demographic information to provide a more comprehensive understanding of the variables under investigation.

5. Conclusion

We found the negative factors of self-compassion to be correlated with feeling uneasy about one’s professional future among Japanese dental hygiene students. To improve students’ academic motivation and mental well-being, it is necessary to assess their self-compassion.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Authors’ Contributions

Maya Izumi and Sumio Akifusa equally contributed to the conception/design, data collection and curation, analysis, and interpretation of the data, and the drafting of the manuscript. Both authors critically revised the manuscript for important intellectual content.

References

K. Gillespie, L. D. Boyd, K. R. Perry, and J. Vineyard, “Faculty caring behavior and effect on dental hygiene students’ worry or anxiety,” Journal of Dental Education, vol. 87, no. 2, pp. 148–157, 2023.
View at: Publisher Site | Google Scholar
K. L. Reeve, C. J. Shumaker, E. L. Yearwood, N. A. Crowell, and J. B. Riley, “Perceived stress and social support in undergraduate nursing students’ educational experiences,” Nurse Education Today, vol. 33, no. 4, pp. 419–424, 2013.
View at: Publisher Site | Google Scholar
A.-M. Goff, “Stressors, academic performance, and learned resourcefulness in baccalaureate nursing students,” International Journal of Nursing Education Scholarship, vol. 8, no. 1, 2011.
View at: Publisher Site | Google Scholar
M. R. Jeffreys, “Tracking students through program entry, progression, graduation, and licensure: assessing undergraduate nursing student retention and success,” Nurse Education Today, vol. 27, no. 5, pp. 406–419, 2007.
View at: Publisher Site | Google Scholar
G. R. Deeb, S. Braun, C. Carrico, P. Kinser, D. Laskin, and J. Golob Deeb, “Burnout, depression and suicidal ideation in dental and dental hygiene students,” European Journal of Dental Education, vol. 22, no. 1, pp. e70–e74, 2018.
View at: Publisher Site | Google Scholar
M. Harris, J. C. Wilson, S. Holmes, and D. R. Radford, “Perceived stress and well-being among dental hygiene and dental therapy students,” British Dental Journal, vol. 222, no. 2, pp. 101–106, 2017.
View at: Publisher Site | Google Scholar
M. Harris, J. C. Wilson, S. Hughes, R. J. M. Knevel, and D. R. Radford, “Perceived stress and well-being in UK and Australian dental hygiene and dental therapy students,” European Journal of Dental Education, vol. 22, no. 3, pp. e602–e611, 2018.
View at: Publisher Site | Google Scholar
M. Harris, J. C. Wilson, S. Hughes, and D. R. Radford, “Does stress in a dental hygiene and dental therapy undergraduate programme contribute to a sense of well-being in the students?” British Dental Journal, vol. 223, no. 1, pp. 22–26, 2017.
View at: Publisher Site | Google Scholar
J. M. Montiel-Company, C. Subirats-Roig, P. Flores-Martí, C. Bellot-Arcís, and J. M. Almerich-Silla, “Validation of the Maslach Burnout Inventory—human services survey for estimating burnout in dental students,” Journal of Dental Education, vol. 80, no. 11, pp. 1368–1375, 2016.
View at: Publisher Site | Google Scholar
B. B. Partido and J. Owen, “Relationship between emotional intelligence, stress, and burnout among dental hygiene students,” Journal of Dental Education, vol. 84, no. 8, pp. 864–870, 2020.
View at: Publisher Site | Google Scholar
A. Isobe, M. Izumi, and S. Akifusa, “Relationship between resilience and self-rated health in dental hygiene students and registered dental hygienists,” Journal of Dental Education, vol. 82, no. 12, pp. 1343–1350, 2018.
View at: Publisher Site | Google Scholar
T. Yoshida, Y. Ariizumi, K. Kusakabe et al., “A study of student support from the standpoint of student enrollment in dental hygienist training program—the state of student support and enrollment conditions,” The Journal of Japanese Dental Education Association, vol. 31, no. 2, pp. 55–63, 2015.
View at: Google Scholar
T. Yoshida, Y. Ariizumi, K. Kusakabe et al., “A study of student support from the standpoint of student enrollment in dental hygienist training program—the efficacy and impact of support measures,” The Journal of Japanese Dental Education Association, vol. 32, no. 3, pp. 137–146, 2016.
View at: Google Scholar
K. D. Neff, “The development and validation of a scale to measure self-compassion,” Self and Identity, vol. 2, no. 3, pp. 223–250, 2003.
View at: Publisher Site | Google Scholar
K. Arimitsu, “Development and validation of the Japanese version of the self-compassion scale,” The Japanese Journal of Psychology, vol. 85, no. 1, pp. 50–59, 2014.
View at: Publisher Site | Google Scholar
K. J. Homan and F. M. Sirois, “Self-compassion and physical health: exploring the roles of perceived stress and health-promoting behaviors,” Health Psychology Open, vol. 4, no. 2, Article ID 2055102917729542, 2017.
View at: Publisher Site | Google Scholar
U. Zessin, O. Dickhäuser, and S. Garbade, “The relationship between self-compassion and well-being: a meta-analysis,” Applied Psychology: Health and Well-Being, vol. 7, no. 3, pp. 340–364, 2015.
View at: Publisher Site | Google Scholar
A. Abdollahi, Z. R. Gardanova, P. Ramaiah et al., “Moderating role of self-compassion in the relationships between the three forms of perfectionism with anger, aggression, and hostility,” Psychological Reports, vol. 11, Article ID 332941221087911, 2022.
View at: Google Scholar
A. Abdollahi, A. Taheri, and K. A. Allen, “Perceived stress, self-compassion and job burnout in nurses: the moderating role of self-compassion,” J Res Nurs, vol. 26, no. 3, pp. 182–191, 2021.
View at: Publisher Site | Google Scholar
M. Hirano, “A study of the classification of resilience factors: development of the bidimensional resilience scale (BRS),” Japanese Journal of Personality, vol. 19, no. 2, 2011.
View at: Google Scholar
K. D. Neff, “The self-compassion scale is a valid and theoretically coherent measure of self-compassion,” Mindfulness, vol. 7, no. 1, pp. 264–274, 2016.
View at: Publisher Site | Google Scholar
F. Raes, E. Pommier, K. D. Neff, and D. Van Gucht, “Construction and factorial validation of a short form of the self-compassion scale,” Clinical Psychology & Psychotherapy, vol. 18, no. 3, pp. 250–255, 2011.
View at: Publisher Site | Google Scholar
K. Arimitsu, “Development and validation of the Japanese version of the self-compassion scale,” Japanese Journal of Psychology, vol. 85, no. 1, pp. 50–59, 2014.
View at: Publisher Site | Google Scholar
K. D. Neff, Y.-P. Hsieh, and K. Dejitterat, “Self-compassion, achievement goals, and coping with academic failure,” Self and Identity, vol. 4, no. 3, pp. 263–287, 2005.
View at: Publisher Site | Google Scholar
J. Huberty, J. Green, C. Glissmann, L. Larkey, M. Puzia, and C. Lee, “Efficacy of the mindfulness meditation mobile app “calm” to reduce stress among college students: randomized controlled trial,” JMIR mHealth and uHealth, vol. 7, no. 6, Article ID e14273, 2019.
View at: Publisher Site | Google Scholar
L.-A. Hagerman, L. Manankil-Rankin, and J. K. Schwind, “Self-compassion in undergraduate nursing: an integrative review,” International Journal of Nursing Education Scholarship, vol. 17, no. 1, 2020.
View at: Publisher Site | Google Scholar
C. M. Ko, F. Grace, G. N. Chavez, S. J. Grimley, E. R. Dalrymple, and L. E. Olson, “Effect of seminar on compassion on student self-compassion, mindfulness and well-being: a randomized controlled trial,” Journal of American College Health, vol. 66, no. 7, pp. 537–545, 2018.
View at: Publisher Site | Google Scholar
M. D. Bamber and J. Kraenzle Schneider, “Mindfulness-based meditation to decrease stress and anxiety in college students: a narrative synthesis of the research,” Educational Research Review, vol. 18, pp. 1–32, 2016.
View at: Publisher Site | Google Scholar
Ö. Erkin and F.Şenuzun Aykar, “The effect of the yoga course on mindfulness and self-compassion among nursing students,” Perspectives in Psychiatric Care, vol. 57, no. 2, pp. 875–882, 2021.
View at: Publisher Site | Google Scholar
N. K. Patel, L. Nivethitha, and A. Mooventhan, “Effect of a yoga based meditation technique on emotional regulation, self-compassion and mindfulness in college students,” Explore (NY), vol. 14, no. 6, pp. 443–447, 2018.
View at: Publisher Site | Google Scholar
N. Snaith, T. Schultz, M. Proeve, and P. Rasmussen, “Mindfulness, self-compassion, anxiety and depression measures in South Australian yoga participants: implications for designing a yoga intervention,” Complementary Therapies in Clinical Practice, vol. 32, pp. 92–99, 2018.
View at: Publisher Site | Google Scholar
S. E. Braun, G. Deeb, C. Carrico, and P. A. Kinser, “Brief yoga intervention for dental and dental hygiene students: a feasibility and acceptability study,” Journal of Evidence-Based Integrative Medicine, vol. 24, Article ID 2515690x19855303, 2019.
View at: Publisher Site | Google Scholar
A. R. Bond, H. F. Mason, C. M. Lemaster et al., “Embodied health: the effects of a mind–body course for medical students,” Medical Education Online, vol. 18, no. 1, Article ID 20699, 2013.
View at: Publisher Site | Google Scholar
Y. Kotera, V. Cockerill, J. Chircop, G. Kaluzeviciute, and S. Dyson, “Predicting self-compassion in UK nursing students: relationships with resilience, engagement, motivation, and mental wellbeing,” Nurse Education in Practice, vol. 51, Article ID 102989, 2021.
View at: Publisher Site | Google Scholar
Y. Kotera, M. Aledeh, K. Barnes, A. Rushforth, H. Adam, and R. Riswani, “Academic motivation of Indonesian University students: relationship with self-compassion and resilience,” Healthcare (Basel), vol. 10, no. 10, Article ID 2092, 2022.
View at: Publisher Site | Google Scholar
K. D. Neff, K. Pisitsungkagarn, and Y.-P. Hsieh, “Self-compassion and self-construal in the United States, Thailand, and Taiwan,” Journal of Cross-Cultural Psychology, vol. 39, no. 3, pp. 267–285, 2008.
View at: Publisher Site | Google Scholar
T. Kobayashi, “How did the Japanese religious consciousness and action change? ISSP international comparative research “Religion” from results in Japan,” Broadcast Research and Survey, vol. 69, no. 4, pp. 52–72, 2019.
View at: Google Scholar

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Copyright © 2023 Maya Izumi and Sumio Akifusa. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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