• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.69-78
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• 2004

This paper treats the conditions for the existence of rotating wave solutions of a system modelling the behavior of students in graduate programs at neighbouring universities near each other which is a modified form of the model proposed by Scheurle and Seydel. We assume that both types of individuals are continuously distributed throughout a bounded two-dimension spatial domain of two types (circle and annulus), across whose boundaries there is no migration, and which simultaneously undergo simple (Fickian) diffusion. We will show that at a critical value of a system-parameter bifurcation takes place: a rotating wave solution arises.

• Journal of Life Science
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• v.24 no.10
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• pp.1125-1131
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• 2014

The purpose of this study was to investigate the relationship between quadriceps composition and its functional contractility in obese and nonobese elderly individuals. Thirty-four ($70{\pm}2yr$) individuals (obese, n=21; nonobese, n=13) participated in the study. The thigh composition was assessed with a CT scan, and its functional contractility was measured with an isotonic dynamometer. Variables were analyzed with a $2{\times}2$ two-way ANOVA and a contrast test (p<0.05). There were no between-group differences in the subjects' ages and heights, but individuals in the obese group were approximately 23% heavier and had 18% more fat than those in the nonobese group, regardless of gender. The total thigh volume of the obese elderly was greater (~29%) than that of the nonobese elderly, regardless of gender, and the fat volume (~39%) of the obese elderly was greater than that of the nonobese elderly, regardless of gender (p<0.05). Interestingly, the obese elderly tended to have a greater thigh muscle volume (~17% for males [p<0.05] and ~10% for females) than the nonobese. Despite the greater muscle volume, the peak knee extensor torque of the two groups was comparable or slightly greater in the obese individuals. However, when this was normalized by the total thigh volume, the nonobese males showed significantly greater peak torque (~26% for right and ~20% for left; p<0.05) compared to the obese males. The nonobese females also showed greater peak torque (~8% for both legs) than the obese females after normalization, but the result was not statistically significant. In conclusion, although the obese elderly individuals had greater quadriceps muscle mass than the nonobese, the normalized peak torque of the obese was significantly lower than that of the nonobese, implying a lower degree of muscle contractility.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.207-219
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• 2014

Recognizing the lack of empirical study that evaluates the influence of social care services on care sufficiency of individuals with disability, we have focused our study on the following research questions: What is the level of care sufficiency for individuals with disability?, What is the profile of care for individuals with disability from both formal and informal providers?, What are the service use conditions and determinants of social care service use?. This study analyzed data of 1204 individuals with disability who needed daily assistance from 5th wave of Korea Welfare Panel Study. Results showed that 50% of the respondents experienced care deficit. 77% of the respondents received no care from informal care providers and 90% from formal care providers. Despite social care services brought by the expansion of socialization of care, the average number of social service use on care was less than 1, which suggests that socialization of care did not significantly contribute to care sufficiency. In addition, for people who are 64 or younger, social care services was substituted by care from informal care providers and for those who are 65 or older, social care services supplemented care from informal care providers.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.442-449
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• 2014

This study was carried out to measure the seasonal changes in community structure and species composition of marobenthos on the subtidal area of Saemangeum regions. The macrobenthos comprised 64 species were during this study, predominately annelids (53.0%), arthropods (18.8%), mollusks (18.8%) and 9.4% were from other species. Total abundance was 24,885 individuals, comprising 19,805 individuals of annelids (79.6%), 4,620 individuals of mollusks (18.5%), 295 individuals of other species (1.2%), and 165 individuals of arthropods (0.7%). After analyzing the bray-curtis similarity, had two large groups (A, B) the inside and outside of Saemangeum dike. They all matched the nMDS analysis. I evaluated the benthic community health using BPI (Benthic pollution Index). There are no significant differences between the station position and the inside or outside of Saemangeum dike. But, highest BPI level was in March.

• Journal of the Korean Regional Science Association
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• v.39 no.3
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• pp.65-83
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• 2023

The purpose of this study is to conceptually define "spatial inclusivity" and empirically examine the impact of disability severity and spatial inclusivity on social participation among individuals experiencing physical discomfort. The social and spatial environment of the residential area is crucial for individuals with disabilities who face limited activity range and complex barriers due to physical constraints. In this study, spatial inclusivity from the perspective of people with disabilities is defined as establishment of equal relationships with non-disabled individuals within the local community, as well as the availability of basic facilities and services in a safe urban space that allows for access and utilization. This concept consists of three dimensions: individual networks, social environment, and physical environment. The physical environment encompasses safety levels, natural environment, living environment, public transportation conditions, medical services in residential areas. We used the 2019 Community Health Survey to examine the relationship between disability severity, spatial inclusivity, and social participation using a two level regression model. The findings are as follows: Firstly, personal relationships at the individual level and the physical environment at the local level have a positive impact on social participation. Secondly, when identifying dividing the physical environment into five sub-factors, no significant influence of individual factors is found. Thirdly, trustworthy and friendly social environment at the local level has a negative impact on social participation. These results provide empirical evidence that spatial inclusivity has an effect on the social participation of individuals with disabilities and suggest implications for urban planning to create and enhance conditions for the social participation of individuals with disabilities.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.1
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• pp.59-69
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• 2020

This study investigates the influence of individual blockholder on accounting quality. Prior studies investigating Korean blockholders' influence focus on the influence of controlling shareholders or institutional investors; however, they rarely examine individual blockholders' influence. This paper investigates how individual blockholders in Korean stock markets affect accounting quality of firms listed in Korean Stock Exchange. I analyze individual blockholders' influence on proxies of accounting quality using multivariate regression with hand-collected individual blockholder data. Korean law requires public firms to disclose the list of shareholders having no less than 5% of ownership. From the list of blockholders, individuals who have no explicit personal relation with controlling shareholders were classified as individual blockholders. My empirical results show that firms having individual blockholder(s) use more income-decreasing accruals than those having no individual blockholder. Furthermore, accounting information of firms having individual blockholders(s) is more conservative than that of firms having no individual blockholders. However, the presence of individual blockholder increases the tendency of loss avoidance and earnings management using overproduction and reduction of discretionary expenditure. This paper contributes to the literature by presenting the first evidence of the monitoring role of an individual blockholder on financial reporting of firms listed in the Korean stock markets.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.400-410
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• 2015

Juniperus chinensis (Cupressaceae) is a valuable woody plant resource, but this rare plant is only distributed in restricted regions in Korea. In this study, we surveyed the geographic distribution regions, variation of sex ratio and the dynamics of natural populations of J. chinensis. in order to establish conservation strategies for the sustainable conservation of this important resource tree. The 17 natural populations of J. chinensis are restrictively distributed in the shore cliffs of (1) Ulleungdo island, (2) Gyeongju-si to Gangneung-si of the eastern coast, the riverside cliff along (3) Donggang-river of Jungsun-gun and Pyeongchang-gun and (4) branch of Nakdonggang-river in Uiseong-gun. The populations in Ulleungdo island showed continuous population distribution of over 200 individuals, but populations in other regions had discontinuous population distribution of under 200. The population of J. chinensis surveyed in Korea was estimated in ca. 3,200 individuals. The sex ratio (male/female) among populations of J. chinensis was diverse with variation from 0.46~1.67 range, but showed no significance. The sex ratio of the total individuals by species level was 0.74, and the percentage of female tree was significantly higher than the male. The results of dynamics analysis within population among regions showed that seedlings and saplings of J. chinensis in three regions surveyed were continuously regenerating. The distribution of DBH class showed a stable population structure of inverse J shape graph, but fragmentation and decrease in populations because of invading broad-leaved shrubs and trees from the surroundings were concerned. Further studies, and in situ and ex situ conservation strategies for the sustainable conservation on natural populations of this rare resources woody plant, J. chinensis in Korea are recommended.

• The korean journal of orthodontics
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• v.45 no.5
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• pp.261-267
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• 2015

Objective: To measure aspartate aminotransferase (AST) activity in the pulp of teeth treated with fixed appliances for 6 months, and compare it with AST activity measured in untreated teeth. Methods: The study sample consisted of 16 healthy subjects (mean age $25.7{\pm}4.3$ years) who required the extraction of maxillary premolars for orthodontic reasons. Of these, 6 individuals had a total of 11 sound teeth extracted without any orthodontic treatment (the control group), and 10 individuals had a total of 20 sound teeth extracted after 6 months of orthodontic alignment (the experimental group). Dental pulp samples were extracted from all control and experimental teeth, and the AST activity exhibited by these samples was determined spectrophotometrically at $20^{\circ}C$. Results: Mean AST values were $25.29{\times}10^{-5}U/mg$ (standard deviation [SD] 9.95) in the control group and $27.54{\times}10^{-5}U/mg$ (SD 31.81) in the experimental group. The difference between these means was not statistically significantly (p = 0.778), and the distribution of the AST values was also similar in both groups. Conclusions: No statistically significant increase in AST activity in the pulp of mechanically loaded teeth was detected after 6 months of orthodontic alignment, as compared to that of teeth extracted from individuals who had not undergone orthodontic treatment. This suggests that time-related regenerative processes occur in the dental pulp.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.3
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• pp.23-30
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• 2022

PURPOSE: This study was designed to investigate the effects of keeping contraction of abdominal and pelvic floor muscles on 3D pelvic stability in individuals with nonspecific chronic low back pain (CLBP) during normal speed walking. METHODS: The subjects were 20 adults with CLBP deformity and had moderate pain intensity of the visual analog scale. A three-dimensional camera capture system was used to collect kinematic pelvic motion data with and without contraction of the abdominal and pelvic floor muscles during gait. The subjects were asked to walk on a walkway in the lab room and they were attached 40 reflective markers to their pelvic segment and lower extremities. A Visual3D Professional V6 program and Vicon Nexus software were used to analyze 3D pelvic kinematic data. RESULTS: There were significant differences between with and without contraction of the abdominal and pelvic floor muscles of the pelvic depression and the total pelvic motion in coronal plane during gait (p < .05). However, there were no significant differences in any of the maximal motion of the pelvic segment in sagittal and transverse motion plane according to the different muscle contraction conditions (p > .05). CONCLUSION: The results of this study suggest that maintaining co-contraction of the abdominal and pelvic floor muscles in individuals with CLBP increased pelvic stability and contributed to preventing excessive pelvic movements during gait.

• Physical Therapy Rehabilitation Science
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• v.2 no.2
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• pp.92-98
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• 2013

Objective: Constraint induced aphasia therapy (CIAT) is a more intensive form of language treatment for aphasia as compared to traditional treatments. This study examined whether there are differences in cortisol stress levels between the two methods of aphasia treatment as well as effects on language skills. Design: Randomized controlled trial. Methods: A total of 20 participants with expressive aphasia were randomly placed into one of the two treatment groups. The CIAT group received 10 days of intensive treatment over two weeks. The traditional therapy group received 6 days of treatment over 2 weeks. All participants in each group provided salivary cortisol samples before treatment, at the mid-point of treatment, and at the conclusion of treatment. Language skills were assessed before treatment and at the conclusion of treatment. Results: A significantly higher proportion of individuals in the CIAT treatment group had increased salivary cortisol stress levels when compared to the traditional treatment group at the mid-point of the program (80% versus 30% respectively, p<0.05). There was no significant difference in the proportion of individuals with increased cortisol stress by the end of the treatment. Language scores for word repetition and overall aphasia quotient significantly improved for the CIAT group when compared to the traditional group (p<0.05). Conclusions: The CIAT treatment appears to initially create increased psychophysiological stress as compared to the traditional treatment. In spite of the initial increases in psychophysiological stress, participants appear to become conditioned to the challenge and ultimately have enhanced benefit from CIAT treatment.