• Journal of the Korea Computer Graphics Society
• /
• v.29 no.3
• /
• pp.69-77
• /
• 2023

This study proposes a rigid-body tracking based virtual avatar application method to increase the social presence and provide various experiences of virtual reality(VR) users in an immersive virtual environment. The proposed method estimates the motion of a virtual avatar through inverse kinematics based on real-time rigid-body tracking based on motion capture using markers. Through this, it aims to design a highly immersive virtual environment with simple object manipulation in the real world. Science experiment educational contents are produced to experiment and analyze applications related to immersive virtual environments through virtual avatars. In addition, audiovisual education, full-body tracking, and the proposed rigid-body tracking method were compared and analyzed through survey. In the proposed virtual environment, participants wore VR HMDs and conducted a survey to confirm immersion and educational effects from virtual avatars performing experimental educational actions from estimated motions. As a result, through the method of utilizing virtual avatars based on rigid-body tracking, it was possible to induce higher immersion and educational effects than traditional audiovisual education. In addition, it was confirmed that a sufficiently positive experience can be provided without much work for full-body tracking.

• 한국노년학
• /
• v.39 no.2
• /
• pp.231-240
• /
• 2019

The study aimed to identify risk factors for falls as well as hospitalization status according to disease and demographic characteristics of demented inpatients by investigating the in-depth Injury Patient Surveillance System data collected by Korea Centers for Disease Control and Prevention(KCDC). Older adults over 60 years old who were diagnosed with dementia were included(n=1,732). Their data were analyzed after being assigned to either a fall group or a non-fall group. STATA was used for statistical analyses, such as frequency analysis, chi-square (χ²) test, and logistics regression. It was found that 8.0% of the demented inpatients experienced falls. According to the analysis on category of fall and non-fall group were statistically significant difference in age and Charlson Comorbidity Index(CCI) and bone density deficiency. Based on the logistic regression analysis of factors affecting falls, older adults over 80 are 2.386 times more likely to fall and based on a target with a CCI of 0, the risk of falls is 0.421 times lower, finally based on those without bone density disorder, the fall risk for those with bone density disorder was 3.581 times higher. Therefore, we expect that the important about the factors relating to falls identified in this can not only be found valuable for educating inpatients with dementia and care-givers, but also be used as reference that supports clinical professionals to make decisions on falls management for patients with dementia.

• Therapeutic Science for Rehabilitation
• /
• v.12 no.4
• /
• pp.67-80
• /
• 2023

Objective : This study aimed to investigate the current status of physical therapy in children and adolescents. Methods : Sixty questionnaires from physical therapists treating children and adolescents with disabilities were analyzed. The questionnaire consisted of questions on physical therapy, participants, satisfaction, and the assessment of pediatric and adolescent physical therapy. Descriptive statistics and frequencies were used to investigate the current status, participants, and satisfaction. Differences between physical therapy participation difficulty, importance-ability of major aspects of pediatric and adolescent physical therapy, and therapy goal frequency were analyzed using paired T-test. Results : 11 to 15 cases (66.7%) and one-on-one treatment (95.0%) were performed independently (95.0%). The main ages of the subjects were preschool and school, the diagnoses were brain lesions and developmental delay, and treatment was conducted for up to 20 years or older. Satisfaction with pediatric and adolescent physical therapy was high (70.0%), as was the intensity of work (71.7%). Neurodevelopmental therapy, gait training, and goal-directed rehabilitation were the main treatments, and Gross Motor Function Measures of 88 and 66, respectively, were used. Respondents said that current fee system is inadequate (66.1%) and appropriate fee system is needed. Conclusion : This study extensively investigated the content of and factors related to pediatric and adolescent physical therapy. Based on the current situation, efforts to improve the expertise and continuity of pediatric and adolescent physical therapists and apply the latest treatment techniques are required.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1273-1281
• /
• 2023

Absolute radiometric calibration is a crucial process in converting the electromagnetic signals obtained from satellite sensors into physical quantities. It is performed to enhance the accuracy of satellite data, facilitate comparison and integration with other satellite datasets, and address changes in sensor characteristics over time or due to environmental conditions. In this study, field campaigns were conducted to perform vicarious calibration for the multispectral channels of the CAS500-1. Two valid field observations were obtained under clear-sky conditions, and the top-of-atmosphere (TOA) radiance was simulated using the MODerate resolution atmospheric TRANsmission 6 (MODTRAN 6) radiative transfer model. While a linear relationship was observed between the simulated TOA radiance of tarps and CAS500-1 digital numbers(DN), challenges such as a wide field of view and saturation in CAS500-1 imagery suggest the need for future refinement of the calibration coefficients. Nevertheless, this study represents the first attempt at absolute radiometric calibration for CAS500-1. Despite the challenges, it provides valuable insights for future research aiming to determine reliable coefficients for enhanced accuracy in CAS500-1's absolute radiometric calibration.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.25 no.3
• /
• pp.151-171
• /
• 2023

This study analyzed farmer's responses to the pilot project in advance of the nationwide expansion of the farm-customized early warning service for weather risk management by conducting a survey among all farmers who received text messages of this service. We analyzed not only the satisfaction of farmers with the early warning service, but also the effectiveness of the service in preventing agrometeorological disasters through cross-tabulation analysis of survey results. More than 330 farmers participated in the survey, and more than 60% of the respondents said that they had prevented or mitigated crop disasters by using the early warning service. The cross-tabulation analysis showed that farmers who perceived the field-specific weather information of the early warning service to be more accurate than the weather forecast were statistically significantly more likely to prevent crop disasters than those who did not. According to our case study, farmers who grew open field fruit crops were particularly sensitive to weather information and confirmed that early warning services, along with disaster prevention facilities, were effective in preparing for freezing and frost injury that had been occurring frequently under the influence of climate change. This study is significant in that it is the first to systematically analyze the effectiveness of the farm-customized early warning service for weather risk management based on extensive surveys. It is expected to contribute to exploring ways to develop the service ahead of the nationwide expansion of the early warning service in the near future.

• KIPS Transactions on Software and Data Engineering
• /
• v.12 no.12
• /
• pp.505-518
• /
• 2023

3D point cloud semantic segmentation is a computer vision task that involves dividing the point cloud into different objects and regions by predicting the class label of each point. Existing 3D semantic segmentation models have some limitations in performing sufficient fusion of multi-modal features while ensuring both characteristics of 2D visual features extracted from RGB images and 3D geometric features extracted from point cloud. Therefore, in this paper, we propose MMCA-Net, a novel 3D semantic segmentation model using 2D-3D multi-modal features. The proposed model effectively fuses two heterogeneous 2D visual features and 3D geometric features by using an intermediate fusion strategy and a multi-modal cross attention-based fusion operation. Also, the proposed model extracts context-rich 3D geometric features from input point cloud consisting of irregularly distributed points by adopting PTv2 as 3D geometric encoder. In this paper, we conducted both quantitative and qualitative experiments with the benchmark dataset, ScanNetv2 in order to analyze the performance of the proposed model. In terms of the metric mIoU, the proposed model showed a 9.2% performance improvement over the PTv2 model using only 3D geometric features, and a 12.12% performance improvement over the MVPNet model using 2D-3D multi-modal features. As a result, we proved the effectiveness and usefulness of the proposed model.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.52 no.2
• /
• pp.39-50
• /
• 2024

Color is an essential visual element that has a significant impact on the formation of a city's image and people's perceptions. Quantitative analysis of color in urban environments is a complex process that has been difficult to implement in the past. However, with recent rapid advances in Machine Learning, it has become possible to analyze city colors using photos shared by tourists. This study selected Dali City, a popular tourist destination in China, as a case study. Photos of Dali City shared by tourists were collected, and a method to measure large-scale city colors was explored by combining machine learning techniques. Specifically, the DeepLabv3+ model was first applied to perform a semantic segmentation of tourist sharing photos based on the ADE20k dataset, thereby separating artificial elements in the photos. Next, the K-means clustering algorithm was used to extract colors from the artificial elements in Dali City, and an adjacency matrix was constructed to analyze the correlations between the dominant colors. The research results indicate that the main color of the artificial elements in Dali City has the highest percentage of orange-grey. Furthermore, gray tones are often used in combination with other colors. The results indicated that local ethnic and Buddhist cultures influence the color characteristics of artificial elements in Dali City. This research provides a new method of color analysis, and the results not only help Dali City to shape an urban color image that meets the expectations of tourists but also provide reference materials for future urban color planning in Dali City.

• Food Science and Preservation
• /
• v.30 no.5
• /
• pp.811-821
• /
• 2023

This study investigated the storability of onions according to manual and mechanical harvesting. Moreover, we simulated the onion-to-onion impact during the mechanical harvesting process and investigated the storability after artificially subjecting the onions to impact treatment. The onion harvesting methods included hand plucking + manual collection, digger + manual, and digger + mechanical collection. The maximum impact height during the mechanical harvesting process was 0.5 m. Immediately after harvesting, no significant difference in the bruise and wound rate among the harvesting methods was observed. Any increased bruise or wound rate because of mechanical harvesting was presumed to be influenced by soil conditions, such as the presence of gravel, and machine operation factors. Furthermore, the storability during the 8.5 months storage showed no significant difference according to the harvesting methods. In treatments by simulating the impacts during the mechanical harvesting process, the impact heights were 0.0 m (0.0 J), 0.25 m (0.86 J), 0.5 m (1.72 J), and 0.75 m (2.57 J), each performed once, and four times at the same position (3.43 J) and four times at different positions (3.43 J) at 0.25 m. Throughout all the treatments, there were no significant differences in the storability during the 8.5 months storage period.

• Therapeutic Science for Rehabilitation
• /
• v.13 no.2
• /
• pp.27-40
• /
• 2024

Objective : This study aimed to conduct a systematic review of the assessment tools used to assess the housing environment of older adults. Methods : Data were collected from January 2015 to August 31st, 2023, by searching databases including the Cochrane Library, PubMed, and ProQuest. From the 267 articles, nine assessment tools were selected for analysis based on their original instruments. These tools were categorized and systematically organized for analysis based on their frequency of use, assessment purposes, sub-domains, scales, and other relevant criteria. Results : Among the nine tools, HOME FAST and IPAQ-E were the most frequently used (20% each). The objectives of these tools are to assess friendliness, physical barriers, fall prevention, dementia-friendly environments, physical activity, and accessibility. The measurement scope encompassed various factors, such as outdoor spaces, buildings, transportation, housing, and community support. Conclusion : When considering the suitability of housing for the older adults population, providing foundational data for the rational selection of evaluation tools with logical validity is important. This includes factors such as the objectives and measurement scopes of housing environment assessment tools.

• Therapeutic Science for Rehabilitation
• /
• v.13 no.2
• /
• pp.41-51
• /
• 2024

Objective : This study aimed to assess the applicability of the Yonsei Lifestyle Profile (YLP), initially developed for adults, for adolescents and verify its reliability and validity. Methods : This study evaluated the reliability and validity of the YLP among 436 middle and high school students in South Korea. The internal consistency of this scale was analyzed using Cronbach's alpha and Spearman-Brown's coefficient. Concurrent validity was assessed using Pearson's correlation coefficient with the Korean Youth Physical Activity Questionnaire, the Korean version of the Children and Adolescents Participation Scale, and the Nutrition Quotient for Adolescents. Results : The overall internal consistency of the YLP items demonstrated high reliability, with a Cronbach's α of .811 and Spearman-Brown's coefficient of .779. Significant positive correlations were observed for physical activity (r=.555, p<.01), activity participation (r=.177, p<.01), and dietary habits (r=.633, p<.05), indicating consistent correlations with the related scales. Conclusion : This study analyzed the YLP targeting adolescents and confirmed its high reliability and significant validity in the areas of physical activity, activity participation, and dietary habits. These findings suggest that the YLP can be utilized as a reliable tool for evaluating healthy lifestyles among adolescents.