• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.289-297
• /
• 2022

The purpose of this study was to investigate the perception of dental students based on their experiences of online classes after taking non-face-to-face education courses for all the school semesters in 2020. For the research method, an online survey was conducted on A survey was conducted on 161 dental students enrolled in A University. The analytical method was conducted through frequency analysis, correlation analysis, and multiple regression analysis. The survey analysis findings showed that the satisfaction of dental students' about the non-face-to-face education course was above 4.2, and the detailed items were in the order of the appropriateness of the attendance processing method, satisfaction with recorded video lectures, and the assessment method of the course grade. In the case of the factors that affect the satisfaction of non-face-to-face education courses, the learning system and assessment method were statistically significant. The online class type that is most preferred by the students is recorded video lectures, and the highest number of participants chose 21~30 minutes as the appropriate time for the class content. It is considered that the application of the online system will continue to be used together with face-to-face education courses in the education site and various university-level efforts like systematic support are required to achieve effective learning achievements. This study only investigated the non-face-to-face education operation conditions of A University, so it cannot be generalized to all universities, but it can be used as basic data to provide education curriculum design and supportive measures for the compatibility of face-to-face and non-face-to-face courses.

• The korean journal of orthodontics
• /
• v.52 no.2
• /
• pp.150-160
• /
• 2022

Objective: To provide reliable prediction models based on dentoskeletal and soft tissue variables for customizing maxillary incisor positions and to optimize digitalized orthodontic treatment planning. Methods: This study included 244 Chinese women (age, 18-40 years old) with esthetic profiles after orthodontic treatment with fixed appliances (133 in group I: 1° ≤ The angle between the nasion [N]-A point [A] plane and the N-B point [B] plane [ANB] ≤ 4°; 111 in group II: 4° < ANB ≤ 7°). Dental, skeletal, and soft tissue measurements were performed on lateral cephalograms of the participants. Correlation and multiple linear regression analyses were used to determine the influence of dentoskeletal and soft tissue variables on maxillary incisor position. Results: The ideal anteroposterior position of the maxillary incisor varied between sagittal skeletal patterns. The position of the maxillary incisor correlated with the sagittal discrepancy between the maxilla and the mandible (ANB), protrusion of the midface, nasal tip projection, development of the chin, and inclination of both the maxillary and mandibular incisors. Distance from the maxillary central incisor to nasion-pogonion plane predicted using multiple linear regression analysis was accurate and could be a practical measurement in orthodontic treatment planning. Conclusions: Instead of using an average value or norm, orthodontists should customize a patient's ideal maxillary incisor position using dentoskeletal and soft tissue evaluations.

• Korean Journal of Construction Engineering and Management
• /
• v.24 no.4
• /
• pp.3-13
• /
• 2023

The purpose of this study is to compare and analyze the performance and work productivity of wet type pavement cutters and sludge suction type pavement cutters (hereinafter referred to as automatic pavement cutters) developed to reduce scattering dust. We first investigated the development status of wet type manual pavement cutters that are mainly used in Korea and automatic pavement cutters, and analyzed the pavement cutting work in detail. And the standard cutting performance was derived by measuring the cutting time by depth by applying the two equipment to the test bed under the same conditions. However, there is a limitation that the data measured in the test bed does not reflect the various variables of the actual pavement cutting site. Therefore, in this study, data was collected through field surveys, and the correlation between cutting distance and time was analyzed, and then a model for calculating the productivity of pavement cutters was presented through simple regression analysis. As a result of comparative analysis of the values derived from the regression equation with the standard cutting performance derived from the test bed, the cutting performance derived through the regression equation showed a similar trend to the standard cutting performance. Finally, we verified the usability of the automated pavement cutter developed by qualitatively analyzing three tasks that are difficult to measure quantitatively but affect productivity.

• Journal of the Korean Regional Science Association
• /
• v.40 no.1
• /
• pp.89-110
• /
• 2024

REITs are very closely related to real estate management, but there have been no prior studies analyzing the location of REITs assets. Therefore, this study analyzed the location characteristics of REITs assets in two aspects to clarify the location characteristics by using spatial information of REITs assets. First, the characteristics of the type of city where REITs assets are distributed were analyzed, and second, the characteristics of the zoning where REITs assets are distributed were analyzed. As a result of analyzing the characteristics of the city where REITs assets are distributed by type, it was analyzed that in the case of the capital area, both the ratio of cities with REITs assets location and the intensity of REITs assets location (number of REITs assets per city) have location characteristics by city hierarchy in the order of metropolitan city > big city > small and medium-sized city. In the case of non-capital area's metropolitan and large cities, the ratio of REITs assets location cities is similar to that of the capital area, but the location intensity of REITs assets was analyzed to be significantly lower than that of the capital area. As a result of the analysis of REITs assets by type, housing REITs assets tend to be located in the old downtown commercial zoning and the new downtown residential zoning, office REITs assets are characterized by concentration of location in specific commercial zoning of Seoul, and retail REITs assets are located mainly in the old downtown station area. In addition, it was found that logistics REITs assets tend to be located in management zoning, centering on key logistics hub cities in the region.

• Land and Housing Review
• /
• v.15 no.1
• /
• pp.117-134
• /
• 2024

This study examines the factors contributing to waterfront satisfaction among different generations, utilizing a survey on the use and perception of waterfront areas by residents of apartment houses in Tokyo's coastal region. The variables used in this study are developed through a review of existing literature, focusing on factors related to waterfront usage. Specifically, we select the proximity to the waterfront, duration of stay at the waterfront, and frequency of visits to the waterfront as key variables for investigation. In addition, the study further incorporates aspects related to waterfront recognition, such as the space, user behavior, and management status of the waterfront. Utilizing these variables, we carry out a correlation analysis to investigate the association between generational use and perception of the waterfront and their satisfaction with water-related experiences. The results identify three key factors to enhance waterfront satisfaction: First, to increase visits from both younger and older generations, improving pedestrian access to the waterfront is essential. Second, for middle-aged and older generations, creating waterfront areas closer to their residences can reduce travel distance and time, encouraging more frequent use. Third, maintaining clean and well-kept waterfront spaces is fundamental for all generations to enjoy relaxing experiences, thereby improving overall satisfaction.

• Journal of the Korean Society of Radiology
• /
• v.85 no.2
• /
• pp.381-393
• /
• 2024

Purpose Metabolic abnormalities in hepatic encephalopathy (HE) cause brain edema or demyelinating disease, resulting in symmetric regional cerebral edema (SRCE) on MRI. This study aimed to investigate the usefulness of the clustering analysis of SRCE in predicting the development of brain failure. Materials and Methods MR findings and clinical data of 98 consecutive patients with HE were retrospectively analyzed. The correlation between the 12 regions of SRCE was calculated using the phi (φ) coefficient, and the pattern was classified using hierarchical clustering using the φ² distance measure and Ward's method. The classified patterns of SRCE were correlated with clinical parameters such as the model for end-stage liver disease (MELD) score and HE grade. Results Significant associations were found between 22 pairs of regions of interest, including the red nucleus and corpus callosum (φ = 0.81, p < 0.001), crus cerebri and red nucleus (φ = 0.72, p < 0.001), and red nucleus and dentate nucleus (φ = 0.66, p < 0.001). After hierarchical clustering, 24 cases were classified into Group I, 35 into Group II, and 39 into Group III. Group III had a higher MELD score (p = 0.04) and HE grade (p = 0.002) than Group I. Conclusion Our study demonstrates that the SRCE patterns can be useful in predicting hepatic preservation and the occurrence of cerebral failure in HE.

• Journal of Environmental Impact Assessment
• /
• v.26 no.4
• /
• pp.272-289
• /
• 2017

This study analyzed the status of the naturalized plants in islands in Jeollanamdo from an island biogeographic perspective. As a result of a floristic analysis at 47 inhabited islands and 194 uninhabited islands, 30 families and 134 species naturalized plants are reported. The most commonly occurring naturalized plant from 141 islands was Rumex crispus. The average number of naturalized plants by islands is 20.6 species (${\pm}14.22$) at the inhabited islands and 3.7 species (${\pm}3.89$) at the uninhabited islands. Presence of fifty nine naturalized species at Geumodo in Yeosu-si is the largest in number. The naturalization ratio, which is the ratio of naturalized plants to native plants, is 7.66% (${\pm}3.96$) in the inhabitable islands and 4.97% (${\pm}3.70$) in the uninhabitable islands. The naturalization ratio among islands of the West Sea in Jeollanam-do is 5.92% (${\pm}4.49$), and it is higher than 4.96% (${\pm}2.15$) in islands in the South Sea. Especially, the naturalization ratio at the inhabitable islands, i.e., 8.39% (${\pm}4.37$) at the islands of the West Sea is higher than 5.80% (${\pm}1.41$) at islands in the South Sea. The naturalization ratio of naturalized plants at the islands shows positive correlation with the size of the island (r=0.412, p<0.01), but the correlations with distance from the mainland and altitude above sea level are not significant. Eight ecosystem disturbing species designated by law are reported, and each species shows distinct distributional ranges. The regional differences in the number of naturalized plant species seem to be a result of the complex reflection of natural and human environmental factors, such as the degree of traffic between mainland and islands, degree of cultivation activities, along with the physical environmental differences. Since islands have limited habitats and resources, islands could be more vulnerable to the incoming species from outside, and environmental changes than mainland. Therefore, continuous monitoring and management against the naturalized plants in islands are needed.

• The KIPS Transactions:PartB
• /
• v.11B no.6
• /
• pp.749-758
• /
• 2004

In this paper, we propose a new method utilizing only raw corpus without additional human effort for disambiguation of target word selection in English-Korean machine translation. We use two data-driven techniques; one is the Latent Semantic Analysis(LSA) and the other the Probabilistic Latent Semantic Analysis(PLSA). These two techniques can represent complex semantic structures in given contexts like text passages. We construct linguistic semantic knowledge by using the two techniques and use the knowledge for target word selection in English-Korean machine translation. For target word selection, we utilize a grammatical relationship stored in a dictionary. We use k- nearest neighbor learning algorithm for the resolution of data sparseness Problem in target word selection and estimate the distance between instances based on these models. In experiments, we use TREC data of AP news for construction of latent semantic space and Wail Street Journal corpus for evaluation of target word selection. Through the Latent Semantic Analysis methods, the accuracy of target word selection has improved over 10% and PLSA has showed better accuracy than LSA method. finally we have showed the relatedness between the accuracy and two important factors ; one is dimensionality of latent space and k value of k-NT learning by using correlation calculation.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.5
• /
• pp.435-444
• /
• 2001

Daily time series of longshore wind at 8 stations, sea surface temperature (SST) at 11 stations in the eastern coast of the Korean peninsula during $1983\~1997$ and the NOAA/AVHRR satellite data during $1990\~1998$ were used in order to study the temporal and spatial variations of the upwelling cold water which occurred in the summer season. The cold water occurred frequently in the eastern coastal waters of Korea such as Soimal, Kijang, Ulgi, Kampo, Pohang, Youngduk, Chukbyun, Chumunjin and Sokcho, During the upwelling cold water phenomenon, SST came down more than $-5^{\circ}C$ in a day. The maximum of the averaged RMS amplitude of daily SST was $5.8^{\circ}C$ along the eastern coast of Korea on Julian day 212 from $1983\~1997$. The cross correlation coefficients were higher than 0.5 between Sokcho and Chumunjin in the northern part of the East Sea, and along Soimal, Kijang, Ulgi, Kampo and Pohang in the southern part of the East Sea. In late July, 1995 the cold water occurred at Ulgi coastal area and extended to Ullung island which is located 250 km off the Ulgi coast. Even though the distance between Soimal and the Ulgi coast area is more than 120 km, the cross correlation coefficient related to the anomalies of SST due to upwelling cold water was the highest (0.7) in the southeastern coastal area of the Korean peninsula. This connection may be due to the cyclonic circulation of the Tsushima Current in this area and the topography of the ocean rather than the local south wind which induced the coastal upwelling.

• Journal of the Korean earth science society
• /
• v.36 no.1
• /
• pp.109-124
• /
• 2015

A novel approach, hybrid surface rainfall (KNU-HSR) technique developed by Kyungpook Natinal University, was utilized for improving the radar rainfall estimation. The KNU-HSR technique estimates radar rainfall at a 2D hybrid surface consistings of the lowest radar bins that is immune to ground clutter contaminations and significant beam blockage. Two HSR techniques, static and dynamic HSRs, were compared and evaluated in this study. Static HSR technique utilizes beam blockage map and ground clutter map to yield the hybrid surface whereas dynamic HSR technique additionally applies quality index map that are derived from the fuzzy logic algorithm for a quality control in real time. The performances of two HSRs were evaluated by correlation coefficient (CORR), total ratio (RATIO), mean bias (BIAS), normalized standard deviation (NSD), and mean relative error (MRE) for ten rain cases. Dynamic HSR (CORR=0.88, BIAS= $-0.24mm\;hr^{-1}$, NSD=0.41, MRE=37.6%) shows better performances than static HSR without correction of reflectivity calibration bias (CORR=0.87, BIAS= $-2.94mm\;hr^{-1}$, NSD=0.76, MRE=58.4%) for all skill scores. Dynamic HSR technique overestimates surface rainfall at near range whereas it underestimates rainfall at far ranges due to the effects of beam broadening and increasing the radar beam height. In terms of NSD and MRE, dynamic HSR shows the best results regardless of the distance from radar. Static HSR significantly overestimates a surface rainfall at weaker rainfall intensity. However, RATIO of dynamic HSR remains almost 1.0 for all ranges of rainfall intensity. After correcting system bias of reflectivity, NSD and MRE of dynamic HSR are improved by about 20 and 15%, respectively.