• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.331-338
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• 2011

Objective: The present study developed a comprehensive usability testing and analysis framework based on a physical interface model of product and user and applied the proposed framework to usability testing of canister-type vacuum cleaner. Background: The development of a user-centered product design is important to satisfy customers who want to use the product with ease of use and to keep the manufacturer competitive in the market. Method: The proposed testing and analysis framework consists of (1) characterization of physical product-user interface, (2) preparation and administration of usability testing questionnaire, and (3) analysis and interpretation of usability testing results. A usability evaluation of five vacuum cleaners was planned and administered based on the proposed framework and its analysis produced detailed and overall usability testing results for various aspects such as tasks, usability criteria, and design components. Results: The testing results were further utilized to identify usability problems and preferred design features of the vacuum cleaners. Conclusion: The proposed usability testing and analysis framework was found effective to identify preferred features and problems of a product design in a systematic, holistic manner. Application: The proposed framework can be of effective use for practitioners of product design and development to obtain comprehensive, quantitative usability testing information in a systematic manner.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.61-67
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• 2016

OBJECTIVES : The objective of this study is to detect road cavities using multi-channel 3D ground penetrating radar (GPR) tests owned by the Seoul Metropolitan Government. METHODS : Ground-penetrating radar tests were conducted on 204 road-cavity test sections, and the GPR signal patterns were analyzed to classify signal shape, amplitude, and phase change. RESULTS : The shapes of the GPR signals of road-cavity sections were circular or ellipsoidal in the plane image of the 3D GPR results. However, in the longitudinal or transverse direction, the signals showed mostly unsymmetrical (or symmetrical in some cases) parabolic shapes. The amplitude of the GPR signals reflected from road cavities was stronger than that from other media. No particular pattern of the amplitude was found because of nonuniform medium and utilities nearby. In many cases where road cavities extended to the bottom of the asphalt concrete layer, the signal phase was reversed. However, no reversed signal was found in subbase, subgrade, or deeper locations. CONCLUSIONS : For detecting road cavities, the results of the GPR signal-pattern analysis can be applied. In general, GPR signals on road cavity-sections had unsymmetrical hyperbolic shape, relatively stronger amplitude, and reversed phase. Owing to the uncertainties of underground materials, utilities, and road cavities, GPR signal interpretation was difficult. To perform quantitative analysis for road cavity detection, additional GPR tests and signal pattern analysis need to be conducted.

• Restorative Dentistry and Endodontics
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• v.42 no.4
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• pp.273-281
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• 2017

Objectives: The aims of this study were to quantify tug-back by measuring the pulling force and investigate the correlation of clinical tug-back pulling force with in vitro gutta-percha (GP) cone adaptation score using micro-computed tomography (${\mu}CT$). Materials and Methods: Twenty-eight roots from human single-rooted teeth were divided into 2 groups. In the ProTaper Next (PTN) group, root canals were prepared with PTN, and in the ProFile (PF) group, root canals were prepared using PF (n = 14). The degree of tug-back was scored after selecting taper-matched GP cones. A novel method using a spring balance was designed to quantify the tug-back by measuring the pulling force. The correlation between tug-back scores, pulling force, and percentage of the gutta-percha occupied area (pGPOA) within apical 3 mm was investigated using ${\mu}CT$. The data were analyzed using Pearson's correlation analysis, one-way analysis of variance (ANOVA) and Tukey's test. Results: Specimens with a strong tug-back had a mean pulling force of 1.24 N (range, 0.15-1.70 N). This study showed a positive correlation between tug-back score, pulling force, and pGPOA. However, there was no significant difference in these factors between the PTN and PF groups. Regardless of the groups, pGPOA and pulling force were significantly higher in the specimens with a higher tug-back score (p < 0.05). Conclusions: The degree of subjective tug-back was a definitive determinant for master cone adaptation in the root canal. The use of the tug-back scoring system and pulling force allows the interpretation of subjective tug-back in a more objective and quantitative manner.

• Korean Journal of Remote Sensing
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• v.27 no.6
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• pp.703-715
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• 2011

Forests have been considered one of the most important ecosystems on the earth, affecting the lives and environment. The sustainable forest management requires accurate and timely information of forest and tree parameters. Appropriately interpreted remotely sensed imagery can provide quantitative data for deriving forest information temporally and spatially. Especially, analysis of individual tree detection and crown delineation is significant issue, because individual trees are basic units for forest management. Individual trees in aerial imagery have reflectance characteristics according to tree species, crown shape and hierarchical status. This study suggested a method that identified individual trees and delineated crown boundaries through adopting gradient method algorithm to amplified greenness data using red and green band of aerial imagery. The amplification of specific band value improved possibility of detecting individual trees, and gradient method algorithm was performed to apply to identify individual tree tops. Additionally, tree crown boundaries were explored using spectral intensity pattern created by geometric characteristic of tree crown shape. Finally, accuracy of result derived from this method was evaluated by comparing with the reference data about individual tree location, number and crown boundary acquired by visual interpretation. The accuracy ($\hat{K}$) of suggested method to identify individual trees was 0.89 and adequate window size for delineating crown boundaries was $19{\times}19$ window size (maximum crown size: 9.4m) with accuracy ($\hat{K}$) at 0.80.

• Economic and Environmental Geology
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• v.28 no.3
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• pp.271-277
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• 1995

The geological information analysis based on spatial statistical techniques have been studied in relation to mineral exploration. The applicability of outlier detection using moving-window statistics and directional cross-variography analysis have been verified by using geochemical data sets surveyed in the Taebaek area for mineral exploration. The directional variogram analysis has been basically known as a geostatistical method for spatial continuity measures. In this study, the application of this proposed method was extended to measure spatial correlation or similarity problems between two geochemical elements. For the appraisal of the usefulness of this scheme, five kinds of variogram functions were computed for original data and revised data, obtained by removing outliers detected by moving-window statistics and the results were compared. It is concluded that these advanced spatial statistical methods at the interpretation stage of spatial similarity provide us with valuable quantitative results as decision-supporting information for regional mineral exploration task.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.15-27
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• 2005

The water and carbon cycles in terrestrial ecosystems are the essential database for better understanding of the causes and the current processes of climate change and for the prediction of its future change. CarboKorea and HydroKorea are dedicated research efforts to develop technologies to quantitatively interpret and forecast carbon/water cycles in typical landscapes of Korea. For this, stable isotope studies have been launched to genetically partition various components of carbon/water cycles in terrestrial ecosystems. From stable isotope studies, practical deliverables such as evaporation, transpiration and gross primary productivity (GPP) can be provided at scales from tower (footprint) to large watersheds. Such reliable field-based information will form an important database to be used for validation of the results from various eco-hydrological models and satellite image analysis which constitute main components of Carbo/HydroKorea project. Stable isotope studies, together with other relevant researches, will contribute to derive quantitative interpretation of carbon/water cycles in terrestrial ecosystems and support Carbo/HydroKorea to become a leading research infrastructure to answer pending scientific and socio-economic questions in relation to global changes.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1495-1499
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• 2020

The study of climate and respiratory viral infections using big data may enable the recognition and interpretation of relationships between disease occurrence and climatic variables. In this study, real-time reverse transcription quantitative PCR (qPCR) methods were used to identify Human respiratory coronaviruses (HCoV). infections in patients below 10 years of age with respiratory infections who visited Dankook University Hospital in Cheonan, South Korea, from January 1, 2012, to December 31, 2018. Out of the 9010 patients who underwent respiratory virus real-time reverse transcription qPCR test, 364 tested positive for HCoV infections. Among these 364 patients, 72.8% (n = 265) were below 10 years of age. Data regarding the frequency of infections was used to uncover the seasonal pattern of the two viral strains, which was then compared with local meteorological data for the same time period. HCoV-229E and HCoV-OC43 showed high infection rates in patients below 10 years of age. There was a negative relationship between HCoV-229E and HCoV-OC43 infections with air temperature and wind-chill temperatures. Both HCoV-229E and HCoV-OC43 rates of infection were positively related to atmospheric pressure, while HCoV-229E was also positively associated with particulate matter concentrations. Our results suggest that climatic variables affect the rate in which children below 10 years of age are infected with HCoV. These findings may help to predict when prevention strategies may be most effective.

• Journal of Korean Medical classics
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• v.23 no.5
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• pp.23-34
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• 2010

Contemporary topic of the culture is turning to the Nature. In this situation, The Paradigms of realization about Human body and medical science are changing. The new interpretation of the value of Health is another method of recovering the Nature. Oriental medicine has mainly dealt with health preserving idealogy in origin, and pursued it. Get out of the curing medicine, the health preserving idealogy which aims to live up to one's lifespan has been becoming the main idea of Oriental medicine. In this respect, we can extract insperation from the concept of Meebyung and preventive treatments which came from the ideas of preventive medicine in Oriental medicine. Among the researches of Meebyung in Oriental medical classics and in Oriental tri-countries, we grasped and analyzed the trends of them. In connection with the most fundamental project in Meebyung study which is to set up the concept of Meebyung, we inspected the standards which can categorize and diagnose Meebyung. In contrast with 'Ibyeong', Meebyung in Oriental medical classics can be attained from living in harmony with the Nature, four seasons, Eum-and-Yang and the Five Phases. However the classification of Meebyung, Yogbyeong, Ibyeong in medical classics made foundation of post preventive medicine. From the various studies we can find as follws. Promting national project in Meebyung, China is trying to reestablish classifications of Meebyung, as Japanese Meebyung scholars are focusing on quantitative methods. Although there are not enough research products, Korea must absorb the products of such other countries, as to categorize Meebyung through the pattern identification system of Oriental medicine, and achieve our goal of promotion of health.

• The Journal of Korean Association of Computer Education
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• v.6 no.2
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• pp.81-93
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• 2003

The purpose of the study was to explore the potential of the Social Network Analysis as an analytical tool for scientific investigation of learner-learner, or learner-tutor interaction within an e-Learning environment. Theoretical and methodological implication of the Social Network Analysis had been discussed. Following theoretical analysis, an exploratory empirical study was conducted to test statistical correlation between traditional performance measures such as achievement and team contribution index, and the centrality measure, one of the many quantitative measures the Social Network Analysis provides. Results indicate the centrality measure was correlated with the higher order learning performance and peer-evaluated contribution indices. An interpretation of the results and their implication to instructional design theory and practices were provided along with some suggestions for future research.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.63-70
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• 2000

The quantitative analyses and the mechanical interpretation of discontinuity planes are the most important factor for the study of strength and deformation properties of rock masses containing discontinuity planes. However, the relationship between the factors investigated in the field and the actual mechanical properties of discontinuity planes is not fully understood. The main purpose of this study is to investigate the effects of density, length, and spacing of joints on elastic modulus of rock masses as these values vary. A new parameter which has a direct relation with the elastic modulus of discontinuity planes is also preposed in this study. The combination of finite element methods and homogenization methods has been used for the numerical analyses of a uintcell with discontinuity planes, which is generated using random-number generation methods. The elastic modulus of the discontinuity plane is found from the numerical analyses. The final results propose not only the relation between the investigation parameters of discontinuity planes and the elastic modulus of rock masses but also a new parameter, an effect area ratio having a linear relation with the elastic modulus of rock masses.