• Imaging Science in Dentistry
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• v.30 no.3
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• pp.183-188
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• 2000

Purpose: This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X -ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results: Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANP AS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. Conclusion: HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X -ray equipment should be managed in the planned and organized fashion.

• The Journal of Korean Medicine
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• v.32 no.1
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• pp.121-129
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• 2011

Objective: The propose of this study is to build a conceptual framework for representing clinical findings in Traditional East Asian Medicine(TEAM). As the existing standard models have been developed without considering features of Traditional Medicine, in this study we introduced unique characteristics for the TEAM. Method: This study was composed of three steps. First, we analyzed whether the existing clinical information models are suitable for representing clinical findings. Second, we analyzed ISO/TS 22789 model which is a ISO medical informatics standard, to find out the problem by applying clinical findings of TEAM into the model. Finally, we defined semantic links and a concept hierarchy in our model based on the analyzed results. The model includes the concepts for clinical findings and terms, and the semantic links can be regarded as relations between concepts, so that the representating clinical findings are completed by connecting concepts with other concepts. Results: Our framework was developed by removing unnecessary semantic links, and adding some necessary ones based on ISO/TS 22789 model. The ISO/TS 22789 model has a simple concept hierarchy, but in this study we subdivided the hierarchy and also considered interoperability with other terminological systems and standard models. Conclusions: This research needs more discussions, but is meaningful as proposing a way how to develop Traditional Medicine terminological systems. This study shows the limitations of existing models in describing clinical findings for TEAM, and what should be considered to represent Traditional Medicine knowledge, and propose a solution to improve the problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4472-4477
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• 2013

This paper describes the color features of smoke in each standard color model in order to present the most suitable color model for somke detection in video surveillance system. Histogram intersection technique is used to analyze the difference characteristics between color of smoke and color of non smoke. The considered standard color models are RGB, YCbCr, CIE-Lab, HSV, and if the calculated histogram intersection value is large for the considered color model, then the smoke spilt characteristics are not good in that color model. If the calculated histogram intersection value is small, then the smoke spilt characteristics are good in that color model. The analyzed result shows that the RGB and HSV color models are the most suitable for color model based smoke detection by performing respectively 0.14 and 0.156 for histogram intersection value.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.5
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• pp.262-270
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• 2020

An outdoor free-running model test system was designed for assessing ship maneuverability with test uncertainty. The test model was a surface combatant of tumblehome hull geometry. The straight forward tests were conducted first to obtain the relationship between the propeller revolution rate and advance speed. During the outdoor tests, the propeller revolution rate to achieve a certain Froude number condition was higher than that in the indoor free-running model tests. Turning circle and zigzag tests for evaluating ship maneuverability criteria were carried out at the propeller revolution rate determined by the straight forward test results. The random and systematic standard uncertainties of maneuvering criteria were obtained by repeated tests and comparison with the indoor free-running model test results, respectively. The test uncertainty was largely dominated by the systematic standard uncertainty, while the random standard uncertainty was small with good repeatability.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.432-438
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• 2023

Purpose: The purpose of this study is to enable users to conveniently report risks by automatically classifying risk categories in real time using AI for images reported in the life safety prevention service app. Method: Through a system consisting of a life safety prevention service platform, life safety prevention service app, AI model serving server and sftp server interconnected through the Internet, the reported life safety images are automatically classified in real time, and the AI model used at this time An AI learning algorithm for generation was also developed. Result: Images can be automatically classified by AI processing in real time, making it easier for reporters to report matters related to life safety.Conclusion: The AI image automatic classification system presented in this paper automatically classifies reported images in real time with a classification accuracy of over 90%, enabling reporters to easily report images related to life safety. It is necessary to develop faster and more accurate AI models and improve system processing capacity.

• Structural Engineering and Mechanics
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• v.84 no.2
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• pp.143-154
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• 2022

Corrosion of steel reinforcement is considered as the main cause of concrete structures deterioration, especially those under humid environmental conditions. Hence, fiber reinforced polymer (FRP) bars are being increasingly used as a replacement for conventional steel owing to their non-corrodible characteristics. However, predicting the shear strength of beams reinforced with FRP bars still challenging due to the lack of robust shear theory. Thus, this paper aims to develop an explicit data driven based model to predict the shear strength of FRP reinforced beams using multi-objective evolutionary polynomial regression analysis (MOGA-EPR) as data driven models learn the behavior from the input data without the need to employee a theory that aid the derivation, and thus they have an enhanced accuracy. This study also evaluates the accuracy of predictive models of shear strength of FRP reinforced concrete beams employed by different design codes by calculating and comparing the values of the mean absolute error (MAE), root mean square error (RMSE), mean (𝜇), standard deviation of the mean (𝜎), coefficient of determination (R²), and percentage of prediction within error range of ±20% (a20-index). Experimental database has been developed and employed in the model learning, validation, and accuracy examination. The statistical analysis illustrated the robustness of the developed model with MAE, RMSE, 𝜇, 𝜎, R², and a20-index of 14.6, 20.8, 1.05, 0.27, 0.85, and 0.61, respectively for training data and 10.4, 14.1, 0.98, 0.25, 0.94, and 0.60, respectively for validation data. Furthermore, the developed model achieved much better predictions than the standard predictive models as it scored lower MAE, RMSE, and 𝜎, and higher R² and a20-index. The new model can be used in future with confidence in optimized designs as its accuracy is higher than standard predictive models.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.5
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• pp.15-27
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• 2024

Agriculture is recognized as an important anthropogenic cause of non-point source loads. Improved understanding of non-point source loads according to fertilization practices can promote climate change and eutrophication mitigation. Thus, this study evaluated the impact of conventional and standard fertilization practices on non-point pollution (NPP) loads in a dual-cropping system, utilizing the Agricultural Policy/Environmental eXtender (APEX) model. Our research objectives were twofold: firstly, to calibrate and validate the APEX model with observed data through experiments from 2018 to 2023; and secondly, to compare the NPP loads under conventional and standard fertilization practices. The model calibration and validation showed satisfactory performance in simulating nitrogen (N) and phosphorus (P) loads, illustrating the model's applicability in a Korean agricultural setting. The simulation results under conventional fertilization practices revealed significantly higher NPP loads compared to the standard fertilization, with P loads under conventional practices being notably higher. Our findings emphasize the crucial role of recommended fertilization practices in reducing non-point source pollution. By providing a quantitative assessment of NPP loads under different fertilization practices, this study contributes valuable information to sustainable nutrient management in agricultural systems facing the dual challenges of climate change and environmental conservation.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2626-2631
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• 2011

In recent carbody design of rolling stocks, the development of a new carbody structure rather than designing the carbody structure by applying a proven new way to design the carbody structure has been applied. Structural requirements of the carbody being equal, the same applies to the carbody structure means that it is possible to design a carbody structure. By kinematic envelope & speed and the environment, etc., the carbody design is in progress. Accordingly, if all conditions are the same as the existing carbody structure by the same criteria is that you can go get the same. Rather than developing a new carbody structure, carbody structure by applying proven that safety is secured is made possible. Proven standard model of the carbody structure of rolling stocks to secure a new carbody design has made it possible to apply. In addition, the size of the different carbody but structural requirements are the same body design is easier to be expected. In this paper, a model standard carbody of rolling stocks is chosen and of a new carbody design that can be applied to the carbody design will attempt to demonstrate the case.

• Journal of the Korean Society of Visualization
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• v.14 no.3
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• pp.46-50
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• 2016

The objective of the present study is to perform experiments for water filled cavity heated and cooled from the side at $Ra=8.5{\times}108$. This experiment can provide validation database of the standard k-${\varepsilon}$ turbulence model for single-phase turbulent natural convection which has been regarded as one of the important phenomena in nuclear safety. For the natural convection inside a cavity, temperature and velocity were obtained by thermometry and PIV (Particle Image Velocimetry) methods. These results would be used for validation of standard k-${\varepsilon}$ turbulence model.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.5
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• pp.445-453
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• 2001

The multiple targets tracking problem has been one of the main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimen-sion filter, input estimation filter, interacting multiple model(IMM) filter, dederated variable dimension filter with input estimation, etc., have proposed to address the tracking and sensor fusion issues. In this pa- per, two existing tracking algorithm, i.e, the IMM filter and the variable dimension filter with input estima-tion(VDIE), are combined for the purpose of improving the tracking performance for maneuvering targets. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns, i.e., waver, pop-up, and high-diver motions, are defined and are applied to the modified IMM filter as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMM filter than the standard IMM filter are demonstrated though computer simulations.