• Journal of Conservation Science
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• v.25 no.2
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• pp.115-130
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• 2009

This study was focused on digital restoration and structural stability evaluation applying 3D scanning system of five-storied Magoksa temple stone pagoda in Gongju. For these, the digital restoration of the pagoda was completed using laser scan data which is measured 16 directions and data processing program of 7 stages. As a result of digital restoration, the overall height and width of stone properties showed a little difference in directions and the width of roof stones appeared very high difference of each floor. The width of pagoda body become smaller to the fifth floor, but gradual decrease rate showed irregular characteristics. Also, as result of 3D image analysis for structural stability evaluation, the displacement occurred toward northwest in second body stone to upper final stone except for central axis of the first body stone which inclines toward southwest. Such 3D image analysis is required quantification of survey method and should be applied to various field such as quantitative damage maps in order to utilize a conservation of stone cultural heritages, continuously.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.405-416
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• 2021

The safety speed 5030 policy, which is currently being implemented nationwide, tends to increase citizens' dissatisfaction due to reduced mobility and inconvenience. In order to successfully promote the Safety Speed 5030 policy, it is important to collect various opinions of citizens who use roads by deviating from quantitative policy evaluation criteria such as traffic accidents and traffic speed. Therefore, in this study, citizens who use roads were classified into a driver group and a non-driver group, and civic consciousness analysis such as adequacy evaluation of speed limit, satisfaction evaluation of road service quality (MDS), and importance-satisfaction analysis (IPA) was conducted. As a result of the analysis of civic consciousness, in particular, satisfaction with mobility, economy, and environment was low. Accordingly, it was intended to promote the successful implementation of the Safety Speed 5030 policy by presenting measures to improve the speed limit and quality of road service for roads with low satisfaction.

• Investigative Magnetic Resonance Imaging
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• v.19 no.3
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• pp.178-185
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• 2015

Purpose: To compare the frequency of posterior globe flattening between two-dimensional T2-weighted imaging (2D T2WI) and three-dimensional (3D T2WI). Materials and Methods: Sixty-nine patients (31 female; mean age, 44.4 years) who had undergone both 5-mm axial T2WI and sagittal 3D 1-mm isovoxel T2WI of the whole brain for evaluation of various diseases (headache [n = 30], large hemorrhage [n = 19], large tumor or leptomeningeal tumor spread [n = 15], large infarct [n = 3], and bacterial meningitis [n = 2]) were used in this study. Two radiologists independently reviewed both sets of images at separate sessions. Axial T2WI and multi-planar imaging of 3D T2WI were visually assessed for the presence of globe flattening. The optic nerve sheath diameter (ONSD) was measured at a location 4 mm posterior to each globe on oblique coronal imaging reformatted from 3D T2WI. Results: There were significantly more globes showing posterior flattening on 3D T2WI (105/138 [76.1%]) than on 2D T2WI (27/138 [19.6%], P = 0.001). Inter-observer agreement was excellent for both 2D T2WI and 3D T2WI (Cohen's kappa = 0.928 and 0.962, respectively). Intra-class correlation coefficient for the ONSD was almost perfect (Cohen's kappa = 0.839). The globes with posterior flattening had significantly larger ONSD than those without on both 2D and 3D T2WI (P < 0.001; $6.14mm{\pm}0.44$ vs. $5.74mm{\pm}0.44$ on 2D T2WI; $5.90mm{\pm}0.47$ vs. $5.56mm{\pm}0.34$ on 3D T2WI). Optic nerve protrusion was significantly more frequent on reformatted 1-mm 3D T2WI than on 5-mm 2D T2WI (8 out of 138 globes on 3D T2WI versus one on 2D T2WI; P = 0.018). Conclusion: Posterior globe flattening is more frequently observed on 3D T2WI than on 2D T2WI in patients suspected of having increased intracranial pressure. The globes with posterior flattening have significantly larger ONSD than those without.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.300-306
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• 2004

Eight cation or anion-responsive polymer membranes were prepared by a casting procedure employing polyvinyl chloride, Bis (2-ethylhexyl)sebacate and each electroactive material in the ratio of 66 : 33 : 1. The resulting membranes were separately installed onto the sensitive area of the ionic electrodes to produce an 8-channel taste sensor array. The taste sensors of the array were connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a PC via an A/D converter. The taste evaluation system was applied to a discriminant analysis on six groups of marketed beverages like sikhye, sujunggwa, tangerine juice, ume juice, ionic drink and green tea. When the signal data from the sensor array were analyzed by principal component analysis after normalization, the 1st, 2nd and 3rd principal component explained most of the total data variance. The six groups of the analyzed beverages were discriminated well in the three dimensional principal component space. The half of the five groups of the analyzed beverages was also discriminated in the two dimensional principal component plane.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.257-263
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• 2013

In this study, dynamic behaviors of a wave energy generation system (WEGS) that converts wave energy into electric energy are analyzed using multibody dynamics techniques. Many studies have focused on reducing the effects of a mooring system on the motion of a WEGS. Several kinematic constraints and force elements are employed in the modeling stage. Three-dimensional wave load equations are used to implement wave loads. The dynamic behaviors of a WEGS are analyzed under several wave conditions by using MSC/ADAMS, and the rotating speed of the generating shaft is investigated for predicting the electricity capacity. The dynamic behaviors of a WEGS with a mooring system are compared with those of a WEGS without a mooring system. Stability evaluation of a WEGS is carried out through simulation under extreme wave load.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.2 s.17
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• pp.1-8
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• 2005

Microwave tomographic imaging technology using a bi-focusing operator has been developed in order to detect the internal voids/objects inside concrete structures. The imaging system consists of several cylindrical or planar array antennas for transmitting and receiving signals, and a numerical focusing operator is applied to the external signals both in transmitting and in receiving fields. In this study, the authors developed 3-dimensional (3D) electromagnetic (EM) imaging technology to detect such damage and to identify exact location of steel rebars or dowel. The authors have developed sub-surface two-dimensional (2D) imaging technique using tomographic antenna array in previous works. In this study, extending the earlier analytical and experimental works on 2D image reconstruction, a 3D microwave imaging system using tomographic antenna way was developed, and multi-frequency technique was applied to improve quality of the reconstructed image and to reduce background noises. Numerical simulation demonstrated that a sub-surface image can be successfully reconstructed by using the proposed tomographic imaging technology. For the experimental verification, a prototype antenna array was fabricated and tested on a concrete specimen.

• Journal of Radiation Protection and Research
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• v.43 no.3
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• pp.97-106
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• 2018

Background: A cargo container scanner using a high-energy X-ray generates a fan beam X-ray to acquire a transmitted image. Because the generated X-rays by LINAC may affect the image quality and radiation protection of the system, it is necessary to acquire accurate information about the generated X-ray beam distribution. In this paper, a diode-based multi-channel spatial dose measuring device for measuring the X-ray dose distribution developed for measuring the high energy X-ray beam distribution of the container scanner is described. Materials and Methods: The developed high-energy X-ray spatial dose distribution measuring device can measure the spatial distribution of X-rays using 128 diode-based X-ray sensors. And precise measurement of the beam distribution is possible through automatic positioning in the vertical and horizontal directions. The response characteristics of the measurement system were evaluated by comparing the signal gain difference of each pixel, response linearity according to X-ray incident dose change, evaluation of resolution, and measurement of two-dimensional spatial beam distribution. Results and Discussion: As a result, it was found that the difference between the maximum value and the minimum value of the response signal according to the incident position showed a difference of about 10%, and the response signal was linearly increased. And it has been confirmed that high-resolution and two-dimensional measurements are possible. Conclusion: The developed X-ray spatial dose measuring device was evaluated as suitable for dose measurement of high energy X-ray through confirmation of linearity of response signal, spatial uniformity, high resolution measuring ability and ability to measure spatial dose. We will perform precise measurement of the X-ray beamline in the container scanning system using the X-ray spatial dose distribution measuring device developed through this research.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.41-51
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• 2023

In this paper, we propose a technique of multi-time window feature extraction for anger detection in gait data. In the previous gait-based emotion recognition methods, the pedestrian's stride, time taken for one stride, walking speed, and forward tilt angles of the neck and thorax are calculated. Then, minimum, mean, and maximum values are calculated for the entire interval to use them as features. However, each feature does not always change uniformly over the entire interval but sometimes changes locally. Therefore, we propose a multi-time window feature extraction technique that can extract both global and local features, from long-term to short-term. In addition, we also propose an ensemble model that consists of multiple classifiers. Each classifier is trained with features extracted from different multi-time windows. To verify the effectiveness of the proposed feature extraction technique and ensemble model, a public three-dimensional gait dataset was used. The simulation results demonstrate that the proposed ensemble model achieves the best performance compared to machine learning models trained with existing feature extraction techniques for four performance evaluation metrics.

• ETRI Journal
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• v.26 no.3
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• pp.218-228
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• 2004

Using stereo images with ephemeris data from the Korea Multi-Purpose Satellite-1 electro-optical camera (KOMPSAT-1 EOC), we performed geometric modeling for three-dimensional (3-D) positioning and evaluated its accuracy. In the geometric modeling procedures, we used ephemeris data included in the image header file to calculate the orbital parameters, sensor attitudes, and satellite position. An inconsistency between the time information of the ephemeris data and that of the center of the image frame was found, which caused a significant offset in satellite position. This time inconsistency was successfully adjusted. We modeled the actual satellite positions of the left and right images using only two ground control points and then achieved 3-D positioning using the KOMPSAT-1 EOC stereo images. The results show that the positioning accuracy was about 12-17 m root mean square error (RMSE) when 6.6 m resolution EOC stereo images were used along with the ephemeris data and only two ground control points (GCPs). If more accurate ephemeris data are provided in the near future, then a more accurate 3-D positioning will also be realized using only the EOC stereo images with ephemeris data and without the need for any GCPs.

• Structural Engineering and Mechanics
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• v.49 no.2
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• pp.203-223
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• 2014

The extensive use of prestressed reinforced concrete (PSC) highway bridges in marine environment drastically increases the sensitivity to both fatigue-and corrosion-induced damage of their critical structural components during their service lives. Within this scenario, an integrated method that is capable of evaluating the fatigue reliability, identifying a condition-based maintenance, and predicting the remaining service life of its critical components is therefore needed. To accomplish this goal, a procedure for fatigue reliability prediction of PSC highway bridges is proposed in the present study. Vehicle-bridge coupling vibration analysis is performed for obtaining the equivalent moment ranges of critical section of bridges under typical fatigue truck models. Three-dimensional nonlinear mathematical models of fatigue trucks are simplified as an eleven-degree-of-freedom system. Road surface roughness is simulated as zero-mean stationary Gaussian random processes using the trigonometric series method. The time-dependent stress-concentration factors of reinforcing bars and prestressing tendons are accounted for more accurate stress ranges determination. The limit state functions are constructed according to the Miner's linear damage rule, the time-dependent S-N curves of prestressing tendons and the site-specific stress cycle prediction. The effectiveness of the methodology framework is demonstrated to a T-type simple supported multi-girder bridge for fatigue reliability evaluation.