• Progress in Medical Physics
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• v.19 no.4
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• pp.241-246
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• 2008

Patient's respiration can have an effect on movement of tumor range and peripheral organs. Therefore, the respiratory signal was acquired by relation between external markers and movement of patient's abdomen during radiational therapy in order to minimize the effect of respiration. Based on this technique, many studies of rational therapy to irradiate at particular part of stable respiratory signals have executed and they have been clinically applied. Nevertheless, the phase-based method is preferred to the amplitude-based method for the rational therapy related to respiration. Because stabilization of the respiratory signal are limited. In this study, a in-house respiratory signal analysis program was developed for the phase reassignment and the analysis of the irregular respiratory signals. Various irregular respiratory patterns was obtained from clinical experimental volunteers. After then, the in-house program analyzed the factors affecting to phase assignment which is directly related to irradiated sector. Subsequently, accuracy of phase assignment was improved with removement of irregular signals by self-developed algorithm. This study is considered to be useful for not only image reconstruction and elevation of irradiating accuracy through phase assignment of RPM system but also analysis of respiratory signals. Moreover, development of 4D CT image is planed with phantom researches or clinical experiments based on this program.

• Journal of Korea Foundry Society
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• v.30 no.3
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• pp.100-110
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• 2010

The solidification sequence and formation of intermetallic phase of Fe-rich Al-Si-Cu alloy were investigated by using real-time imaging of synchrotron X-ray radiation. Effects of cooling rate during uni-directional solidification on the resultant solidification behavior was also studied in a specially constructed vacuum chamber in the SPring-8 facility. The series of radiographic images were complementarily analyzed with conventional analysis of OM and SEM/EDX for phase identification. Detailed solidification sequence and formation mechanisms of various phases were discussed based on real-time image analysis. The growth rates of $\alpha$-AlFeMnSi and ${\beta}-Al_5FeSi$ were measured in order to understand the growth behavior of each phase. It is suggested that real-time imaging technique can be a powerful tool for the precise understanding of solidification behavior of various industrial materials.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.151-158
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• 2018

Objective: In this study, we analyzed kinematic changes in the start phase of speed skating before and after physical training. Method: We introduced a new strength training program (2017) that was improved in terms of exercise type and intensity [%, one repetition maximum (1RM)] compared with the previous strength training program (2016). The new program was applied to elite speed skating athletes (four males and four females). To determine the improvement in starting technique, we recorded race images during the start phase of the 500-m race held in 2016 and 2017. The race images were collected using five high-speed cameras and kinematic characteristics of the start phase were analyzed by three-dimensional image analysis. Results: The 1RMs were improved by 11% on an average after the strength training. In 2017, records of four out of the eight athletes were shortened in terms of the initial lap time (100 m), and 500-m records were shortened in six athletes. The time to nine strokes was shortened in five athletes, and the ratio of correct kinetic chain was increased or maintained at a high level in six athletes. Conclusion: In this study, the new strength training program (2017), applied to elite speed skating athletes, showed a positive effect on starting technique and reduced the record times.

• Journal of Mechanical Science and Technology
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• v.19 no.12
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• pp.2253-2262
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• 2005

The focus of this work is placed on the analysis of the mixture formation mechanism under the evaporative diesel spray of impinging and free conditions. As an experimental parameter, ambient gas density was selected. Effects of density variation of ambient gas on liquid and vapor-phase inside structure of evaporation diesel spray were investigated. Ambient gas density was changed between ${\rho}a=5.0\;kg/m^3$ and $12.3\;kg/m^3$. In the case of impinging spray, the spray spreading to the radial direction is larger due to the decrease of drag force of ambient gas in the case of the low density than that of the high density. On the other hand, in the case of free spray, in accordance with the increase in the ambient gas density, the liquid-phase length is getting short due to the increase in drag force of ambient gas. In order to examine the homogeneity of mixture consisted of vapor-phase fuel and ambient gas in the spray, image analysis was conducted with statistical thermodynamics based on the non-dimensional entropy (S) method. In the case of application of entropy analysis to diesel spray, the entropy value always increases. The entropy of higher ambient density is higher than that of lower ambient gas density during initial injection period.

• 한국전자현미경학회:학술대회논문집
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• 1994.05a
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• pp.31-31
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• 1994

• The Journal of Economics, Marketing and Management
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• v.6 no.4
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• pp.1-16
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• 2018

Purpose - This study will investigate and identify the relationship between brand image, brand attitude and intent to purchase based on subjects that have remembered or watched more than one storytelling marketing ad related to airlines. The purpose of the project is to secure market competitiveness by presenting the basis for and use of the marketing strategy using storytelling, which can capture the goodwill of the aerospace competition market in the future. Research, design, data, and methodology - Prior to the research model and hypothesis testing phase, a verification factor analysis was conducted to assess internal consistency among each measurement item and to ensure reliability and validity of the measurement tool. Further, the organization was assessed for validity by calculating the mean variance estimation (AVE) and the construction concept reliability (CCR) through a positive factor analysis. Hypothesis verification was analyzed through a structural equation model, and each concept set in the hypothesis was entered as a potential variable, and each measurement item was entered as an observation variable. Results - Airline's storytelling marketing has a significant impact on the brand image and two emotional and cognitive responses have been shown to influence the brand image. In addition, airline storytelling marketing has a significant impact on brand attitudes and airline storytelling marketing derived from factor analysis has shown two emotional and cognitive responses to brand attitudes. Conclusions - The parts derived based on the research results show that storytelling marketing has a strong influence on the airline's brand image and attitude, and that it is necessary for airlines to have a brand image and attitude. Also, forming a favorable brand image has a significant impact on brand attitudes. We believe that by presenting basic data to the aviation industry in future research on airline storytelling, we will be able to increase understanding and contribution to development of storytelling marketing in aviation.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2326-2333
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• 2015

Stator turn faults in permanent magnet synchronous motors (PMSMs) are more dangerous than those in induction motors (IMs) because of the presence of spinning rotor magnets that can be turned off at will. Condition monitoring and fault detection and diagnosis of the PMSM have been receiving a growing amount of attention among scientists and engineers in the past few years. The aim of this study is to propose a new detection technique of stator winding faults in a three-phase PMSM. This technique is based on the image analysis and recognition of the stator current Concordia patterns, and will allow the identification of turn faults in the stator winding as well as its correspondent fault index severity. A test bench of a vector controlled PMSM motor behaviors under short circuited turn in two phases stator windings has been built. Some experimental results of the phase to phase short circuits have been performed for diagnosis purpose.

• Journal of the Korean Society for Nondestructive Testing
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• v.37 no.2
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• pp.75-83
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• 2017

In this paper, we investigate the capacity of the lock-in infrared thermography technique for the evaluation of non-uniform top layers of a silicon carbide coating with a nickel based superalloy sample. The method utilized a multilayer heat transfer model to analyze the surface temperature response. The modelling of the sample was done in ANSYS. The sample consists of three layers, namely, the metal substrate, bond coat and top coat. A sinusoidal heating at different excitation frequencies was imposed upon the top layer of the sample according to the experimental procedures. The thermal response of the excited surface was recorded, and the phase angle image was computed by Fourier transform using the image processing software, MATLAB and Thermofit Pro. The correlation between the coating thickness and phase angle was established for each excitation frequency. The most appropriate excitation frequency was found to be 0.05 Hz. The method demonstrated potential in the evaluation of coating thickness and it was successfully applied to measure the non-uniform top layers ranging from 0.05 mm to 1 mm with an accuracy of 0.000002 mm to 0.045 mm.

• Current Optics and Photonics
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• v.6 no.6
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• pp.598-607
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• 2022

In this paper, a simple nondestructive technology is used to investigate unstained biological blood cells in three dimensions (3D). The technology employs a reflective phase-only spatial light modulator (SLM) for displaying the phase hologram of the object being tested, and a Fourier lens for its reconstruction. The phase hologram is generated via superposing a digital random phase on the 2D image of the object. The phase hologram is then displayed by the SLM with 256 grayscale levels, and reconstructed by a Fourier lens to present the object in 3D. Since noise is the main problem in this method, the windowed Fourier filtering (WFF) method is applied to suppress the noise of the reconstructed object. The quality of the reconstructed object is refined and the noise level suppressed by approximately 40%. The technique is applied to objects: the National Institute of Standards (NIS) logo, and a film of unstained peripheral blood. Experimental results show that the proposed technique can be used for rapid investigation of unstained biological blood cells in 3D for disease diagnosis. Moreover, it can be used for viewing unstained white blood cells, which is still challenging with an optical microscope, even at large magnification.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.86-91
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• 2010

Among various fuel cells, solid oxide fuel cells (SOFCs) offer the highest energy efficiency, when taking into account the thermal recycling of waste heat at high temperature. However, the highest efficiency and lowest pollution for a SOFC can be achieved through the sophisticated control of its constituent components such as electrodes, electrolytes, interconnects and sealing materials. The electrochemical conversion efficiency of a SOFC is particularly dependent upon the performance of its electrode materials. The electrode materials should meet highly stringent requirements to optimize cell performance. In particular, both mass and charge transport should easily occur simultaneously through the electrode structure. Matter transport or charge transport is critically related to the configuration and spatial disposition of the three constituent phases of a composite electrode, which are the ionic conducting phase, electronic conducting phase, and the pores. The current work places special emphasis on the quantification of this complex microstructure of composite electrodes. Digitized images are exploited in order to obtain the quantitative microstructural information, i.e., the size distributions and interconnectivities of each constituent component. This work reports regarding zirconia-based composite electrodes.