• Progress in Medical Physics
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• v.9 no.1
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• pp.1-9
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• 1998

In order to provide complementary image data, CT(computed tomography), MR(magnetic resonance) and angiography have been used in the field of Stereotactic Radiosurgery(SRS) and neurosurgery. The aim of this work is to develop 3-D stereotactic localization system in order to determine the precise shape, size and location of the lesion in the brain in the field of Stereotactic Radiosurgery(SRS) and neurosurgery using multi-image modality and multi purpose QA phantom. In order to obtain accurate position of a target, Hitchcoke stereotactic frame and CT/angiography localizers were rigidly attached to the phantom with nine targets dispersed in 3-D space. The algorithms to obtain a 3-D stereotactic coordinates of the target have been developed using the images of the geometrical phantom which were taken by CT/angiography. Positions of targets computed by our algorithms were compared to the absolute position assigned in the phantom. Outlines of targets on each CT image were superimposed each other on angiography images. A spatial mean distance errors were 1.02${\pm}$0.17mm for CT with a 512${\times}$512 matrix and 2mm slice thickness, 0.41${\pm}$0.05mm for angiogra- phy localization. The resulting accuracy in the target localization suggests that the developed system has enough Qualification for Stereotactic Radiosurgery (SRS).

• Progress in Medical Physics
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• v.20 no.1
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• pp.7-13
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• 2009

This work is for the preliminary study for the calibration of an $^{192}Ir$ brachytherapy source based on an absorbed dose to water standards. In order to calibrate brachytherapy sources based on absorbed dose to water standards using a clyndirical ionization chamber, the beam quality correction factor $k_{Q,Q_0}$ is needed. In this study $k_{Q,Q_0}s$ were determined by both Monte carlo simulation and semiexperimental methods because of the realistic difficulties to use primary standards to measure an absolute dose at a specified distance. The 5 different serial numbers of the PTW30013 chamber type were selected for this study. While chamber to chamber variations ran up to maximum 4.0% with the generic $k^{gen}_{Q,Q_0}$, the chamber to chamber variations were within a maximum deviation of 0.5% with the individual $k^{ind}_{Q,Q_0}$. The results show why and how important ionization chambers must be calibrated individually for the calibration of $^{192}Ir$ brachytherapy sources based on absorbed dose to water standards. We hope that in the near future users will be able to calibrate the brachytherapy sources in terms of an absorbed dose to water, the quantity of interest in the treatment, instead of an air kerma strength just as the calibration in the high energy photon and electron beam.

• Tuberculosis and Respiratory Diseases
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• v.70 no.6
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• pp.498-503
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• 2011

Background: The causes of exertional desaturation in patients with COPD can be multifactorial. We aimed to investigate factors predict exertional desaturation in patients with moderate to severe COPD. Methods: We tested 51 consecutive patients with stable COPD (FEV1/FVC, $40{\pm}13%$ predicted). Patients performed a six minute walk test (6MWT). Pulse oxymetric saturation (SpO2) and pulse rate were recorded. Results: Oxygen desaturation was found in 15 subjects after 6MWT, while 36 subjects were not desaturated. Lung diffusing capacity was significantly lower in desaturation (DS) group ($62{\pm}18%$ predicted) compared with not desaturated (ND) group ($84{\pm}20$, p<0.01). However there was no statistical difference of FEV1/FVC ratio or residual volume between two groups. The pulse rate change was significantly higher in the desaturated compared with the not desaturated group. Six minute walking distance, subjective dyspnea scale, airflow obstruction, and residual volume did not predict exertional oxygen desaturation. Independent factors assessed by multiple logistic regression revealed that a pulse rate increment (odd ratio [OR], 1.19; 95% confidence interval [CI], 1.01~1.40; p=0.02), a decrease in baseline PaO2 (OR, 1.105; 95% CI, 1.003~1.218; p=0.04) and a decrease in lung diffusing capacity (OR, 1.10; 95% CI, 1.01~1.19; p=0.01) were significantly associated with oxygen desaturation. Receiver operator characteristic (ROC) analysis showed that an absolute increment in pulse rate of 16/min gave optimal discrimination between desaturated and not desaturated patients after 6MWT. Conclusion: Pulse rate increment and diffusion capacity can predict exertional oxygen desaturation in stable COPD patients with moderate to severe airflow obstruction.

• Journal of the Korean Home Economics Association
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• v.11 no.1
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• pp.107-121
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• 1973

As Korean society of today is rapidly changing, the value system which has been traditionally accepted in the family ought to undergo inevitable changes. This paper aims at investigating and analyzing the prevalent value system of the family and the degree to which it is changing in the middle-class families in Seoul. Particular attention has been paid in this paper to the relationship between a married women and her mother-in-law. The conclusion at which this paper has arrived are as follows : (1) more than the half of both married women and their mothers-in-law of the middle class in Seoul feel satisfaction for the family life ; yet the rest who have responded in terms of "average" seem in fact to feel unsatisfactory in their marriage, even though they do not specifically regard themselves "unhappy" ; (2) generally, married women, including their mothers-in-law, prefer the independent, autonomous household management ; (3) both married women and their mothers-in-law wish to live independently but the former prefer the living-together with their mothers-in-law ; (4) married women plan to support economically the parents-in-law more than the latter want to be supported ; (5) the relationship between the parents-in-law and the married women is regarded as "good" by 62% of the former while the latter in 41% only see it in "good" terms, which indicates actually their unhappy psychological state ; (6) married women in general dislike their husband's sisters in comparison with their mothers-in-law, which seems to betray the commonly accepted view that married women go worst off with their mothers-in-law ; (7) the absolute majority of women, whether a parent and her son's wife, believe that the maintenance of a good relationship between families is essential to the happiness of marriage ; (8) surprisingly, a great majority of married women whichever their side may be think that no interference with their children's home is better ; (9) more than a half of mothers-in-law expect their son's wife to live distance from her own parents ; (10) married women believe that the good cause for a better marriage lies in mutual understanding and help exchangeable between them and their mothers-in-law. This investigation has shown, to be sure, some of the salient problems in family relations which will certainly encourage further attempts to study.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.1 s.307
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• pp.45-52
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• 2006

In this paper, a real-time stereoscopic image conversion method using a single frame from a 2-D image is proposed. The Stereoscopic image is generated by creating depth map using vortical position information and parallax processing. For a real-time processing of stereoscopic conversion and reduction of hardware complexity, it uses image sampling, object segmentation by standardizing luminance and depth map generation by boundary scan. The proposed method offers realistic 3-D effect regardless of the direction, velocity and scene conversion of the 2-D image. It offers effective stereoscopic conversion using images suitable conditions assumed in this paper such as recorded image at long distance, landscape and panorama photo because it creates different depth sense using vertical position information from a single frame. The proposed method can be applied to still image because it uses a single frame from a 2-D image. The proposed method has been evaluated using visual test and APD for comparing the stereoscopic image of the proposed method with that of MTD. It is confirmed that stereoscopic images conversed by the proposed method offers 3-D effect regardless of the direction and velocity of the 2-D image.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.5
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• pp.458-463
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• 2010

Since the acoustic nonlinearity is sensitive to the minute variation of material properties, the nonlinear ultrasonic technique(NUT) has been considered as a promising method to evaluate the material degradation or fatigue. However, there are certain limitations to apply the conventional NUT using the bulk wave to thin plates. In case of plates, the use of Lamb wave can be considered, however, the propagation characteristics of Lamb wave are completely different with the bulk wave, and thus the separate study for the nonlinearity of Lamb wave is required. For this work, this paper analyzed first the conditions of mode pair suitable for the practical application as well as for the cumulative propagation of quadratic harmonic frequency and summarized the result in for conditions; (1) phase matching, (2) non-zero power flux, (3) group velocity matching, and (4) non-zero out-of-plane displacement. Experimental results in aluminum plates showed that the amplitude of the secondary Lamb wave and nonlinear parameter growed up with increasing propagation distance at the mode pair satisfying the above all conditions and that the ration of nonlinear parameters measured in Al6061-T6 and Al1100-H15 was closed to the ratio of the absolute nonlinear parameters.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.137-145
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• 2012

According to the National Police Agency, the total number of traffic accidents which occurred in 2010 was 226,878. Intersection accidents accounts for 44.8%, the largest portion of the entire traffic accidents. An research on the signalized intersection is constantly made, while an research on the unsignalized intersection is yet insufficient. This study selected traffic volume, road width, and sight distance as the input variables which affect unsignalized intersection accidents, and number of accidents as the output variable to build a model using ANFIS(Adaptive Neuro-Fuzzy Inference System). The forecast performance of this model is evaluated by comparing the actual measurement value with the forecasted value. The compatibility is evaluated by R2, the coefficient of determination, along with Mean Absolute Error (MAE) and Mean Square Error (MSE), the indicators which represent the degree of error and distribution. The result shows that the $R^2$ is 0.9817, while MAE and MSE are 0.4773 and 0.3037 respectively, which means that the explanatory power of the model is quite decent. This study is expected to provide the basic data for establishment of safety measure for unsignalized intersection and the improvement of traffic accidents.

• Journal of Korea Water Resources Association
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• v.46 no.11
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• pp.1079-1088
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• 2013

Groundwater pumping from a well has different impacts on streamflow depletion because hydraulic properties of the aquifer and the stream bed differ depending on its location. Therefore, quantitative assessment of streamflow depletion due to each groundwater pumping with different well locations is needed for the effective groundwater development and streamflow management. In this study, a watershed-based surface water and groundwater integrated model, SWAT-MODFLOW was used to assess the streamflow depletion near stream reach due to groundwater pumping from a well located within the Sinduncheon watershed. The arbitrary 50 wells among the currently used groundwater pumping wells were selected within the study area and the streamflow responses to each groundwater pumping were simulated at nearby and downstream reaches. In particular, the applicability of the Stream Depletion Factor (SDF) and Stream Bed Factor (SBF), which are widely used for evaluating the degree of streamflow depletion due to groundwater pumping, was evaluated. The simulated results demonstrated that the streamflow depletion rate divided by the pumping rate significantly differ depending on well locations and distance between well and stream, showing a wide range of values from below 20% to above 90%. From the simulated results, it was found out that the SDF or the SBF can be a partial referred value but not an absolute criterion in determining whether a pumping well has a great impact on streamflow depletion or not.

• Convergence Security Journal
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• v.17 no.5
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• pp.41-47
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• 2017

The Marine Environment Observation Information System supplies oceanographic information elements such as water temperature, chlorophyll, float, etc. based on satellite images to consumers. The data produced by the Korean marine environmental observatories are located in the coastal areas of Korea. But if the range is too far from a particular area of interest, due to distance or spatial constraints, the accuracy and up-to-dateness of the data can not be relied upon. Therefore, it is necessary to perform fusion and complex operation to solve the difference between the field observation and the marine satellite image. In this study, we develop a system that can process marine environmental information in the user's area of interest in the form of layered character (numeric) information considering the readability and light weight rather than the satellite image. In order to intuitively understand satellite image information, we characterize (quantify) the marine environmental information of the area of interest and we process the satellite image band values into layered characters to minimize the absolute amount of transmitted / received data. Also we study modular location-based interest information service method to be able to flexibly extend and connect interested items that diversify various observation fields as well as application technology to serve this.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.653-662
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• 2021

This is a thesis about the whole process of cooperative study for the project, 'Jeju Tamranun idea' which produced by Capstone Design Class in communication design Dept, Hongik University. The purpose of this thesis is to know the primary educational goal and essence of capstone design class and to find the enhancement plan for the local design industry. The exhibitional project, 'Jeju Tamranun idea' was operated three times by hongik university with the company based on Jeju from 2017 to 2019. After the research, There are three positive effects of this project which are the new social function of the discarded assignments, the improvement of educational standard through the autonomous competition, and the growth of students' social consciousness in the process of considering local industries. And there are several points to be reviewed for a better capstone design class with local design industries. It is necessary to utilize the untact system for solving distance issues. And also, absolute evaluations, giving equal reward, and copyright protection are needed. Lastly, the continuous development of the curriculum to improve local design industries is needed.