• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.92-102
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• 2020

Porous pavement (PP) has attracted attention as a new alternative measure against road traffic noise. PP refers to pavement that reduces the fines in the asphalt mixture to form voids. These voids can reduce traffic accidents and friction noise. For active application, verification of the noise reduction effect is required. In this study, the noise reduction of single-layer PP(SLPP) and double layer PP(DLPP) was analyzed. First, the Sejong section was selected, and traffic noise was measured using the SPB method on the roadside. The traffic volume, speed, and mixing ratio of large vehicles were measured. As a result, the DLPP was evaluated to be 7.95 dB(A) smaller on average and 7.57dB(A) smaller at the 95% reliability level than the SLPP. The traffic volume was more influential than the speed and the mixing rate of large vehicles. As the traffic volume increased, the noise increased, but the difference in noise between the two pavements decreased gradually. The results showed that the most effective way to reduce road traffic noise is to change the road pavement rather than reduce traffic speed, restrict traffic for heavy vehicles, or reduce traffic volume.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.493-500
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• 2012

The previous geoid model developed in early 2000s shows 14cm level of precision due to the problems on distribution, and quality of the land gravity and GPS/Leveling data. From 2007, the new land and airborne gravity data as well as GPS/Leveling data having high quality and regular distribution has been obtained. In 2011, a new gravimetric geoid model has been constructed with precision of 5.29cm which was improved about 27% comparing to the previous model. However, much more land gravity data has been collected at the control point, bench marks and triangulation points since 2010. Also, GPS/Leveling data having 10km spacing over whole country has been obtained through the project which is for the construction of new control points. In this study, new gravimetric geoid has been calculated based on the all available gravity data up to present. The geoid height shows the range from 18.05m to 32.70m over whole country and its precision is 5.76cm. The degree of fit and precision of hybrid geoid model are 3.60cm and 4.06cm, respectively. At the end, 3.35cm of the relative precision in 15km baseline has been calculated to confirm its practical usage. Especially, it has been founded that regional bias occurred at the Kangwon and coastal area due to problems on the leveling data. Also, some inland points show inconsistent large difference which needs to be verified by analyzing the unified control points results.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.29-33
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• 2007

All pixels of image sensor do not react uniformly even if the light of same radiance enters into the camera. This non-uniformity comes from the sensor pixel non-uniformity and non-uniformity induced by the changing transmission of the telescope over the field. The first contribution to the non-uniformity has high spatial frequency nature and has an influence on the result and quality of the data compression. The second source of non-uniformity has low frequency nature and has no influence of the compression result. As the contribution resulting from the sensor PRNU(Photo Response Non-Uniformity) is corrected inside the camera electronics, the effect of the remaining non-uniformity to the compression result will be negligible. The non-uniformity correction result shall have big difference according to the sensor modeling and the calculation method to get correction coefficient. Usually, the sensor can be modeled with one dimensional coefficients which are a gain and a offset for each pixel. Only two measurements are necessary theoretically to get coefficients. However, these are not the optimized value over the whole illumination level. This paper proposes the algorithm to calculate the optimized non-uniformity correction coefficients over whole illumination radiance. The proposed algorithm uses several measurements and the least square method to get the optimum coefficients. The proposed algorithm is verified using the own camera electronics including sensor, electrical test equipment and optical test equipment such as the integrating sphere.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.587-595
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• 2014

This research aimed at analyzing the influence of complex-exercise on diabetes outbreak prediction rate, body composition and vascular compliance in obese smokers and suggesting effective exercise program for obese smokers' healthy life. The research object was composed of the 20 employees, obese smokers in their age of 40s, of T company, which is the subcontractor of H company in D Metropolitan City, who learned the purpose of this research enough and wrote the consent form of voluntary participation, who have no medical history and currently no special disease, as well as no experience in regular exercise. The researcher conducted an inspection on diabetes outbreak prediction rate and body composition, vascular compliance, also, implemented descriptive statistics to calculate the average and standard deviation before the test and after implementing 12 weeks' complex-exercise program, and verification on the difference between before after the test was analyzed by using Paired t-test. With statistical significance level p<.05, the research results are as follows. after participating in 12 weeks' complex-exercise program, diabetes outbreak prediction rate, weight, body fat percentage, skeletal muscle mass, abdominal fat rate and vascular compliance showed statistically meaningful level of change in upper extremities(right hand, left hand), nether extremities(right foot, left foot) p.<05.

• Communications of Mathematical Education
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• v.26 no.1
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• pp.85-108
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• 2012

The comprehensive implication in justification activity that includes the proof in the elementary school level where the logical and formative verification is hard to come has to be instructed. Therefore, this study has set the following issues. First, what is the mathematical justification type shown in the Number and Operations, and Geometry? Second, what are the errors shown by students in the justification process? In order to solve these research issues, the test was implemented on 62 third grade elementary school students in D City and analyzed the mathematical justification type. The research result could be summarized as follows. First, in solving the justification type test for the number and operations, students evenly used the empirical justification type and the analytical justification type. Second, in the geometry, the ratio of the empirical justification was shown to be higher than the analytical justification, and it had a difference from the number and operations that evenly disclosed the ratio of the empirical justification and the analytical justification. And third, as a result of analyzing the errors of students occurring during the justification process, it was shown to show in the order of the error of omitting the problem solving process, error of concept and principle, error in understanding the questions, and technical error. Therefore, it is prudent to provide substantial justification experiences to students. And, since it is difficult to correct the erroneous concept and mistaken principle once it is accepted as familiar content that it is required to find out the principle accepted in error or mistake and re-instruct to correct it.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1711-1717
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• 2020

X-ray of up to 9MeV are used for container inspection. X-ray intensity must be maintained stably regardless of changes in time. If dose is not constant, it may affect the image quality, and as a result, may affect the inspection of abnormal cargo. Therefore, to acquire high-quality images, continuous dose monitoring is required. In this study, the ion-chamber based device was developed for monitoring the dose change in high-energy x-ray. And to estimate the performance of signal-processing device change according to the environmental change, the output changing due to the change of temperature and humidity was observed. In addition, verification of the device was performed by measuring the output change. As a result of the measurement, there was no significant difference in performance due to changes in temperature and humidity, and the change in output according to the change in exposure was linear. Therefore, it was found that the developed device is suitable for the dose monitoring of high-energy x-ray.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.1-9
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• 2024

This study proposes a multi-scale template matching technique with image pyramids (TMI) to measure structural dynamic displacement using a vision sensor under atmospheric turbulence conditions and evaluates its displacement measurement performance. To evaluate displacement measurement performance according to distance, the three-story shear structure was designed, and an FHD camera was prepared to measure structural response. The initial measurement distance was set at 10m, and increased with an increment of 10m up to 40m. The atmospheric disturbance was generated using a heating plate under indoor illuminance condition, and the image was distorted by the optical turbulence. Through preliminary experiments, the feasibility of displacement measurement of the feature point-based displacement measurement method and the proposed method during atmospheric disturbances were compared and verified, and the verification results showed a low measurement error rate of the proposed method. As a result of evaluating displacement measurement performance in an atmospheric disturbance environment, there was no significant difference in displacement measurement performance for TMI using an artificial target depending on the presence or absence of atmospheric disturbance. However, when natural targets were used, RMSE increased significantly at shooting distances of 20 m or more, showing the operating limitations of the proposed technique. This indicates that the resolution of the natural target decreases as the shooting distance increases, and image distortion due to atmospheric disturbance causes errors in template image estimation, resulting in a high displacement measurement error.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.224-232
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• 2012

This study Seoul, Kyonggi area hospital and data were collected from 211 people in radiation therapy technologist. The collected data were analyzed by using SPSS 17 version, For verification of the differences among groups, coefficient of Pearson was executed. It was composed of social demographic characteristics, Job stress and the impact the organization effectiveness and reliability analysis of factors. Organization culture and self leadership of each of the types to classify the results of conducted analysis factors are as follows: And the difference in the gender, age, and satisfaction with the Organization. Organization commitment and working in accordance with each part working experience is different. Radiation therapy duties analysis results of correlation between the uniqueness. Job satisfaction(p<0.001), organization commitment(p<0.001), stress(p<0.001), organization culture, gastric-oriented(p=0.008), organization culture and innovation-oriented(p<0.002), organization culture, relationship-oriented(p<0.001). The research shows that job satisfaction of radiation therapy technologist determined the work environment. Therefore more improvements must be made for radiation therapy technologist to be more in their job satisfaction.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.318-331
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• 2020

The purpose of this study was to find ways to effectively utilize job creation activities that can be an alternative to employment and entrepreneurship in diverse and subdivided labor markets. The effect of business capability on the job creation intention and the mediating effect of entrepreneurship were identified, and gender was used as a control variable for comparison among groups. The questionnaire was composed of 4 questions for 6 variables, and a 7-point Likert scale was used. Frequency analysis, exploratory factor analysis, reliability analysis, descriptive statistics analysis, correlation analysis, confirmatory factor analysis, structural relationship analysis, mediating effect and moderating effect were conducted on 392 people who answered the questionnaire sincerely. As a result of analysis the relationship between the job creation intention in business capability, the entrepreneur passion in business capability and the job creation intention in entrepreneur passion had a positive (+) effect. Entrepreneur passion in the verification of bootstrapping mediating effects played a mediating role in the relationship between business capability and job creation intention. It was found that there was no difference in the job creation intention according to the gender that was compared between groups. The job creation activities must overcome the negative perspectives and worries around them with the differentiation of items experience and know-how a business model that reflects recent trends and a passionate and persistent Jobcreatorship.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.57-64
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• 2020

The leading technologies of the ADAS (Advanced Driver Assist System) are ACC (Advanced Cruise Control), LKAS (Lane Keeping Assist System), and AEB (Autonomous Emergency Braking). LKAS is a system that uses cameras and infrared sensors to control steering and return to its running lane in the event of unintentional deviations. The actual test is performed for a safety evaluation and verification of the system. On the other hand, research on the system evaluation method is insufficient when an additional steering angle is applied. In this study, a model using Prescan was developed and simulated for the scenarios proposed in the preceding study. Comparative analyses of the simulation and the actual test were performed. As a result, the modeling validity was verified. A difference between the front wheels and the lane occurred due to the return velocity. The results revealed a maximum error of 0.56 m. The error occurred because the lateral velocity of the car was relatively small. On the other hand, the distance from wheels to the lanes displayed a tendency of approximately 0.5 m. This can be verified reliably.