• Proceedings of the KSR Conference
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• 2011.05a
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• pp.109-116
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• 2011

In this paper, we investigate the scheme to improve the position accuracy using GNSS(Global Navigation Satellite System). Then we configure the real-time DGPS environment with use of NTRIP currently being in service on the DGNSS central office of MLTM(Ministry of Land and Transportation). And we verify the improvement of position accuracy and the continuity of GPS correction data through the DGPS test in Chungbuk line and Joongang line.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2768-2774
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• 2011

In this paper, we investigate the methods to improve the position accuracy using DGNSS(Differential Global Navigation Satellite System). Then we configure the real-time DGNSS environment with use of GPS and MSAS as SBAS(Satellite Based Augmentation System) currently being in service by Japan. And we verify the improvement of position accuracy and the continuity of GPS correction data through the realtime DGNSS test in Joongang line, Kyungbu line, Honam line.

• The Journal of the Acoustical Society of Korea
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• v.3 no.1
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• pp.25-35
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• 1984

This paper analysis the Dynamic Time Warping algorithms for time normalization of speech pattern and discusses the Dynamic Programming algorithm for spoken Korean isolated digits recognition. In the DP matching, feature vectors of the reference and test pattern are consisted of first three formant frequencies extracted by power spectrum density estimation algorithm of the ARMA model. The major differences in the various DTW algorithms include the global path constrains, the local continuity constraints on the path, and the distance weighting/normalization used to give the overall minimum distance. The performance criterias to evaluate these DP algorithms are memory requirement, speed of implementation, and recognition accuracy.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.15-25
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• 2000

The purpose of this paper is to examine the visual evaluation structure about the formal changes of streetscape by the different moving speed in two alternative control plans for the building height and the setback regulation. The virtual reality system is applied to the experimental tool. Eighty-two experimental models are made in consideration of the height and the setback of the building regulation cased by Midou-suji street in Osaka City, Japan. and ten typical models are selected by pre-experiment. Since the changes of the landscape structure consists of the height and the setback of the building, four the evaluation items are set: grade of continuity, order, openness, preference. As there are eighty-two landscape models which are too many to be applied in this experiment, ten role models are drawn out and used in this experiment. The mean difference test, discriminant analysis, and multiple linear regression methods had been used for the statistical analysis methods. The results of this study are as follows; 1) It is found out the fact of the difference evaluation structure amount experiments models. 2) From the sketch analysis and interview, it is found out difference cognition structure by the moving speed and alternatives. 3) From the discriminant and regression analysis, it is found out that the evaluation value about continuity becomes low by the moving speed change from walking speed to driving speed. We suggest that continuous experiment should be made with a variety of groups and models, and general and universal results should also be come out of the experiments above.

• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.119-128
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• 2010

The purpose of this thesis is to analyze and test hypotheses that the internet shopping customer's satisfaction would be differences between customer's lifestyle and a type of buying product characteristics. In addition, this study tested differences between lifestyle groups and product type in terms of customer's transaction continuity. In result, we find that there are significant differences of customer's satisfaction and customer's continuity in terms of the lifestyle, but not in the product types. This study provide useful informations on market segmentation strategy to the firms which had been doing on-line shopping and will help them minimize the possible risks when firms enter into internet shopping market.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.253-260
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• 1999

Main objective of this study is to examine the hysteretic behaviors and to evaluate the capacity of precast concrete (PC) large panel structures simulated from the prototype of 15-story building, Two 1/2 scaled precast concrete wall specimens and one monolithic reinforced concrete specimen were designed and tested under the cyclic loading conditions. The main parameter of test specimens in PC large panel structure is the type of details for vertical continuity of vertical steel in horizontal joint. Also the behaviors of PC large panel structures are compared with that of monolithic reinforcement concrete wall structure. From the results, the stiffness and energy dissipation ratio of the precast concrete specimens are shown little bit lower than those of monolithic reinforced concrete specimen. In the PC large panel structures, the specimen connected vertically by welding (strong connection) showed higher strength than that of the specimen connected vertically by joint box. However the failure pattern of the former showed more brittle than that of the latter due to the diagonal compressive failure of wall panels.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.235-242
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• 2021

Unmanned Aerial Vehicles (UAVs), which were used for military purposes, are gradually expanding their application fields under the influence of electrification and digitalization. Starting from the field of aerial imaging and Intelligence Surveillance and Reconnaissance (ISR) mission, nowadays the possibility of Urban Air Mobility (UAM), which transports passengers and cargo with drones, is widely under discussion. In order to occupy the rapidly growing global unmanned aerial vehicle market in advance, it is necessary to secure core technologies and develop key UAVs components based on the new technologies. In the navigation field, it is necessary to secure a precise position with guaranteed reliability and continuity, unrelated to the operating environments. The reliability and continuity should be secured in the algorithm level and in the H/W component levels also. In order to achieve this technical goal, the Ministry of Science and ICT has launched the 'Unmanned Vehicle Core Technology Research and Development Program' in 2019 to support the R&D on the unmanned vehicle technologies. In this paper, authors introduce the unmanned vehicle core technology research and development program to the related researchers. The authors summarize the backgrounds of the program and show the technological tasks and objectives on the sub-programs in the unmanned vehicle navigation program. We present the program schedules especially focused on the test and evaluation of the developed technologies and components.

• Journal of the Korean Society of School Health
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• v.4 no.2
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• pp.193-215
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• 1991

This study is aimed at providing basic information applicable to setting up the education programs and strategies to prevent smoking among high school students by analysing smoking behavior and influencing factors. The samples consisted of 814 students, 557 parents and 362 teachers selected randomly from 8 high schools, one from each school district in Seoul. Date Analyses were made through Chi-Square test, Factor Analysis, One Way ANOVA, Multiple Regression, Correlation. SPSS/$PC^+$program was utilized. Smoking behavior (continuous smoking, re-smoking, ex-smoking, never smoking, daily smoking, occasional smoking) were used as dependent variables. Influencing factors (male students, habits, attitudes and knowledge toward smoking, home life, school life, juvenile delinquency, friendship, demographic parent's and teacher's recognition toward male students smoking) were used as in dependent variables. The major findings of the study are as follows : 1. The total smoking rate occupies 41.1% whereas the continuous smoking rate stands at 19.2%, re-smoking rate 9.5%, ex-smoking rate 12.4% and never smoking rate 58.9%. 2. The total smoking rate among high school students is significantly correlated with their monthly expenditures and type of school (p<0.001). The continuous smoking rate also shows the same tendency. As the length of butt get shorter, the current smoking rate increase. The duration of smoking is in proportion to its continuity. The major motive of smoking is curiousity whereas that re-smoking is to follow friend's behavior. The study shows that peer pressure is the most powerful factor influencing smoking behavior of students. Friends and fellow students encourage to pick up smoking and resume smoking even alter one stops smoking. 3. The correlationship between favorable attitudes toward smoking and the current smoking rate and its continuity is statistically significant(p<0.05, p<0.01, p<0.001). 4. The stability and harmony of family life and the current smoking rate show negative correlationship. The daily smoking amount of father is in proportion to the continuity of students' smoking. When parents are in favor of smoking, it is more likely that the experimental smoking rate increase the smoking rate increases, and vice versa. The more acceptable attitudes toward smoking among siblings is also one of the factors to increase the smoking rate and continuity (p<0.001). The more lenient the attitudes of parents toward their children's association with smoking friends, the higher the smoking rate. When students have difficulties in adjusting to school life, it is more likely that the current smoking rate and continuity increase. 5. The continuity of smoking and friendship are significantly correlated (p<0.05, p<0.01, p<0.001). 6. The continuity of smoking and juvenile delinquency are significantly correlated (p<0.001). 7. The difference in attitudes and smoking reasons of parents and students is significantly correlated to different smoking behavior (p<0.01, p<0.001). While smoking knowledge does not significantly influence their smoking behavior, it is noted that in the case of teachers, smoking reason (p<0.05), attitudes (p<0.001) and knowledge (p<0.05) strongly influence their smoking behavior. 8. There is a significantly correlation among the smoking reasons, attitudes and knowledge between students and parents(p<0.001). As for the correlationship between regularity and smoking amount and other influencing factors, the daily smoking amount is in proportion to depth of inhalation and duration of smoking, negative attitudes of parents unstability of family, dissatisfaction of family members, juvenile delinquency, strong smoking reasons and positive attitudes towards smoking. 9. In the case of daily smokers depth of inhalation is significantly correlated to the duration of smoking, juvenile delinquency, acceptability of parents, dissatisfaction of family members and smoking reasons. The duration of smoking motives is significantly correlated to juvenile delinquency, high acceptability of parents, strong smoking motive and positive attitudes toward smoking. 10. It is noted that 40% of parents and 30% of teachers do not recognize the significant correlationship between and the relative influencing factors mentioned above.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.89-97
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• 2002

Purpose: The objective of this study is to find the differentiating characteristics of ameloblastomas and odontogenic keratocysts of the jaw by analyzing computed tomography (CT) images of the lesions, clarify radiological characteristics associated with jaw lesions, and to make a diagnsis based on these findings. Materials and Methods : Test subjects were chosen among the patients who were diagnosed as having an odontogenic keratocyst or ameloblastoma at the Yonsei University Dental Hospital from January 1996 to December 2000 and had CT scans taken preoperatively. The subject pool was comprised of 51 cases of odontogenic keratocyst and 37 cases of ameloblastoma. The following measures were used for image analysis of the lesion: the anatomic location, CT pattern, mesiodistal width, buccolingual width, the ratios between mesiodistal width and buccolingual width, height, CT number, homogeneity of radiodensity, the appearance of a sclerotic rim, continuity of adjacent cortical bone, and displacement and resorption of adjacent teeth. Results: Comparing the CT patten, mesiodistal width, buccolingual width, height, CT number, homogeneity, appearance of sclerotic rim, continuity of adjacent cortical bone, there were statistically significant differences between ameloblastoma and odontogenic keratocyst test subjects (p<0.05). Comparing the ratios between mesiodistal width and buccolingual width, displacement and resorption of adjacent teeth, there were no statistically significant differences (p>0.05). Conclusion: We compared odontogenic keratocysts and ameloblastomas in CT scans. They occurred most frequently in the posterior to the ramus of the mandible. The findings of patterns of the CT images showed that size and border of lesions were more aggressive in ameloblastomas than in odontogenic keratocysts. The internal contents represented an increased attenuation area (IAA) in odontopenic keratocyst. Odontogenic keratocysts were shown to have higher CT numbers than ameloblastomas.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.510-516
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• 2011

For using Global Navigation Satellite System(GNSS) in the civil aviation, it should satisfies the Required Navigation Performances(RNPs) which are defined by International Civil Aviation Organization(ICAO). RNP defines the required accuracy, integrity, availability, continuity of each flight procedure. In order to guarantee user's integrity, user's protection level has to be overestimated. On the other hand, for improving user's availability, user's protection level has to be estimated tightly. Therefore protection level should be estimated as tight as possible while it assuring the user's integrity. This paper describes the current integrity function of Korean WAD GNSS test bed, and predicts the availability performance of Korean WAD GNSS by simulation.