• Journal of the Korean Magnetics Society
• /
• v.21 no.1
• /
• pp.23-31
• /
• 2011

From among the NDT (nondestructive testing) methods, the MFL (magnetic flux leakage) method is specially suitable for testing pipelines because pipeline has high magnetic permeability. The system applied to MFL method is called the MFL PIG. The previous MFL PIG showed high performance in detecting the metal loss and corrosions. However, MFL PIG is highly unlikely to detect the cracks which occur by exterior-interior pressure difference in pipelines and the shape of crack is long and very narrow. In MFL PIG, the magnetic field is performed axially and there is no changes of cross-sectional area at cracks that the magnetic field passes through. Cracks occur frequently in the pipelines and the risk of the accident from the cracks is higher than that from the metal loss and corrosions. Therefore, the new PIG is needed to be researched and developed for detecting the cracks. The circumferential MFL (CMFL) PIG performs magnetic fields circumferentially and can maximize the magnetic flux leakage at the cracks. In this paper, CMFL PIG is designed and the distribution of the magnetic fields is analyzed by using 3 dimensional nonlinear finite element method (FEM). In CMFL PIG, cracks, standards of NACE, are detectable. To estimate the shape of crack, the leakage of magnetic fields for many kinds of cracks is analyzed and the method is developed by signal processing.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.6
• /
• pp.132-142
• /
• 2014

In this paper, we propose a traffic lights detection method using visual attention and spot-lights detection. To detect traffic lights in city streets at day and night time, the proposed method is used the structural form of a traffic lights such as colors, intensity, shape, textures. In general, traffic lights are installed at a position to increase the visibility of the drivers. The proposed method detects the candidate traffic lights regions using the top-down visual saliency model and spot-lights detect models. The visual saliency and spot-lights regions are positions of its difference from the neighboring locations in multiple features and multiple scales. For detecting traffic lights, by not using a color thresholding method, the proposed method can be applied to urban environments of variety changes in illumination and night times.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.9 s.351
• /
• pp.49-59
• /
• 2006

DAS(Driver Assistance Systems) support the driver's decision making to increase safety and comfort by issuing the naming signals or even exert the active control in case of dangerous conditions. Most previous research and products intend to offer only a single warning service like the lane departure warning, collision warning, lane change assistance, etc. Although these functions elevate the driving safety and convenience to a certain degree, New type of DAS will be developed to integrate all the important functions with an efficient HMI (Human-Machine Interface) framework for various driving conditions. We propose an all-around sensing based on the integrated DAS that can also remove the blind spots using 2 cameras and 8 sonars, recognize the driving environment by lane and vehicle detection, construct a novel birds-eye HMI for easy comprehension. it can give proper warning in case of imminent danger.

• Journal of the Korean School Mathematics Society
• /
• v.14 no.4
• /
• pp.423-442
• /
• 2011

The purpose of this study was to examine the effects of tasks setting for mathematical modelling in the complex real situations. The tasks setting(MMa, MeA) in mathematical modelling was so important that we can't ignore its effects to develop meaning and integrate mathematical ideas. The experimental setting were two groups ($N_1=103$, $N_2=103$) at public high school and non-experimental setting was one group($N_3=103$). In mathematical achievement, we found meaningful improvement for MeA group on modelling tasks, but no meaningful effect on information processing tasks. The statistical method used was ACONOVA analysis. Beside their achievement, we were much concerned about their modelling approach that TSG21 had suggested in Category "Educational & cognitive Midelling". Subjects who involved in experimental works showed very interesting approach as Exploration, analysis in some situation ${\Rightarrow}$ Math. questions ${\Rightarrow}$ Setting models ${\Rightarrow}$ Problem solution ${\Rightarrow}$ Extension, generalization, but MeA group spent a lot of time on step: Exploration, analysis and MMa group on step, Setting models. Both groups integrated actively many heuristics that schoenfeld defined. Specially, Drawing and Modified Simple Strategy were the most powerful on approach step 1,2,3. It was very encouraging that those experimental setting was improved positively more than the non-experimental setting on mathematical belief and interest. In our school system, teaching math. modelling could be a answer about what kind of educational action or environment we should provide for them. That is, mathematical learning.

• Fire Science and Engineering
• /
• v.33 no.3
• /
• pp.143-153
• /
• 2019

The aim of this study was to reduce the number of negligent accidents by improving the fire safety consciousness of infant and child teachers working in a day care center. For this purpose, 242 early childhood teachers working in the national nursery school in Daejeon and Chungcheongnam-do were surveyed. For the survey, the questionnaire consisted of job satisfaction, teacher's efficacy, and fire safety consciousness. The survey data were analyzed using the SPSS 20.0 win program. The factor of job satisfaction and teacher's efficacy had a significant positive influence on the fire safety consciousness of the early childhood teachers (<.05). The teacher's efficacy was found to mediate the relationship between the job satisfaction and fire safety consciousness. In conclusion, this study suggests that teacher's fire safety consciousness is high when the teacher's job satisfaction and efficacy are high. This study is expected to contribute to basic research to increase the teachers' consciousness of fire safety.

• Spatial Information Research
• /
• v.22 no.1
• /
• pp.75-84
• /
• 2014

Power lines are one of the main obstacles causing an aircraft crash and thus their realtime detection is significantly important during flight. To avoid such flight obstacles, the use of LIDAR has been recently increasing thanks to its advantages that it is less sensitive to weather conditions and can operate in day and night. In this study, we suggest a fast method to detect power lines from LIDAR data for flight obstacle avoidance. The proposed method first extracts non-ground points by eliminating the points reflected from ground surfaces using a filtering process. Second, we calculate the eigenvalues for the covariance matrix from the coordinates of the generated non-ground points and obtain the ratio of eigenvalues. Based on the ratio of eigenvalues, we can classify the points on a linear structure. Finally, among them, we select the points forming horizontally long straight as power-line points. To verify the algorithm, we used both real and simulated data as the input data. From the experimental results, it is shown that the average detection rate and time are 80% and 0.2 second, respectively. If we would improve the method based on the experiment results from the various flight scenario, it will be effectively utilized for a flight obstacle avoidance system.

• Journal of Digital Convergence
• /
• v.15 no.8
• /
• pp.391-400
• /
• 2017

The purpose of this paper is to present the effect of image stimulation on body stability as a conceptual model and to investigate the effect of image stimulus(2D, VR) on body stability(hand stability) through experiments Recently, stereoscopic images such as virtual and augmented reality are combined with smart phones and exercise equipments, and the diffusion is becoming active. The possibility of a safety accident or human error is also increasing as it temporarily affects the balance of the body and hand stability after the image stimulus is removed. The conceptual model is presented based on the results of previous studies. Based on the experimental results, the conceptual model has been explained in combination with the human information processing process and cognitive resource models that take place in the brain. Twenty subjects were exposed to 2D and VR stimuli, and display fatigue was measured by cybersickness questionnaire and hand stability by hand steadiness tester. Experimental results show that VR images induce higher display fatigue and lower hand stability than 2D. In this study, it is meaningful that hand stability according to image type and display fatigue level which have not been tried yet is revealed through conceptual model and experiment.

• The Korean Journal of Air & Space Law and Policy
• /
• v.19 no.1
• /
• pp.183-212
• /
• 2004

Die Haftung des Luftfrachtf${\"{u}}$hrers nach dem ge${\"{a}}$nderten Luftverkehrsgesetz 2004 In dieser Arbeit handelt es sich um das ge${\"{a}}$nderte Luftverkehrsgesetz in Deutschland. Neuerdings werden die bisherige Vielzahl von v${\"{o}}$lkerrechtlichen Abkommen und Protokollen, europarechtlichen Bestimmungen und privatrechtlichen Vereinbanmgen durch das Montrealer ${\"{U}}$bereinkommen 1999 zu einem einzigen Instrument zusammengefuhrt. Am 4. 11. 2003 ist das ${\"{U}}$bereinkommen von Montreal f${\"{u}}$r die Ratifikationsstaaten in Kraft getreten. Der Anwendungsbereich des Montrealer ${\"{U}}$bereinkommen beschr${\"{a}}$nkt sich jedoch nach dessen Art. 1 auf die internationale Bef${\"{o}}$rderung. Urn bei reinen Inlandf${\"{a}}$llen einen Gleichlauf zu gew${\"{a}}$hrleisten, will der deutsche Gesetzgeber im Zuge der Ratifikation in ${\S}$ 46 LuftVG eine entsprechende nationale Haftungsbestimmung schaffen.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.482-492
• /
• 2019

This study began with the assumption that the phonetics-centered interpretation of 100 Chinese characters would enhance thinking ability and comprehension. For this purpose, two experimental groups and a comparative group were recruited from the graduate students from June 3, 2017 to February 22, 2018. The experimental group participated in the phonetics-centered Chinese character lecture for 4 hours per week for 6 weeks for a total of 24 hours. QEEG were measured before and after the phonetics-centered Chinese character lecture. A total of 18 subjects ( nine subjects in the experimental group and nine comparative subjects) were included in the study, and the difference between before and after the QEEG of the experimental and comparative groups was analyzed, respectively. The conclusions drawn from this study are as follows. First, the Chinese character lecture changed brain waves. Second, the LORETA analysis before and after the lecture in the experimental group significantly decreased the delta wave in the brain region (Broadmann 40) associated with the meaning of language and phonology. This study result is meaningful because it shows the significant changes of EEG via the lecture.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.3
• /
• pp.564-568
• /
• 2020

Problem-based learning (PBL) is applied to various subjects for the sake of learners' creative thinking, problem-solving skills, presentation skills, confidence, self-directed learning, cooperation, and for the communication skills required in a rapidly changing society. Among them, the English language-an official language-is invested in 2.3 times more than other subjects, according to the English education company Yoon's Teacher. Therefore, PBL is an important learning method. However, the reality is that teacher-centered instruction, acquiring knowledge of the best answers only, and traditional evaluations are the main subjects. In order to supplement these weak points, this study designed a learning model for English subjects based on Barrows & Myers (2002) and the analyze, design, develop, implement, and evaluate (ADDIE) model. As a result of a PBL English class based on the ADDIE model, the learners were able to improve their presentation skills by 86%, their interest in learning by 86%, their understanding of learning by 86%, and cooperation by 100%. As such, studies on designing the learning model should be carried out continuously to achieve the purpose of 21st century English education, which is to improve learners' communication skills and information processing skills.