• Particle and aerosol research
• /
• v.7 no.2
• /
• pp.59-68
• /
• 2011

The objective of the study was to investigate the main factors that contribute the variation of $PM_{10}$ concentration of Seoul and to quantify their effects using generalized additive model (GAM). The analysis was performed with 3 year air pollution data (2004~2006) measured at 27 urban sites and 7 roadside sites in Seoul, a background site in Gangwha and a rural site in Pocheon. The diurnal variation of urban $PM_{10}$ concentrations of Seoul showed a typical bimodal pattern with the same peak times as that of roadside, and the maximum difference of $PM_{10}$ level between urban and roadside was about $14{\mu}g/m^{3}$ at 10 in the morning. The wind direction was found to be a major factor that affects $PM_{10}$ level in all investigated areas. The overall $PM_{10}$ level was reduced when air came from east, but background $PM_{10}$ level in Gangwha was rather higher than the urban $PM_{10}$ level in Seoul, indicating that the $PM_{10}$ level in Gangwha is considerably influenced by that in Seoul metropolitan area. When hourly variations of $PM_{10}$ were analyzed using GAM, wind direction and speed explained about 34% of the variance in the model where the variables were added as a 2-dimensional smoothing function. In addition, other variables, such as diurnal variation, difference of concentrations between roadside and urban area, precipitation, month, and the regression slope of a plot of carbon monooxide versus $PM_{10}$, were found to be major explanatory variables, explaining about 64% of total variance of hourly variations of $PM_{10}$ in Seoul.

• Korean Journal of Childcare and Education
• /
• v.9 no.3
• /
• pp.253-272
• /
• 2013

The purpose of this study was to supplement the NURI Curriculum by investigating the practicing level of the NURI Curriculum for 5-year olds according to the demographic backgrounds of early childhood teachers. The subjects of this study were 201 early childhood teachers who work at kindergartens and child care centers located in Gyeonggi Province and were in charge of 5-year olds. The instrument used was a questionnaire measuring the practicing level of the NURI Curriculum. The results of this study were as follows. First, the practicing level of the NURI Curriculum for 5-year olds generally showed high scores. A total average of 3.24 on a 4 scale was found. In each case, educational contents have the highest score, 3.40, and educational evaluation has the lowest score, 3.03. Secondly, teachers' age, teaching career and educational background had an affect on the practicing level of the NURI Curriculum for 5-year olds, but their certificate and institution type did not. That is, the higher the teachers' age, teaching career and educational background, the higher the practicing level of the NURI Curriculum for 5-year olds.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.6
• /
• pp.1839-1845
• /
• 2016

Detecting remote targets is important to active protection system (APS) or infrared search and track (IRST) applications. In normal situation, the well-known constant false alarm rate (CFAR) detector works properly. However, decoys in APS or closely spaced targets in IRST degrade the detection capability by increasing background noise level in the CFAR detector. This paper presents a context aware CFAR detector by the intensity sorting and selection of background region to reduce the effect of neighboring targets that lead to incorrect estimation of background statistics. The existence of neighboring targets can be recognized by intensity sorting where neighboring targets usually show highest ranks. The proposed background statistics (mean, standard deviation) estimation method from median local pixels can be aware of the background context and reduce the effects of the neighboring targets, which increase the signal-to-clutter ratio. The experimental results on the synthetic APS sequence, real adjacent target sequence, and remote pedestrian sequence validated that the proposed method produced an enhanced detection rate with the same false alarm rate compared with the hysteresis-CFAR (H-CFAR) detection.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.10
• /
• pp.4976-4994
• /
• 2018

The diffusion-based salient object detection methods have shown excellent detection results and more efficient computation in recent years. However, the current diffusion-based salient object detection methods still have disadvantage of detecting the object appearing at the image boundaries and different scales. To address the above mentioned issues, this paper proposes a multi-scale diffusion-based salient object detection algorithm with background and objectness seeds. In specific, the image is firstly over-segmented at several scales. Secondly, the background and objectness saliency of each superpixel is then calculated and fused in each scale. Thirdly, manifold ranking method is chosen to propagate the Bayessian fusion of background and objectness saliency to the whole image. Finally, the pixel-level saliency map is constructed by weighted summation of saliency values under different scales. We evaluate our salient object detection algorithm with other 24 state-of-the-art methods on four public benchmark datasets, i.e., ASD, SED1, SED2 and SOD. The results show that the proposed method performs favorably against 24 state-of-the-art salient object detection approaches in term of popular measures of PR curve and F-measure. And the visual comparison results also show that our method highlights the salient objects more effectively.

• Journal of the Optical Society of Korea
• /
• v.20 no.6
• /
• pp.745-751
• /
• 2016

A detection algorithm, based on the combined local-global (CLG) optical-flow model and Gaussian pyramid for a moving target appearing against a dynamic background, can compensate for the inadaptability of the classic Horn-Schunck algorithm to illumination changes and reduce the number of needed calculations. Incorporating the hypothesis of gradient conservation into the traditional CLG optical-flow model and combining structure and texture decomposition enable this algorithm to minimize the impact of illumination changes on optical-flow estimates. Further, calculating optical-flow with the Gaussian pyramid by layers and computing optical-flow at other points using an optical-flow iterative with higher gray-level points together reduce the number of calculations required to improve detection efficiency. Finally, this proposed method achieves the detection of a moving target against a dynamic background, according to the background motion vector determined by the displacement and magnitude of the optical-flow. Simulation results indicate that this algorithm, in comparison to the traditional Horn-Schunck optical-flow algorithm, accurately detects a moving target undergoing illumination changes against a dynamic background and simultaneously demonstrates a significant reduction in the number of computations needed to improve detection efficiency.

• Nuclear Engineering and Technology
• /
• v.50 no.3
• /
• pp.462-469
• /
• 2018

The background spectrum of a $3^{{\prime}{\prime}}{\times}3^{{\prime}{\prime}}$ NaI(Tl) well-type scintillation SILENA detector was measured without shielding, in 6 cm thick lead shielding, and with 2 mm thick electrolytic copper covering the detector inside the lead shielding. The relative remaining background of the lead shield lined with copper was found to be ideal for low-level environmental radioactive spectroscopy. The background total count rate in the (20-2160 KeV) was reduced 28.7 times by the lead and 29 times by the Cu + Pb shielding. The effective reduction of background (1.04) by the copper mainly appeared in the energy range from X-ray up to 500 KeV, while for the total energy range the ratio is 1.01 relative to the lead only. In addition, a strong relation between the full-energy peak absolute efficiency and the detector well height was found using gamma-ray isotropic radiation point sources placed inside the detector well. The full-energy peak efficiency at a midpoint of the well (at 2.5 cm) is three times greater than that on the detector surface. The energy calibrations and the resolution of any single energy line are independent of the locations of the gamma source inside or outside of the well.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.9
• /
• pp.1673-1678
• /
• 2016

In the area of the speech recognition processing, background noises are caused the incorrect response to the speech input, therefore the speech recognition rates are decreased by the background noises. Accordingly, a more high level noise processing techniques are required since these kinds of noise countermeasures are not simple. Therefore, this paper proposes an algorithm to distinguish between the stationary background noises or non-stationary background noises and the speech signal having short time duration in the noisy environments. The proposed algorithm uses the characteristic parameter of the improved speech signal as an important measure in order to distinguish different types of the background noises and the speech signals. Next, this algorithm estimates various kinds of the background noises using a multi-layer perceptron neural network. In this experiment, it was experimentally clear the estimation of the background noises and the speech signals.

• Journal of Engineering Education Research
• /
• v.19 no.6
• /
• pp.32-37
• /
• 2016

The purpose of this study is to extract a skill level of human resource in the field of science and technology. To accomplish the goal of this study, precedent research was conducted and then, the draft of skill level for Human Resource in the field of Science and Technology (HRST) was created by wrap-up meeting. The skill level of the HRST was finalized after confirming verification of 20 SMEs (Subject Matter Experts) from January to February 2016 by two times. The conclusions are as follows; First, the skill level of the HRST consists five categories. Each of the level has educational background, work experience, certification, duty, major and so on. Second, the contents of the skill level were found to be mostly valid.

• The Journal of Korean Society for School & Community Health Education
• /
• v.11 no.1
• /
• pp.41-55
• /
• 2010

Objectives: This study was conducted to identify the characteristics of health behavior and self-esteem and the relationship between the two factors among elementary school students with multi-cultural family background. Participants: Survey participants were 87 multi-cultural family children who lived in Seoul and Kyoungi areas and were registered in the local elementary schools. Methods: Data collection was conducted by face-to-face interview survey. Elementary education majored undergraduate students who participated in the education support program for multi-cultural family children in the Ministry of Education and Science and primary researcher of this study interviewed the target students and finished the survey questionnaire based on the students' responses. Survey included general characteristics, multi-cultural family characteristics, self-esteem, and (physical, mental, and social) health behavior. Results: 1. The self-esteem scores of the multi-cultural families children were greater in girl than boys among the children whose parents were graduated from college or more, and whose father had his job. The participants' health behavior scores were different by mothers' educational level. 2. The better they speak in English the greater the self-esteem scores. There was no statistical difference in health behavior scores by the participants' multi-cultural family background. 3. Self-esteem had moderate level correlation with health behavior (r= .56, p= .00) including all sub-categories of physical, mental, and social health. Conclusions: Positive self-esteem level is more sensitive to explain multi-cultural family children's health behaviors, which means that self-esteem is an important factor determining multi-cultural children's health behaviors and their health status in future. Therefore, more research to identify the factors related to health behaviors should be supported and the health promotion programs utilizing self-esteem should be developed for the child and youth with multi-cultural family backgrounds.

• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.2
• /
• pp.174-183
• /
• 2017

The background level and timely variation characteristics of atmospheric $^{222}Rn$ concentrations have been evaluated by the real time monitoring at Gosan site of Jeju Island, Korea, during 2008~2015. The average concentration of atmospheric radon was $2,480mBq\;m^{-3}$ for the study period. The cyclic seasonality of radon was characterized such as winter maximum and summer minimum, consistent with the reduction in terrestrial fetch going to summer. On monthly variations of radon, the mean concentration in October was the highest as $3,041mBq\;m^{-3}$, almost twice as that in July ($1,481mBq\;m^{-3}$). The diurnal radon concentrations increased throughout the nighttime approaching to the maximum ($2,819mBq\;m^{-3}$) at around 7 a.m., and then gradually decreased throughout the daytime by the minimum ($2,069mBq\;m^{-3}$) at around 3 p.m. The diurnal radon cycle in winter showed comparatively small amplitude due to little variability in atmospheric mixing depth, conversely, large amplitude was observed in summer due to relatively a big change in atmospheric mixing depth. The cluster back-trajectories of air masses showed that the high radon events occurred by the predominant continental fetch over through Asia continent, and the radon concentrations from China continent were about 1.9 times higher on the whole than those from the North Pacific Ocean. The concentrations of $PM_{10}$ also increased in proportion to the high radon concentrations, showing a good linear correlation between $PM_{10}$ and radon concentrations.