• Electronics and Telecommunications Trends
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• v.37 no.1
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• pp.10-20
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• 2022

A drone without attaching guns or bombs can be a dangerous weapon, since its motor speed is greater than 3000 rpm, which is similar to that of a mower powered by a LiPo battery. The anti-drone system is the only means of detecting and neutralizing drone attacks. Many defense companies around the world provide solutions using various types of equipment (for example, radar, cameras, jamming guns, and net guns). ETRI has also developed a Low-Altitude Drone Detection (LADD) system consisting of Ku-band radar and an Electro-Optical/Infra-Red (EO/IR) camera. In this paper, we summarize recent technical advances in anti-drone systems around the world and introduce the features and describe the performance of the LADD system.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.497-510
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• 2019

Objectives: The aim of this study was to secure the reliability of using the CalTOX model when evaluating LADD (or ADD) and Risk (or HQ) among local residents for the emission of BTEX (Benzene, Toluene, Ethylbenzene, Xylene) and by closely examining the difference in the confidence interval of the assessment outcomes according to the difference in the probability density function of input variables. Methods: The assessment was made by dividing it according to the method ($I^{\dagger}$) of inputting the probability density function in meteorological variables of the model with log-normal distribution and the method of inputting ($II^{\ddagger}$) after grasping the optimal probability density function using @Risk. A T-test was carried out in order to analyze the difference in confidence interval of the two assessment results. Results: It was evaluated to be 1.46E-03 mg/kg-d in LADD of Benzene, 1.96E-04 mg/kg-d in ADD of Toluene, 8.15E-05 mg/kg-d in ADD of Ethylbenzene, and 2.30E-04 mg/kg-d in ADD of Xylene. As for the predicted confidence interval in LADD and ADD, there was a significant difference between the $I^{\dagger}$ and $II^{\ddagger}$ methods in $LADD_{Inhalation}$ for Benzene, and in $ADD_{Inhalation}$ and ADD for Toluene and Xylene. It appeared to be 3.58E-05 for risk in Benzene, 3.78E-03 for HQ in Toluene, 1.48E-03 for HQ in Ethylbenzene, and 3.77E-03 for HQ in Xylene. As a result of the HQ in Toluene and Xylene, the difference in confidence interval between the $I^{\dagger}$ and $II^{\ddagger}$ methods was shown to be significant. Conclusions: The human risk assessment for BTEX was made by dividing it into the method ($I^{\dagger}$) of inputting the probability density function of meteorological variables for the CalTOX model with log-normal distribution, and the method of inputting ($II^{\ddagger}$) after grasping the optimal probability density function using @Risk. As a result, it was identified that Risk (or HQ) is the same, but that there is a significant difference in the confidence interval of Risk (or HQ) between the $I^{\dagger}$ and $II^{\ddagger}$ methods.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.11a
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• pp.17-27
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• 2001

• Medical Lasers
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• v.10 no.3
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• pp.181-184
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• 2021

Scars can cause great psychological stress among patients. Currently, there are numerous topical agents, laser and surgical treatments available for skin rejuvenation and scar minimization. Laser-assisted drug delivery (LADD) is a treatment method that increases drug delivery by stimulating the skin physically and chemically to enhance the penetration of topical agents. This is one of the areas of great interest in the treatment of various skin diseases in addition to its use for cosmetic purposes. In particular, LADD is relatively non-invasive and has advantages in terms of accessibility and stability. Poly-L-lactic acid (PLLA) is a collagen stimulator known to gradually restore skin volume by inducing inflammation and fibroplasia. Herein, we report a case of treatment of an atrophic scar with fractional carbon dioxide laser-assisted PLLA delivery.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.5
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• pp.447-452
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• 2019

Purpose: Few studies have reported non-acute long-term morbidity rates in children with intestinal malrotation. The aim of this study was to investigate the rate of constipation in children undergoing Ladd's procedure for isolated intestinal malrotation. Methods: This retrospective study included children aged <15 years who underwent Ladd's procedure for intestinal malrotation between 2001 and 2016. Demographics, presence of volvulus perioperatively, need for bowel resection, short term (<30 days) and long-term complications, including mortality were recorded. Constipation was defined as treatment with laxatives at 1-year follow-up. Results: Of the 43 children included in the study, 49% were boys. The median age at surgery was 28 days (0-5, 293 days). Volvulus occurred in 26 children (60.5%), and bowel resection was required in 4 children (9.3%). Short-term complications categorized as grades II-V according to the Clavien-Dindo classification occurred in 13 children (30.2%). Of these, 5 children (11.6%) required re-operation. Constipation was observed in 9 children (23.7%) at the 1-year follow-up. No difference was observed in the rate of perioperative volvulus between children with and without constipation (44% vs. 65%, p=0.45). Excluding re-operations performed within 30 days after surgery, 3 children (6%) underwent surgery for intestinal obstruction during the study period. Conclusion: Many children undergoing Ladd's procedure require bowel management even at long-term follow-up, probably secondary to constipation. It is important to thoroughly evaluate bowel function at the time of follow-up to verify or exclude constipation, and if treatment of constipation is unsuccessful, these children require evaluation for dysmotility disorders and/or intestinal neuronal dysplasia.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.255-269
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• 2003

The objective of this study was to estimate human exposure to benzo (a)pyrene through multimedia/multi-pathway exposure scenario. The human exposure scenario for benzo(a)pyrene was consisted of 12 multiple exposure pathways, and the multipathway human exposure model based on this scenario constituted. In this study, the multipathway human exposure model was used to estimate the concentrations in the exposure contact media, human intake factors and lifetime average daily dose (LAD $D_{model}$) of benzo(a)pyrene in the environment. Sensitivity analysis was performed to identify the important parameters and Monte-Carlo simulation was undertaken to examine the uncertainty of the model. The total LAD $D_{model}$ was estimated to be 5.52${\times}$10$^{-7}$ mg/kg-day (2.06${\times}$10$^{-7}$ -8.65${\times}$10$^{-7}$ mg/kg-day) using the multipathway human exposure model. The inhalation dose accounted for 78% of the total LADD, whereas ingestion and dermal contact intake accounted for 20.2% and 1.8% of the total exposure, respectively. Based on the sensitivity analysis, the most significant contributing input parameter was benzo (a)pyrene concentration of ambient air. Consequently, exposure via inhalation in outdoor/indoor air was the highest compared with the exposure via other medium/pathways.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2191-2192
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• 2009

• Journal of Environmental Health Sciences
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• v.48 no.3
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• pp.151-158
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• 2022

Background: Chemical emissions in the environment have rapidly increased with the accelerated industrialization taking place in recent decades. Residents of industrial complexes are concerned about the health risks posed by chemical exposure. Objectives: This study was performed to suggest modeling methods that take into account multimedia and multi-pathways in human exposure and risk assessment. Methods: The concentration of benzene emitted at industrial complexes in Daesan, South Korea and the exposure of local residents was estimated using the Caltox model. The amount of human exposure based on inhalation rate was stochastically predicted for various activity stages such as resting, normal walking, and fast walking. Results: The coefficient of determination (R²) for the CalTOX model efficiency was 0.9676 and the root-mean-square error (RMSE) was 0.0035, indicating good agreement between predictions and measurements. However, the efficiency index (EI) appeared to be a negative value at -1094.4997. This can be explained as the atmospheric concentration being calculated only from the emissions from industrial facilities in the study area. In the human exposure assessment, the higher the inhalation rate percentile value, the higher the inhalation rate and lifetime average daily dose (LADD) at each activity step. Conclusions: Prediction using the Caltox model might be appropriate for comparing with actual measurements. The LADD of females was higher ratio with an increase in inhalation rate than those of males. This finding would imply that females may be more susceptible to benzene as their inhalation rate increases.

• International Journal of Knowledge Content Development & Technology
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• v.2 no.2
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• pp.47-56
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• 2012

This study analyzes gender bias in children's informational books about science and science careers to determine how these early resources are affecting the disparity between males and females in science and engineering fields. The study focused on the number of male and female scientists both in pictures and text, and how much space was devoted to discussion of scientists of each gender. Overall, the findings of the study show that only 18% of the pictured scientists were female as well as only 16% of the scientists discussed in the text. These numbers are below current industry data that puts the number of females working in science and engineering fields at 26%.

• International Journal of Knowledge Content Development & Technology
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• v.1 no.2
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• pp.5-14
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• 2011

This study analyzes sexism in children's picture books that incorporate mathematical problems and problem-solving into the plot to determine if children's earliest reading material is affecting the achievement gap between males and females in this subject area. The study focused not just on overall totals of male and female characters, but also analyzed which genders most often portrayed gender stereotyped behaviors and personality traits and which characters were most often shown with mathematical skills. The findings of the study show that there were twice as many male as female characters, and the math problem-solving was generally done by males in the majority of titles.