• ETRI Journal
• /
• v.38 no.5
• /
• pp.799-806
• /
• 2016

In this paper, we propose an emergency wake-up alert system (EWAS) for providing accurate and rapid emergency information. The proposed system can provide an emergency wake-up alert service without an additional frequency allotment by utilizing the guard band of the Advanced Television Systems Committee (ATSC) Terrestrial Digital Television (DTV) system. The design target of the proposed system is to match the indoor reception coverage of EWAS with the outdoor reception coverage of the ATSC DTV system. To achieve this, the proposed system should be about 35.65 dB more robust than the ATSC DTV system. The simulation results show that the proposed system offers an emergency wake-up alert service supporting a data rate of up to 23 bps.

• Annals of Occupational and Environmental Medicine
• /
• v.35
• /
• pp.27.1-27.12
• /
• 2023

Background: Environmental exposure is characterized by low concentration, chronic, and complex exposure. Traditional epidemiological studies show limitations in reflecting these characteristics since they usually focus on a single or very limited number of exposure factors at a time. In this study, we adopted the methodology of environment-wide association study (EWAS) to figure out the association of human liver function with various environmentally hazardous substances. Methods: We analyzed 2,961 participants from the Korean National Environmental Health Survey Cycle 4 (2018-2020). Using generalized linear model (GLM) analysis, we analyzed the association of 72 variables with 3 liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma glutamyl transferase [GGT]). Finally, we visualized our results with Manhattan plot. Results: In GLM analysis, perfluorooctanesulfonate were positively associated with ALT (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.39-3.46; p_adjusted = 0.0147) and perfluorodecanoic acid showed positive association with GGT (OR: 2.73; 95% CI: 1.36-5.5; p_adjusted = 0.0256). Plasma mercury showed positive association with GGT (OR: 1.45; 95% CI: 1.14-1.84; p_adjusted = 0.0315). Using a plastic container while keeping food in the refrigerator was associated with elevated GGT compared to using a glass container (OR: 1.51; 95% CI: 1.16-1.95; p_adjusted = 0.0153). 2-ethyl-5-oxohexyl phthalate, showed a negative trend with all 3 indices, with AST (OR: 0.54; 95% CI: 0.39-0.73; p_adjusted = 0.00357), ALT (OR: 0.5; 95% CI: 0.34-0.75; p_adjusted = 0.036), GGT (OR: 0.55; 95% CI: 0.4-0.76; p_adjusted = 0.00697). Bisphenol S and frequent use of sunblock cream showed negative association with ALT (OR: 0.77; 95% CI: 0.66-0.89), and GGT (OR: 0.25; 95% CI: 0.11-0.55), respectively. Conclusions: We conducted an exploratory study on environmental exposure and human liver function. By using EWAS methodology, we identified 7 factors that could have potential association with liver function.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.9
• /
• pp.63-74
• /
• 1999

When a fuel was injected with opening the intake valve of a port fuel injection engine, the spray atomization and flow characteristics in the intake port have a strong influence on the mixture formation of a combustion chamber. Thus , this study was to clarify the spray flow characteristics of the air-assist gasoline spray with fine dropkets across the suction air stream in model intake port. For the simulated opening intake valve in port, suction air stream was varied to 10m/s ∼30m/s. And fuel pressur ewas fixed to 300kPa, but air assist pressure was varied to 0∼25kPa for a vairable spray conditions. Spray flow trajectory was investigated by means of laser sheet visualization and the measurements of droplet sizes and velocities were made by PDPA system. Measured droplets within the spray flow field were subdivided into five size groups and then, the flow characteristics of droplet size groups were investigated to the spray across a suction air stream.

• Journal of Nutrition and Health
• /
• v.31 no.8
• /
• pp.1324-1377
• /
• 1998

This study was conducted for two purposes ; (1) to develop a database for zinc levels in commonly usef Korean food items ; and (2) to calculated the zinc intake fo Korean adults living in a rural area. The currently used Korean food compositinotable was supplemented in term sof zinc content using several methods ; (1) analyzing 98 Korean Food items frequently consumed by Korean adults living in rural area. ; (2) adapting values from U.S Minnesota for 71 items ; and (3) imputing values from similar food for 282 items. A new zinc nutrient databse was constructed including zinc contentrs of 1,195 food items. Zinc intake of rural Korean adults was estimated by a 240hours recall method from 2 ,037 adults over 30 over 30years of age in Yeonchon -gun , Kyunggi province of Korea. Mean daily zinc intake of all subjects was 61mg an dmean intake level of males (7.0mg/day, 46.85 of RDA) was significantly thigher than females(5.2mg/day, 43.0% of RDA). Subjects in their 40's had the highest zinc intak ewhile those over 70 years of age consumed the least amount of zinc. The food group that contributed most to the dietary ainc intake of subjects was cereals and grain products supplying 38% of total zinc intake. The next most important group for zinc intak ewas the meat, poultry , and product group supplying 26% ot total intake. This group was followed by fishes and shellfishes, legumes and their products, and vegetales . For individual food items , reicecontribued most, supplying 27% of total zinc intake follwoed by beef(10%) and prok(9%) . Altogether, plant foods supplied 68% of zinc intake suggesting that the bioabailability of dietary ainc is low. In conclusion, these results show ethat the zinc intake of rural Korean adults is low and that sources of dietary zinc are mainly plant foods, suggesting low bioavailability . Further studies are needed to determine zinc intake and status of Korean population. The zinc database developed in this study will be very valuable for such studies.