• Journal of Advanced Technology Convergence
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• v.2 no.3
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• pp.17-24
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• 2023

I am designing a research paper with the aim of studying hybrid vehicles. Hybrid vehicles, as the next-generation automobiles, feature a combination of internal combustion engines and battery engines, resulting in a revolutionary reduction in fuel consumption and harmful gas emissions compared to conventional vehicles. The electric motor in hybrid cars derives power from a high-voltage battery installed within the vehicle, which is recharged during vehicle motion. In contrast to traditional cars, which often experience energy losses due to idling caused by traffic congestion, hybrid systems optimize efficiency by skillfully managing the interplay between the internal combustion engine and the electric motor. This approach effectively addresses the inherent drawbacks of gasoline or diesel engines.Hybrid cars offer an array of benefits, including improved fuel efficiency, environmental friendliness, cost-effectiveness, and reduced noise emission. Consequently, they are progressively becoming a favored alternative among a growing number of individuals. This research endeavor has the potential to contribute towards curbing environmental pollution and dedicating efforts to future automotive research.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.330-336
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• 2023

Rapid urbanization is rapidly progressing around the world, and urban problems such as traffic congestion, environmental pollution, and noise pollution are emerging, due to this urban concentration phenomenon, logistics and transportation costs are increasing. Urban Air Mobility(UAM) is a three-dimensional futuristic urban transportation that is expected to become an important transportation axis of smart cities as a service(MaaS) linked to roads, railways, and personal transportation. However, as of July 2023, research on airspace systems, Bertieport design, navigation, and communication for UAM operation is actively being conducted, but little research has been conducted on the concept of pilot education and training and education and training programs. Therefore, this paper aims to present a suitable plan for the domestic pilot training system through SWOT analysis of vertical takeoff and landing(VTOL) pilot education and training programs in the United States and Europe.

• Journal of Preventive Medicine and Public Health
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• v.4 no.1
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• pp.41-64
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• 1971

During the period from July 1st to the end of November 1970, a survey on air pollution and noise level was made in Seoul, Pusan and Taegu, the three largest cities in Korea. Each city was divided into 4-6 areas; the industrial area, the semi-industrial area, the commercial area, the residential area, the park area and the downtown area. Thirty eight sites were selected from each area. A. Method of Measurement : Dustfall was measured by the Deposit Gauge Method, sulfur oxides by $PbO_2$ cylinder method, suspended particles by the Digital Dust Indicator, Sulfur dioxide ($SO_2$) and Carbon Monoxide (CO) by the MSA & Kitakawa Detector and the noise levels by Rion Sound Survey meter. B. Results: 1. The mean value of dustfall in 3 cities was $30.42ton/km^2/month$, ranging from 8.69 to 95.44. 2. The mean values of dustfall by city were $33.17ton/km^2/month$ in Seoul, 32.11 in Pusan and 25.97 in Taegu. 3. The mean values of dustfall showed a trend of decreasing order of semi-industrial area, downtown area, industrial area, commercial area, residential area, and park area. 4. The mean value of dustfall in Seoul by area were $52.32ton/km^2/month$ in downtown, 50.54 in semi-industrial area, 40.37 in industrial area, 24,19 in commercial area, 16.25 in park area and 15.39 in residential area in order of concentration. 5. The mean values of dustfall in Pusan by area were $48.27ton/km^2/month$ in semi-industrial area, 36.68 in industrial area 25.31 in commercial area, and 18.19 in residential area. 6. The mean values of dustfall in Taegu by area were $36.46ton/km^2/month$ in downtown area, 33.52 in industrial area, 20.37 in commercial area and 13.55 in residential area. 7. The mean values of sulfur oxides in 3 cities were $1.52mg\;SO_3/day/100cm^2\;PbO_2$, ranging from 0.32 to 4.72. 8. The mean values of sulfur oxides by city were $1.89mg\;SO_3/day/100cm^2\;PbO_2$ in Pusan, 1.64 in Seoul and 1.21 in Taegu. 9. The mean values of sulfur oxides by area in 3 cities were $2.16mg\;SO_3/day/100cm^2\;PbO_2$ in industrial area, 1.69 in semi-industrial area, 1.50 in commercial area, 1.48 in downtown area, 1.32 in residential area and 0.94 in the park area, respectively. 10. The monthly mean values of sulfur oxides contents showed a steady increase from July reaching a peak in November. 11. The mean values of suspended particles was $2.89mg/m^3$, ranging from 1.15 to 5.27. 12. The mean values of suspended particles by city were $3.14mg/m^3$ in Seoul, 2.79 in Taegu and 2.25 in Pusan. 13. The mean values of noise level in 3 cities was 71.3 phon, ranging from 49 to 99 phon. 14. The mean values of noise level by city were 73 phon in Seoul, 72 in Pusan, and 69 in Taegu in that order. 15. The mean values of noise level by area in 3 cities showed a decrease in the order of the downtown area, commercial area, industrial area and semi-industrial area, park area and residential area. 16. The comparison of the noise levels by area in 3 cities indicated that the highest level was detected in the downtown area in Seoul and Taegu and in the industrial area in Pusan. 17. The daily average concentration of sulfur dioxides ($SO_2$) in 3 cities was 0.081 ppm, ranging from 0.004 to 0.196. 18. The daily average concentrations of sulfur dioxides by city were 0.092 ppm in Seoul, 0.089 in Pusan and 0.062 in Taegu in that order. 19. The weekly average concentration of carbon monoxides(CO) was 27.59 ppm. 20. The daily average concentrations of carbon monoxides by city were 33.37 ppm. in Seoul, 25.76 in Pusan and 23.65 in Taegu in that order. 21. The concentration of $SO_2$ and CO reaches a peak from 6 p. m. to 8 p. m. 22. About 3 times probably the daily average concentration of CO could be detected in the downtown area probably due to heavy traffic emission in comparison with that in the industial area. 23. As for daily variation of the concentration of $SO_2$ and CO it was found that the concentration maintains relatively higher value during weekdays in the industrial area and on the first part of the week in the downtown area.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.296-302
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• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking 'environmentally sustainable transportation (EST)' projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents accumulated for last six years. The EIA for railroad construction projects .accounts for only $4.9\%$ of total project EIAs during 1998-2003. However, the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water quality, wast management, noise, etc. We also compared the characteristics of environmental impacts of railroad construction with those of vehicle road construction. The result shows that railroad construction usually requires 3${\~}$4 times longer tunnels and bridges for a given length than vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than $40\%$ of those in vehicle road construction. In order to develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly required.

• Journal of the Korean housing association
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• v.19 no.5
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• pp.85-92
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• 2008

The aim of this research is to develop the sentiment indicators of housing welfare for evaluating housing welfare policies conducted by the Korean government. The methods of this research are used by analysis of related documents, FGI (Focus Group Interview), and survey. The survey was made by experts and consumers. To analyze the survey, this research also uses confirmatory factor analysis by SPSS (Statistical Package for the Social Science) program, AHP (Analytical Hierarchy Process) by Expert Choice program, frequency, average, percentages, Factor analysis etc. As a result of this research, selected housing welfare indicators are settled as follows: In the housing welfare aspect, 11 indicators in the department of 'Housing Satisfaction' and 11 indicators in the department of 'Community Satisfaction' (22 in total) are suggested. The indicators are 1) Water Supply and Distribution Equipment 2) Heating equipment 3) the size of the exclusive residential area 4) the number of rooms 5) Ventilation and Lighting 6) Sound Insulation (Indoor Noise) 7) Air Pollution/Odor 8) House Deposit 9) Rent Paid 10) Maintenance (Dwelling) Cost 11) The length of Occupation 12) Proximity to Welfare Facilities 13) Educational Environment 14) Convenience of Facilities (shops, hospitals etc.) 15) Convenience of Transportation and Commuting 16) Distance from Workplace 17) Landscape and Green Space (Tree, Flowers, Grass etc.) 18) Vandalism (Destruction Behavior, graffiti etc.) 19) Privacy 20) Noise in Public Places (Drinking, Loudly Talking etc.) 21) Safety from Crime 22) Safety from a Disaster. As of 2007, the housing welfare sentiment index is measured by the survey of 1,000 inhabitants in the public housing, which shows 3.51.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.4
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• pp.175-184
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• 2017

With the improvement of living standards, the ventilation for the mitigation of indoor or outdoor air-pollution problems has recently attracted a lot of attention. Consequently, the ventilation for the supply of outdoor fresh air into a room is treated as an important building-design factor. The ventilation is generally divided into the forced and natural types; here, the former can control the ventilation rate by using mechanical devices, but it has the disadvantages of the equipment costs, maintenance costs, and noise generation, while the latter is applied to most workshops due to the absence of noise and the low installation and maintenance costs. In this experimental study, the ventilation performance of a typical rotating-type natural ventilator, which is called a "wind turbine," was investigated with the outdoor-wind velocity and the indoor/outdoor-temperature difference. From the experiment results, it was confirmed that the temperature difference of $10^{\circ}C$ corresponds to the ventilation driving force with an outdoor-wind velocity of 1.0 m/s. Additionally, the intake-opening area of a building also exerts a great effect on the ventilation rates.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.227-232
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• 2023

Underwater noise pollution has a significant impact on the marine environment. This study proposed a simple approach to estimate the acoustic radiation efficiency of structures with air bubble layers. The method considered the insertion loss caused by the air bubble layer through post-processing of numerical results, assuming that insertion loss is equivalent to attenuation as demonstrated by previous studies. The proposed approach was validated by comparing it with a fully coupled analysis for plate structure models. The commercial finite element program COMSOL Multiphysics was used for the acoustic-structure interaction analysis, and the acoustic characteristics of air bubble layer for the fully coupled analysis was simulated by on the Commander and Prosperetti theory. The trends indicated good agreement between the simple approach and the fully coupled analysis in terms of radiation efficiency. It is confirmed that the proposed method is providing insight into the principal mechanism of underwater noise reduction for the bubble layer on the wedge-shaped structure.

• Journal of the Korea Institute of Building Construction
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• v.24 no.2
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• pp.261-271
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• 2024

The widespread adoption of aluminum slab formwork in modern construction, evident in both domestic and international projects, offers numerous advantages. However, a critical challenge persists regarding the dismantling process for these slabs. The current industry standard involves dropping the slabs to the ground floor upon removal. This practice raises several concerns, notably the generation of significant noise pollution that disrupts nearby communities. More importantly, the risk of worker injuries due to falls from height during the dismantling process is a serious safety hazard. Additionally, the impact from dropping the slabs can damage the aluminum itself, leading to increased replacement costs. These drawbacks necessitate the exploration of alternative dismantling techniques that prioritize worker safety, material sustainability, and overall process efficiency. Accordingly, in this study, when the entire first-generation slab formwork of an apartment house is simultaneously lowered to a reachable position for workers, it is then disassembled and lifted for transport to the next floor. This approach has the potential to demonstrate improvements in safety, quality, economy, and process efficiency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.195-200
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• 2020

With the growing interest in fossil fuel depletion and environmental pollution, railroad cars operating in Korea are in progress as the conversion from diesel to electric vehicles expands. The photovoltaic system, which is applied as an example of the conversion of electric vehicles, is infinite and pollution-free, and can produce energy without generating hazards such as air pollution, noise, heat, and vibration, and maintain fuel transportation and power generation facilities. There is an advantage that is rarely needed. However, the amount of electricity produced depends on the amount of solar radiation by region, and the energy density is low due to the power generation of about 25㎡/ kWp, so a large installation area is required and the installation place has limited problems. In view of these problems, many studies have been applied to fuel cells in the railway field. In particular, the plan to link the fuel cell power generation system railroad power supply system must be linked to the power supply system that supplies power to the railroad, unlike solar and wind power. Therefore, it has a close relationship with railroad cars and the linkage method can vary greatly depending on the system topology. Therefore, in this paper, we study the validity through simulation modeling related to linkage analysis according to system topology.

• Journal of Preventive Medicine and Public Health
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• v.5 no.1
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• pp.1-7
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• 1972

During the period from June 1st 1971 to November 30 th 1971, studies on air pollution were made in Kwangju city. The city was divided into 6 areas; the downtown area, the semi-downtown area, the heavy traffic area, the commercial area, the residential area, the park area, 13 surveying sites were selected each representing the characteristics of the area. The Measurement methods which were used are described below. Sulfur oxides were measured by $PbO_2$ cylinder method, sulfur dioxides ($SO_2$) and carbon monoxide (CO) by the MSA & Kitakwa detector, dustfall by the Deposit gauge method, and the noise levels by the Kanomax soundlevel meter. The results obtained are as follows: 1. The mean value of sulfur oxides in Kwangju city was $1.16mg\;SO_3/day/100cm^2\;PbO_2$, ranging from $0.45mg\;SO_3/day/100cm^2\;PbO_2$ to $3.10mg\;SO_3/day/100cm^2\;PbO_2$. 2. The mean values of sulfur oxides according to its specific area in the city were $1.45mg\;SO_3/day/100cm^2\;PbO_2$ in heavy traffic area, 1.36 in downtown area, 1.23 in semi-downtown area, 1.11 in commercial area, 0.96 in residential area, and 1.07 in park area, respectively. 3. The average concentration of sulfur dioxide was 0.063 ppm from 2 to 5 P.M in Kwangju city. 4. The average concentrations of sulfur dioxides according to its specific area, from 2 to 5 P.M, in the city were 0.084 ppm in heavy traffic area & downtown area, 0.067 in commercial area, 0.053 in semi-downtown area, 0.052 in residential area, and 0.036 in park area. 5. The average concentration of carbon monoxide was 22.3 ppm from 2 to 5 P.M, in Kwangju city. 6. The average concentrations of carbon monoxide according to its specific area, from 2 to 5 P.M, in the city were 27.0 ppm in downtown area, 26.3 in semi-downtown area, 23.0 in heavy traffic area, 21.7 in commercial area, 20.0 in residential arera, and 17.6 in park area. 7. The mean value of dusifall in Kwangju city was $29.28ton/km^2/month$, ranging from $9.85ton/km^2/month$ to $66.34ton/km^2/month$. 8. The mean values of dustfall according to its specific area in the city were $50.37ton/km^2/month$ in semi-downtown area, 42.76 in heavy traffic area, 34.67 in downtown area, 17.77 in commercial area, 14.40 in park area, and 14.76 in residential area. 9. The mean values of the soluble dust in Kwangju city was $10.23ton/Km^2/month$ and that of the insoluble dust was $19.05ton/Km^2/month$. 10. The mean value of noise level in Kwangju city was 62 phon, ranging from 37 phon to 88 phon. 11. The mean values of noise level according to its specific area in the city were 76 phon in heavy traffic area, 67 in semi-downtown area, 64 in downtown area, 59 in commercial area, 52 in part area, and 50 in residential area.