• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.79-87
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• 2024

This paper is a study on the optimal microdroplet generation conditions in indirect charging electrostatic spraying. Unlike the direct charging method, which applies power to the nozzle, the indirect charging method applies power to the discharge electrode between the nozzle and the collection electrode. Therefore, an electrically simplified system can be obtained by minimizing the insulation part a stable spray pattern can be obtained with a wide spray angle, and a stable spray pattern can be obtained with a wide spray angle. To conduct the study, an indirect charging type electrostatic spray visualization system was constructed and the static characteristics of the microdroplets were analyzed through image processing of the spray shape of the microdroplets. The total number of microdroplets and the number of microdroplets per power consumption are confirmed according to the changes in the distance between the discharge electrode and the collection electrode, the flow rate, and the applied voltage, which affect the generation of microdroplets, and using this, the optimal generation conditions are derived and the corresponding microdroplet size distribution was analyzed. As a result of the experiment, it was confirmed that the optimal generation condition was at a flow rate of 15 to 20 mL/min and a voltage of -22.5 to -25 kV in terms of the number of microdroplets, and at a flow rate of 15 to 20 mL/min and a voltage of -20 kV in terms of energy consumption efficiency.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E2
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• pp.74-82
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• 2008

We have examined seasonal and annual means of clear-sky solar noon and daily erythemal ultraviolet-B irradiances measured in Anmyeon. The intensity of the EUV-B irradiance is mainly dependent on solar zenith angle (SZA) and total ozone amounts on clear day conditions. The daily maximum occurs near solar noon time and the highest monthly accumulated EUV-B is seen in July in Anmyeon. The maximum daily variation occurs in June and July due to precipitation and clouds. The 7-year trend of EUV-B irradiance shows that it is slightly increasing. Additionally, we could confirm that aerosol effects such as Asian Dust decreases the EUV-B irradiance reaching the ground surface by 35% to 60%. For more than 45% of the summer days, EUV-B irradiacne was high enough that the UV index registered higher than category Extremely High. This information will be very important for evaluation of the UV index for prevention of both skin cancer and ecosystem damages as well as to understand UV climatology over the Korean Peninsula.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.319-325
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• 2017

In this study, the new particulate matter emissions considering condensable PM (CPM) of stationary pollutant sources were calculated to modify the CAPSS emissions based on only filterable PMs in Seoul and Incheon. When the new calculated emissions were compared to the existing filterable PM based emissions of local governments, different contribution patterns of emission sources were found. For example, the proportion of mobile sources was high when the filterable PM was considered; however, the contribution of non-industrial sources was dominant in Seoul when the emissions of CPM were considered. Also, the proportion of energy industrial combustion and manufacturing combustion sources was significant in Incheon when CPM emissions considered. Therefore, it seems to be much desirable to consider CPM emissions for determining adequate locations of collective energy facilities and manufacturing combustion facilities in the future. In addition, CPM should be considered to solve the dust problem nationwide. The emission analysis, diagnosis, prediction and countermeasures using CPM emissions should be appropriately performed.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.253-256
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• 2006

For nuclear concrete structures on the coast, the prevention and management against salt damage is needed because they are being under the influence of the sea water at all times. In general, the deterioration of the concrete is generated in concrete surface firstly and then extended into concrete gradually as its service life increases. Therefore, the protective layer on the concrete surface is needed to establish and manage the durability of concrete. To enhance the durability performance of the existing and new concrete, the development and application of a high-performance penetration sealer is needed. The sealer has to have the functions that are able to prevent the attack of the moisture, carbon dioxide, and harmful substance from the outside. Therefore, the aim of this project is to guarantee the long service-life and waterproof performance of a nuclear concrete structures by increasing the density of the existing and new concrete surface layer, and to enhance the dust-proof performance of the uncoating part of the nuclear safety-relative structures.

• Fashion & Textile Research Journal
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• v.8 no.6
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• pp.634-638
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• 2006

The significance of this study is the demonstration of a new method of preservation procedure for national-treasure-class cultural-assets by examining the characteristics of the Jeogori relic, presumed to be that of King SeJo, and validating the preservation process. This Jergori as well as the wooden Munsu-donja Buddha statue from which they were found are designated as national treasure. The Jeogori relic is made of light silk and dimensions mark 77 cm in length, 67 cm in width, and 94 cm in sleeve length. It is a typical Jeogori worn in the Chosun Dynasty. Preservation procedure was in the following order: Removing dust and pollutants by vacuum, washing, removing creases, reinforcing the clothes, settling at paulownia backboard, and packing. Storage and exhibition of remains was executed with as minimal folding as possible, and microbiological damage prevention was performed by dyeing antibacterial treatment with eugenol onto supporting cloth. The relic, conservatively treated in accordance with the above procedure, is currently kept at the storage facility of the citadel Museum in the Woljeong Temple. It is displayed annually to the general public for approximately two weeks.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.251-257
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• 2015

Recently, techniques for detecting the movement of the object of energy saving, impact prevention, such as automatic door opening and closing has been applied to various fields. Doppler sensor does not receive a large impact on the environment, such as conventional infrared ray sensor, a problem with an ultrasonic sensor as a sensor which can compensate the temperature, noise, dust and so on. In this paper, when the object to be detected, the LED lamp is turned on 24 hours a Doppler sensor ON, if not switch to the OFF state, the illumination of the LED lamp has been developed for controlling the two-stage converter. Doppler sensor developed by applying the converter module and the power-saving control section leader and demonstrated the power savings.

• International Journal of Safety
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• v.9 no.2
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• pp.35-40
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• 2010

Many casualties are being occurred due to many misses the railway platform, and the accident occurrence is being increased. Recently in Korea, efforts to prevent casualties fundamentally are being made by installing and operating the PSD(Passenger Screen Door) as to prevent these casualties of passengers. However, in case of the PSD system, although it can solve the problem of public casualties at platform fundamentally, it is impossible to install it at whole railway platforms. This paper proposes the safety equipment using LaserRadar sensor for the prevention against casualties of passengers at platform. The safety equipment using novel sensor is the safety equipment making an approaching train stopped if the falling object is a person by detecting the obstacle at platform, and it has the merit possible to apply it to platform since it may detect accurately under ambient environmental elements such as the snow, rain and yellow dust, etc. also. We manufactured a prototype of the safety equipment to reduce public casualties at platform by using LaserRadar sensor and carried out its performance test, and the result is presented in this paper.

• Journal of Urban Science
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• v.11 no.1
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• pp.29-35
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• 2022

Waste to Energy Plant were recognized as hateful facilities, and there were many conflicts in the location due to social problems such as the NIMBY phenomenon due to problems such as damage to property in the surrounding area, odor, and image loss. Problems such as air pollution and odor are solved by the development of advanced prevention facilities such as electric dust collectors, wet cleaning systems, semi-dry reaction towers, bag filters, and catalyst towers (SCR: Selective Catalytic Reduction), and air recycling facilities in waste storage tanks. However, it is being avoided because of the perception that it is an incinerator. To resolve these conflicts, the government installs and operates resident convenience facilities to compensate residents near resource recovery facilities, provides green space and improves the environment, and supports heating expenses in accordance with the 「Waste Treatment Facility Support Act」. The purpose of this study is to derive implications through the analysis of domestic and overseas case studies for resident convenience facilities and environment improvement for the promotion of local communities in resource recovery facilities and use them as basic data for community promotion and environmental improvement when installing resource recovery facilities in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.194-195
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• 2021

Due to urban regeneration projects or changes in the living environment, there is an increasing need to demolish old buildings that have lost their functions. Demolition of above ground and underground structures is an important construction project that greatly affects the construction period and safety of the entire process. However, it is difficult for the safety officer to manage the demolition work due to the lack of specific and diverse data applicable to the site of the demolition plan. Therefore, in this study, items that need to be improved in structural safety when the above-ground and underground structures are demolished are reviewed and organized. For the main contents of structural safety management in demolition work, 1) structural review reflecting the order of demolition work, 2) installation and dismantling of steel pipe scaffolding and dust nets, 3) installation and dismantling of system scaffolding, 4) installation and dismantling of fall prevention nets, 5) jack support Installation and dismantling, 6) movement of equipment, movement and planning between floors, 7) equipment for demolition of structures, height of remnants, 8) site cleanup, and 9) equipment operators were categorized and arranged.

• Safety and Health at Work
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• v.15 no.2
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• pp.123-128
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• 2024

Background: Coal miners are highly prone to occupational health risks, such as black lung disease. This study aims to assess the prevalence of black lung disease and the factors associated with black lung disease among coal miners in Asia. Method: This systematic review, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, searched through the scientific literature of the following databases: EBSCO, ScienceDirect, PubMed, and Scopus. We selected articles that studied black lung disease among coal miners from 48 countries in Asia and were published between 2014 and 2023. Article quality was evaluated using the Critical Appraisal Skills Program. Result: The seven articles that we review studied a total of 653,635 coal miners from various types of coal mines from three countries in Asia. Of these miners, 59,998 experienced black lung disease. Black lung disease is prevalent among 9.18% of coal miners in Asia, which is approximately four times higher than the worldwide prevalence. Common factors that influence black lung disease in Asia include age, years of dust exposure, smoking, drinking, working types, and sizes of mines, type of mines, respiratory functions, spirometry parameters, tenure, lack of attention to occupational health, inefficient surveillance, and weak occupational health service. Conclusion: Although the prevalence of black lung disease among coal miners in Asia is considerably high, it can be addressed through effective prevention measures, monitoring, control, and case reporting.