• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.2
• /
• pp.101-109
• /
• 2006

The objective of this study is to provide fundamental data for pertinent management of indoor air quality through investigating the size-based characteristics of bioaerosol distributed in the general hospital. Measurement sites are main lobby, ICU, ward and laboratory and total five times were sampled with six-stage cascade impactor. Based on the result of this study, concentrations of airborne bacteria and fungi were the highest in main lobby as followed by an order of ward, ICU and laboratory. Concentrations of airborne bacteria was generally higher than those of airborne fungi and the ratio of indoor and outdoor concentration of both exceeded 1.0 in all the measurement sites of the general hospital. The predominant genera of airborne bacteria identified in the general hospital were Staphylococcus spp.(50%), Micrococcus spp.(15-20%), Corynebacterium spp.(5-20%), and Bacillus spp.(5-15%). On the other hand, the predominant genera of airborne fungi identified in the general hospital were Cladosporium spp.(30%), Penicillium spp.(20-25%), Aspergillus spp.(15-20%), and Alternaria spp.(10-20%). In regard to size distribution of bioaerosol, the detection rate was generally highest on 5 stage($1.1-2.1{\mu}m$) for airborne bacteria and on 1 stage(>$7.0{\mu}m$) for airborne fungi. Cleanliness of facilities in the general hospital and condition of HVAC system should be monitored regularly to prevent indoor air contamination by airborne microorganisms.

• Journal of the Korean Society of Systems Engineering
• /
• v.4 no.2
• /
• pp.45-54
• /
• 2008

This paper describes an operational concept of the network based future airborne force power using a systems engineering approach. The battlefield is changing to new system of systems that command and control by the network based BM/C4ISR. Also, it is composed of various sensors and shooters in an single theater. Future threats may be characterized as unmanned moving bodies that the strategic effect is great such as UAVs, cruise missile and tactical ballistic missiles. New threats such as low altitude stealth cruise missile may also appear. The implementation of future airborne force power network systems against these future threats is required to complex and integrated approach based on systems engineering. This work developed the operational concepts of the future airborne network system, and then derived the requirements for performing missions effectively. In addition, the scheme of future airborne force power network systems is presented.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.5
• /
• pp.709-717
• /
• 2015

Airborne bacteria from hog farms may have detrimental impacts on human health, particularly in terms of antibiotic resistance and pathogen zoonosis. Despite human health risks, very little is known about the composition and diversity of airborne bacteria from hog farms and hog-related spray fields. We used pyrosequencing analysis of 16S rRNA genes to compare airborne bacterial communities in a North Carolina hog farm and lagoon spray field. In addition, we isolated and identified antibiotic-resistant bacteria from both air samples. Based on 16S rRNA gene pyrosequence analysis, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla in airborne bacterial communities from both hog farm and spray field sites. Within the Firmicutes genera, Clostridium spp. were more abundant in the hog farm, whereas Staphylococcus spp. were higher in the spray field. The presence of opportunitic pathogens, including several Staphylococcus species and Propionibacterium acnes, was detected in both bioaerosol communities based on phylogenetic analysis. The isolation and identification of antibiotic-resistant bacteria from air samples also showed similar results with dominance of Actinobacteria and Proteobacteria in both hog farm and spray field air. Thus, the existence of opportunistic pathogens and antibiotic resistant bacteria in airborne communities evidences potential health risks to farmers and other residents from swine bioaerosol exposure.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.1 no.2
• /
• pp.144-153
• /
• 1991

This study was conducted to evaluate worker exposure to airborne asbestos fibers by industry, and to evaluate polarized-light microscopy for determining airborne asbestos fibers. A total of 11 plants including asbestos textile, brake-lining manufacturing, slate manufacturing, and automobile maintenance shops were investigated. Rsults of the study are summarized as follows. 1. Worker exposure levels to airborne asbestos fibers were the highest in asbestos textile industry, followed by brake-lining manufacturing, slate manufacturing, and automobile maintenance shops, in order. In asbestos textile industry, large variation of asbestos levels was found by plants. The worst plant indicated airborne fiber concentrations in excess of 10 fibers/cc, however, the best plant showed concentrations within 0.50 fibers/cc. 2. Characterization of airborne fibers by industry indicated that fibers from asbestos textile industry were the longest with the largest aspect ratio. Fibers from automobile maintenance shops were the shortest with the smallest aspect ratio. Based on characteristics of fibers and the highest levels of concentrations, it is concluded that workers in the asbestos textile industry are exposed to the highest risk of producing asbestosis, lung cancer, and mesothelioma. 3. Result s obtained using polarized-light microscopy were $43.7{\pm}12.3%$ of the results obtained using phase contrast microscopy. This may be resulted from the worse resolution of polarized-light microscopy than that of phase contrast microscopy. Based on the results, it is recommended that polarized-light microscopy be used for mainly bulk sample analyses and further study be performed to improve the method for determining airborne samples. However, polarized-light microscopy can be used for determining thick fibers.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.8
• /
• pp.1213-1218
• /
• 2013

Recently, although the need of marine robots such as the underwater robot, surface robot and airborne robot being raised in extreme areas, the basis is very deficient. Fortunately, as the need of the robot education is increasing, it is desirable to establish the R&D basis of marine robots and to train future talents through the development and diffusion of marine robot kits. However, in conventional case, there is no marine robot-kit based on the balloon, which has the abilities of the airborne locomotion and obstacle avoidance. To solve this problem, a balloon-based autonomous airborne robot-kit that has the ability of the obstacle avoidance with an infrared sensor, is developed. The test and evaluation results show the possibility of the real applications and the necessity of additional work.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.6
• /
• pp.13-21
• /
• 2023

In this study, the coastal airborne chlorides were investigated in the Incheon Port, South Korea. Monthly measurements of coastal airborne chlorides were taken for a total of 2 years from September 2021 to August 2023 at 15 locations in North, South, and New Port. We analyzed the distribution characteristics of airborne chloride based on port facilities and measurement environments, as well as the reduction characteristics of the airborne chloride with respect to coastal distance. As a result, the monthly distribution range of the airborne chloride in the North, South, and New Port varied similarly, ranging from 0.4 to 3.3 mdd. Due to the influence of seasonal winds considering the direction of the coastline, both the North Port and South Port had higher the airborne chloride in winter, while the New Port had higher content in summer. The airborne chlorides were higher at locations inside an inland sea compared to those outside an inland sea. This is because the wind coming from the sea passed through the inland sea. Even in the same region with identical coastal distances, there were variations in airborne chloride levels depending on the height above the ground. In tidal zone, the monthly airborne chlorides were significantly higher in the lower part than in the upper part. The rate of decrease equation of airborne chlorides for each port based on the distance from the coastline was derived, and the results showed that as the distance from the coastline increased, the rate of decrease in airborne chlorides was the highest for New Port and the lowest for South Port.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.3
• /
• pp.492-500
• /
• 2011

The airborne backbone network(ABN) provides communication transport services between airborne nodes, surface nodes and satellite nodes. Such ABN is generally constructed with wide-body and high-capacity planes such as AWACS, which can fly long-term along pre-defined flight paths. In this paper, we propose an efficient method to improve routing performances by reconfiguring routing path before link failure based on the prediction of link state with the information of pre-defined backbone nodes' trajectories. Since the proposed method does not need additional information exchange between airborne nodes in order to acknowledge the link failure, it can be effectively used for airborne backbone network with limited bandwidths.

• Environmental Engineering Research
• /
• v.17 no.4
• /
• pp.211-216
• /
• 2012

Quantification of the airborne microorganisms (bacteria and fungi) at a swine wastewater treatment plant was performed. Microbial samples were collected at three different phases of the treatment process over a 1-yr period. Cultivation methods based on the viable counts of mesophilic heterotrophic bacteria and fungi were performed. The concentrations of airborne bacteria ranged up to about $5{\times}10^3$ colony-forming unit (CFU)/$m^3$, and those of airborne fungi ranged up to about $9{\times}10^2CFU/m^3$. The primary treatment (e.g., screen, grit removal, and primary sedimentation) was found to be the major source of airborne microorganisms at the site studied, and higher levels of airborne bacteria and fungi were observed in summer. High levels of the respirable bioaerosol (0.65 to $4.7{\mu}m$ in size) were detected in the aeration phase. Among the environmental factors studied, temperature was strongly associated with fungal aerosol generation (with a Spearman correlation coefficient of 0.90 and p-value <0.01). Occupational biorisks are discussed based on the observed field data.

• Journal of Aerospace System Engineering
• /
• v.13 no.1
• /
• pp.62-68
• /
• 2019

The software installed on an aircraft is directly related to its safety. Therefore, it shall comply with the standards of the airworthiness certification to ensure safety of flight. Airborne software should be developed in accordance with the DO-178 (Software Consideration in Airborne Systems and Equipment Certification) to comply with the airworthiness certification criterion. However, the military airborne software has been developed in accordance with the DAPA weapons system software development and management manual. In this paper, we completed a questionnaire survey of software experts. We also suggest a military airborne software development/certification process based on DO-178.

• Journal of Environmental Health Sciences
• /
• v.38 no.5
• /
• pp.407-414
• /
• 2012

Objectives: This study was performed to assess based on field investigation the distribution characteristics of airborne fungi in an area of Seongdong-gu, Seoul. Methods: Three sites, a living area, forest and traffic site, were selected for evaluation of monthly level of outdoor airborne fungi. An on-site survey was executed between January 2009 and December 2009. During the experimental period, air sampling was performed every month in the afternoon (2:00 pm-5:00 pm) using a cascade impactor. Results: Outdoor airborne fungi measured in Seoul, Korea over one year showed a concentration range from 850CFU $m^{-3}$ to 15,200CFU $m^{-3}$. The mean respirable fraction of outdoor airborne fungi was 67% compared to total concentration. Regardless of measurement site, there was no significant concentration difference in outdoor airborne fungi between periods of yellow dust and non-yellow dust (p>0.05). There was no significant correlation relationship between outdoor airborne fungi and atmospheric factors such as temperature and relative humidity. The predominant genera of airborne fungi identified were Aspergillus, Cladosporium, Paecilomyces and Penicillium. Conclusion: Monthly levels of outdoor airborne fungi were highest in April and November and lowest in August. In seasonal concentration distribution, the autumn showed the highest level of outdoor airborne fungi, followed by spring, summer and winter. In regional concentration distribution, the highest level of outdoor airborne fungi was generally found in the forest, followed by the living area and traffic site.