• 한국산업보건학회지
• /
• 제16권2호
• /
• 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.

• 시스템엔지니어링학술지
• /
• 제4권2호
• /
• 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
• /
• 제25권5호
• /
• 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.

• 한국산업보건학회지
• /
• 제1권2호
• /
• 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.

• 한국전자통신학회논문지
• /
• 제8권8호
• /
• pp.1213-1218
• /
• 2013

최근에는 극한 분야에서 수상로봇, 수중로봇, 공중로봇과 같은 해양로봇의 필요성이 제기되고 있음에도 불구하고, 그 기반은 매우 부족하다. 다행히도, 로봇교육에 대한 요구가 증가하고 있으므로, 해양로봇키트의 개발 및 보급을 통하여 연구개발 기반을 마련하고 미래 인재를 양성하는 것이 바람직하다. 그러나, 기존에는 공중 이동 및 장애물회피가 가능한 풍선기반의 해양로봇키트가 없다. 이 문제를 해결하기 위해서, 적외선 센서를 이용하여 장애물회피가 가능한 풍선기반 자율 공중로봇키트가 개발되었다. 시험평가 결과는 실제 적용 가능성과 추가 연구의 필요성을 보여준다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제27권6호
• /
• pp.13-21
• /
• 2023

본 연구에서는 인천항만 시설물의 대기 중 비래염분량을 조사하였다. 2021.9 ~ 2023.8월, 총 2년 동안 북항, 남항, 신항에 총 15개의 염분포집기를 설치하여 대기 중 비래염분량을 측정하고, 항만시설물과 측정환경에 따른 비래염분량의 분포 특징과, 해안거리에 따른 비래염분량의 감소 특성을 분석하였다. 그 결과, 북항, 남항, 신항의 월별 비래염분량 분포는 0.4 ~ 3.3 mdd로 유사하게 나타났으며, 해안선의 방향을 고려한 계절풍의 영향으로 북항과 남항은 겨울에, 신항은 여름에 비래염분량이 높게 나타났다. 측정환경에 따른 비래염분량의 특징으로는 동일 지역에서 내해보다 내륙에 위치하여 바다에서 부는 바람이 내해를 통과하여 지나가는 위치에 있는 지점에서 비래염분량이 높게 나타났다. 또한 동일지역에서 해안거리가 동일한 두 지점일지라도 지면으로부터 높이에 따라서 비래염분량에 차이가 있었다. 한편 간만대의 경우, 월별 비래염분량은 상부보다는 하부에서 현저히 높게 나타났으며, 예외적으로 상부의 비래염분량이 하부만큼 높은 기간은 최고조위와 조위차가 높은 특징이 있었다. 해안으로부터 거리에 따른 항별 비래염분량의 감소율식을 도출하였으며, 그 결과, 해안으로부터 멀어질수록 비래염분량의 감소율은 신항이 가장 크고, 남항이 가장 작게 나타났다.

• 한국군사과학기술학회지
• /
• 제14권3호
• /
• 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
• /
• 제17권4호
• /
• 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.

• 항공우주시스템공학회지
• /
• 제13권1호
• /
• pp.62-68
• /
• 2019

항공기에 탑재되는 소프트웨어는 안전과 직결되기 때문에 안전 비행을 위해서는 감항인증 기준을 따라야만 한다. 항공기 탑재 소프트웨어는 감항인증기준에 명시된 DO-178을 따라 개발되어야 하지만 방사청 무기체계 소프트웨어 개발 및 관리 매뉴얼에 따라 개발되고 있다. 본 논문에서는 소프트웨어 전문가 설문조사를 수행하였고 DO-178을 기반으로 소프트웨어 개발 및 인증 절차를 제안하였다.

• 한국환경보건학회지
• /
• 제38권5호
• /
• 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.