• 한국항공우주학회지
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• 제32권5호
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• pp.24-29
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• 2004

본 논문에서는 저속통제기로부터 비상 시 분리되는 외부연료탱크 및 LAU-131 로켓발사기의 분리안전성을 보이기 위하여 수행한 자유낙하 풍동시험, MSAP을 이용한 해석과 비행 시험의 연구결과를 종합하였다. 자유낙하형의 bomb rack을 사용하는 비행시험 중의 분리안 전성의 확인과 MSAP의 보정용 자료 생성을 위하여 수행한 아음속풍동을 이용한 자유낙하 시험의 결과에 대하여 기술하였다. 보정된 MSAP으로 자유낙하형과 사출형의 bomb rack 을 사용하였을 때의 분리안전성 해석을 수행하였다. MSAP 해석 결과를 이용한 상관관계 해석을 통하여 자유낙하형의 bomb rack을 사용할 경우의 투하 안전성도 보였다. 또한, 실기 비행시험을 통하여 투하시험을 수행하였으며 이를 해석결과와 비교하였다. 마지막으로, 풍동 시험, 해석결과 및 비행시험의 결과를 종합하여 저속통제기의 안전투하영역을 확정하였다.

• 한국지반신소재학회논문집
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• 제17권4호
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• pp.93-102
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• 2018

차수용 박층 멤브레인은 폴리머로 구성된 재료로 기존 방수포(sheet membrane)를 대체할 수 있는 뿜어 붙이는 방식의 차수 재료이다. 시공에 있어서 뿜어 붙이는 방식을 사용하기 때문에 타설이 용이하고 상대적으로 높은 부착성능을 보인다. 차수용 박층 멤브레인의 배합은 영구 지보재로 쓰이는 TSL(Thin Spray-on Liner)와 매우 유사한 구성을 갖으나 적용 목적에 따라 차수와 지보재로 구분하고 있다. 본 연구에서는 차수용 박층 멤브레인의 차수 성능을 확보한 상태에서 구조적인 성능을 보강할 수 있도록 배합비를 조절하였다. 이를 검토하기 위해, 영구 지보재용 멤브레인 재료에 사용되는 성능 기준에 따라 시험을 수행하고 결과를 검토하였다. 시험결과 본 연구에서 고려한 차수용 박층 멤브레인의 구조적 성능은 영구 지보재로도 사용이 가능한 정도의 성능을 보였다.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• 해양환경안전학회지
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• 제29권7호
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• pp.812-818
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• 2023

해양수산부는 2016년부터 2020년까지 국제사회의 이내비게이션 도입에 선제적으로 대응하고 어선 등 소형선박의 해사안전 증진을 위해 "초고속 해상무선통신망(LTE-M)" 구축을 포함한 한국형 이내비게이션 구축사업을 추진하였으나, 초고속 해상무선통신망의 활용 관점에서 특정 목적에 한정하는 등의 한계점이 식별되었다. 이에 따라 통신망의 활용성 증대를 위해 사용자를 대상으로 설문 조사 및 인터뷰를 수행한 결과, 망 활용의 범위 확대, 망 활용 대상 확장, 망 활용 방식 다각화, 그리고 규제 완화 측면에서의 법·제도적 개선 사항을 확인할 수 있었다. 본 연구에서 도출한 사용자 요구사항을 기반으로 하여 향후 관련 법제 정비방안에 기여할 수 있을 것으로 기대한다.

• 전기학회논문지
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• 제67권8호
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• pp.1080-1088
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• 2018

General methods of controlling a drone are divided into manual control and automatic control, which means a drone moves along the route. In case of manual control, a man should be able to figure out the location and status of a drone and have a controller to control it remotely. When people control a drone, they collect information about the location and position of a drone with the eyes and have its internal information such as the battery voltage and atmospheric pressure delivered through telemetry. They make a decision about the movement of a drone based on the gathered information and control it with a radio device. The automatic control method of a drone finding its route itself is not much different from manual control by man. The information about the position of a drone is collected with the gyro and accelerator sensor, and the internal information is delivered to the CPU digitally. The location information of a drone is collected with GPS, atmospheric pressure sensors, camera sensors, and ultrasound sensors. This paper presents an investigation into drone control by a remote computer. Instead of using the automatic control function of a drone, this approach involves a computer observing a drone, determining its movement based on the observation results, and controlling it with a radio device. The computer with a Depth camera collects information, makes a decision, and controls a drone in a similar way to human beings, which makes it applicable to various fields. Its usability is enhanced further since it can control common commercial drones instead of specially manufactured drones for swarm flight. It can also be used to prevent drones clashing each other, control access to a drone, and control drones with no permit.

• 대기
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• 제32권4호
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• pp.323-340
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• 2022

We analyzed the high-resolution wind data of Aircraft-Based Observation from the Mode-Selective Enhanced Surveillance (Mode-S EHS) data in Korea. For assessment of its quality, the Mode-S wind data was compared with the ECMWF ReAnalysis 5 (ERA5) reanalysis and Aircraft Meteorological Data Relay (AMDAR) data for more than 3-months from 7 May 2021 to 24 August 2021 near Incheon International Airport, Korea. Considering that the AMDAR reports are not provided by all commercial aircraft, total number of the Mode-S derived wind data with a second sampling rate was about twice larger than that of available AMDAR wind data. After the quality control procedures by removing erroneous samples, it was found that the root mean square errors (RMSEs) of the Mode-S retrieved winds are similar to that from the AMDAR winds. In particular, between 550 and 650 hPa levels, RMSE of the Mode-S (AMDAR) zonal wind against ERA5 data was about 2.3 m s^-1 (1.9 m s^-1), and those increased to 3.3 m s^-1 (2.4 m s^-1) in 200~500 hPa levels. A similar trend was found in the meridional wind, but a distinct positive mean bias of 2.16 m s^-1 was observed between 875 and 1,000 hPa levels. Winds retrieved from the Mode-S also showed a good agreement directly with AMDAR data. As the Mode-S provides a large amount of data with a reliable quality, it can be useful for both data assimilation in the numerical weather prediction model and situational awareness of wind and turbulence for aviation safety in Korea.

• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.151-159
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• 2016

Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 μg/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections.

• Tuberculosis and Respiratory Diseases
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• 제82권1호
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• pp.71-80
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• 2019

Background: Efficacy and safety of tiotropium bromide, a muscarinic receptor antagonist, in treatment of asthma have been reported. However, its effect on airway remodeling in chronic asthma of the elderly has not been clearly verified. The objective of this study was to investigate the effect of tiotropium and expression of muscarinic receptors as its related mechanism in an aged mouse model of chronic asthma with airway remodeling. Methods: BALB/c female mice age 6 weeks, 9 and 15 months were sensitized and challenged with ovalbumin (OVA) for three months. Tiotropium bromide was administered during the challenge period. Airway hyperresponsiveness (AHR) and pulmonary inflammation were measured. Parameters of airway remodeling, and expression levels of $M_2$ and $M_3$ receptors were examined. Results: Total cell with eosinophils, increased in the OVA groups by age, was decreased significantly after treatment with tiotropium bromide, particularly in the age group of 15 months. AHR and levels of interleukin (IL)-4, IL-5, and IL-13 were decreased, after tiotropium administration. In old aged group of 9- and 15-months-treated groups, hydroxyproline contents and levels of ${\alpha}$-smooth muscle actin were attenuated. Tiotropium enhanced the expression of $M_2$ but decreased expression of $M_3$ in all aged groups of OVA. Conclusion: Tiotropium bromide had anti-inflammatory and anti-remodeling effects in an aged mouse model of chronic asthma. Its effects seemed to be partly mediated by modulating expression $M_3$ and $M_2$ muscarinic receptors. Tiotropium may be a beneficial treatment option for the elderly with airway remodeling of chronic asthma.

• IMMUNE NETWORK
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• 제12권1호
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• pp.8-17
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• 2012

Background: Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract diseases in infancy and early childhood. Despite its importance as a pathogen, there is no licensed vaccine against RSV yet. The attachment glycoprotein (G) of RSV is a potentially important target for protective antiviral immune responses. Recombinant baculovirus has been recently emerged as a new vaccine vector, since it has intrinsic immunostimulatory properties and good bio-safety profile. Methods: We have constructed a recombinant baculovirus-based RSV vaccine, Bac-RSV/G, displaying G glycoprotein, and evaluated immunogenicity and protective efficacy by intranasal immunization of BALB/c mice with Bac-RSV/G. Results: Bac-RSV/G efficiently provides protective immunity against RSV challenge. Strong serum IgG and mucosal IgA responses were induced by intranasal immunization with Bac-RSV/G. In addition to humoral immunity, G-specific Th17- as well as Th1-type T-cell responses were detected in the lungs of Bac-RSV/G-immune mice upon RSV challenge. Neither lung eosinophilia nor vaccine-induced weight loss was observed upon Bac-RSV/G immunization and subsequent RSV infection. Conclusion: Our data demonstrate that intranasal administration of baculovirus-based Bac-RSV/G vaccine is efficient for the induction of protection against RSV and represents a promising prophylactic vaccination regimen.

• Smart Structures and Systems
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• 제21권5호
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• pp.611-621
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• 2018

Compared with the highway bridges, the relatively higher requirement on the safety and comfort of vehicle makes the high-speed railway (HSR) bridges need to present enhanced dynamic performance. To this end, installing a health monitor system (HMS) on selected key HSR bridges has been widely applied. Typically, the HSR takes fully enclosed operation model and its skylight time is very short, which means that it is not easy to operate the acquisition devices and download data on site. However, current HMS usually involves manual operations, which makes it inconvenient to be used for the HSR. Hence, a HMS named DASP-MTS (Data Acquisition and Signal Processing - Monitoring Test System) that integrates the internet, cloud computing (CC) and virtual instrument (VI) techniques, is developed in this study. DASP-MTS can realize data acquisition and transmission automatically. Furthermore, the acquired data can be timely shared with experts from various locations to deal with the unexpected events. The system works in a Browser/Server frame so that users at any places can obtain real-time data and assess the health situation without installing any software. The developed integrated HMS has been applied to the Xijiang high-speed railway arch bridge. Preliminary analysis results are presented to demonstrate the efficacy of the DASP-MTS as applied to the HSR bridges. This study will provide a reference to design the HMS for other similar bridges.