• Journal of Aerospace System Engineering
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• v.16 no.2
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• pp.13-24
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• 2022

As the scale of airborne system software increases, the use of OOT (Object-Oriented Technology) is increasing for functional expansion, efficient development, and code reuse, but the verification method for airborne object-oriented software is conducted from the perspective of the existing procedure-oriented program. The purpose of this paper was to analyze the characteristics of OOT and the vulnerabilities derived from the functional characteristics of OOT, and present a verification method applicable to each software development process (Design, Coding and Testing) to ensure the functional safety integrity of aviation software to which OOT is applied. Additionally, we analyzed the meaning of the static analysis results among the step-by-step verification measures proposed by applying LDRA, a static analysis automation tool, to PX4, an open source used to implement flight control software.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.2
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• pp.93-101
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• 2022

It is essential to prevent LoC(Loss-of-Control) or upset situations caused by stall, icing or sensor malfunction in aircraft, because it may lead to the crash of the aircraft. With this regard, it is crucial to correctly identify the dynamic characteristics of aircraft in such upset conditions. In this paper, we present a SID(System IDentification) method utilizing the moving-window based least-square and the adaptive-order ZKF(Zonotopic Kalman Filter), which is more effective than the existing Kalman-filter based SID for the aircraft in upset condition at a high angle of attack with temporary sensor malfunction. The proposed method is then tested on real flight data and compared with the existing one.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.358-364
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• 2022

The Inter Communication System for avionics is in charge of processing all voice signals that internal calls between Pilot and Co-pilot, internal calls between Pilots and Crews, external calls through communication equipment such as Ultra/Very High Frequency Receiver/Transmitter(U/VHF RT), audio signal monitoring for navigation and mission equipment such as VHF Omnidirectional Range/Instrument Landing System(VOR/ILS), Tactical Air Navigation(TACAN), audio signal output for voice recording to Flight Data Recorder(FDR) and Data Transfer System(DTS), and warning/caution audio signal generate about the status and threat of aircraft. Because Inter Communication System for avionics is sensitive to noise in the case of analog audio signals, a redundant design that can protect audio signal from electromagnetic noise inside/outside of aircraft is required for the mission of pilots and crews. In this paper, Normal/Back-up operation mode and redundancy design plan based on digital method for the redundancy of the digital Inter Communication System for avionics and manufacturing, verification results are described.

• Animal Bioscience
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• v.34 no.9
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• pp.1552-1558
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• 2021

Objective: This work was carried out to evaluate the effects of zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RH) combined with immunocastration on the welfare traits of feedlot Nellore cattle. Methods: Ninety-six Nellore males (average body weight [BW] = 409±50 kg; average 20 mo of age) were divided into two groups according to BW; half of the animals in each group received two doses of an immunocastration (ImC) vaccine in a 30 day interval, and the other half did not receive the vaccine (NoC). Afterward, the animals were housed and fed a common diet for 70 days. Then, they were split into three groups and fed one of the following diets for 30 additional days: control (CO) diet, with no β-AA; ZH diet, containing 80 mg/d ZH; and RH diet, containing 300 mg/d RH. Welfare traits were assessed by monitoring body surface temperature using infrared thermography (IRT) and plasma cortisol and temperament measurements. Results: There was no interaction between sexual condition and diet for any trait. The ImC and NoC groups did not differ in rectal and ocular temperatures. The ImC animals had higher flight speeds (p = 0.022) and tended to have higher cortisol levels (p = 0.059) than the NoC animals. Animals fed ZH and RH did not differ in cortisol levels, respiratory rate, rectal temperature, temperature measured by IRT, or temperament behaviour. Conclusion: The ImC animals showed a less stable temperament during handling practices than NoC, whereas ZH and RH supplementation had no adverse effects on animal welfare.

• The Plant Pathology Journal
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• v.38 no.2
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.33-41
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• 2023

As seen in the case of the Boeing 737 Max accident, the proportion of aircraft software is rapidly increasing. However, it is vulnerable to safety issues. In case of domestic aircraft software, to operate a Light Unmanned Aerial Vehicle (LUAV) less than an empty weight of 150 kg, safety certification is required for an Ultra-Light Vehicle (ULV). However, software certification procedure is not included. Since the use of LUAVs has increased recently, software verification is required. This paper proposed a checklist of LUAV software that could be applied to LUAV referring DO-178C, an aviation software certification standard. A case study of applying the proposed checklist to the Model-based Development-based Helicopter Flight Control Computer (FCC) project currently used by domestic and foreign advanced companies and institutions was conducted.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.658-665
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• 2023

Take-off weight is a key factor for improving accuracy when estimating an aircraft's carbon emissions and fuel consumption. However, the takeoff weight contains sensitive payload information that can infer the airline's management strategy, making it impossible to leak it outside. Although several models for estimating takeoff weight have been presented in previous studies, the researcher points out that there are limitations of the study caused by variables at the pilot's discretion. In this paper, several variables related to takeoff weight are identified to suggest a way to control these limits. Among them, variables that can improve the accuracy of takeoff weight are selected and an estimation equation is presented by applying them to ADS-B information. The proposed estimation does not estimate the average takeoff weight but has the advantage of being able to estimate all ranges of the takeoff weight.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.9-15
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• 2023

In order to effectively prevent and respond to disasters, several techniques have been developed in which the pilot wearing a see-through Head Mounted Display (HMD) performs disaster-related rescue activities using images transmitted from an Unmanned Aerial Vehicle (UAV). However, these techniques have limitations in quickly determining and executing tasks appropriate to the on-site situation because the pilot cannot recognize the entire field in an integrated manner. In order to overcome these problems, we propose an AR based-interface technique that allows the rescuer wearing a see-through HMD to operate a UAV efficiently. Simulation results show that the proposed interface technique allows the rescuer wearing a see-through HMD to control the gimbal and flight of the UAV at a high speed based on finger gestures in a visibility situation.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.79-87
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• 2024

The Korean launch vehicle (KSLV-II) has used commercial aviation jet fuel, Jet A-1. Fuel specifications were introduced from Jet A-1 specifications. However, specifications and inspection methods of moisture and particulate matters were changed digitally for convenience and accuracy. To control fuel quality, a fuel management system was established to determine suitability by inspecting it at each stage of warehousing, storage, and application. An analysis room was then established at the Naro Space Center. The possibility of fuel mixing was blocked by warehousing inspection. Long-term component changes were then observed by storage inspection. Finally, suitability of the engine test or the launch vehicle test was determined through application inspection. Long-term analysis verified that the space center's fuel oil storage method was appropriate and that the quality management system was able to handle hundreds of engine tests and several flight tests.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.257-268
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• 2024

Drone-mounted hyperspectral sensors (DHSs) have revolutionized remote sensing in agriculture by offering a cost-effective and flexible platform for high-resolution spectral data acquisition. Their ability to capture data at low altitudes minimizes atmospheric interference, enhancing their utility in agricultural monitoring and management. This study focused on addressing the challenges of radiometric and geometric distortions in preprocessing drone-acquired hyperspectral data. Radiometric correction, using the empirical line method (ELM) and spectral reference panels, effectively removed sensor noise and variations in solar irradiance, resulting in accurate surface reflectance values. Notably, the ELM correction improved reflectance for measured reference panels by 5-55%, resulting in a more uniform spectral profile across wavelengths, further validated by high correlations (0.97-0.99), despite minor deviations observed at specific wavelengths for some reflectors. Geometric correction, utilizing a rubber sheet transformation with ground control points, successfully rectified distortions caused by sensor orientation and flight path variations, ensuring accurate spatial representation within the image. The effectiveness of geometric correction was assessed using root mean square error(RMSE) analysis, revealing minimal errors in both east-west(0.00 to 0.081 m) and north-south directions(0.00 to 0.076 m).The overall position RMSE of 0.031 meters across 100 points demonstrates high geometric accuracy, exceeding industry standards. Additionally, image mosaicking was performed to create a comprehensive representation of the study area. These results demonstrate the effectiveness of the applied preprocessing techniques and highlight the potential of DHSs for precise crop health monitoring and management in smart agriculture. However, further research is needed to address challenges related to data dimensionality, sensor calibration, and reference data availability, as well as exploring alternative correction methods and evaluating their performance in diverse environmental conditions to enhance the robustness and applicability of hyperspectral data processing in agriculture.