• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.10
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• pp.829-839
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• 2021

Autonomous system for UAVs has a capability to decide an appropriate current action to achieve the goal based on the ultimate mission goal, context of mission, and the current state of the UAV. We propose a decision-making system that has an ability to operate ISR mission autonomously under the realistic limitation such as low altitude operation with high risk of terrain collision, a set of way points without change of visit sequence not allowed, and position uncertainties of the objects for the mission. The proposed decision-making system is loaded to a Hardware-In-the-loop Simulation environment, then tested and verified using three representative scenarios with a realistic mission environment. The flight trajectories of the UAV and selected actions via the proposed decision-making system are presented as the simulation results with discussion.

• Advances in aircraft and spacecraft science
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• v.6 no.2
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• pp.117-144
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• 2019

High Altitude and Long Endurance (HALE) aircraft are capable of providing intelligence, surveillance and reconnaissance (ISR) capabilities over vast geographic areas when equipped with advanced sensor packages. As their use becomes more widespread, the demand for additional range, endurance and payload capability will increase and designers are exploring non-conventional configurations to meet the increasing demands. One such configuration is the joined-wing concept. A joined-wing aircraft is one that typically connects a front and aft wings in a diamond shaped planform. One such example is the Boeing SensorCraft configuration. While the joined-wing configuration offers potential benefits regarding aerodynamic efficiency, structural weight, and sensing capabilities, structural design requires careful consideration of elastic buckling resulting from the aft wing supporting, in compression, part of the forward wing structural loading. It has been shown already that this is a nonlinear phenomenon, involving geometric nonlinearities and follower forces that tend to flatten the entire configuration, leading to structural overload due to the loss of the aft wing's ability to support the forward wing load. Severe gusts are likely to be the critical design condition, with flight control system interaction in the form of Gust Load Alleviation (GLA) playing a key role in minimizing the structural loads. The University of Victoria Center for Aerospace Research (UVic-CfAR) has built a 3-meter span scaled and flexible wing UAV based on the Boeing SensorCraft design. The goal is to validate the nonlinear structural behavior in flight. The main objective of this research work is to perform Ground Vibration Tests (GVT) to characterize the dynamic properties of the scaled flight vehicle. Results from the experimental tests are used to characterize the modal dynamics of the aircraft, and to validate the numerical models. The GVT results are an important step towards a safe flight test program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.211-217
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• 2019

In an complicated battlefield environment, information from enemy's camp is an important factor in carrying out military operations. For obtaining this information, the number of UAVs that can be deployed to the mission without our forces' loss and at low cost is increasing. Because the mission environment has anti-aircraft weapons, mission space is needed for UAV to guarantee survivability without being killed. The concept of Configuration Space is used to define the mission space considering with range of weapons and detect range of UAV. UAV must visit whole given area to obtain the information and perform Coverage Path Planning for this. Based on threats to UAV and importance of information that will be obtained, area that UAV should visit first is defined. Grid Map is generated and mapping threat information to each grid for UAV path planning. On this study, coverage conditions and path planning procedures are presented based on the threat information on Grid Map, and mission space is expanded to improve detection efficiency. Finally, simulations are performed, and results are presented using the suggested UAV path planning method in this study.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.173-181
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• 2021

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains (Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1-3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 µmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.90.1-90
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• 2003

Colonization of Pseudomonas chlororaphis O6, a nonpathogenic rhizobacterium, on the roots induced systemic resistance in cucumber plants against tai-get leaf spot, a foliar disease caused by Corynespora cassiicola. A cDNA library was constructed using mRNA extracted from the cucumber leaves 12 h after inoculation with C. cassiicola, which roots had been previously treated with O6. To identify the genes involved in the O6-mediated induced systemic resistance (ISR), we employed a subtractive hybridization method using mRNAs extracted from C cassiicola-inoculated cucumber leaves with and without previous O6 treatment on the plant roots. Differential screening of the cDNA library led to the isolation of 5 distinct genesencoding a GTP-binding protein, a putative senescence-associated protein, a galactinol synthase, a hypersensitive-induced reaction protein, and a putative aquaporin. Expressions of these genes are not induced by O6 colonization alone. Before challenge inoculation, no increase in the gene transcriptions could be detected in previously O6-treated and untreated plants but, upon subsequent inoculation with the pathogenic fungus, transcription levels in O6-treated plants rose significantly faster and stronger than in untreated plants. Therefore, the O6-mediated ISR may be associated with an enhanced capacity for the rapid and effective activation of cellular defense responses which becomes apparent only after challenge inoculation on the distal, untreated plant parts, as suggested by Conrath et al. (2002). This work was supported by a grant R11-2001-092-02006-0 from the Korea Science and Engineering Foundation through the Agricultural Plant Stress Research Center at Chonnam National University.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.45-60
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• 2003

As we live in real If era, If become a mandatory component for nations and organizations to survive in severe competition. If is also thought of as strategic asset for effective business operations, yet there is no proved statement on the interoperability and system integration which causes serious problem in terms of requirement engineering among current systems. The National Defense Enterprise Architecture Framework is a strategic information asset base, which define the military operation activities for the mission, the information necessary for military operations, the technologies necessary for implementing new technology in response to changing operational needs. It is an integrated model or representation. Information Systems will be evolved by the National Defense Enterprise Architecture framework. The purpose of this framework is to present overall picture of national defense information system domain so that information systems are interoperated, integrated and information sharing is increased among affiliated organization of Defense Military.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1181-1184
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• 2005

In this paper, we proposed small scale real-time operating system for embedded system. Real-time system is characterized by the severe consequences that result if logical as well as timing correctness properties of system are not met. On real-time system, real-time operating system allows real-time applications to be designed and expanded easily. Functions can be added without requiring major changes to the software. We design small scale real-time operating system for preemptive kernel, and design kernel component such as multitasking, scheduler, task priority, semaphore, inter-task communication, clock tick timer, ISR(Interrupt Service Routine) mechanism has low interrupt latency.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.6
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• pp.347-357
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• 2013

Cyber-Physical system(CPS) is characterized by collaborating computational elements controlling physical entities. In CPS, human desire to acquire useful information and control devices anytime and anywhere automatically has increased the necessity of a high reliable system. However, the physical world where CPS is deployed has management complexity and maintenance cost of 'CPS', so that it is impossible to make reliable systems. Thus, this paper presents an 'Autonomic Control System towards High-reliable Cyber-Physical Systems' that comprise 8-steps including 'fault analysis', 'fault event analysis', 'fault modeling', 'fault state interpretation', 'fault strategy decision', 'fault detection', 'diagnosis&reasoning' and 'maneuver execution'. Through these activities, we fascinate to design and implement 'Autonomic control system' than before. As a proof of the approach, we used a ISR(Intelligent Service Robot) for case study. The experimental results show that it achieves to detect a fault event for autonomic control of 'CPS'.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.311-315
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• 2015

In this study, we estimated the topside scale height of plasma density (Hm) using the Swarm constellation and ionosondes in Korea. The Hm above Korean Peninsula is generally around 50 km. Statistical distributions of the topside scale height exhibited a complex dependence upon local time and season. The results were in general agreement with those of Tulasi Ram et al. (2009), who used the same method to calculate the topside scale height in a mid-latitude region. On the contrary, our results did not fully coincide with those obtained by Liu et al. (2007), who used electron density profiles from Arecibo Incoherent Scatter Radar (ISR) between 1966 and 2002. The disagreement may result from the limitations in our approximation method and data coverage used for estimations, as well as the inherent dependence of Hm on Geographic LONgitude (GLON).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.213-217
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• 2015

Microwave Photonic(MWP) filters capable of use a bandpass filter or a notch filter with large bandwidth have been proposed. 4-lines${\times}$2-bit fiber-optic delay lines with a unit time-delay difference of 50 ps were experimentally realized. By changing the time-delay difference and the coefficients of microwave-modulated optical signals, the bandpass and notch filters were implemented and characterized.