• Korean Journal of Environmental Biology
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• v.34 no.1
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• pp.30-36
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• 2016

We investigated the diversity pattern of spring moths across two regions of South Korea, Yongin city (middle part) and Muan gun (southern part) and the effects of climatic variables on moth species richness and abundance. Moths were weekly collected using UV light trap in April from 2013 to 2015. Climatic factors included growth degree day with base temperature 8 (GDD8), average temperature, precipitation, duration of sunshine, wind speed, and snow cover. The climatic effects on moth species richness and abundance were analyzed by short (0~3 weeks before collecting) and long (4~12 weeks before collecting) time periods, respectively. The diversity of spring moths showed the similar pattern of species composition at family level. However the dominant family differed depending on the region: Geometridae at middle part and Noctuidae at southern part. In addition the dominant species of Noctuidae occurred early in April and that of Geometridae moths occurred later in April. Three short-term climatic factors, GDD8, duration of sunshine, and precipitation one week before collecting were significant on moth species richness and abundance, while only one long-term climatic factor, temperature four weeks before collecting was significantly affected on moth species richness. We found that both Geometridae and Noctuidae were dominant in spring moth fauna across South Korea and they were different in the dominance and flying time in April. The occurrences of spring moths were largely affected by warmness and precipitation. The current global warming could affect the occurrence of spring moths and this should be monitored consistently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.774-780
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• 2021

The auxiliary power unit (APU) of a rotorcraft starts the engine during operation/flying. The APU is composed of a gas turbine engine type. The starting principle of the component is that the electric start motor generates the power required for starting by rotating the shaft. In this study, quality improvement was performed by applying an over-running clutch (ORC) between the APU and the starter motor to secure the operability of the starter motor of the APU mounted on the rotorcraft. The starter motor has the main role of starting the APU, but during operation, it is rotated without load by the rotational force of the APU gear shaft, resulting in friction at the brush. This phenomenon causes abrasion of the brush of the starter motor. Consequently, when the APU operation time increases, the brush life decreases, and the operability of the APU is affected. In this study, an ORC that separates the interlocking between the start motor brush abrasion and the APU operation time was applied to improve the operability/durability of the APU starter motor. The effect was verified through a test, and the technical feasibility of the design change was analyzed.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.381-385
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• 2008

A 69-year-old man was admitted to our hospital for deep vein thrombosis, and he had experienced two episodes of left leg swelling: one happened after an 11 hour-air trip from Europe in June 2007, and the other developed 3 days after an operation for a herniated lumbar disc in July 2007. We treated him for a deep vein thrombosis of the deep femoral vein after admission. However, we arrived at the final diagnosis of angioleiomyosarcoma after the operation for the tentative diagnosis of deep vein thrombosis. We removed the firmly engorged deep femoral vein on the second operation. We report here on a case of angioleiomyosarcoma that arose from the deep femoral vein.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.4
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• pp.283-289
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• 2018

Launch Acceptability Region(LAR) means an area for successfully hitting the target. And LAR should be calculated in real time on aircraft so that LAR can be seen by pilot. LAR can be changed by the launch condition of the bomb, the impact condition of the target, and the atmospheric condition at the time of flight of the bomb. In this paper, we propose the calculation method of LAR using Artificial Neural Network(ANN). The learning data was generated by changing each condition from existing LAR model, and LAR model was derived through ANN learning. We confirmed the accuracy of the new LAR model by comparing the difference between the result data of existing LAR model and the new LAR model. And we confirmed the possibility of real time calculation of the LAR model on the aircraft by comparing the calculation time.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.1-10
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• 2008

The Bird strike to small aircraft has not been an issue because of it's low speed and usage as a private aircraft. So, the compliance of the bird strike regulation is limited to large fixed-wing aircraft such as the commuter category in FAR Part 23 and the civil aircraft in FAR Part 25, generally. However, the forecast of dramatic increasing of VLJ(Very Light Jet) and (light time of general aviation due to Air-taxi for the point to point transportation, would rise up the need of bird strike regulations and a safety enhancement in normal and utility categorized aircraft. In this study, the safety enhancement concept using a crushable foam for the bird strike to small aircraft wing leading edge, and the evaluation about the safety of the bird strike to small aircraft are proposed using the explicit finite element analysis.

• Analytical Science and Technology
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• v.28 no.2
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• pp.132-138
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• 2015

Rosiglitazone metabolites in rat plasma were analyzed after intraperitoneal and oral administration to rats. Seven metabolites (M1-M7) were detected in rat plasma (IP and PO), and the structures were confirmed using liquid chromatography-triple time of flight (TOF) mass spectrometry; as a result, the most abundant metabolite was M5, a de-methylated rosiglitazone. Other minor in vivo metabolites were driven from monooxygenation and demethylation (M2), thiazolidinedione ring-opening (M1, M3), mono-oxygenation (M4, M7), and mono-oxygenation followed by sulfation (M6). Among them, M1 was found to be a 3-{p-[2-(N-methyl-N-2-pyridylamino)ethoxy]phenyl}-2-(methylsulfinyl)propionamide, which is a novel metabolite of rosiglitazone. There was no significant difference in the metabolic profiles resulting from the two administrations. The findings of this study provide the first comparison of circulating metabolite profiles of rosiglitazone in rat after IP and PO administration and a novel metabolite of rosiglitazone in rat plasma.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.127-133
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• 2014

This paper proposes a determination method of waypoints to maximize the survivability of a UAV. Voronoi diagram which is used for the initial selection of waypoint candidates is the most widely used path planning technique to avoid the threat as far as possible when the location and strength of the threat are given. But if threat strength is different each other and flight path is constrained along with straight lines, Voronoi diagram has limitations in real applications. In this study, the initial waypoints obtained from Voronoi diagram are optimized considering the shape of each threat. Here, a waypoint is optimized while adjacent waypoints are fixed. By repeating this localized optimization until whole waypoints are converged, computation time for finding the best waypoints is greatly reduced.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.5
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• pp.335-342
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• 2020

Tailless aircraft designed for stealth efficiency uses spoilers instead of rudders for the directional control. When the spoiler is rapidly deployed, highly nonlinear and unsteady aerodynamic characteristics can be generated, resulting in adverse effects on aircraft flight performance. This paper investigates the aerodynamic characteristics of an airfoil with moving spoiler using dynamic mesh CFD technique. The effects of spoiler operation speed, mounting location, and deployment scheduling are analyzed to reduce the adverse effects of the spoiler's dynamic operation. The results shows that the adverse effects of dynamic spoiler can be reduced by appropriate selection of the spoiler mounting location and deployment scheduling.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.29-32
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• 2010

The neutron capture cross section of $^{197}Au$ has been measured relative to the $^{10}B(n,{\gamma})$ standard cross section by the neutron time-of-flight(TOF) method using a 46-MeV electron linear accelerator(linac) at the Research Reactor Institute, Kyoto University(KURRI). In order to experimentally prove the result obtained, the supplementary cross section measurement has been made from 0.1 eV to 10 keV using the Kyoto University Lead slowing-down spectrometer (KULS) coupling to the linac. The relative measurement by the TOF method has been normalized to the reference value(24.5 b) at 1 eV. The evaluated capture cross sections in JENDL/D-99 Dosimetry have been compared with the current measurements by the KULS experiments.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.829-846
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• 2018

Crop monitoring can provide useful information for farmers to establish farm management strategies suitable for optimum production of vegetables. But, traditional monitoring has used field measurements involving destructive sampling and laboratory analysis, which is costly and time consuming. Unmanned Aerial vehicle (UAV) could be effectively applied in a field of crop monitoring for estimation of cultivated area, growth parameters, growth disorder and yield, because it can acquire high-resolution images quickly and repeatedly. And lower flight altitude compared with satellite, UAV can obtain high quality images even in cloudy weather. This study examined the possibility of utilizing UAV in the field of crop monitoring and was to suggest the application method for production of crop status information from UAV.