• Journal of the Korean institute of surface engineering
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• v.57 no.1
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• pp.31-37
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• 2024

The surge in demand for lithium is primarily fueled by the expanding electric vehicle market, the necessity for renewable energy storage, and governmental initiatives aimed at achieving carbon neutrality. This study proposes a straightforward method for lithium extraction utilizing cellulose nanofiber (CNF) via a vacuum filtration process. This approach yields a porous CNF film, showcasing its potential utility as a lithium extractor and indicator. Given its abundance and eco-friendly characteristics, cellulose nanofiber (CNF) emerges as a material offering both economic and environmental advantages over traditional lithium extraction techniques. Hence, this research not only contributes to lithium recovery but also presents a sustainable solution to meet the growing demand for lithium in energy storage technologies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.354-361
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• 2018

This paper describe the Lateral Navigation algorithm design and verification that implementation on Mission Computer's OFP for Korean Utility Helicopter(KUH) instead of Auto Flight Control System(AFCS) Vehicle Management System. The LNAV function transmits Roll command into the AFCS System. The Roll command value will be calculated by control algorithms in MC. The Operational Flight Program(OFP) shall use for its calculations different measurements of the aircraft's attitude and place. Using these inputs, the OFP will translate a navigational demand(for example-to perform the selected flight plan) into Roll commands to the autopilot. By conducting integration test using SIL and ground test, flight test, it is confirmed that the introduced algorithm meets the requirements of the Mission Equipment Package(MEP) system. LNAV function is verified through the System Integration Laboratory(SIL) test, ground and flight test.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.291-299
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• 2021

In 2019, SUV sales surpassed sedans in the domestic sales market with phenomenal domestic sales. The strength of SUVs around the world is expected to continue in the future. South Korea's K-company aggressively launched small SUVs in the SUV market. Its simple lineup is recognized as a brand image, not as a SUV. It is time to evaluate this. Therefore, it influences the purchasing decisions of potential customers and buyers of small SUVs through the evaluation of design images of small SUVs in Korea. Rather than the functional properties of the SUV model, it is purchased by emotional characteristics, brand symbolism, and image. Subconsciousness of the purchasing psychology of the end consumer was used by metaphor extraction techniques. Customers wanted to study the evaluation of small SUV design images that fit their needs. We wanted to see if consumers who intend to purchase or purchase small SUVs in Korea had a connection with the image of design of small SUVs in Korea. The conclusion of the study was extracted through ZMET, a metaphor extraction technique, with the latent consciousness of the primary ambiguous message from the consumer's feeling and representation of the image. Therefore, based on the results of this study, we hope that the images presented in SUVs in the future will be used as a design guide in the development of small SUVs to influence customer thinking and behavior.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.555-562
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• 2021

Recently, in the field of geospatial information construction, unmanned aerial vehicles have been increasingly used because they enable rapid data acquisition and utilization. In this study, photogrammetry was performed using fixed-wing, rotary-wing, and VTOL (Vertical Take-Off and Landing) unmanned aerial vehicles, and geospatial information was constructed using two types of unmanned aerial vehicle LiDAR (Light Detection And Ranging) sensors. In addition, the accuracy was evaluated to present the utility of spatial information constructed through unmanned aerial photogrammetry and LiDAR. As a result of the accuracy evaluation, the orthographic image constructed through unmanned aerial photogrammetry showed accuracy within 2 cm. Considering that the GSD (Ground Sample Distance) of the constructed orthographic image is about 2 cm, the accuracy of the unmanned aerial photogrammetry results is judged to be within the GSD. The spatial information constructed through the unmanned aerial vehicle LiDAR showed accuracy within 6 cm in the height direction, and data on the ground was obtained in the vegetation area. DEM (Digital Elevation Model) using LiDAR data will be able to be used in various ways, such as construction work, urban planning, disaster prevention, and topographic analysis.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.32-42
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• 2022

The strategy to develop a launch vehicle family by bundling multiple rocket engines of a single type has been proven by SpaceX and their reusable fleet comprised of Falcon 9 and Falcon Heavy. In this study, we revisit a potential launch vehicle family out of a 35 tonf-class methalox staged combustion cycle engine and evaluate their utility and performance in various space missions. For example, a Korean version of Falcon 9 can deliver 4.7 tons of payload into 500 km SSO in an expendable mode while the payload is reduced to 2.16 tons in a sea-landing reusable mode. A Korean version of Falcon Heavy can deliver 4.4 tons into GTO when launched from the Naro Space Center, indicating that this common booster core configuration can handle Cheollian 2 albeit the high inclination. Once developed, the same methaloax engine can power the first-stage of smallsat launch vehicles and air launch vehicles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.53-60
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• 2017

This paper is to design and implement the drone that supports a wideband multimedia communication and a long-range to save people in maritime. The drone is an Unnamed Aerial Vehicle (UAV) that is controlled by a radio wave not by people boarding the machine. We use the drone to respond quickly to the boating accident. To develop a smart drone for the high speed seamless video streaming in a long-range maritime, a necessary techniques are hardware design techniques that design structure of a drone, controlling techniques that operate a drone and communication techniques that control a drone in a long distance. In this paper, the limitations and techniques to design and implement the structure of drone supporting wideband multimedia communication for long-range maritime are explained. By expanding this communication drone network, it is aimed at improving utility of a drone.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.309-313
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• 2006

Many researchers have studied on the lightness of automobile. These researches are such as a body shell, sub frame, fuel tank, engine etc. The transmission Part is a magnitude one in the aspect of weight. A drive shaft (propeller shaft) transmits the engine power to rear differential gear assembly. It is used in the compact car that is a single drive shaft. But in the case of long body cars such as SUV (Sports Utility Vehicle), truck and large vehicle, two or three divided drive shaft are used to prevent the vibration damage from a drive shaft that has been taken high torsion and rotation. This multi-divided drive shaft structure is so heavy because it is assembled by yoke, center bearing and solid spline axis. When the rear axle move up and down, the spline shaft adjust the variation of a length between the transmission and rear axle gearbox. In this paper, it is studied in the experimental method that is a bending vibration characteristic of slip in tube shaped propeller shaft. This type propeller shaft is developed to combine the spline axis with drive shaft and can be light in weight of transmission part.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.177-184
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• 2019

The Defense Technology Security Act was enacted in 2015 to protect the defense industrial technology from being duplicated or interfering technologies being developed, which prevents its value and utility from deterioration and prevents inappropriate export. Defense industrial technology refers to technology that should be protected for national security among the national defense science and technology related to the defense industry. However, technical identification criteria of identification and management system of protection technology are not regulated. Therefore, in this study, through the Delphi survey, diesel engine core technology identification criteria related to the high efficiency internal combustion engine propulsion technology among the 141 defense industrial technologies is established to improve the identification and management system of the technology to be protected among the defense industrial technology protection system. As a result of the study, operational operability, durability, safety, sequencing and modularization were established as diesel engine core technology identification criteria.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.620-626
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• 2019

With the development of robot technology, the expectation of autonomous mission operations has increased, and the research on robot control architectures and mission planners has continued. A scalable and robust control architecture is required for unmanned surface vehicles (USVs) to perform a variety of tasks, such as surveillance, reconnaissance, and search and rescue operations, in unstructured and time-varying maritime environments. In this paper, we propose a robot control architecture along with a new utility function that can be extended to various applications for USVs. Also, an additional structure is proposed to reflect the operator's command and improve the performance of the autonomous mission. The proposed architecture was developed using a robot operating system (ROS), and the performance and feasibility of the architecture were verified through simulations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.441-446
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• 2008

The source transfer receiver model ('Source $\times$ Transfer = Response' model) which is widely used by NVH development process of vehicle/transport/machinery to analyze effectively and manage efficiently the structural dynamic behavior is also applicable to construction structure. If the evaluation assessment of the vibration level does not meet the target level, there are two methods, one is source treatment or replacement and the other is the reduction treatment on the transfer structure. In case of source treatment, it is done by source supplier and so, the latter is more practical method to reduce the vibration level. In this study, in order to get the accurate Transfer FE model(floor structure FE model), Experimental modal analysis of part of floor structure and FEM modal analysis of full floor structure are performed, then updating of FE model is performed after correlation analysis between these two results and finally, the modal model and FRF are compared between FE and Experimental results.