• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.225-226
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• 2022

In order to secure the practicality of services using drones, improve on-site operability, and improve the convenience of aircraft maintenance, it is necessary to develop a drone station that can be safely stored while ensuring charging performance. Therefore, a total seven points of improvement were derived through laboratory experiments after the development of the first prototype, and an improved second prototype will be developed in the future based on the preceding processes.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.508-513
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• 2017

Maintainability in engineering terms means ease of maintenance / management of the product. Aircraft automatic test equipment (ATE) is heavily influenced by the design changes of the unit under test(UUT) since the test procedure is developed according to the function / performance characteristics of the UUT. Moreover, if the integrated ATE is an environment that checks more than one UUT, it is not easy to maintain the ATE for the UUT design changes. Developers should be able to flexibly cope with the change of development staff by selecting an easy and clear development method to improve the maintainability of ATE. It is also necessary to limit the area affected by the UUT design change to a specific range to minimize the area to be modified. In this paper, we propose ATE development method which focuses on maintenance improvement based on the aircraft ATE development process.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.95-100
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• 2014

In hypersonic aircraft, increase of aerodynamic heat and engine heat leads heat loads in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, exo-tetrahydrodicyclopentadiene was selected as a model endothermic fuel and experiments on endothermic properties were investigated with pore structure controlled zeolite catalyst using metal deposition. We secured the catalyst that had better endothermic performance than commercial catalyst. The object of this study is inspect catalyst properties which have effect on heat absorption improvement. Synthetic catalyst could be applied to system that use exo-THDCP as endothermic fuel instead of other commercial catalyst.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.73-83
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• 2022

The purpose of this paper was to identify a method to improve received noise in a specific frequency band, caused by RF radiation signals during aircraft operation. The communication equipment of the aircraft is critical to the performance and safety of the flight mission, as it is responsible for the function of internal and external communications. Noise-free, clean communication quality, as well as transmission and receiving functions have to be implemented. Thus, the cause analysis of the reception noise in a specific frequency band, was analyzed through trouble shooting. The receiving noise due to the RF radiation signal emitted from the subsystem unit inside the aircraft, was improved by shielding with a CAP with electroless nickel plating applied. Additionally, the measurement and verification results of the improvement method are also described.

• Journal of computational fluids engineering
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• v.18 no.4
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• pp.41-46
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• 2013

The selection of the optimal position of the flap was performed in order to improve the aerodynamic performance during the take-off and landing processes of aircraft. For this, the existing airfoils of the main wing and flap are selected as the baseline model and the lift coefficients (cl) according to angle of attacks (AOA) were calculated with the change of the position of flap airfoil. The objective function was defined as the consideration of the maximum cl, lift to drag ratio and cl at certain AOA. Then, at 121 experimental points within $20mm{\times}20mm$ domain, two dimensional flow simulations with Spalart-Allmaras turbulence model were performed concerning the AOA from 0 to 15 degree. If the optimal position was located at the domain boundary, the domain moved to the optimal position. These processes were iterated until the position was included in the inside of the domain. From these processes, the flow separation at low AOA was removed and cl increased linearly comparing with that of the baseline model.

• Journal of Communications and Networks
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• v.17 no.3
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• pp.286-295
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• 2015

Avionic databuses fulfill a critical function in the connection and communication of aircraft components and functions such as flight-control, navigation, and monitoring. Ethernet-based avionic databuses have become the mainstream for large aircraft owning to their advantages of full-duplex communication with high bandwidth, low latency, low packet-loss, and low cost. As a new generation aviation network communication standard, avionics full-duplex switched ethernet (AFDX) adopted concepts from the telecom standard, asynchronous transfer mode (ATM). In this technology, the switches are the key devices influencing the overall performance. This paper reviews the avionic databus with emphasis on the switch architecture classifications. Based on a comparison, analysis, and discussion of the different switch architectures, we propose a new avionic switch design based on a time-division switch fabric for high flexibility and scalability. This also merges the design concept of space-partition switch fabric to achieve reliability and predictability. The new switch architecture, called space partitioned shared memory switch (SPSMS), isolates the memory space for each output port. This can reduce the competition for resources and avoid conflicts, decrease the packet forwarding latency through the switch, and reduce the packet loss rate. A simulation of the architecture with optimized network engineering tools (OPNET) confirms the efficiency and significant performance improvement over a classic shared memory switch, in terms of overall packet latency, queuing delay, and queue size.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.101-127
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• 2017

Even with the most advanced aviation technology benefits, aircraft accidents are constantly occurring while air passenger transportation volume is expected to double in the next 15 years. Since it is not possible to secure aviation safety only by the post aircraft accident safety action of accident investigations, it has been recognized and consensus has been formed that proactive and predictive prevention measures are necessary. In this sense, the aviation safety management system (SMS) was introduced in 2008 and has been carried out in earnest since 2011. SMS is a proactive and predictive aircraft accident preventive measure, which is a mechanism to eliminate the fundamental risk factors by approaching organizational factors beyond technological factors and human factors related to aviation safety. The methodology is to collect hazards in all the sites required for aircraft operations, to build a database, to analyze the risks, and through managing risks, to keep the risks acceptable or below. Therefore, the improper implementation of SMS indicates that the aircraft accident prevention is insufficient and it is to be directly connected with the aircraft accident. Reports of duty performance related hazards including their own errors are essential and most important in SMS. Under the policy of just culture for voluntary reporting, the guarantee of information providers' anonymity, non-punishment and non-blame should be basically secured, but to this end, under-reporting is stagnant due to lack of trust in their own organizations. It is necessary for the accountable executive(CEO) and senior management to take a leading role to foster the safety culture initiating from just culture with the safety consciousness, balancing between safety and profit for the organization. Though a Ministry of Land, Infrastructure and Transport's order, "Guidance on SMS Implementation" states the training required for the accountable executive(CEO) and senior management, it is not legally binding. Thus it is suggested that the SMS training completion certificates of accountable executive(CEO) and senior management be included in SMS approval application form that is legally required by "Korea Aviation Safety Program" in addition to other required documents such as a copy of SMS manual. Also, SMS related items are missing in the aircraft accident investigation, so that organizational factors in association with safety culture and risk management are not being investigated. This hinders from preventing future accidents, as the root cause cannot be identified. The Aircraft Accident Investigation Manuals issued by ICAO contain the SMS investigation wheres it is not included in the final report form of Annex 13 to the Convention on International Civil Aviation. In addition, the US National Transportation Safety Board(NTSB) that has been a substantial example of the aircraft accident investigation for the other accident investigation agencies worldwide does not appear to expand the scope of investigation activities further to SMS. For these reasons, it is believed that investigation agencies conducting their investigations under Annex 13 do not include SMS in the investigation items, and the aircraft accident investigators are hardly exposed to SMS investigation methods or techniques. In this respect, it is necessary to include the SMS investigation in the organization and management information of the final report format of Annex 13. In Korea as well, in the same manner, SMS item should be added to the final report format of the Operating Regulation of the Aircraft and Railway Accident Investigation Board. If such legal and institutional improvement methods are complemented, SMS will serve the purpose of aircraft accident prevention effectively and contribute to the improvement of aviation safety in the future.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.3
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• pp.30-41
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• 2023

Aviation turbulence, caused by atmospheric eddies, is a disruptive phenomenon that leads to abrupt aircraft movements during flight. To minimize the damages caused by such aviation turbulence, the Aviation Meteorological Office provides turbulence information through the Korea aviation Turbulence Guidance (KTG) and the Global-Korean aviation Turbulence Guidance (GKTG). In this study, we evaluated the performance of the KTG and GKTG models by comparing the in-situ EDR observation data and the generated aviation turbulence prediction data collected from the mid-level Korean Peninsula region from January 2019 to December 2021. Through objective validation, we confirmed the level of prediction performance and proposed improvement measures based on it. As a result of the improvements, the KTG model showed minimal difference in performance before and after the changes, while the GKTG model exhibited an increase of TSS after the improvements.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.143-150
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• 2020

To enhance the effectiveness of the FMS (flexible manufacturing system), it is necessary for the manufacturing control system to be upgraded by integrating the cyber and the physical manufacturing systems. Using the CPPS (Cyber-Physical Production System) concept, this study proposes a 4-stage vertical integration and control framework for an aircraft parts manufacturing plant. In the proposed framework, the process controller prepares the operations schedule for processing work orders generated from the APS (advanced planning & scheduling) system. The scheduled operations and the related control commands are assigned to equipments by the dispatcher of the line controller. The line monitor is responsible for monitoring the overall status of the FMS including work orders and equipments. Finally the process monitor uses the simulation model to check the performance of the production plan using real time plant status data. The W-FMCS (Wing rib-Flexible Manufacturing Control & Simulation) are developed to implement the proposed 4-stage CPPS based FMS control architecture. The effectiveness of the proposed control architecture is examined by the real plant's operational data such as utilization and throughput. The performance improvement examined shows the usefulness of the framework in managing the smart factory's operation by providing a practical approach to integrate cyber and physical production systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.2
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• pp.171-178
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• 2016

An aircraft in flight and ATC(: Air Traffic Controllers) working in the Ground Control Center carry out a voice communication using the radio. Voice signal to be transmitted from the aircraft is received to a plurality of terrestrial sites around the country at the same time. The ATC receives the various quality of voice signal from the aircraft depending on the distance, speed, weather conditions and adjusted condition of the antenna and the radio. The ATC carries out a voice communication with aircraft in the optimal conditions finding the best voice signal. However, the present system chooses the values of the CD(: Carrier Dectect) which is determined to be superior to, based on the input voice level, as optimal channel. Thus this system can not be seen to select the optimal channel because it doesn't consider the effect of the noise which influences on the communication quality. In this paper, after removing the noise in the voice signal, we could give the digitized information and an improved voice signal quality, so that users can select an optimal channel. By using it, when operating the training eavesdropping system or the aircraft control, we can expect prevention accident and improvement of training performance by selecting the improved quality channel.