• Advances in aircraft and spacecraft science
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• v.9 no.2
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• pp.103-117
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• 2022

In this paper, a novel morphing mechanism using a deployable scissor structure was proposed for a variable camber morphing wing. The mechanism was designed through the optimization process so that the rib can form the target airfoils with different cambers. Lastly, the morphing wing was manufactured and its performance was successfully evaluated. The mechanism of the morphing wing rib was realized by a set of deployable scissor structure that can form diverse curvatures. This characteristic of the structure allows the mechanism to vary the camber that refers to the airfoil's curvature. The mechanism is not restrictive in defining the target shapes, allowing various airfoils and overall morphing wing shape to be implemented.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.3
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• pp.43-60
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• 2005

In september 2004, a new pilot certificate scheme referred to as Sport Pilot Certificate was declared official and standardized in the US. The designation of Light-sport aircraft and the details of the relevant pilot certificate policy was announced out of the perception that a new regulation is required to be applied whereby the limitations on the manufacturing process enhancements and current aviation rules are considered the triggering factors. US Federal Aviation Regulation retains a comprehensive range of airworthiness certificates and aircrafts are managed systematically in accordance with FAR 21, 103. The airworthiness are further segregated into sub categories, which allows differentiated management. Korean Aviation Law classify aircraft into five different categories and powered air vehicle that weighs more than 150kg(19liters fuel capacity) for one seat, 225kg for two seats(38liters fuel capacity) while the systems that fall under a specific mass threshold level are known as ultralight vehicle. The research discusses the policy of the sport pilot certificate and the light-sport aircraft ratings announced official by the Federal Aviation Administration in an intuitive fashion with the analysis of the operations providing the evidence as to the viability of adopting the policy in local grounds. Based on the findings, the report discusses the case for introducing the light-sport aircraft and make recommendation on a strategy of applying the policy in Korea with respect to the pilot certificates, safety agenda, and the written test for the pilot certificate, and operating efficiency.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.261-266
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• 2020

When a KW-class power control unit is installed in an aircraft installation, a heat dissipation design for a large amount of heat generated during power conversion should be considered. Failure to provide adequate heat dissipation can lead to equipment malfunction and fire, which can be a fatal factor in aviation operations. This paper describes the heat dissipation design of a KW-class power control unit installed in aircraft installation. The design and manufacturing test were conducted through computerized analysis, and the analysis model was corrected by confirming the rapid heat generation phenomenon of the heating element due to high power control. After the model revision, the design was improved, and the high-temperature operation test of the US military standard MIL-STD-810G was performed to confirm the feasibility of the improved design.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.95-103
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• 2023

Aircraft engine parts repair is a field belonging to the lowest level in the hierarchy of the aircraft industry, and it is marginalized in terms of research, compared to aircraft manufacturing or maintenance that belong to the upper level. On the other hand, in 2019, Korean Air's Powerplant Maintenance Center paid USD $130 million to foreign countries for engine parts repair, making it an industry with great need for localization. To achieve the goal of localizing engine parts repair, a certification system is needed that can perform independent repairs based on the development of repair technology, aligning contractual relationships with engine manufacturers, and free from dependence on engine manufacturers or foreign repair companies. The purpose of this study is to provide a basis for subsequent research to secure an actual certification system by suggesting the need for securing such a certification system.

• The Journal of Information Systems
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• v.30 no.1
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• pp.151-177
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• 2021

Purpose This paper aims to improve management performance by effectively responding to production needs and reducing inventory through synchronizing production planning and procurement in the aviation industry. In this study, the differences in production planning and execution were first analyzed in terms of demand, supply, inventory, and process using the big data collected from a domestic aircraft manufacturers. This paper analyzed the problems in procurement and inventory management using legacy big data from ERP system in the company. Based on the analysis, we performed a simulation to derive an efficient procurement and inventory management plan. Through analysis and simulation of operational data, we were able to discover procurement and inventory policies to effectively respond to production needs. Design/methodology/approach This is an empirical study to analyze the cause of decrease in inventory turnover and increase in inventory cost due to dis-synchronize between production requirements and procurement. The actual operation data, a total of 21,306,611 transaction data which are 18 months data from January 2019 to June 2020, were extracted from the ERP system. All them are such as basic information on materials, material consumption and movement history, inventory/receipt/shipment status, and production orders. To perform data analysis, it went through three steps. At first, we identified the current states and problems of production process to grasp the situation of what happened, and secondly, analyzed the data to identify expected problems through cross-link analysis between transactions, and finally, defined what to do. Many analysis techniques such as correlation analysis, moving average analysis, and linear regression analysis were applied to predict the status of inventory. A simulation was performed to analyze the appropriate inventory level according to the control of fluctuations in the production planing. In the simulation, we tested four alternatives how to coordinate the synchronization between the procurement plan and the production plan. All the alternatives give us more plausible results than actual operation in the past. Findings Based on the big data extracted from the ERP system, the relationship between the level of delivery and the distribution of fluctuations was analyzed in terms of demand, supply, inventory, and process. As a result of analyzing the inventory turnover rate, the root cause of the inventory increase were identified. In addition, based on the data on delivery and receipt performance, it was possible to accurately analyze how much gap occurs between supply and demand, and to figure out how much this affects the inventory level. Moreover, we were able to obtain the more predictable and insightful results through simulation that organizational performance such as inventory cost and lead time can be improved by synchronizing the production planning and purchase procurement with supply and demand information. The results of big data analysis and simulation gave us more insights in production planning, procurement, and inventory management for smart manufacturing and performance improvement.

• Composites Research
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• v.27 no.6
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• pp.231-235
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• 2014

Autoclave processing has a good quality of product, but manufacturing cost is expansive. After curing of composite, the unwanted deformation and distortion increase the manufacturing cost by redesign of tool parts. Therefore, manufacturing cost down is a big issue in processing level. For the reduction of tool costs, it is important to investigate the effects of tool materials and tool surface conditions. In this paper, we organized user subroutine in ABAQUS to consider the thermal effects of part and tool, and the results are compared with commercial code, COMPRO. And this paper suggests reference point for the selection of tool materials to reduce manufacturing costs.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.31-40
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• 2008

The aircraft manufacturing industry is a profitable business and has the potential to be an important export business. Our trade deficit needs to be improved in aircraft manufacturing part. Our national aircraft industry, which has been recognized for its quality in many domestic and international Air Shows, has developed the T/A-50 aircraft from the origins of the KT-1. With the ongoing development of the next generation fighter planes and helicopters, business for the next generation domestic air cargo has bright prospects. Judging by the history of the overseas air force dispatch during the Vietnam, Gulf, and Iraqi wars whose main mission was air transportation, there will be many opportunities to show the excellence of Korean air cargo in the future. The purpose of this study is to discover the optimal scale of air cargo development using the AHP method. The authors evaluated the scale of air cargo in size and capacity based on the following 5 standards used Korean developing airliner: usability, economics, technology, safety, and environmental friendliness. Then, the authors modified specific standards suitable for air cargo based on literature review Decision-making groups were chosen for suitability of expert staff in charge because they could represent for leading opinions in this specialized area especially as in practical aspects. The participants of the evaluation were pilots, transportation officers and management staff in the KAI who have experienced over 5years.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.2
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• pp.9-21
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• 1992

Sheet metal forming with hydraulic counter-pressure has several advantages compared with conventional drawing, such as higher forming limits, higher accuracy of formed parts and the achievement of complicated formed shapes. About 50 special press machines have already been used in Japan for manufacturing lighting reflectors, aircraft parts and automobile parts. This report descirbes the techniques and the equipment used in the application of process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.64-69
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• 2002

The purpose of this paper was to investigate the welding characteristics and the fatigue crack propagation behavior of titanium commonly using power station, aircraft and ship. The experimented material was TIG welded in order to look over the characteristics according to the notch position and compare with other materials. We compared and reviewed the fatigue crack propagation behavior of nontch base metal and welded specimens having different notch position to evaluate the fatigue crack propagation behavior by welding condition.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.758-759
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• 1995

In large-scale industry such as shipbuilding, aircraft manufacturing, and construction industry etc., it is required to consider two or three-dimensional spatial availability as one of bottlenecked resource constraints. We call this kind of scheduling a spatial scheduling, which considers the dynamic spatial layouts of objects as well as the traditional resource constraints. Since 1991, we have researched on the spatial scheduling for shipbuilding plant (Lee & Lee, 1992; Lee et al., 1994, Lee et al., 1995). In this paper, we present the various issues of spatial scheduling for the researchers and developers attacking spatial scheduling problems.