• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.90-95
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• 2006

For single engine application like T-50, advanced supersonic jet trainer, airstart capability is very important. This paper presents the results of airstart tests performed to verify T-50 airstart capability for various flight condition. The tests include spooldown, APU assisted and auto-relight airstart tests. Except for the auto-relight tests T-50 engine was successfully restarted for all airstart tests. After modifying FADEC flameout detection schedule, auto-relight tests also were successfully demonstrated. Through T-50 engine airstart tests excellent T-50 airstart capability was validated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.308-315
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• 2007

This study is performed to find out the climb performance of light airplane, Chang Gong-91, as a part of flight test to acquire the certification. Chang Gong-91 is a 5-passenger light aircraft of normal category with single reciprocating engine, and the first officially certified by Korean Ministry of Construction and Transportation in 1993. These flight test procedure and data for climb performance are used to get type certification. We have got maximum climb rate for operating altitude, best angle of climb speed, best rate of climb speed, and absolute ceiling of Chang Gong-91 using drag polar data reduction method from sawtooth climb flight data. Also we compare the form drag coefficient from the results of climb performance and Oswald's effectiveness coefficient to design values using lift-drag curve of light airplane.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.1
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• pp.104-111
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• 2010

This paper deals with the world civil helicopter market scope, world market analysis based on the operating fleet ages, preconditions for market entry, and market forecast which are necessary for Korean industry to enter into world market. According to the analysis, the heavy single class demand is rapidly declined. The demand is moving toward the heavier class than that operated now. Korean industry had better have strategic positioning to heavy twin and light medium twin classes. A considerable amount of Korean civil helicopter based on Surion can be sold if there are appropriate efforts for price, specification, marketing strategy and so on.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.417-424
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• 2019

Purpose: In this study, the goal is to analyze this case to prevent the same accidents when using one-shot rifle. Methods: Detailed analysis of damaged parts must first be made in order to determine the cause of the abnormal explosion. The cause of abnormal operation can be determined by analyzing the information of damaged components and the firing mechanism of the weapon step by step. Also we can refer to a statement of shooter, witness and accident scene situation. Based on this theory, cause of abnormal firing can be narrow down. Results: Fracture of pin for fixing firing and latch is cause of abnormal operation of firing. Conclusion: It is deemed that periodic inspection and fundamental improvement of the structure are required to prevent the same accident as this.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.31-36
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• 2021

In the era of the 4th industrial revolution represented by AI technology, various AI education is being conducted in the education field. However, AI education in the educational field is mostly one-off project education or teacher-centered education. In order to practice student-centered, field-oriented education, an artificial intelligence education program was developed based on design thinking. The AI education program based on design thinking will improve understanding and ability to use AI through the process of solving everyday problems with AI, and will develop the ability to create new values beyond understanding AI. It is expected that various AI education will take place in the educational field through design thinking-based artificial intelligence education programs.

• The Journal of the Korean bone and joint tumor society
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• v.19 no.2
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• pp.78-82
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• 2013

Langerhans cell histiocytosis is known as one of the diseases related to excessive proliferation of normal monocytes and has the variety of clinical courses and treatment. Especially, in cases with the spine, it shows a feature of single or multiple osteolysis. According to the location, disease progression and concomitant symptom, variety of treatments (observation, radiotherapy, chemotherapy, surgery, etc.) have been attempted, however, appropriate treatment has not been established yet. The authors introduce the case of single system Langerhans cell histiocytosis which involves cervical and lumbar vertebrae simultaneously with bone marrow destruction and pathologic fracture.

• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1195-1207
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• 2004

Schema matching is prerequisite to an automated transformation of XML documents. Because previous works about schema matching compute all semantically-possible matchings, they produce many-to-many matching relationships. Such imprecise matchings are inappropriate for an automated transformation of XML documents. This paper presents an efficient schema matching algorithm that computes precise one-to-one matchings between two schemas. The proposed algorithm consists of two steps: preliminary matching relationships between leaf nodes in the two schemas are computed and one-to-one matchings are finally extracted based on a proposed path similarity. Specifically, for a sophisticated schema matching, the proposed algorithm is based on a domain ontology as well as a lexical database that includes abbreviations and synonyms. Experimental results with real schemas from an e-commerce field show that the proposed method is superior to previous works, resulting in an accuracy of 97% in average.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.10
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• pp.791-797
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• 2018

In this work, the high-altitude environment simulation study was carried out at an altitude of 65 km exceeding Mach number of 6 after the launch of Korean Space Launch Vehicle using a shock tunnel. To minimize the flow disturbance due to the strut support of test model as much as possible, a few different types of strut configurations were considered. Using the configuration with minimum disturbance, the high-altitude environment simulation experiment including a propulsion system with a single-plume, was conducted. From the thruster test through flow visualization, not only a shockwave pattern, but a general flow-field pattern from the mutual interaction between the exhaust plume and the free-stream undisturbed flow, was experimentally observed. The comparison with the computation fluid dynamic(CFD) results, showed a good agreement in the forebody whereas in the afterbody and the nozzle the disagreement was about ${\pm}7%$ due to unwanted shockwave formation emanated from the nozzle-exit.

• Archives of design research
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• v.16 no.2
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• pp.271-280
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• 2003

In digital age, multimedia technology has changed the learning method as a learner-directed way. CD-rom and internet that are major two multimedia learning way, has aimed at edutainment which combine education and entertainment. However, existing educational contents can only induce temporary learning motivation, and are in short of entertaining factors enough to induce continuous and ingenuous learning motivation. Therefore, in order to be used by users efficiently, educational software have to adapt characteristics of educational game more actively. In this paper, adoption method of characteristics of educational game in learning contents is sought and the specific example of adoption is demonstrated by a case study of developing vocabulary learning educational game.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.728-731
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• 2015

Nowadays, the majority of the manufacturing plant equipment tend to be transformed with automation system than traditional manual equipment. Production manager to make the process decision-making, not accustomed to manage and take advantage of professional decision-making technique. So rather than using the system proposed, it is common to undergo sporadic measures through the external intermediary. In this paper, whether possible delivery to match the delivery through the issue and decision-making system of the data input to be generated in the manufacturing process, review the supply information of the material used in the process, a plurality of input / output device We have proposed an input module that utilizes the Android Application and ATmega2560. As a result, easily cope with the improvement and change of process information of the work efficiency of the production business of the manufacturing process, and reduced plant data missing tasks, and management improvement to the improvement of the delivery compliance and product satisfaction by improving productivity we try to contribute to.