• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.17-28
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• 2021

Recently, eVTOL, the next-generation of eco-friendly transportation, has been in the spotlight due to global warming along with traffic jams in large cities of many countries. This study benchmark the external features of Hyundai Motors S-A1, a compound eVTOL combined fixed and tilt rotors among many types of eVTOLs, to create the basic configuration using reverse design techniques. Basic configurations were created using CATIA and aerodynamic analyses were performed using the aircraft design and aerodynamic analysis programs, OpenVSP, XFLR5, and the aircraft wetted area, drag, and lift were calculated after selecting the airfoil, incidence angle, and dihedral and anhedral angles through trade study. Also, required powers were estimated for completing the given mission profile and components weight and the total weight were predicted using the estimation formula and data survey.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.277-280
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• 2006

This paper describes the aerodynamic interference characteristics between the ing and the engines in a commercial airplane which is realized by reverse engineering based on the photo measurement. Steady three-dimensional compressible inviscid Euler equation is solved in the unstructured grid system under the cruise condition. The lift and drag forces in the wing with engines increase by 1.49% and 3.9%, respectively compared with the wing without engines.

• Journal of Science Education
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• v.35 no.2
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• pp.283-294
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• 2011

The purpose of this study were to develop a tutorial for secondary students to understand of basic concepts of special relativity, which is appropriate for the cognition level of secondary student. We developed the concept evaluation tool and the tutorial material. Result from pretest and post-test are presented to verify the effect of the tutorial for helping student understanding of the concept such as time, event, reference frame, relativity of simultaneity. Secondary student had intense cognitive conflict about the complex concepts such as simultaneity, length contraction and time expansion. This tutorial could be proposed methodology to overcome cognitive difficulty for understanding these concepts.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.1
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• pp.5-27
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• 2017

The goal of this study is to suggest various improvements and expanding strategies of the public library ecosystem. For this goal, researcher reviewed and analyzed the realistic landscapes and social recognitions about the public library ecosystem as local public goods, and discoursed the basic principles and structural terrain of public library ecosystem based on natural ecosystem. As a result, researcher proposed multifaceted alternatives (ensure library's identity and publicity applying Law of Karma, strengthen librarian's professionalism on the premise of overcoming the Minerva's syndrome, optimize the library service and collection management based on the Pareto principle, reduce reading room and differentiated program through resolution of Halo effect, eliminate usage bias by life cycle based on the Gauss distribution, acceptance of the digital paradigm and use-friendly spatialization that ruminates the Icarus paradox, incorporate small library into public library system through a clear understanding of the Gresham's law, and enforce communication and spread social and cultural value through the practice of the Pompeii paradox).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2210-2220
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• 2009

Independent-suspension type axles for heavy duty special vehicles are usually produced by only a few specialized companies. The special techniques, such as designing, producing, testing techniques has been unveiled. The test of durability with the vehicle in which is installed a prototype taking several years is required for setting the designing parameters. In this research, through-drive the core-component of the independent-suspension type axle has been tested with the reverse engineering and the testing methods for the confirmation of the accomplishment in the development goal has been suggested. Also the prototype is developed from designing and testing the design with the CAD and CAE tools. As a result, the process and testing methods studied in this research are useful in the development of power train.

• The Microorganisms and Industry
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• v.13 no.2
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• pp.31-32
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• 1987

노동집약적인 물량위주의 수출산업정책에서 기술집약적 첨단제품 수출정책으로의 전환을 강요 받고 있는 때에 정부와 산업계에서는 자구책을 강구하기 위하여 부심하고 있으며 경제계에서 먼저 과학기술의 필요성을 역설하고 있는 실정이다. 과학기술분야의 투자가 증가되고 있다고는 하나 그중에서 가장 중용한 부분을 차지하는 인력개발 두뇌개발을 위하여 우리는 어떤 방법을 강구하고 어떤 정책을 시행하여 효율적으로 투자하는 것이 지속적이고 안정된 경제성장을 유지할 수 있겠는가에 대해 이제는 구체적이고 현실성있게 논의해야 할 단계에 온것이 아니냐는 전제하에서 산학협동을 중심으로 몇가지 제언을 하고자하는 바이다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.178-182
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• 2008

Automotive manufacturers lay their eyes on the new manufacturing technologies because of the strengthened competition. Among them, a simultaneous forming is one of the innovative forming technologies to be able to reduce production time and cost. Several parts can be simultaneous manufactured by process, while the conventional stamping demands the same number of die sets with the number of parts. In this study, the automotive front side member was manufactured by the simultaneous forming. The position and the size of initial blank were determined by forming analysis and try-outs, and the blank movement during the forming was controlled by introducing the pilot pin.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.12 no.6 s.105
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• pp.31-39
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• 1991

소득의 증가로 생활수준이 향상됨에 따라 건강에 대한 소비자의 관심이 그 어느때 보다 고조되고 있다. 농산물(식품)중에 잔류하는 미량의 농약성분, 특히 발암위해성과 관련이 있는 농약성분의 잔류분에 대한 안전성 평가에 많은 관심이 모아지고 있는 것은 우리나라 뿐만 아니라 전세계적인 추세이다. 특히 미국에서는 관련법규(연방살충$\cdot$살균$\cdot$살서제법과 연방식품$\cdot$의약품$\cdot$화장품법)의 내용과 해석 차이로 US/EPA가 농약의 효율적인 관리를 위한 법률적용에 많은 어려움을 겪고 있으며, 현재도 관련법규나 제도를 계속 보완$\cdot$개정하려는 법안이 국회에 계류되어 심의중에 있다. 여기에 소개하는 내용은 US/EPA가 세계농약공업연맹(GIFAP)에 서신으로 보낸 ''델라네이 역설''(Delaney Paradox addressed by US EPA : GIFAP Bulletin Vol. 15(1). 1989)에 관한 것이다.

• Journal of KIBIM
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• v.6 no.4
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• pp.18-26
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• 2016

Recently, for the purpose of maintenance of facilities and energy, there have been growing cases of the 3D image scan-based reverse design technology mostly in the manufacturing field. In the MEP field, because of differences between design and physical model, the reverse technology has been utilized in factory facilities such as a semiconductor factory. Because 3D point clouds from scanning include accurate 3D object information, the efficiency of management works related to the complex MEP facilities can be enhanced. In this study, the reverse technology was surveyed, and the MEP facility management based on 3D image scanning was analyzed. Based on the results, a method of 3D image scan-based MEP facility management was proposed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.6
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• pp.705-712
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• 2004

An inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure has been conducted in this study. Net energy exchange method was used to calculate the radiative heat flux on each surface, and a hybrid genetic algorithm was adopted to minimize an objective function, which is expressed by sum of square errors between estimated and measured or desired heat fluxes on the design surface. We have examined the effects of the measurement error as well as the number of measurement points on the estimation accuracy. Furthermore, the effect of a variation in one boundary condition on the other boundary conditions was also investigated to get the same desired heat flux and temperature distribution on the design surface.