• Cartoon and Animation Studies
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• s.46
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• pp.63-84
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• 2017

Overwhelming images of vividly colored aircraft flying across the blue sky and steam gushing from massive machines are reminiscent of Japanese animation films, especially of works by master director Hayao Miyazaki. By presenting together steam engines, which are mechanical devices of the Industrial Age in the past, and aircraft of the future age, the director constructs ambiguous space and time. These special time and space constitute nostalgia for past time, with devices called steam engines as a medium, and a longing for science and the future as represented by aircraft. In addition, the anticipation and disappointment, ideals and regrets of humans who see these two from the perspective of the present are projected on the works. This shares the characteristic of the steam punk genre, which seeks to return to the past rather than to face current problems. A subgenre of science fiction (henceforth "sci-fi"), steam punk reflects fundamental skepticism of science and technology and mechanized civilization, which have developed beyond human control. In addition, as works that clearly display such characteristics, director Miyazaki's and < $Nausica{\ddot{a}}$ of the Valley of Wind> can be examined. With spectacles of steam engines and aircraft, these two works enticingly visualize narratives about nature and humans and about the environment and destruction. Such attractiveness on the part of the master director's works has led to support from fans worldwide. However, often in the backgrounds of director Miyazaki's works, which have depicted ideal worlds of nature, environment, and community as highly concentrated fantasies, lie presuppositions of war and the end of the world. As works that are especially prominent in such characteristics, there are and . These two works betray the expectations of the audience by establishing the actual wartime as the temporal background and proceeding toward narratives of reality. Trapped in the ontological identity of the director himself, the war depicted by him projects a subjective and romantic attitude. Such a problem stems also from the ambiguity of the hybrid space and time, which is basic to the steam punk genre. This is because the basic characteristic of steam punk is to transplant past time, which humans were able to control, in the future from a perspective of optimism and longing via steam engines rather than to face current problems. In this respect, steam punk animation films in themselves can be seen as having significance and limitations at the same time.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1487-1494
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• 1990

In this paper the dynamic characteristics of self acting air lubricated slider bearing of hard disk/head system are investigated. The dynamic equations of magnetic head mechanism considering both parallel and pitch motion and the time dependent modified Reynolds equation are analyzed and the dynamic pressure distribution of air film is numerically calculated in frequency domain by small perturbation method and finite difference scheme with variable grid. The dynamic response of the slider spacing is obtained accordingly as the moving recording surface vibrates in parallel mode.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.4
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• pp.73-80
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• 2013

Endothermic fuel utilizing technology is considered as a unique practical method of hypersonic vehicle for long distance flight. Research activities about characteristics of fuel injection and combustion using cracked by endothermic reaction are reviewed. Studies on characterization of supercritical fuel injection and mixing within supersonic flow field are surveyed. Researches on combustion characteristics such as ignition delay time, laminar burning velocity and combustion efficiency at supersonic model combustor are reviewed. In addition, domestic research activities on endothermic fuel are surveyed.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.3-43
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• 2018

Auf die ganze Welt macht unbemannte $Flugger{\ddot{a}}te$(sog.Drohnen) in vielen Bereichen rasch Fortschritte und Anwendungen gezeigt. Nachdem ferngesteuerte Drohnen $urspr{\ddot{u}}nglich$ $prim{\ddot{a}}r$ $f{\ddot{u}}r$ $milit{\ddot{a}}rische$ Zwecke entwickelt wurden, $erh{\ddot{o}}cht$ sich derzeit ihre zivile Nutzung sowohl im Freizeit- als auch im Dienstleistungsbereich(Paketdrohnen, Drohnen-taxi) stetig. Mit der vermehrten Drohnennutzung steigen allerdings auch die damit verbundenen Risiken und Herausforderungen. In Zusammenhang damit stellt sich dann die Frage, ob $gegenw{\ddot{a}}rtige$ Vorschriften im Bereich von Luftrecht zurecht gekommen sind. Es sieht sich gerade der zwei Schwerpunkt $gegen{\ddot{u}}ber$. Erstens kann $Passagierebef{\ddot{o}}rderung$ mit unbemanntem Luftfahrzeug(mehr als 150kg) im $gegenw{\ddot{a}}ritigen$ Luftrecht keine Anwendung finden. Denn das kor. Luftsicherheitsgesetz und sein Durchsetzungsverordnung definieren die Terminologie von unbemannten Luftfahrzeugen und unbemannten $Flugger{\ddot{a}}te$ als "wenn eine Person nicht an Bord geht und ferngesteuert wird". Also soll Drohne nach dieser gesetzlichen Definition nur "ohne Person" geflogen werden. Das besagt ohne Piloten und ohne Passagiere. Zweitens ist unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) nicht auf Handelsgesetz anzuwenden, auf das ${\ddot{u}}ber$ Anspruchsgrundlage und Zurechnungsnorm des gewerblichen Luftverkehr geregelt ist. Der unbemannte Luftfahrzeuglieferdienst bringt nicht nur die Gefahr einer $Besch{\ddot{a}}digung$ des Frachtguts mit sich, sondern auch die Gefahr von $Bodensch{\ddot{a}}den$ durch Dritte. Gemäß ${\S}$ 896 des Handelsgesetzes ist aber die Anwendung von unbemannte $Flugger{\ddot{a}}te$(weniger als 150kg) $hierf{\ddot{u}}r$ begrenzt, weil unbemannt $Flugger{\ddot{a}}te$ $einschl{\ddot{a}}gig$ in Ultralight $Flugger{\ddot{a}}t$ ist, die im Handelsgesetz ausschließlich besteht. Technische Fortschritt und die dadurch $erm{\ddot{o}}glichten$ kommerziellen Anwendungen werden die Nachfrage nach unbemannter $Flugger{\ddot{a}}te$ wecken. Die Umsetzung der $bez{\ddot{u}}glichen$ Vorschriften sollte auch diese Entwicklung aktiv begleitet und $fr{\ddot{u}}hzeitig$ kommuniziert und erarbeitet werden, damit Hersteller und Nutzer $fr{\ddot{u}}hzeitig$ Planungssicherheit haben.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.139-147
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• 2013

This paper proposes a novel method for feature selection for mass spectrometric proteomic data based on Random Forest. The method includes an effective preprocessing step to filter a large amount of redundant features with high correlation and applies a tournament strategy to get an optimal feature subset. Experiments on three public datasets, Ovarian 4-3-02, Ovarian 7-8-02 and Prostate shows that the new method achieves high performance comparing with widely used methods and balanced rate of specificity and sensitivity.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.134-134
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• 2016

CMC(Ceramic Matrix Composites)는 $1500^{\circ}C$ 이상의 고온에서 내열성, 내산화성, 내식성이 우수하여, 초음속 비행체, 가스터빈 엔진 및 원자로용 초고온 부품 등에 수요가 증가하고 있다. 하지만 이러한 특성은 비산소 환경에 국한되는 것으로 약 $400^{\circ}C$ 이상의 산화 분위기에는 탄소섬유가 산화되는 문제로 인하여 적용의 한계를 가지고 있다. 따라서 CMC의 적용범위 확대를 위하여 내산화 코팅으로 CMC의 초고온 산화특성을 개선하는 것이 필수적이며, 장시간 초고온 산화환경 분위기에서 사용되기 위하여 안정적인 코팅기술이 최근 기술개발의 핵심현안으로 부각되고 있다. 본 연구에서는 pack cementation 공정을 이용하여 내산화성이 우수한 SiC 코팅층을 제조하였다. Pack cementation 공정에 사용된 코팅 분말은 57wt.% SiC, 30wt.% Si, 3wt.% B, 10wt.% Al2O3의 비율로 혼합된 것이다. 실험은 3D 직조된 CMC 모재를 혼합분말 내에 침적한 후, Ar 분위기에서 $1600^{\circ}C$, 4~12시간 반응시켜 수 마이크론 두께의 SiC 코팅층을 형성하였다. 더 우수한 산화 특성을 부여하기 위하여 pack 처리된 CMC 표면에 초고온 세라믹인 TaC 소재를 진공플라즈마 코팅 공정으로 적층시켰다. 제조된 코팅층을 SEM, XRD를 이용하여 미세구조 및 결정구조를 분석하였으며, pack cementation에 따른 내산화 특성을 비교 분석하고자 $2000^{\circ}C$에서 산화 실험을 진행하였다. 산화 실험 이후 미세구조 및 결정구조 분석으로 산화거동을 규명하고자 하였다.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.196.2-196.2
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• 2012

본 논문은 달착륙선의 개념설계를 위하여 고려한 전력시스템의 설계와 달착륙선의 지상시험모델용 추력기 밸브구동 전원장치 개발에 대해 기술하였다. 달착륙선의 임무특성을 고려하여 전력시스템의 구조를 검토하고, 극한의 온도환경에서 달착륙선의 임무수행을 위하여 필요한 전력에너지를 충분히 공급할 수 있도록 태양전지 배열기와 배터리의 용량, 그리고 전장품의 용량을 설계하였다. 특히 경량의 달착륙선 개발을 위하여 고효율의 태양전지를 이용한 태양전지 배열기와 리튬-이온 배터리를 검토하였다. 극한의 우주환경에서 태양전지배열기의 동작특성을 검토하고 생성될 수 있는 최대 전력을 분석하여 최적의 태양전지 배열기의 면적을 분석하고, 장시간의 월식을 고려하여 배터리의 방전특성에 따른 배터리의 전압특성을 검토하였다. 그리고 달착륙선의 전력시스템 개념설계의 타당성 검토를 위하여 유럽에서 개념설계 중인 달착륙선의 전력시스템 사양과 용량에 대해 비교검토를 수행하였다. 현재 개발중인 지상검증모델용 달착륙선의 전력시스템 설계와 추력기 밸브구동 전원장치의 개발에 관해 기술하였다. 지상검증용 전력시스템은 태양전지배열기의 장착 없이 배터리의 전력만을 사용하여 지상검증모델용 달착륙선의 부하에 전력을 공급할 수 있도록 설계되었다. 달착륙선 지상시험모델의 비행시간과 임무에 따른 부하특성을 고려하여 상용 리튬-이온 배터리의 용량을 선정하였으며, 부하의 전력을 고려하여 간단한 보호회로를 설계하였다. 그리고 지상검증용 전원시스템은 추력기의 밸브구동을 위한 추력기 밸브구동 전원장치, DC/DC 컨버터 전원 모듈, 모니터링 모듈, 그리고 위급상황에서 전원을 차단하기 위한 "Emergency STOP" 모듈로 구성되어 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.27-34
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• 2011

A numerical analysis was peformed for the supersonic aircraft with variable pitch thrust vector nozzle. Based on the requirement of the mixed turbofan engine of the supersonic aircraft, two dimensional thrust vector nozzle with variable pitch angle was designed. To investigate the effect of the thrust vectoring nozzle, the numerical analysis was conducted by using Fluent under the several pitch deflection angle.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.176-184
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• 2007

The missile for this study has shown different natural frequency characteristics depending on the test conditions; natural frequencies obtained from its flight test are higher than those in its ground test. It was found that the hinged joints connecting front airframe to rear one had the nonlinear stiffness and caused the missile to show very complex dynamic characteristics. The angular stiffness at hinged joints was calculated using 3D finite element analysis, and it was verified that there was a highly nonlinear relationship between angular stiffness and external load. Natural frequencies calculated considering the nonlinearity of angular stiffness were nearly the same as test results. Through this study, the dynamic characteristics of a missile having split airframes with hinged joints could be clearly identified and a way of maintaining its natural frequencies consistent was generated.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.4
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• pp.16-20
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• 2010

The dynamic characteristics of flight sensors is obtained by a simple method that deploys a pendulum with a rotary encoder. The encoder output is used with kinematic relations to derive reference signals for various flight sensors, including position, velocity, attitude, and angular rate sensors as well as accelerometer and magnetic sensors. A time delay of 0.4 seconds is found in the position output of the flight sensor under investigation. A logic to compensate for the time delay using a velocity information is proposed and validated in flight tests.