• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.6
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• pp.98-116
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• 2006

For the next two decades the civil aviation industry is expected to grow. Both Airbus and Boeing predict a delivery of almost 20,000 new Large Civil Aircraft (LCA). LCA is defined as a large civil jet aircraft with 100 seats or more. Airbus offers the Superjumbo, A380 (>555 seats), while Boeing presents the Dreamliner, B787 (200 – 300 seats). Their philosophies are very different. In the wake of B787, Airbus intends to offer a new aircraft, A350, as the competitor against B787, with the same engines developed for B787. The U.S. government pushed by Boeing, on the day of October 6, 2004, filed a suit against Airbus for wrongful subsidy to the World Trade Organization (WTO). A brief overview is given on the LCA development status in the world commercial aircraft market. Since there have been little changes in engine and avionics manufacturers in the LCA industry, the airframe area only is the object of this study. An analysis is carried out to find out the differences in development and marketing strategies of two major LCA manufacturers, Airbus and Boeing. The authors predict that Boeing will recapture its No. 1 position soon, while the leading edge in technology may be slipped away from Boeing.

• Bulletin of the Korean Mathematical Society
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• v.47 no.4
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• pp.787-792
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• 2010

Let A and B be some standard operator algebras on complex Banach spaces X and Y, respectively. We give the concrete forms of linear idempotence preserving maps $\Phi\;:\;A\;{\rightarrow}\;B$ on finite-rank operators.

• The Journal of Aerospace Industry
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• s.69
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• pp.99-113
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• 2007

본 연구는 발전하는 항공운수시장에서 신기종인 A380과 B787 항공기의 잠재적 역할에 초점을 맞추었다. 이들 항공기들이 글로벌 시장의 전반적 운영에 적합한 방법을 살펴본다. 무엇보다 초장거리노선 서비스를 위해 디자인된 이들 항공기들이 네트워크 정황 안에서 서로 다른 방향으로 전개될 수 있는 대안들을 살펴보기로 한다.

• Aerospace Industry
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• s.107
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• pp.54-57
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• 2010

신형 항공기 개발비 상승, 환경변화에 따른 새로운 탄소배출 규제조건, 항공운송 시장의 급격한 변화 등에도 불구하고 21세기 항공우주산업은 춘추전국시대를 방불케 하고 있다. 사실상 세계 민항기 시장을 양분하고 있는 보잉과 에어버스의 아성에 크고 작은 항공기 제작사들의 거센 도전이 계속되고 있기 때문 특히 지구 온난화에 따른 새로운 환경규제는 거대기업 보잉과 에어버스의 생존조차도 위협하고 있다. 생존할 것인가 도태될 것인가? 급변하는 21세기 항공우주시장 환경에서도 1위 자리를 고수하기 위해 보잉과 에어버스가 야심차게 준비하고 있는 비밀무기, B787과 A350을 비교해 본다.

• Composites Research
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• v.23 no.6
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• pp.1-6
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• 2010

The electrical conductivity of carbon-fiber reinforced plastics (CFRP's) has been improved by indium-tin oxide (ITO) nano-particle coating on carbon fibers for the purpose of lightning strike protection of composite fuselage skins. ITO nano-particles were coated on the surface of carbon fibers by spraying the colloidal suspension with 10~40% ITO content. The electrical conductivity of the CFRP has been increased more than three times after ITO coating, comparable to or higher than that of B-787 composite fuselage skins with metal wire-meshes on the outer surface, without sacrificing the tensile property due to the existence of nano-particles at fiber-matrix interface. The damage area by the simulated lightning strike was also verified for different materials and conditions by using ultrasonic C-scan image. As the electrical conductivity of 40% nano-ITO coated sample surpass that of the B-787 sample, the damage area by lightning strike also appeared comparable to that of the materials currently employed for composite fuselage construction.

• Journal of the Korean Mathematical Society
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• v.44 no.4
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• pp.787-797
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• 2007

In this paper, the following fourth-order rational difference equation $$x_{n+1}=\frac{{x_n^b}+x_n-2x_{n-3}^b+a}{{x_n^bx_{n-2}+x_{n-3}^b+a}$$, n=0, 1, 2,..., where a, b ${\in}$ [0, ${\infty}$) and the initial values $X_{-3},\;X_{-2},\;X_{-1},\;X_0\;{\in}\;(0,\;{\infty})$, is considered and the rule of its trajectory structure is described clearly out. Mainly, the lengths of positive and negative semicycles of its nontrivial solutions are found to occur periodically with prime period 15. The rule is $1^+,\;1^-,\;1^+,\;4^-,\;3^+,\;1^-,\;2^+,\;2^-$ in a period, by which the positive equilibrium point of the equation is verified to be globally asymptotically stable.

• Aerospace Industry
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• s.92
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• pp.20-23
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• 2006

• Aerospace Industry
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• s.86
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• pp.32-33
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• 2005

• Journal of Environmental Science International
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• v.23 no.5
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• pp.787-792
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• 2014

The objective of this study was to investigate the effects of the Crataegus pinnatifida BUNGE extract supplementation of non esterified fatty acid (NEFA), concentrations of serum protein and electrolyte in sera on the hyperlipidemic rats. Concentrations of NEFA and globulin were remarkably lower in the Crataegus pinnatifida BUNGE extract group (HW group) than in the hyperlipidemic group (HD group), but no difference between control group (CO group) and extract of Crataegus pinnatifida BUNGE supplement in control group (NW group). However, concentrations of electrolyte K and A/G were higher in the HW group than HD group. Concentrations of total protein, albumin, electrolyte of total Ca, Pi, Na and Cl were no difference between HW group than HD group. The results indicate that Crataegus pinnatifida BUNGE extract was in the improvement of hyperlipidemic rats.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.787-794
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• 2005

Nowadays chronic degenerative diseases such as arthritis are increasing rapidly, even though acute infectious diseases are decreasing due to the advance of modern medicine. Although many of remedies are developed for arthritis healing, there is no precise medical prescription, and pathogenesis is not examined exactly. In this study, we confirmed gene expression of BMP 1A, BMP 2B, osteonectin and MGP which are genes related with bone formation in osteoblast by using ultrasonic stimulation. Through this study, we also evaluated the fact that ultrasound could be applied to arthritis healing by making activated osteoblast induce remodeling of cartilage. As a result of this research, BMP 2B and MGP have higher rates of expression in specific ultrasound mode. In conclusion, it is expected that ultrasound could be used efficiently for healing arthritis if we use ultrasounds according to symptoms of arthritis on reasonable terms.