• 한국초전도학회:학술대회논문집
• /
• 2007.07a
• /
• pp.84-84
• /
• 2007

• Journal of applied mathematics & informatics
• /
• v.18 no.1_2
• /
• pp.235-246
• /
• 2005

We present an interpolating, univariate subdivision scheme which preserves the discrete curvature and tangent direction at each step of subdivision. Since the polygon have a geometric information of some original(in some sense) curve as a discrete curvature, we can expect that the limit curve has the same curvature at each vertex as the control polygon. We estimate the curvature bound of odd vertices and give an error estimate for restoring a curve from sampled vertices on curves.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.1
• /
• pp.224-226
• /
• 2010

• Satellite Communications and Space Industry
• /
• v.8 no.1 s.18
• /
• pp.81-85
• /
• 2000

항공우주산업은 국가 안보에 직결되는 기간산업이며 기술파급효과가 높은 첨단산업으로서 규모의 경제 실현 및 정부 주도의 체계적 발전전략 수립을 위하여 국내 항공업체간 통합 필요성이 제기된다. 이에 따라 설립된 한국항공우주산업주식회사(KAI)는 국내 유일의 위성 체계종합업체로서 정부 사업의 주 계약업체로 성장, 국내 항공기/우주 시스템 개발 산업을 선도해온 리딩 컴퍼니이며, 알아주는 유망기업으로서 항공우주산업발전에 크게 일조하고 있는 회사이다. 한국항공우주산업주식회사가 추진하고 있는 주요 산업과 그 동안의 업적, 발전방향에 대하여 살펴보았다.

• The Korean Journal of Air & Space Law and Policy
• /
• v.35 no.1
• /
• pp.153-180
• /
• 2020

This study is meaningful in finding out what legal and policy issues need to be improved in order to foster the aircraft industry, which is relatively underdeveloped compared to the fact that some heavy industries, such as the automobile industry and shipbuilding industry, have achieved a high level of production and technology globally. Korea's aircraft industry has been growing at a slower pace than other industries, largely due to the country's economic growth and the lack of a market structure to properly use variables such as the level of development in related industries, aircraft technology and demand for aircraft manufacturing. While most industries are privately led by the market structure of the competition system, heavy industries such as the aircraft industry generally grow under the market structure of the incomplete competition system, because only by securing huge initial investment costs, high technology, and sufficient demand, they can maintain minimum economic feasibility. The Korean aircraft industry was focused on developing and mass-producing military aircraft focusing on military demand, but it sought to turn the tide by signing the BASA (Bileral Aviation Safety Agreement) with the U.S. A preliminary feasibility study was conducted in 2010 to develop next-generation medium-sized aircraft, but was cancelled due to differences in position with Canada's Bombardier, which is subject to the concourse, and Korea Aerospace Industries (KAI) is pushing for the production of Bombardier's Q400 license on its own. Compared to the mid-to-large sized civil aircraft that are facing difficulties in development, KAI and KARI are successfully developing technologies to unmanned aerial vehicles and civil helicopters. In addition, the unmanned aerial vehicle sector is not yet suitable for manufacturers that have an exclusive global influence, so we believe that it is necessary to pursue government-led research and development projects with a focus on the areas of commercial helicopters and unmanned aerial vehicles in order to foster the aircraft industry in the future. In addition, since military aircraft such as KT-1 and T-50 are currently being exported smoothly, and it cannot be overlooked that the biggest demand for aircraft manufacturing in the Korea is the military, it is necessary to push forward national R&D projects and defense R&D program simultaneously to enable both civilian-military development. However, there are many differences between the two projects in the way they are implemented, the department in charge and the royalty system. Through this study, we learned about the technology ownership and implementation rights of national R&D projects and defense R&D programs, as well as the royalty system. In addition, problems with the system were identified and improvement measures were derived.

• Bulletin of the Korean Mathematical Society
• /
• v.58 no.6
• /
• pp.1341-1354
• /
• 2021

Let r ≥ 2, and let k_i ≥ 2 for 1 ≤ i ≤ r. Mixed van der Waerden's theorem states that there exists a least positive integer w = w(k₁, k₂, k₃, …, k_r; r) such that for any n ≥ w, every r-colouring of [1, n] admits a k_i-term arithmetic progression with colour i for some i ∈ [1, r]. For k ≥ 3 and r ≥ 2, the mixed van der Waerden number w(k, 2, 2, …, 2; r) is denoted by w₂(k; r). B. Landman and A. Robertson [9] showed that for k < r < $\frac{3}{2}$(k - 1) and r ≥ 2k + 2, the inequality w₂(k; r) ≤ r(k - 1) holds. In this note, we establish some results on w₂(k; r) for 2 ≤ r ≤ k.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.3
• /
• pp.1649-1654
• /
• 2013

Objective: This work aimed to evaluate the safety and clinical efficacy of transcatheter arterial chemoembolization (TACE) combined with c-arm cone-beam CT guided synchronous radiofrequency ablation (RFA) in treatment of large hepatocellular carcinoma (HCC). Methods: 21 patients with large HCC were studied from January 2010 to March 2012. TACE combined with synchronous C-arm cone-beam CT guided RFA were performed on a total of 25 lesions. Conventional imaging examination (CEUS, enhanced CT or MRI) and AFP detection were regularly conducted to evaluate the technical success rate of combined treatment, complications, treatment response, time without disease recurrence and survival rate. Results: The technical success rate of combined treatment was 100%, without any significant complication. After 1 month, there were 19 cases with complete response and 2 cases with partial response, with an complete response rate of 90.4% (19/21) and a clinical effective rate of 100% (21/21). The complete response rates of single nodular lesions (100%, 17/17) was significantly higher than that of multiple nodular lesions (50%, 2/4) (P<0. 05). During 2 to 28 months of follow-up, in 19 cases with complete response, the average time without disease recurrence was $10.8{\pm}6$ months. The total survival rates of 6, 12 and 18 months in 21 patients were 100%, respectively. Conclusion: TACE combined with synchronous C-arm CT guided RFA is safe and effective for treatment of large HCC. The treatment efficacy for single nodular lesion is better than that for multiple nodular lesions.

• Architectural research
• /
• v.22 no.1
• /
• pp.1-11
• /
• 2020

From 1990s to the present, in China, residential communities has developed rapidly in terms of government policies and living environments. With economic development, dwelling commercialization and socialization gradually reshaped the housing distribution system and local government management in Chinese urban area. After this process, dwellings were endowed with commodity attributes, which were planned and designed depending on residents' requirements of life. During the 30 years of social transformation, Chinese citizens' lifestyle also had huge changes. In this period, the forms of residential area improved constantly to keep pace with social development. This study aims to research the features of contemporary communities and survey citizens' lifestyle changes to find the reasons of the evolution of communities. Moreover, in this paper, there is a clear explanation of the reasons why gated communities are popular in Chinese urban area. In addition, comprehensive data analysis is derived from a questionnaire administered in Shanghai, China. In this part, the questionnaire surveys what factors about lifestyle influence the transformation of living environments and residential buildings. The results of survey show that residents have housing preferences dependent on their lifestyles, and their daily needs related with environmental features.

• Journal of the Korean Mathematical Society
• /
• v.56 no.2
• /
• pp.329-352
• /
• 2019

In this paper, we study conformally flat (${\alpha}$, ${\beta}$)-metrics in the form $F={\alpha}(1+{\sum_{j=1}^{m}}\;a_j({\frac{\beta}{\alpha}})^j)$ with $m{\geq}2$, where ${\alpha}$ is a Riemannian metric and ${\beta}$ is a 1-form on a smooth manifold M. We prove that if such conformally flat (${\alpha}$, ${\beta}$)-metric F is of weakly isotropic scalar curvature, then it must has zero scalar curvature. Moreover, if $a_{m-1}a_m{\neq}0$, then such metric is either locally Minkowskian or Riemannian.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.6
• /
• pp.984-988
• /
• 2019

Blue mold in citrus is caused by Penicillium italicum. In this study, the P. italicum-specific primers were developed for rapid detection based on the conserved genes RPB1 and RPB2 among Penicillium genomes. The two primer pairs RPB1-a and RPB1-b proved to be specific to detect P. italicum. The PCR assay among 39 fungal isolates and the colonial, pathogenic morphologies and molecular methods validated the specificity and reliability of these two primer pairs. This report provided a method and P. italicum-specific primers, which might greatly contribute to citrus postharvest industry.