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The Australian Aerospace Industry
Professor Cees Bil 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
The Australian aerospace industry is a competitive and technically sophisticated supplier to both domestic and overseas markets across a wide range of aerospace activities. The industry operates in both the civil and defence aerospace markets and is a mixture of domestic companies, Australian subsidiaries of international companies and supporting niche industries. Activities include aircraft component manufacturing, for civil and military aircraft including helicopters, aircraft repair and maintenance, light aircraft manufacturing, system design and development, aviation training and air traffic management products.
AERODYNAMIC ANALYSIS OF A DUCTED FAN VTOL UAV FOR TRANSITION MANOUEVRE
Hui Wen Zhao,Cees Bil,Bok-Hyun Yoon 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
The development of a dynamic model for a new ducted fan VTOL UAV is presented to analyze the transition maneuver from vertical to horizontal flight. The objective is to ensure that the UAV can achieve a smooth transition from vertical climb or hover ing to horizontal flight by using conventional control surfaces which are affected by the propeller exit flow behind the duct. As a pan of the development of the dynamics model, this paper presents a simplified duct design methodology based on an annular wing theory and explains how the slipstream affects control surface and generates high efficiency lift force. The theoretical results are to be compared with CFD analysis. Computational fluid dynamics was used to evaluate the aerodynamic coefficients at different speeds and angles of attack. The interaction between the fan flow and duct causes complex flow structures depending on the flight condition. To evaluate the aerodynamic characteristics of the duct, 3D analytical models were used. The full-scale model of UAV with due ted fan rotating is also simulated using computational fluid dynamics approach in hopes of analyzing the process of UAV in full flow field.
BWB MILITARY CARGO TRANSPORT FUSELAGE DESIGN AND ANALYSIS
Sung Hwan Cho,Cees Bil,Javid Bayandor 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-
A Columned Multi-Bubble Fuselage (CMBF) concept is proposed for a Blended Wing Body Ultra Heavy Lin aircraft design. Inter-cabin wall sections of Multi Bubble Fuselage were replaced with columns to provide a large and contiguous area The configuration allows the membrane stresses of the round wing panels to be balanced with the tensile stresses In the columns CMBF was analysed and compared with a conventional Multi Bubble Fuselage (MBF) to verify its structural performance regarding weight reduction and stiffness. Initial analysis shows that the CMBF has a significant weight advantage over conventional MBF. The paper introduces the objectives of tile project and presents preliminary structural design and analysis results.
Alessandro Ceruti,Pier Marzocca,Alfredo Liverani,Cees Bil 한국CDE학회 2019 Journal of computational design and engineering Vol.6 No.4
The paper broadly addresses how Industry 4.0 program drivers will impact maintenance in aviation. Specifically, Industry 4.0 practices most suitable to aeronautical maintenance are selected, and a detailed exposure is provided. Advantages and open issues are widely discussed and case studies dealing with realistic scenarios are illustrated to support what has been proposed by authors. The attention has been oriented towards Augmented Reality and Additive Manufacturing technologies, which can support main-tenance tasks and spare parts production, respectively. The intention is to demonstrate that Augmented Reality and Additive Manufacturing are viable tools in aviation maintenance, and while a strong effort is necessary to develop an appropriate regulatory framework, mandatory before the wide-spread introduc-tion of these technologies in the aerospace systems maintenance process, there has been a great interest and pull from the industry sector.
Investigating possible causes of bias in a progress test translation: an one-edged sword
Dario Cecilio-Fernandes,André Bremers,Carlos Fernando Collares,Wybe Nieuwland,Cees van der Vleuten,René A. Tio 한국의학교육학회 2019 Korean journal of medical education Vol.31 No.3
Purpose: Assessment in different languages should measure the same construct. However, item characteristics, such as item flaws and content, may favor one test-taker group over another. This is known as item bias. Although some studies have focused on item bias, little is known about item bias and its association with items characteristics. Therefore, this study investigated the association between item characteristics and bias. Methods: The University of Groningen offers both an international and a national bachelor’s program in medicine. Students in both programs take the same progress test, but the international progress test is literally translated into English from the Dutch version. Differential item functioning was calculated to analyze item bias in four subsequent progress tests. Items were also classified by their categories, number of alternatives, item flaw, item length, and whether it was a case-based question. Results: The proportion of items with bias ranged from 34% to 36% for the various tests. The number of items and the size of their bias was very similar in both programmes. We have identified that the more complex items with more alternatives favored the national students, whereas shorter items and fewer alternatives favored the international students. Conclusion: Although nearly 35% of all items contain bias, the distribution and the size of the bias were similar for both groups. The findings of this paper may be used to improve the writing process of the items, by avoiding some characteristics that may benefit one group whilst being a disadvantage for others.
Aafke J. de Groot,Elizabeth M. Wattel,Romke van Balen,Cees M.P.M. Hertogh,Johannes C. van der Wouden 대한노인병학회 2023 Annals of geriatric medicine and research Vol.27 No.4
Background: We assessed the vulnerability of patients aged ≥70 years during hospital admission based on the Short Dutch Safety Management Screening (DSMS). Screening of four geriatric domains aims to prevent adverse outcomes and may support targeted discharge planning for post-acute care. We explored whether the DSMS criteria for acutely admitted patients were associated with rehabilitation-oriented care needs. Methods: This retrospective cohort study included community-dwelling patients aged ≥70 years acutely admitted to a tertiary hospital. We recorded patient demographics, morbidity, functional status, malnutrition, fall risk, and delirium and used descriptive analysis to calculate the risks by comparing the discharge destination groups. Results: Among 491 hospital discharges, 349 patients (71.1%) returned home, 60 (12.2%) were referred for geriatric rehabilitation, and 82 (16.7%) to other inpatient post-acute care. Non-home referrals increased with age from 21% (70–80 years) to 61% (>90 years). A surgical diagnosis (odds ratio [OR]=4.92; 95% confidence interval [CI], 2.03–11.95), functional decline represented by Katz-activities of daily living positive screening (OR=3.79; 95% CI, 1.76–8.14), and positive fall risk (OR=2.87; 95% CI, 1.31–6.30) were associated with non-home discharge. The Charlson Comorbidity Index did not differ significantly between the groups. Conclusion: Admission diagnosis and vulnerability screening outcomes were associated with discharge to rehabilitation-oriented care in patients >70 years of age. The usual care data from DSMS vulnerability screening can raise awareness of discharge complexity and provide opportunities to support timely and personalized transitional care.