7,346 research outputs found
Transonic airfoil analysis and design in nonuniform flow
A nonuniform transonic airfoil code is developed for applications in analysis, inverse design and direct optimization involving an airfoil immersed in propfan slipstream. Problems concerning the numerical stability, convergence, divergence and solution oscillations are discussed. The code is validated by comparing with some known results in incompressible flow. A parametric investigation indicates that the airfoil lift-drag ratio can be increased by decreasing the thickness ratio. A better performance can be achieved if the airfoil is located below the slipstream center. Airfoil characteristics designed by the inverse method and a direct optimization are compared. The airfoil designed with the method of direct optimization exhibits better characteristics and achieves a gain of 22 percent in lift-drag ratio with a reduction of 4 percent in thickness
Calculation of vortex lift effect for cambered wings by the suction analogy
An improved version of Woodward's chord plane aerodynamic panel method for subsonic and supersonic flow is developed for cambered wings exhibiting edge separated vortex flow, including those with leading edge vortex flaps. The exact relation between leading edge thrust and suction force in potential flow is derived. Instead of assuming the rotated suction force to be normal to wing surface at the leading edge, new orientation for the rotated suction force is determined through consideration of the momentum principle. The supersonic suction analogy method is improved by using an effective angle of attack defined through a semi-empirical method. Comparisons of predicted results with available data in subsonic and supersonic flow are presented
VORCAM: A computer program for calculating vortex lift effect of cambered wings by the suction analogy
A user's guide to an improved version of Woodward's chord plane aerodynamic panel computer code is presumed. The guide can be applied to cambered wings exhibiting edge separated flow, including those with leading edge vortex flow at subsonic and supersonic speeds. New orientations for the rotated suction force are employed based on the momentum principal. The supersonic suction analogy method is improved by using an effective angle of attack defined through a semiempirical method
TRANDESNF: A computer program for transonic airfoil design and analysis in nonuniform flow
The use of a transonic airfoil code for analysis, inverse design, and direct optimization of an airfoil immersed in propfan slipstream is described. A summary of the theoretical method, program capabilities, input format, output variables, and program execution are described. Input data of sample test cases and the corresponding output are given
Laser Cooling of 85Rb Atoms to the Recoil Temperature Limit
We demonstrate the laser cooling of 85Rb atoms in a two-dimensional optical
lattice. We follow the two-step degenerate Raman sideband cooling scheme
[Kerman et al., Phys. Rev. Lett. 84, 439 (2000)], where a fast cooling of atoms
to an auxiliary state is followed by a slow cooling to a dark state. This
method has the advantage of independent control of the heating rate and cooling
rate from the optical pumping beam. We operate the lattice at a Lamb-Dicke
parameter eta=0.45 and show the cooling of spin-polarized 85Rb atoms to the
recoil temperature in both dimension within 2.4 ms with the aid of adiabatic
cooling
Comparing large covariance matrices under weak conditions on the dependence structure and its application to gene clustering
Comparing large covariance matrices has important applications in modern
genomics, where scientists are often interested in understanding whether
relationships (e.g., dependencies or co-regulations) among a large number of
genes vary between different biological states. We propose a computationally
fast procedure for testing the equality of two large covariance matrices when
the dimensions of the covariance matrices are much larger than the sample
sizes. A distinguishing feature of the new procedure is that it imposes no
structural assumptions on the unknown covariance matrices. Hence the test is
robust with respect to various complex dependence structures that frequently
arise in genomics. We prove that the proposed procedure is asymptotically valid
under weak moment conditions. As an interesting application, we derive a new
gene clustering algorithm which shares the same nice property of avoiding
restrictive structural assumptions for high-dimensional genomics data. Using an
asthma gene expression dataset, we illustrate how the new test helps compare
the covariance matrices of the genes across different gene sets/pathways
between the disease group and the control group, and how the gene clustering
algorithm provides new insights on the way gene clustering patterns differ
between the two groups. The proposed methods have been implemented in an
R-package HDtest and is available on CRAN.Comment: The original title dated back to May 2015 is "Bootstrap Tests on High
Dimensional Covariance Matrices with Applications to Understanding Gene
Clustering
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An Investigation of Creative Tourists’ Experience and Revisit Intention
As Richards (2008) asserted, creative tourism is a new form of tourism that has the potential to change tourism development and make a significant contribution in differentiating and changing the tourism experience. Reviewing current literature, despite increased attention being given to the conception of creative tourism, there has been little empirical work focused on the tourists’ consumption psychology of creative tourism. Thus, this study attempts to reveal tourists’ intention to revisit creative tourism destinations by applying the theory of planned behavior, to explore tourists’ experience on visiting creative tourism destinations and to explain the relationship between tourists’ experience and intention to revisit creative tourism destinations. The findings of this study will benefit tourism business managers the in ensuing thematic characteristics planning and designing of their product to fit the preferences of target markets, and they will benefit marketing strategy planning and targeted consumer recognition as well
Nationalism in Chinese Language Textbooks for Primary Schools in Pre-Independence Malaya (1904-1957)
Prior to the period of World War II, nationalism of the overseas Chinese in Malaya was closely related to the history of modern China. This was proved by historical records and research. It can also be seen from the publication of Chinese textbooks. During pre-World War II and beginning years after World War II, Chinese schools adopted textbooks imported from mainland China. Textbooks were promoted the strong spirit of anti-imperialism and anti-colonialism, reflecting a strong sense of Chinese nationalism. In 1951, the colonial government in Malaya accepted recommendations from the Fenn-Wu Report and set up a Chinese School Textbook Revision Committee to adapt Chinese school textbooks. Textbooks were revised to invoke local awareness through the portrayal of a Malayan orientation. Since then, a new era started in Malaya, with textbooks containing local identity. From beginning of the 20th century to early years after World War II, was the period of Chinese in mainland China seeking self-preservation and self-strengthening to the nation. How did nationalism appear in Chinese schools’ textbooks in Malaya? Did it change from time to time ? What was its relations with historical processes? This study will analyse and probe the above mentioned questions through the Chinese Language textbooks.
This study focuses on Chinese Language textbooks used by Chinese primary schools in Malaya between 1904 to 1957. It attempts to examine the ideological content of the textbooks, to determine the types of nationalism that emerged and its changes, as well as its relations with historical processes. The thesis consists of six chapters. Chapter 1 is the introduction. Chapter 2 provides an overview of the development of new-type Chinese education in Malaya. This is necessary as background knowledge in the discussion at the later part. The subsequent three chapters form the core of this study, examining the emergence of nationalism in Chinese Language textbooks during the period of the late Qing dynasty, till the Republic of China and before the independence of Malaya. Chapter 6 is the conclusion.
This study concludes that from the first decade of the 20th century to the mid 20th century, the ideological contents which are embodied in Malayan Chinese Language textbooks are closely related to the historical development. It reflects the changes of the orientation of national identity as well as the cultural identity of Chinese in Malaya which have changed from China-centred to Malaya-orientated. To a certain extent, it could be perceived as microcosm as well as the process of shaping of Malayan Chinese ethno-nationalism.
Key words: Chinese Language, textbooks, nationalism, Malaya, pre-independenc
Some normal state and superconducting state properties of ultra high purity vanadium
http://www.worldcat.org/oclc/1228771
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