On the application of ENO scheme with subcell resolution to conservation laws with stiff source terms

Two approaches are used to extend the essentially non-oscillatory (ENO) schemes to treat conservation laws with stiff source terms. One approach is the application of the Strang time-splitting method. Here the basic ENO scheme and the Harten modification using subcell resolution (SR), ENO/SR scheme, are extended this way. The other approach is a direct method and a modification of the ENO/SR. Here the technique of ENO reconstruction with subcell resolution is used to locate the discontinuity within a cell and the time evolution is then accomplished by solving the differential equation along characteristics locally and advancing in the characteristic direction. This scheme is denoted ENO/SRCD (subcell resolution - characteristic direction). All the schemes are tested on the equation of LeVeque and Yee (NASA-TM-100075, 1988) modeling reacting flow problems. Numerical results show that these schemes handle this intriguing model problem very well, especially with ENO/SRCD which produces perfect resolution at the discontinuity

On the application of subcell resolution to conservation laws with stiff source terms

LeVeque and Yee recently investigated a one-dimensional scalar conservation law with stiff source terms modeling the reacting flow problems and discovered that for the very stiff case most of the current finite difference methods developed for non-reacting flows would produce wrong solutions when there is a propagating discontinuity. A numerical scheme, essentially nonoscillatory/subcell resolution - characteristic direction (ENO/SRCD), is proposed for solving conservation laws with stiff source terms. This scheme is a modification of Harten's ENO scheme with subcell resolution, ENO/SR. The locations of the discontinuities and the characteristic directions are essential in the design. Strang's time-splitting method is used and time evolutions are done by advancing along the characteristics. Numerical experiment using this scheme shows excellent results on the model problem of LeVeque and Yee. Comparisons of the results of ENO, ENO/SR, and ENO/SRCD are also presented

A numerical study of ENO and TVD schemes for shock capturing

The numerical performance of a second-order upwind-based total variation diminishing (TVD) scheme and that of a uniform second-order essentially non-oscillatory (ENO) scheme for shock capturing are compared. The TVD scheme used is a modified version of Liou, using the flux-difference splitting (FDS) of Roe and his superbee function as the limiter. The construction of the basic ENO scheme is based on Harten, Engquist, Osher, and Chakravarthy, and the 2-D extensions are obtained by using a Strang-type of fractional-step time-splitting method. Numerical results presented include both steady and unsteady, 1-D and 2-D calculations. All the chosen test problems have exact solutions so that numerical performance can be measured by comparing the computer results to them. For 1-D calculations, the standard shock-tube problems of Sod and Lax are chosen. A very strong shock-tube problem, with the initial density ratio of 400 to 1 and pressure ratio of 500 to 1, is also used to study the behavior of the two schemes. For 2-D calculations, the shock wave reflection problems are adopted for testing. The cases presented in this report include flows with Mach numbers of 2.9, 5.0, and 10.0

Efficient Neural Network Approach of Self-Localization for Humanoid Robot

[[abstract]]Robot soccer game is one of the significant and interesting areas among most of the autonomous robotic researches. Following the humanoid soccer robot basic movement and strategy actions, the robot is operated in a dynamic and unpredictable contest environment and must recognize the position ofitselfin the field all the time. Therefore, the localization system of the soccer robot becomes the key technology to improve the performance. This work proposes efficient approachesfor humanoid robot and uses one landmark to accomplish the self-localization. This localization mechanism integrates the information from the pan/tilt motors and a single camera on the robot head together with the artificial neural network technique to adaptively adjust the humanoid robot position. The neural network approach can improve the precision of the localization. The experimental results indicate that the average accuracy ratio is 88.5% underframe rate of 15 frames per second (fps), and the average error for the distance between the actual position and the measured position ofthe object is 6.68cm.[[sponsorship]]IEEE Taipei Section; National Science Council; Ministry of Education; Tamkang University; Asia University; Providence University; The University of Aizu; Lanzhou University[[conferencetype]]國際[[conferencetkucampus]]淡水校園[[conferencedate]]20091203~20091205[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

Antidumping Petition: To File or Not To File

Given the “normal value†of a product as common knowledge in an import-competing market, the profitability of a home firm in filing an antidumping (AD) petition against its foreign rival is shown to depend on the marginal cost differential between the home and foreign firms. When the marginal cost differential is “significantly large,†the home firm's ability to put the foreign firm at the risk of an AD violation is limited. But when the marginal cost differential is “significantly small,†the home firm is able to increase its output and lower the price of the product below its normal value, putting the foreign firm in the situation of an illegal dumping. One interesting implication is that, relative to the case without an AD law, the home firm has a stronger incentive to undertake cost-reducing activities (e.g., R&D investment or the adoption of a more efficient technology) under the law.antidumping laws, antidumping duties, dumping margins

Design and commission of a Superconducting wiggler X-ray beamline for advanced Materials investigation at the National Synchrotron Radiation Research Center

[[abstract]]The x-ray beamline BL07A, fascinating over the use of the x-rays generated from a 3.1 Tesla, in-achromatic superconducting wiggler at the NSRRC, is designed for x- ray scattering and x-ray absorption spectroscopy for advanced materials researches in the photon energy range 5-23 keV. The beamline optics is optimized over the sequence of the collimating mirror, the double crystal monochromator, the focusing mirror and the higher harmonic rejection mirror. The beamline exhibits substantially identical performances with the ray-tracing simulation, of photon flux 10^13 photons/s with energy resolution △E/E ~ 2 × 10^(−4), focal size 250 μm × 550 μm (vertical × horizontal, FWHM), and higher-harmonic rejection ratio ~ 10^(−4). Three experimental stations, namely, a diffraction/scattering station equipped with eight-circle diffractometer, an EXAFS station, and a micron beam station, all are located in the experimental hutch, upon which, a wide variety of sample environments, including temperature, pressure, electric field, and magnetic field, greatly extend the capabilities of detection in the extreme and non- ambient conditions.[[notice]]補正完畢[[journaltype]]國內[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]TW

Chapter 37 Introduction to Section 6

This handbook addresses a growing list of challenges faced by regions and cities in the Pacific;Rim, drawing connections around the what, why, and how questions that are fundamental;to sustainable development policies and planning practices. These include the connection;between cities and surrounding landscapes, across different boundaries and scales; the persistence;of environmental and development inequities; and the growing impacts of global;climate change, including how physical conditions and social implications are being anticipated;and addressed. Building upon localized knowledge and contextualized experiences,;this edited collection brings attention to place-;based;approaches across the Pacific Rim and;makes an important contribution to the scholarly and practical understanding of sustainable;urban development models that have mostly emerged out of the Western experiences. Nine;sections, each grounded in research, dialogue, and collaboration with practical examples and;analysis, focus on a theme or dimension that carries critical impacts on a holistic vision of city-;landscape;development, such as resilient communities, ecosystem services and biodiversity,;energy, water, health, and planning and engagement.;This international edited collection will appeal to academics and students engaged in;research involving landscape architecture, architecture, planning, public policy, law, urban;studies, geography, environmental science, and area studies. It also informs policy makers,;professionals, and advocates of actionable knowledge and adoptable ideas by connecting;those issues with the Sustainable Development Goals (SDGs);of the United Nations. The;collection of writings presented in this book speaks to multiyear collaboration of scholars;through the APRU Sustainable Cities and Landscapes (SCL);Program and its global network,;facilitated by SCL Annual Conferences and involving more than 100 contributors;from more than 30 institutions