Effect of blood's velocity on blood resistivity

Blood resistivity is an important quantity whose value influences the results of various methods used in the study of heart and circulation. In this paper, the relationship between blood resistivity and velocity of blood flow was evaluated and analyzed based upon a probe using six-ring electrodes and a circulatory model. The experimental results indicated that the change in blood resistivity was only ±1.1% when the velocity of blood flow changed from 2.83 to 40 cm/s and it rose to 23% when the velocity was lower than 2.83 cm/s

Improving the multi-objective evolutionary optimization algorithm for hydropower reservoir operations in the California Oroville-Thermalito complex

This study demonstrates the application of an improved Evolutionary optimization Algorithm (EA), titled Multi-Objective Complex Evolution Global Optimization Method with Principal Component Analysis and Crowding Distance Operator (MOSPD), for the hydropower reservoir operation of the Oroville-Thermalito Complex (OTC) - a crucial head-water resource for the California State Water Project (SWP). In the OTC's water-hydropower joint management study, the nonlinearity of hydropower generation and the reservoir's water elevation-storage relationship are explicitly formulated by polynomial function in order to closely match realistic situations and reduce linearization approximation errors. Comparison among different curve-fitting methods is conducted to understand the impact of the simplification of reservoir topography. In the optimization algorithm development, techniques of crowding distance and principal component analysis are implemented to improve the diversity and convergence of the optimal solutions towards and along the Pareto optimal set in the objective space. A comparative evaluation among the new algorithm MOSPD, the original Multi-Objective Complex Evolution Global Optimization Method (MOCOM), the Multi-Objective Differential Evolution method (MODE), the Multi-Objective Genetic Algorithm (MOGA), the Multi-Objective Simulated Annealing approach (MOSA), and the Multi-Objective Particle Swarm Optimization scheme (MOPSO) is conducted using the benchmark functions. The results show that best the MOSPD algorithm demonstrated the best and most consistent performance when compared with other algorithms on the test problems. The newly developed algorithm (MOSPD) is further applied to the OTC reservoir releasing problem during the snow melting season in 1998 (wet year), 2000 (normal year) and 2001 (dry year), in which the more spreading and converged non-dominated solutions of MOSPD provide decision makers with better operational alternatives for effectively and efficiently managing the OTC reservoirs in response to the different climates, especially drought, which has become more and more severe and frequent in California

Weak formulation of finite element method using wavelet basis functions

Author name used in this publication: S. L. HoAuthor name used in this publication: H. C. Wong2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Incorporating a priori preferences in a vector PSO algorithm to find arbitrary fractions of the pareto front of multiobjective design problems

Author name used in this publication: S. L. Ho2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Wave attenuation at a salt marsh margin: A case study of an exposed coast on the Yangtze estuary

To quantify wave attenuation by (introduced) Spartina alterniflora vegetation at an exposed macrotidal coast in the Yangtze Estuary, China, wave parameters and water depth were measured during 13 consecutive tides at nine locations ranging from 10 m seaward to 50 m landward of the low marsh edge. During this period, the incident wave height ranged from <0.1 to 1.5 m, the maximum of which is much higher than observed in other marsh areas around the world. Our measurements and calculations showed that the wave attenuation rate per unit distance was 1 to 2 magnitudes higher over the marsh than over an adjacent mudflat. Although the elevation gradient of the marsh margin was significantly higher than that of the adjacent mudflat, more than 80% of wave attenuation was ascribed to the presence of vegetation, suggesting that shoaling effects were of minor importance. On average, waves reaching the marsh were eliminated over a distance of similar to 80 m, although a marsh distance of >= 100 m was needed before the maximum height waves were fully attenuated during high tides. These attenuation distances were longer than those previously found in American salt marshes, mainly due to the macrotidal and exposed conditions at the present site. The ratio of water depth to plant height showed an inverse correlation with wave attenuation rate, indicating that plant height is a crucial factor determining the efficiency of wave attenuation. Consequently, the tall shoots of the introduced S. alterniflora makes this species much more efficient at attenuating waves than the shorter, native pioneer species in the Yangtze Estuary, and should therefore be considered as a factor in coastal management during the present era of sea-level rise and global change. We also found that wave attenuation across the salt marsh can be predicted using published models when a suitable coefficient is incorporated to account for drag, which varies in place and time due to differences in plant characteristics and abiotic conditions (i.e., bed gradient, initial water depth, and wave action).

A fast global optimizer based on improved CS-RBF and stochastic optimal algorithm

Author name used in this publication: S. L. HoAuthor name used in this publication: H. C. Wong2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Increased nausea and dizziness when using tramadol for post-operative patient-controlled analgesia (PCA) compared with morphine after intraoperative loading with morphine

Thirty-eight ASA I-III patients undergoing lower abdominal operations were randomly allocated to receive either morphine (group M, patient-controlled analgesia bolus = 1 mg of morphine) or tramadol (group T, patient-controlled analgesia bolus = 10 mg of tramadol) for post-operative patient-controlled analgesia (PCA) after receiving morphine intraoperatively. There were no between-group differences in the pain, sedation or vomit scores. The nausea scores were significantly higher in group T in the initial 20 h and between 32 and 36 h (P < 0.01, 0-4 and 8-12 h; P < 0.05, 4-8, 12-16, 16-20 and 32-36 h). The incidence of dizziness was also significantly higher in group T (68.4% vs. 31.6%, group T vs. group M, P < 0.05). There was no difference in the overall satisfaction. We conclude that the use of tramadol, compared with morphine, for post-operative PCA after intraoperative loading with morphine is associated with more nausea and dizziness, but with similar sedation, quality of analgesia and patient satisfaction.published_or_final_versio

A response surface methodology based on improved compactly supported radial basis function and its application to rapid optimizations of electromagnetic devices

Author name used in this publication: S. L. HoAuthor name used in this publication: S. Y. YangAuthor name used in this publication: G. Z. NiAuthor name used in this publication: H. C. Wong2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A meshless collocation method based on radial basis functions and wavelets

Author name used in this publication: S. L. HoAuthor name used in this publication: H. C. Wong2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Application of a meshless method in electromagnetics

Author name used in this publication: S. L. HoAuthor name used in this publication: J. M. MachadoAuthor name used in this publication: H. C. Wong2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe