Off-line, handwritten numeral recognition by perturbation method

This paper presents a new approach to off-line, handwritten numeral recognition. From the concept of perturbation due to writing habits and instruments, we propose a recognition method which is able to account for a variety of distortions due to eccentric handwriting. We tested our method on two worldwide standard databases of isolated numerals, namely CEDAR and NIST, and obtained 99.09 percent and 99.54 percent correct recognition rates at no-rejection level respectively. The latter result was obtained by testing on more than 170000 numerals     

连续时间模糊随机系统分析：状态空间模型分析

研究了连续时间模糊随机系统理论，给出了连续时间模糊随机系统的态变模糊订值映射的定义，讨论并解决了连续时间模糊随机系统的状态空间模型分析。     

Sampled- and continuous-time passivity and stability of virtual environments

We propose a new time-domain passivity observer (PO) and passivity controller (PC) which removes the constant-velocity assumption during one sample time, which was used in our previous PO/PC approach. A new sampled-time definition of passivity is introduced, and this new definition is compared with the previous sampled-time definition of passivity. Through this comparison, we propose the more accurate PO/PC approach. The proposed new PO/PC approach is applied to the "Excalibur" haptic interface system with very high stiffness (K = 120 kN/spl middot/m) virtual environment, and stable contact is demonstrated.     

Resource policing to support fine-grain cycle stealing in networks of workstations

We present the design, implementation, and performance evaluation of a suite of resource policing mechanisms that allow guest processes to efficiently and unobtrusively exploit otherwise idle workstation resources. Unlike traditional policies that harvest cycles only from unused machines, we employ fine-grained cycle stealing to exploit resources even from machines that have active users. We developed a suite of kernel extensions that enable these policies to operate without significantly impacting host processes: 1) a new starvation-level CPU priority for guest jobs, 2) a new page replacement policy that imposes hard bounds on physical memory usage by guest processes, and 3) a new I/O scheduling mechanism called rate windows that throttle guest processes' usage of I/O and network bandwidth. We evaluate both the individual impacts of each mechanism, and their utility for our fine-grain cycle stealing.     

Factors Affecting Flow-Mediated Vasodilatation in Hemodialysis Patients

Clinical manifestation of overt vascular disease may be preceded for years by endothelial dysfunction. Objective: This study was undertaken to evaluate endothelial function in ESRD patients and correlation between endothelial function and clinical and biochemical parameters. Methods: 32 stable ESRD patients (male : female = 16 : 16, average age: 55.2 ± 13.0) on hemodialysis were included. A 10‐MHz ultrasound transducer was used to image the brachial artery. Brachial artery diameter was measured, and reactive hyperemia was induced by inflation to 250 mmHg for 5 min and then deflation of a pneumatic cuff. After release of the cuff, brachial artery diameter was measured. Results: In the entire study population and non‐diabetic group, the %FMD (% flow‐mediated dilatation, % change of brachial artery diameter between before and after cuff inflation) did not show any significant correlation with duration of dialysis, age, hypertension, albumin, CRP, total cholesterol, LDL and HDL cholesterol, and triglyceride. However, the %FMD of diabetic patients was lower than that of non‐diabetics. Among the patients with diabetes, the group of patients with FMD of <5.2% showed significant lower serum albumin and significantly higher ln(CRP) levels compared to the group of patients with FMD ≥5.2%. The %FMD showed significant positive correlation with serum albumin level and significant negative correlation with ln(CRP) in diabetic patients. Conclusion: These findings suggest that endothelial dysfunction, estimated by FMD, was significantly more prominent in diabetic ESRD, especially with low serum albumin and high CRP levels.     

Preparation of AZ91D Slurries for Semi-Solid Forming Using Al8 ( Mn, Fe) 5 Precipitates

During the solidification of the AZ91D-alloys, the Al8(Mn, Fe)5 phase is generally precipitated in the melt in advance of the precipitation of the primary α-Mg. The basic principle for manufacturing AZ91D-alloy slurries for semi solid forming is to use the Al8(Mn, Fe)5 precipitates as the heterogeneous nucleation sites for primary α-Mg phases. Microscopic analysis for the location of the Al8(Mn, Fe)5 precipitate explains that the Al8(Mn, Fe)5 precipitate is the effective heterogeneous nucleation site for the primary α-Mg phase. It was also observed that increase of the Mn content in the melt and the cooling rate below to the solid/liquid two-phase region resulted in smaller and more globular primary α-Mg due to the increase of heterogeneous nucleation sites. It was found that the average α-Mg diameter grew as a function of t0.278, where t is the holding time at the solid/liquid two-phase region. This would be attributed to the Ostwald type ripening and coalescence between primary α-Mg phases. The cooling rate below to the solid/liquid two-phase region, Mn content in AZ91D alloy, and the holding time and temperature affected on the quality of slurry.     

High-density mesh flow computations by building-cube method

With the conventional computational fluid dynamics (CFD) approaches like unstructured high-density mesh method, the problem about the solution dependencies on the grid and on the physical models isn’t completely resolved. In this study, thus, a new approach named Building-Cube Method based on a Cartesian mesh is proposed using a high-density mesh in order to solve the problem of the current CFD approaches. In the present method, a flow field is divided into a number of cubes (squares in 2D) of various sizes. Each cube is a computational sub-domain with Cartesian mesh of equal spacing and equal number of nodes. The geometrical size of each cube is determined by adapting to geometry and flow features so as to cope with broadband characteristic lengths of the flow. Equal spacing and equal number of Cartesian mesh in each cube make it easy to parallelize the flow solver and to handle huge data output. The method is applied to several airfoils including NACA0012 and two-element airfoils at relatively low Reynolds number, RAE2822 airfoil with transition trip at high Reynolds number and a four-element airfoil at high Reynolds number. These results validate the capability of the present approach.     

Bouc-Wen model parameter identification for a MR fluid damper using computationally efficient GA

A non-symmetrical Bouc-Wen model is proposed in this paper for magnetorheological (MR) fluid dampers. The model considers the effect of non-symmetrical hysteresis which has not been taken into account in the original Bouc-Wen model. The model parameters are identified with a Genetic Algorithm (GA) using its flexibility in identification of complex dynamics. The computational efficiency of the proposed GA is improved with the absorption of the selection stage into the crossover and mutation operations. Crossover and mutation are also made adaptive to the fitness values such that their probabilities need not be user-specified. Instead of using a sufficiently number of generations or a pre-determined fitness value, the algorithm termination criterion is formulated on the basis of a statistical hypothesis test, thus enhancing the performance of the parameter identification. Experimental test data of the damper displacement and force are used to verify the proposed approach with satisfactory parameter identification results.     

Novel hybrid optimization algorithm using PSO and MADS for the trajectory estimation of a four track wheel skid-steered mobile robot

Several optimization algorithms, such as the particle swarm optimization (PSO), genetic algorithm (GA), and ant colony optimization, have previously been applied in order to reliably obtain more accurate trajectory estimation for mobile robot. However, these optimization algorithms can get easily trapped in local optima when solving a complex system, which has many local optima and many input variables. This paper proposes a novel hybrid optimization algorithm-based tuning of the extended Kalman filter, which involves the PSO and mesh adaptive direct search algorithms, prior to operation. As demonstrated by our experimental results, the advantages of the novel hybrid optimization algorithm resolve the limitations of other algorithms in the trajectory estimation of a four track wheel skid-steered mobile robot (4-TW SSMR).