In this paper we propose a robust watermarking algorithm for 3D mesh. The algorithm is based on spherical wavelet transform. Our basic idea is to decompose the original mesh into a series of details at different scales by using spherical wavelet transform; the watermark is then embedded into the different levels of details. The embedding process includes: global sphere parameterization, spherical uniform sampling, spherical wavelet forward transform, embedding watermark, spherical wavelet inverse transform, and at last resampling the mesh watermarked to recover the topological connectivity of the original model. Experiments showed that our algorithm can improve the capacity of the watermark and the robustness of watermarking against attacks.

Conventional methods for solving intersections between two offset parametric surfaces often include iteratively using computationally expensive SSI (surface/surface intersections) algorithm. In addition, these methods ignore the relations between the intersection curves of parametric surfaces with different offset distances. The algorithm presented in this paper, makes full use of the topological relations between different intersection loops and calculates intersection loops with the help of previously calculated intersection loops. It first pre-processes two parametric surfaces to obtain the characteristic points, called topology transition points (TTPs), which can help in the subsequent finding of the topologies of the intersection curves. Then these points are categorized into several distinct groups, and we can determine the calculation strategy for searching initial points by analyzing the properties of these TTPs on the surfaces. Hence, all intersection curves can be marched from initial points by the tracing algorithm. The proposed algorithm could calculate intersection curves robustly and effectively and has been tested to be capable of overcoming the degenerate conditions such as loop and singularities leaking that occur frequently in conventional algorithms.

A new photonic bandgap (PBG) cover for a patch antenna with a photonic bandgap substrate is introduced. The plane wave expansion method and the FDTD method were used to calculate such an antenna system. Numerical results for the input return loss, radiation pattern, surface wave, and the directivity of the antennas are presented. A comparison between the conventional patch antenna and the new PBG antenna is given. It is shown that the new PBG cover is very efficient for improving the radiation directivity. The physical reasons for the improvement are also given.

A great deal of stabilization criteria has been obtained from study of stabilizing interconnected systems. The results obtained are usually based on continuous systems by state feedback. In this paper, decentralized impulsive control is presented to stabilize a class of uncertain interconnected systems based on Lyapunov theory. The system under consideration involves parameter uncertainties and unknown nonlinear interactions among subsystems. Some new criteria of stabilization under impulsive control are established. Two numerical examples are offered to prove the effectiveness and practicality of the proposed method.

The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000 °C at a heating rate of 10°C/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results.

Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

A new hybrid event based control architecture for tele-robotic systems controlled through the Internet is proposed in this paper. Different from the traditional event based control method, the new framework does not require every part of the system to be strictly event synchronized. Instead, it allows time referenced control components to be integrated into this framework, which makes it more convenient to develop Internet based control systems. Since there are two reference variables, time and event, in this architecture, how to coordinate these components with different references to keep the stability of the whole system is discussed in detail in this paper. To verify this new idea, an experiment was conducted to control the end effector of a PUMA robot tracking a continuous state trajectory given on-line by the remote operator. Experimental results confirmed the stability of such systems being controlled through the Internet in real-time.

Geotechnical research on historical remains can provide new data and distinctive viewpoint for research on soil mechanics. Two Jiangnan Tu-Dun tombs historical remains were investigated by means of in situ and laboratory geotechnical tests. In the present paper the geotechnical properties of these man-made earthworks, especially ageing effect on consolidation and direct shear, and compaction properties of earth fill are discussed.

In this work, the dynamic properties of composite cemented clay under a wide range of strains were studied considering the effect of different mixing ratio and the change of confining pressures through dynamic triaxial test. A simple and practical method to estimate the dynamic elastic modulus and damping ratio is proposed in this paper and a related empirical normalized formula is also presented. The results provide useful guidelines for preliminary estimation of cement requirements to improve the dynamic properties of clays.

This paper presents a semi-active strategy for seismic protection of a benchmark cable-stayed bridge with consideration of multiple-support excitations. In this control strategy, Magnetorheological (MR) dampers are proposed as control devices, a LQG-clipped-optimal control algorithm is employed. An active control strategy, shown in previous researches to perform well at controlling the benchmark bridge when uniform earthquake motion was assumed, is also used in this study to control this benchmark bridge with consideration of multiple-support excitations. The performance of active control system is compared to that of the presented semi-active control strategy. Because the MR fluid damper is a controllable energy-dissipation device that cannot add mechanical energy to the structural system, the proposed control strategy is fail-safe in that bounded-input, bounded-output stability of the controlled structure is guaranteed. The numerical results demonstrated that the performance of the presented control design is nearly the same as that of the active control system; and that the MR dampers can effectively be used to control seismically excited cable-stayed bridges with multiple-support excitations.

Energy dissipators, isolated-resistant and specific structural forms for earthquake resistance are popular topics in the research to improve shock-resistance. In this work, experimental methods were used to investigate the property of low yield strength steel. Carbon content in LYS material is lower than that in other steels; the ultimate stress is three times the yield stress. The ultimate elongation rate is about 62% and the ductility is 2-3 times that of A36 steel. In order to overcome some defects of ordinary use metallic dampers, the mechanical characteristic of low yield strength steel is used to develop added damping and stiffness for rhombic steel plate absorber. Test of the energy dissipation behavior for this newly developed device indicated that LYS could stably dissipate or absorb the input energy of earthquake. Then, the analytical model for the hysteretic behavior of this new device is proposed. Comparison of experimental data and numerical simulation results showed that this analytical model is suitable for simulating the hysteretic energy behavior of this new device.

Suppose {X_i, i≥1} and {Yi, i≥1} are two independent sequences with distribution functions F_X(x) and F_Y(x), respectively. Z_i,n is the combination of X_i and Y_i with a probability pn for each i with 1≤i≤n. The extreme value distribution G_Z(x) of this particular triangular array of the i.i.d. random variables Z_1,n,Z_2,n,...,Z_n,n is discussed. We found a new form of the extreme value distributions i) Φ_α1^A(x)Φ_α2(x) and ii) Ψ_α1^A(x)Ψ_α2(x)(α1<α2), which are not max-stable. It occurs if F_X and F_X belong to the same MDA(Φ) or MDA(Ψ).

In this paper, a G¹, C¹, C² PH-spline is employed as an approximation for a given Bézier curve within error bound and further renders offset which can be regarded as an approximate offset to the Bézier curve. The errors between PH-spline and the Bézier curve, the offset to PH-spline and the offset to the given Bézier curve are also estimated. A new algorithm for constructing offset to the Bézier curve is proposed.

In this work, we made progress on the problem that l_r⊗l_p⊗l_q is a Banach algebra under schur product. Our results extend Tonge\'s results. We also obtained estimates for the norm of the random quadralinear form A:l_r^M×l_p^N×l_q^K×l_s^H→C, defined by: A(e_i, e_j, e_k, e_s)=a_ijks, where the (a_ijks)\'s are uniformly bounded, independent, mean zero random variables. We proved that under some conditions l_r⊗l_p⊗l_q⊗l_s is not a Banach algebra under schur product.

Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of integral equations. The main conditions of our results are local. In other words, the existence of the solution can be determined by considering the “height” of the nonlinear term on a bounded set. This class of problems usually describes the equilibrium state of an elastic beam which is simply supported at both ends.

In September 1994 the University of Twente, the Netherlands, and Zhejiang University, China, decided to cooperate in the field of science, education and management. After several visits of delegations from both sides it was considered worthwhile to explore further opportunities for mutual cooperation. The directors of international cooperation on each side jointly commissioned a project to investigate the potential in a systematic way and to establish further contacts where appropriate. This paper reports on the results of the research cum matching project. To reveal promising matches between multiple departments of both academic institutions a matching model for universities was designed. The study was carried out along two parallel lines. In the research line the theoretical framework was developed into a model for international university co-operation. Moreover, an analysis was carried out on internal, external and cultural aspects resulting in a set of thirty four influencing factors. In the matching line a total of seventy interviews were held in order to identify promising matches between units at both universities. This line resulted in eleven promising matches for further co-operation. The novel model appeared useful in analyzing the variety of factors and in developing matches between both universities. In the further implementation of the model the issues of \"level of co-operation\" and \"top-down versus bottom-up\" need to be addressed in more detail.

This study investigated the instructional preferences of full time adult credential students after they took a live course called Principles of Adult Education at California State University, Long Beach (CSULB) in the fall semester of 2002. These full time adult credential students had been working on their adult teaching credentials to meet the competencies specified by the California Commission on Teacher Credentialing. The course introduced students to Andragogy developed by Malcolm Knowles out of the andragogical model developed by Lindeman (1926). The study used Principles of Adult Learning Scales (PALS), advanced by Gary Conti in 1983 to measure instructional preferences.Data were collected from 30 (100% of 30) full time adult credential students enrolled in a live course to determine their instructional preferences of helping adults learn. The results of the study showed in most cases these adult learning professionals taught adult students andragogically; in some cases they taught adult students pedagogically.