GIS-based highway design review system to improve constructability of design

This paper presents a Geographic Information Systems (GIS) as a tool which can help highway engineers review a completed highway design to improve its constructability. The GIS can link different data sets together using geographical location as the common key between the data sets to perform various spatial operations. In this paper, the GIS is used to integrate various highway design data using a common milepost referencing system. The GIS allows the integration of the highway design information by establishing common spatial relationships between various highway design features and their geographical locations. The GIS can provide a comprehensive platform upon which all aspects of the highway project review process can be built. This paper also addresses the interface of GIS with the existing highway project data bases and computer-aided design files. The proposed GIS-based highway design review system can improve the constructability of the highway design at an early design review stage.     

High Frequency Characteristics of a Front Wheel Suspension

This paper presents a modeling method to analyze the frequency characteristics of a suspension system. The method employs the superelement and lumped methods for structural modeling of flexible bodies, and it is incorporated with a multibidy dynamics formulation in which joint nonlinearities can be considered effectively. To verify the accuracy of the results obtained by the modeling method, a quarter car test was made. Test results showed that the computational model provided fairly accurate frequency characteristics for the suspension system. Other useful conclusions were also drawn from this study.     

Monolithic coupling of the pressure and rigid body motion equations in computational marine hydrodynamics

In Fluid Structure Interaction(FSI) problems encountered in marine hydrodynamics, the pressure field and the velocity of the rigid body are tightly coupled. This coupling is traditionally resolved in a partitioned manner by solving the rigid body motion equations once per nonlinear correction loop, updating the position of the body and solving the fluid flow equations in the new configuration. The partitioned approach requires a large number of nonlinear iteration loops per time–step. In order to enhance the coupling, a monolithic approach is proposed in Finite Volume(FV) framework,where the pressure equation and the rigid body motion equations are solved in a single linear system. The coupling is resolved by solving the rigid body motion equations once per linear solver iteration of the pressure equation, where updated pressure field is used to calculate new forces acting on the body, and by introducing the updated rigid body boundary velocity in to the pressure equation. In this paper the monolithic coupling is validated on a simple 2D heave decay case. Additionally, the method is compared to the traditional partitioned approach(i.e. "strongly coupled" approach) in terms of computational efficiency and accuracy. The comparison is performed on a seakeeping case in regular head waves, and it shows that the monolithic approach achieves similar accuracy with fewer nonlinear correctors per time–step. Hence, significant savings in computational time can be achieved while retaining the same level of accuracy.     

Identity-based verifiably committed signature scheme without random oracles

An identity-based verifiably committed signature scheme （IB-VCS） was proposed, which is proved secure in the standard model （i.e., without random oracles）. It enjoys the setup-free property and stand-alone property, both of which make an exchange protocol more practical. The scheme is unconditionally secure against the cheating signer, its security against the cheating verifier is reduced to the computational Diffie-Hellman （CDH） problem in the underlying group, it is secure against the cheating trusted third party if the underlying Paterson Schuldt＇s identity based signature （IBS） scheme is secure, which is proven true based on the CDH assumption in the standard model.     

Structure-borne sound attenuation at corner interface with dynamic vibration absorber attached

Structure-borne sound attenuation at corner interface of two plates with dynamic vibration absorber attached is investigated by wave approach. Equations governing transmission and reflection coefficients are deduced by introducing some non-dimensional coefficients, which help to reveal the physical sense inside and to simplify the analysis. Numerical investigation on vibration energy transmission of bending wave is carried out as well. The results from measurement and prediction show almost the same trends in the simplified experiment. It is found that energy transmission at corner interface depends greatly on whether the dynamic vibration absorber attached acts at resonance and is relatively lower right after the nature frequency of dynamic vibration absorber. Furthermore, the dynamic vibration absorber attached provides less energy transmission of bending wave than blocking mass at the end of “passing band”.     

Multi-element ultrasound phased array applicator for the ablation of deep-seated tissue

High-intensity focused ultrasound (HIFU) has attracted increasing interests as a promising noninvasive modality for the treatment of deep tumors in the thoracic and abdominal cavity. A 90-element HIFU spherical phased array applicator operated at 1MHz has been developed for deep tissue ablation. The spherical array with a 5 cm wide central hole has a 21 cm diameter and an 18 cm radius of curvature. Annular element distribution with unequal element spacing is used to reduce the number of elements. The array is constructed with piezoelectric lead zirconate titanate (PZT-8) circular elements that are 1.4 cm in diameter and have a wall with thickness of 0.2 cm. The array offers an effective ablating depth of at least 8 cm in the tissue for both simulations and ex vivo experiments. The simulations demonstrate that the developed array can steer the focus with good quality of intensity distributions up to 6mm off center over ranges from 17 to 21 cm when the water depth is set at 11 cm. We also present the beam focusing capability in deep tissue through a series of ex vivo experiments by measuring discoloration areas after sonications. These results indicate that the developed array is ideal for the ablation of deep-seated tissue.     

Numerical analysis of nonlinear rotor-bearing-seal system

The system state trajectory, Poincard maps, largest Lyapunov exponents, frequency spectra and bifurcation diagrams were used to investigate the non-linear dynamic behaviors of a rotor-bearing-seal coupled system and to analyze the influence of the seal and bearing on the nonlinear characteristics of the rotor sys- tem. Various nonlinear phenomena in the rotor-bearing-seal system, such as periodic motion, double-periodic motion, multi-periodic motion and quasi-periodic motion were investigated. The results may contribute to a further understanding of the non-linear dynamics of the rotor-bearing-seal coupled system.     

Feasibility of localizing in vivo micro-devices with electromagnetic methods

In order to measure the location of medical micro-devices in the gastrointestinal tract, electromagnetic methods were developed considering the magnetic permeability of human bodies. Two varieties of electromagnetic localization methods have been implemented： one uses direct current（DC） to generate the electromagnetic field, and the other uses alternating current （AC）. The two varieties of the localization principle were analyzed and relevant experiments were made. The experiments show that the alternating electromagnetic method acquires higher accuracy, higher stability and wider measurement range.     

Chinese to Braille translation based on Braille word segmentation using statistical model

Automatic translation of Chinese text to Chinese Braille is important for blind people in China to acquire information using computers or smart phones. In this paper, a novel scheme of Chinese-Braille translation is proposed. Under the scheme, a Braille word segmentation model based on statistical machine learning is trained on a Braille corpus, and Braille word segmentation is carried out using the statistical model directly without the stage of Chinese word segmentation. This method avoids establishing rules concerning syntactic and semantic information and uses statistical model to learn the rules stealthily and automatically. To further improve the performance, an algorithm of fusing the results of Chinese word segmentation and Braille word segmentation is also proposed. Our results show that the proposed method achieves accuracy of 92.81% for Braille word segmentation and considerably outperforms current approaches using the segmentation-merging scheme.