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Xu W.,Shanghai JiaoTong University | Chen X.,Shanghai JiaoTong University | Xi J.,Shanghai Key Laboratory of Advanced Manufacturing Environment | Xi J.,Xian Jiaotong University
Guangxue Xuebao/Acta Optica Sinica

Based on simulation of the influence of gamma nonlinearity of the projector on phase error, a method of phase error compensation for structural light measurement based on phase shifting is put forward. In this method, quadratic polynomial is used to approximate the intensity of the captured images, meanwhile least square fitting method is used to compensate the phase error, and in this way, system error caused by the gamma nonlinearity of the projector is reduced greatly. Because it doesn't depend on environmental light, camera parameters or DLP parameters, this method has superiority in aspects of universality, complexity and calculation speed. Experimental results show that this method reduces greatly the phase error caused by the gamma nonlinearity of the projector. The average phase error is 5 times smaller than that before error compensation, meanwhile the bit error rate of unwrapping based on look-up table method is reduced 14.5 times. Source

Xiong S.,Shanghai JiaoTong University | Xiong S.,Shanghai Key Laboratory of Advanced Manufacturing Environment | Zhao J.,Hubei University | Jiang Z.,Shanghai JiaoTong University | Dong M.,Shanghai JiaoTong University
International Journal of Advanced Manufacturing Technology

There has been a growing trend among shoe manufacturers to introduce customized shoes to satisfy varying customer style, fit, and comfort needs, thus to increase the product's added value. This study presents a computer-aided design (CAD) system for designing a customized shoe last based on the chosen shoe style and customer's foot features. The CAD system first automatically extracts 18 important foot features from a laser-scanned customer's foot. Then, it applies a global grading with a local deformation approach that can deform the base shoe last with the customer's chosen style to the customized shoe last based on the extracted foot features while maintaining the customer's chosen style. Finally, the system evaluates the final foot shoe last fit and represents the fit in a contoured figure. The experimental results show that the proposed CAD system can be adopted by shoe manufacturers to make customized shoes with the customer's chosen style and foot size and shape. © 2009 Springer-Verlag London Limited. Source

Sun J.,Shanghai JiaoTong University | Sun J.,YAPP Automotive Parts Co. | Chen X.,Institute of Computer Integrated Manufacturing | Liao H.,China Institute of Technology | And 2 more authors.
Rapid Prototyping Journal

Purpose - The purpose of this paper is to propose a template-based framework for nasal prosthesis fabrication using a 3D areal scanner and a CT scanner. Design/methodology/approach - Use of a self-designed 3D areal scanner enables acquisition of accurate data describing the patient's face. Patients with nasal defects have no organization for reference, but the template-based model construction method can ensure successful building of the outer surface of the nasal prosthesis. Since the areal scanner has some difficulties acquiring data for concave areas, preoperative CT data are used to provide concave information, enabling construction of the inner surface for the nasal prosthesis. The combined inner and outer surfaces are used to generate the completed nasal prosthesis. Findings - The results showed that the nasal prosthesis fits the patient's appearance well. Clinical applications confirmed that this framework is attractive and has the potential desired nasal prosthesis in daily clinical practice. Practical implications - The results of this study improve the fabrication accuracy of nasal prostheses. The construction and development technique employs a nasal digital library, 3D areal scanning data and CT scanning data. This technique facilitates fabrication of precise nasal prostheses while helping the patients predict the effect before the prosthesis is manufactured. Originality/value - This template-based framework has strong potential for clinical applications because of its advantages over other methods in terms of accuracy, speed, safety, and cost. © Copyright - 2013 Emerald Group Publishing Limited. All rights reserved. Source

Qiu S.,Shanghai JiaoTong University | Jing X.,Shanghai JiaoTong University | Fan X.,Shanghai JiaoTong University | Fan X.,Shanghai Key Laboratory of Advanced Manufacturing Environment
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics

Currently A-pillar ergonomics evaluation lacks of enabling tool for helping style designer actively participate in automotive design process, therefore, based on augmented reality, a new method for A-pillar evaluation is proposed. Firstly, an assessment environment including hardware and software systems is established, which superimposes the virtual vehicle model to the physical driving mockup precisely in real time. Secondly, virtual visual cone models for left and right eyes are constructed. A calibration method is designed to map the real eye points with the virtual ones in the visual cones, and an algorithm for A-pillar's blind angle calculation is proposed based on vision line collision detection. The method is proved to be reliable through detailed analysis of calibration error's influence on the computational accuracy of blind angle. Lastly, the above system and method are verified by an application of a certain car model's A-pillar evaluation. The virtual visual cones are driven by tracking the user eyes' positions while he is sitting in the physical driving mockup. The blind zone angle of A-pillar can be calculated quickly for different driving postures, and the impact of A-pillar on the front view can be subjectively evaluated by the user. The results show that the method is simple and effective, and a new assessment tool is provided for the automotive A-pillar evaluation. Source

Huang X.,Shanghai JiaoTong University | Shen B.,Shanghai JiaoTong University | Chen D.,Shanghai Key Laboratory of Advanced Manufacturing Environment
DSDE 2010 - International Conference on Data Storage and Data Engineering

IT Service Management (ITSM) is playing an increasing important role in ensuring consistency between information technology and business process nowadays. As the core of ITSM, IT Service Support ensures that the customer has appropriate services to support business function. Therefore£¬many organizations adopt best practices and tools in order to import IT Service Support normative and efficiency, and IT Infrastructure Library (ITIL) has been the international de facto standard. However, current standards and tools are not enough to provide precise, abstract and systematic IT Service Support concepts. Furthermore, process model integration, reuse and exchange still remains a challenge in IT Service Support process development area. In this context, an ITIL-based IT Service Support Process metamodel was presented in this paper. The metamodel extends Business Process Definition Metamodel (BPDM) as an IT Service Support process is also a business process. The metamodel has characteristic of easy operation and simple structure, and it has been preliminary applied in implementation of IT Service Support Process tool. The proposed metamodel soundly support process modeling and business rule customization in the form of ECA (Event-Condition-Action). © 2010 IEEE. Source

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