Xiaoping Liu

Visual Task-driven Based on Task Precedence Graph for Collaborative Design

Reasonable task planning is the key technique to improve cooperation quality and the design efficiency in collaborative design. This paper proposes the concept of Task Precedence Graph (TPG) as the basis of visual task-driven for cooperative task design and task communication. Some constraint transformation rules have been abstracted through the analysis of constraint information, followed which the transformation algorithm based on coupling has been put forward for generation of TPG as well. The collaborative design flow is driven by the visual form of TPG, emphasizing the influence of collaborative design environment on designers. The visual task-driven mode has been verified by a collaborative design system that is applied in domains like Die design and Sofa design, confirming the effectiveness of the mode on task planning and design organization.

A preliminary study on collaborative methods in animation design

Animation design is a complicated group project which usually has a long lifecycle, involves huge participants and has diversified media data. In this paper, the idea of collaborative design is brought into the process of animation design, for finding the difficulties and low efficient sectors caused by the lack of collaboration during the whole design process, with the purpose of questing for appropriate solutions to collaboration. Related technologies of collaborative application to four aspects, including pre-creation, task allocation, data management and collaborative perception, are discussed, in order to improve efficiency, and enhance communications and data sharing to some extent. Finally, two instances about collaborative innovation of character relationship in scripts and animation scene design with collaborative template are given, so the perspective that animation design will be a new domain for researches and applications of collaboration is indicated.

Study on visual design environment of cooperative template

Template technology has a great contribution to domain of design, especially computer aided design. Based on existing technologies and methodology, authors have applied the concept of cooperative template to the study of visual design environment. A framework of visual design environment of cooperative template is introduced including cooperative template description, element constraint, working flow and parallel mechanism. Several instances like Die cooperative & Sofa are provided to demonstrate the features and utility of the design environment. As a new concept, result of application makes authors believe that cooperative template play an important role in information-reducing, relation-order and design efficiency in CSCD environment.

Study on Constraint Information Visualization in CSCD

Constraint information is crucial content of CSCD. It becomes more complicated and various with the expanding application and hard to manage. In order to control collaborative design flow efficiently, detect constraint conflicts early and decrease contradiction extension speed, intuitive and vivid constraint information visualization method is created. This paper discusses detailed signification and formalized description of constraint information visualization in CSCD based on classification and representations, puts forward two key procedures in visualization: one is counterpart modes between constraint information and available visualization techniques. The other one is harmony system of assessment based on constraint harmony concept. Crucial steps of constraint information visualization in CSCD such as constraint information mapping, dynamic track have been pointed out as well. The application of constraint information in collaborative design will give an important direction to complicated system control and complicated constraints management

Study of 3D co-modeling method for /spl omega/ type bar-spring clip

/spl omega/ type bar-spring clip is a very complex space curve for elastic fastening of track. It was very difficult to create its 3D model in general CAD without bugs. In this paper, the structure of /spl omega/ type bar-spring clip is analysed, and the parametric equations and two improved methods based on UG/Open API programming for modeling are given, and the comparison is made between two methods. The presented method is suitable for creation of accurate model. This is meaningful for manufacture, performance analysis, and sedation of the bar-spring clip.

Fast and robust local feature extraction for 3D reconstruction

Abstract Large-scale 3D reconstruction based on structure from motion (SFM) has attracted much attention from the computer vision community. Local feature extraction, which is typically used to locate correspondences between images, is one of the most important components of SFM. In this paper, we propose a fast and robust local feature extraction method, called OOD, for SFM-based 3D reconstruction. First, the adaptive and generic accelerated segment test (AGAST) detector is used to detect keypoints, and the image moment is used to define an orientation for these keypoints. Second, a novel descriptor based on the oriented difference of Gaussians is proposed to describe the keypoints, which can be computed directly from the difference of Gaussian image. Finally, a comprehensive evaluation is conducted using several benchmark datasets. Our experimental results indicate that the OOD method outperforms state-of-the-art methods.

Multi-user mass satellite image collaborative scheduling scheme research

With the ascension of computer processing capacity, the problems of massive satellite images presentation encountered in the rendering frame rate, large data scheduling, external memory organization has been basically solved, Google earth put forward one multi-user solution dependent on the powerful cluster rendering technology and collaborative network transmission technology. However, in the limited resources of the stand-alone system, the display of multi-user collaborative data become another challenge. This paper proposed a collaborative scheduling scheme for multi-user scheduling problem of satellite image data in the stand-alone mode, in the fully enhance the system resource utilization condition, balanced users average experience and data throughput condition. Finally, in the prototype system, we verify its validity and analyze its efficiency and interactivity though the users experience way.

Visualization on relationships of cooperative work logs from semantic dimensional feature space

Cooperative work logs can assist workers in disperse space to share cooperative work information. But there is just work flow control for work logs in currently cooperative work model. At the same time, the show of cooperative work logs is limited by chronological order. In this case, the staff of the cooperative project cannot recognize the relationships of numerous cooperative work logs and the controller cannot fast positioning current core work step. For mining the semantic relationships in cooperative work logs, this paper promotes a novel method, a visualization method of dimension reduction of log text semantic dimensional feature space, which help co-workers arranged in different parts of the cooperative work see the whole semantic structure clearly and assist the controller fast positioning the current core step. Thus, the controller is able to make a strategic decision for further work steps. In the end, the prototype of visualization platform is applied in the practical cooperative design of wire harness and proves this method was effective in fast positioning key emphasis in cooperative work by visualization of semantic relationships in cooperative work logs.

The visualization of constraints conflict in collaborative design

Constraints conflict occurs inevitably in collaborative design process. Therefore, conflict detection and resolution becomes critical for successfully completing the design. This paper puts forward a novel process of constraints conflict visualization to help designers to solve the problem. The process begins with modeling of constraint information based on Constraints Satisfaction Problem (CSP), then presents an effective algorithm to detect conflicts, finally the visualization of constraints result is displayed to designers for pointing out the direction of conflict resolution or personalized improvement. At last, an application of V belt drive design is described, which demonstrates the reasonableness and feasibility of the proposed technique.

Constraint information visualization methodology for cooperative design

It is difficult to manage constraint information in cooperative design due to its variety and changeability. The concept of Constraint Information Visualization (CIV) in cooperative design and CIV framework comprising the CIV methodology are put forward to control cooperative design flow efficiently, detect constraint conflicts early and negotiate the contradiction under the support of visualization. On the basis of classification and representation of constraint information, this paper discusses the importance of CIV and its formalized description for cooperative design. The procedure of visual mapping and harmony evaluation is given in details. The main step of visual mapping is divided into classification mapping, structure and harmony mapping and detailed property mapping. Visual Mapping implements mapping from constraint information to visual representation with corresponding mapping modes. The concepts of local harmony and global harmony are also proposed for cooperation. An application of CIV verifies CIV methodology, which will direct a new way to implement complicated constraints management in cooperative design.