Abstract: In this paper, a Command Search Interface is proposed for contemporary CAD systems. The proposed Interface can help users quickly locate the desired commands by a list of key words and thus helping newbie users boost modeling efficiencies without the need of substantial familiarization of graphical user interfaces. In order to enhance the search intelligence, accuracy and robustness, we developed a novel search mechanism based on a proposed CAD Lexicon List, which is constructed from the help manuals of CAD systems and integrated with synonym word sets. This search engine has been initially designed to search CAD modeling commands from textual input, and further incorporated in our Voice-Enabled CAD systems. The definitions and structure of the CAD Lexicon List is presented in detail. The algorithms of the proposed search engine and its applications in our prototype system are also demonstrated. © 2010 CAD Solutions, LLC.

Abstract: This paper presents an efficient and economic virtual teeth setup system. The virtual teeth set-up procedure follows the traditional method of using aligners to assist the dentist in solving orthodontic problems. Unlike the traditional method, our virtual set- up procedure first digitizes a plaster model using a 3D scanner. Next, crown segmentation algorithm is used to separate the virtual model into the teeth and gum. The virtual teeth can be adjusted by a force feedback device. During the chewing motion, the continuous detection algorithm is used to prevent the teeth from intersecting. In addition, in order to avoid defects while the teeth are moving, the morphing algorithm is used to deform the virtual gum during teeth movement. After orthodontic planning is finished in our system, a new orthodontic treatment method, called clear aligner, will be added to our system. First, each step of set-up model can be milled using a 5-axis machine. Then the clear aligner can be manufactured by vacuum forming technology. Finally, a clinical experiment is conducted to validate our virtual teeth set-up system. The contribution of this paper is to propose an innovative procedure designed for orthodontic alignment. It is believed that our system can greatly reduce the cost of orthodontic treatment and facilitate the conduct of orthodontic study. © 2010 CAD Solutions, LLC.

Abstract: Respirators protect workers from hazardous airborne particles. It is important to evaluate respirator comfort and fit for all workers of diverse anthropometry as contact pressure plays a vital role. This paper presents the procedure and results of studying contact pressure of N95 filtering face-piece respirators (FFR) by using a finite element method. Finite element models of respirators and headforms have been improved based on a previous study. The headform model contains a skin layer, muscle layer, and bone layer. The whole facial area is divided into four parts (two areas for cheeks, one area for upper forehead, and one area for chin). Two N95 FFR models (one is one-size-fits-all and the other FFR has two sizes, i.e., small and medium/large) are used to simulate the interaction between the respirator and the headform. The results show that the respirator with two sizes provides better contact pressure distribution than the one-size-fits-all respirator. It has also been shown that the one-size-fits-all respirator works well for the large, medium, and short/wide headforms, but there are indications of potential leakages for the small and long/narrow headforms. For the respirator with two sizes, the medium/large size respirator works well for the large and long/narrow headforms, while the small size respirator works well for the medium, small, and short/wide headforms. The medium/large size respirator has potential leakages for the medium headform. Furthermore, the N95 FFR with two sizes has a more uniform pressure distribution than the one-size-fits-all respirator. Future studies are needed to validate these observations with human subjects. © 2010 CAD Solutions, LLC.