A rapid prototyping (RP) machine system which combines a PC-based controller with the thermal-extrusion method is presented. The proposed RP system offers a three-axis platform, an extrusion head, a ...temperature controller, and a PC-based control system. Low-cost acrylonitrile-butadiene-styrene (ABS) pellets/powder are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. In order to improve the quality of RP part, the Taguchi method was used to analyzing the process parameters of the proposed RP system. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. The RP software technique includes slicing, support, tool path, and motion code generation. This paper also presents a new adaptive slicing algorithm for RP system. According to this algorithm, the three-dimensional (3-D) computer-aided design (CAD) model can be sliced with different thickness automatically by comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. With this adaptive slicing method, the part can be fabricated faster than it uses uniform slicing method with identical accuracy. Finally, the intelligent web-based RP system allows remote users to upload an STL file, to directly building up of the physical model, and to monitor the actual fabrication process from a charged coupled devices (CCD) camera located in the RP machine itself. The user does not need to buy an expensive RP machine; instead, he can rent time and uses the machine remotely via the Internet. Note to Practitioners-RP has being used as an essential augmented tool between CAD and computer-aided manufacturing (CAM) for product manufacturing. RP uses layered manufacturing technology to produce complicated prototypes directly from a CAD model. As imaging, materials, and processing techniques improve, RP functions such as assembly fit, tooling masters, prototype tools, and prototype parts are made possible. RP technology that can construct parts of multiple materials, colors, and even parts composed of composite materials will soon be available. In this paper, an RP machine system which combines PC-based controller with thermal extrusion method is presented. Low-cost ABS pellets are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. In this paper, a new adaptive slicing algorithm is developed to decrease fabrication time without much reducing the model accuracy. According to this algorithm, the 3-D CAD model can be sliced with different thickness automatically. With this adaptive slicing method, the part can be fabricated much faster than it uses traditional uniform slicing method. Finally, the intelligent web-based RP system has been developed which allows remote users to upload a CAD file of the part, direct building up of the physical model, and monitoring of the actual fabrication process from a CCD camera located in the RP machine itself. The greatest advantage is that user does not need to buy an expensive RP machine; instead he rents time and uses the machine remotely via the Internet. This really drastically reduces the production development cycle for the highly competitive time-to-market challenge.
COREX shaft furnace (SF) is a typical screw feeder with a storage container coupled with eight screw casings and screws. The structure of screw casing plays an important role in the moving behavior ...of burdens, stress distribution, abrasive wear of screws, and energy consumption during the operation of SF. Therefore, a three-dimensional semi-cylindrical model of actual size of COREX-3000 SF was established based on discrete element method to investigate the influences of screw casing structure. The results show that the increase in the gap between the outside of screw flight and screw casing is beneficial for the smooth operation of SF, resulting in uniform descending velocity along the radius of SF in the lower part, decreasing the size of recirculation region, and alleviating stress concentration in the screw casing. Moreover, raising the gap appropriately is also beneficial to weaken screw abrasive wear, decrease energy consumption, and then prolong the service life of the screws. However, enlarging the gap also leads to more undesired high temperature reduction gas into the SF from melter gasifier, thereby deteriorating the operation of SF. Thus, an ideal distance exists between the outside of the screw flight and the screw casing, which is suggested to be equal to the average of particle diameter.
We sequenced the complete mitogenome of northern spotted barramundi Scleropages jardinii, an ancestral bonytongue with economic and conservation value. The mitogenome is 16,670 bp in length with an A ...+ T content of 52.9%, and contains 13 protein-coding genes, 2rRNAs, 22 tRNAs and a control region. The gene order and arrangement is similar to that of other Osteoglossidae species, as is base composition and codon usage. These data will provide useful molecular information for phylogenetic relationships within the family Osteoglossidae species.
Drowsiness of driver is one of the common causes resulting in road crashes. According to the research, there have been twenty percent of the road accidents which are related to the drowsiness of ...drivers. Nowadays, with the development technology, various approaches are introduced to detect the drowsiness of drivers. In this paper, we propose a multi-model fusion system which is composed of the three models to capture driver's face and detect drowsiness in the real-time for telemetric robotics tracking applications. The sensor device we used is an RGB camera which is mounted in front of driver to obtain the facial image. Then, we combine the results based on the state of the eye blink, yawn and head deviation to determine whether the driver is drowsy. We test our models to obtain the weighting factors in drowsy value. In the experiment, we show that our system has the high accuracy of detection.
In this paper we constructed an artificial ecological system (AES) to maintain sensor networks, and define two kinds of species as our sensor nodes; one is called prey and the other called predator. ...In order to keep these sensor nodes reach the maximization of blanker coverage and ensure they will not die out, we use three kinds of models. The sensor nodes dynamics model (SNDM) based on the molecular dynamics is used to implement the diffusion, and the sensor nodes ecological model (SNEM) is used to maintain those sensor nodes. We also establish the population growth limit model (PGLM) to fast reach the desire density of sensor nodes deployment. Base on advantages of those three models, we can create an ecological balance environment with automatic sensor deploy and automatic sensor maintain.
Texture classification is an important first step in image segmentation and image recognition. The classification algorithm must be able to overcome distortions, such as scale, aspect and rotation ...changes in the input texture. In this paper, a new fractal model for texture classification is presented. The model is based on fractional Brownian motion (FBM). It is also shown that this model is invariant to changes in incident light; empirical results are also given. The isotropic nature of Brownian motion is particularly useful for outdoor applications, where the viewing direction may change. Classification results of this model are presented; comparisons with other texture measurement models indicate that the incremental FBM (IFBM) model has better performance for the samples tested.
Facial expression recognition is an essential issue in the field of human and computer interactions. The objective of this paper is to deal with the problem of failure for the feature points on face ...based on active appearance model (AAM) in fitting with different users. We train the fitting model for different users before recognition. A high-quality AAM alignment results rely on appropriate selections of initial positions. In our method, we apply partial AAM fitting on mouth and eyes. Therefore we could have a better alignment for facial features; as a result, it can implement for tracking real-world video and perform real-time alignment. To obtain stable partial AAM, we use multi-level optical flow to determine initial positions of facial feature models. Then we use the Eigen-faces dynamic face recognition system to recognize different users and select the trained fitting model in recognizing the facial expressions, we combine the methodology of facial expression recognition with Eigen-faces dynamic face recognition. In this paper, we have demonstrated our approach which can accurately recognize different user's facial expressions and emotional variation.
To keep autonomous mobile robot in continuously working condition, power supply is an important issue. Typically, rechargeable batteries may provide few hours of peak usage. Recharging is necessary ...before the power of the batteries has exhausted. In this paper, the docking station with an auto-recharging device and robot docking mechanism are implemented. We propose a docking control strategy and automatic recharging device for the security robot recharging. We also propose a power prediction algorithm to determine when the robot needs to navigate back to docking station for recharging. An artificial landmark is detected and recognized by the proposed image processing system. Then the geometrical relationship between the robot and the docking station (the depth and orientation) is estimated. The robot will move directly right in front of the docking station. Finally, the robot approaches to the docking station based on the proposed virtual spring model. In this model, we assume that the robot and the docking station are connected by a virtual spring. The compliant forces act both in the direction of the translation deformation and bending. The motion control parameters, which are velocities of the two wheels, can be derived from the model. Experimental results show that the proposed methods successfully perform the docking and automatic recharging.
Since the aging population is increasingly affecting the society, not only aging problem become an important social issue but also health care will become an important issue. In order to compensate ...for the shortages of nurses and reduce the stress of nursing work, numerous research groups are studying in the field of human-robot interaction and hoping to bring a better life to humankind. Many companion robots were developed to assist elderly people's mental health and promote their independence. In this paper, we describe a personal service robot developed for assisting a user in his/her daily life. This healthcare system equipped with the capability for navigation by visual information and friendly human-robot interface. We can tele-operate healthcare service system via the Internet. This healthcare system improves quality of healthcare and increased hospital throughput.
Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) plays an important role in the metastasis of nasopharyngeal carcinoma (NPC). This study was to investigate the effects of EBV LMP1 on ...the metastasis of NPC cell lines, and explore potential mechanism.
The expression of LMP1, E-cadherin and intercellular adhesion molecule-1 (ICAM-1) in human NPC cell lines CNE1 (well differentiated) and CNE1-GL (CNE1 cells transfected with LMP1) were detected by SP immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The cell-cell adhesion assay, the cell-matrix adhesion assay, the wound-induced migration assay and the migration assay were used to investigate the effects of LMP1 on adhesive and metastatic abilities of NPC cells.
The positive rates of LMP1 and ICAM-1 were significantly lower in CNE1 cells than in CNE1-GL cells 0% vs. (96.60+/-3.03)%, P<0.01; (5.27+/-1.45)% vs. (93.33+/-4.23)%, P<0.01; the positive rate of E-cadherin was significantly higher in CNE1 ce
