A Chinese Text Input Brain–Computer Interface Based on the P300 Speller

In this article the results of a usability study of CONTACT, an application that supports negotiation strategy training via video modeling for enhancing the conflict resolution of adolescents with autism spectrum disorder (ASD), are presented. This application was modified from the NoProblem! prototype based on feedback from two focus groups of typically developing adolescents and therapists and teachers of adolescents with ASD. It has been designed to address social competencies through video modeling and complies with the principles of constructivist learning theory. Twenty-one adolescents with ASD, 12 to 18 years of age, and 27 age- and gender-matched typically developing adolescents participated in this study. The outcome measure used was the Intrinsic Motivation Inventory. Both adolescents with ASD and typically developing adolescents perceived the application to be interesting and enjoyable; they claimed that it did not generate feelings of pressure or tension and that they had independent choices. The results also showed that adolescents with ASD felt significantly more competent than typically developing adolescents when using this application. The findings of this study emphasize the important role that the usability process has when designing and developing new technologies for educational purposes for adolescents with and without ASD.     

Magnetic concentration of particles and cells in ferrofluid flow through a straight microchannel using attracting magnets

Concentrating particles to a detectable level is often necessary in many applications. Although magnetic force has long been used to enrich magnetic (or magnetically tagged) particles in suspensions, magnetic concentration of diamagnetic particles is relatively new and little reported. We demonstrate in this work a simple magnetic technique to concentrate polystyrene particles and live yeast cells in ferrofluid flow through a straight rectangular microchannel using negative magnetophoresis. The magnetic field gradient is created by two attracting permanent magnets that are placed on the top and bottom of the planar microfluidic device and held in position by their natural attractive force. The magnet–magnet distance is mainly controlled by the thickness of the device substrate and can be made small, allowing for the use of a dilute ferrofluid in the developed magnetic concentration technique. This advantage not only enables a magnetic/fluorescent label-free handling of diamagnetic particles, but also renders such handling biocompatible.     

Practical design and implementation of recognition assisted dynamic surveillance system

Open Service Gateway Initiative (OSGi) and Open-source Computer Vision (OpenCV) are widely used for developing applications. OSGi is constructed to provide a service platform with high application interoperability while OpenCV is used to provide many application programming interfaces (APIs) about image processing. In this paper, we design a recognition assisted surveillance system based on OSGi and OpenCV platforms. The system features dynamic monitoring by a camera carried by a robot and a Java 2 Micro-Edition (J2ME) viewer on a mobile phone. With the assistance of image recognition techniques, the captured frames are adaptively reproduced for handheld phones in a limited bandwidth environment. The proposed adaptive pause time control mechanism can efficiently improve the synchronization relationship between captured and viewed frames across heterogeneous networks. The evaluation results show that the proposed scheme can save power for the moveable camera and have a shorter time delay between the captured and viewed frames.     

An integrated MCDM technique combined with DEMATEL for a novel cluster-weighted with ANP method

Traditionally, most importance-assessing methods used to demonstrate the importance among criteria by preference weightings are based on the assumptions of additivity and independence. In fact, people have found that using such an additive model is not always feasible because of the dependence and feedback among the criteria to somewhat different degrees. To solve the issue the analytic network process (ANP) method is proposed by Saaty. The general method is easy and useful for solving the above-mentioned problem. However in ANP procedures, using average method (equal cluster-weighted) to obtain the weighted supermatrix seems to be irrational because there are different degrees of influence among the criteria. Therefore, we intended to propose an integrated multiple criteria decision making (MCDM) techniques which combined with the decision making trial and evaluation laboratory (DEMATEL) and a novel cluster-weighted with ANP method in this paper, in which the DEMATEL method is used to visualize the structure of complicated causal relationships between criteria of a system and obtain the influence level of these criteria. And, then adopt these influence level values as the base of normalization supermatrix for calculating ANP weights to obtain the relative importance. Additionally, an empirical study is illustrated to demonstrate that the proposed method is more suitable and reasonable. By the concept of ideal point, some important conclusions drawn from a practical application can be referred by practitioners.     

Optimisation of electron-beam surface hardening of cast iron for high wear resistance using the Taguchi method

The paper presents the application of the Taguchi method to develop an optimised electron-beam surface hardening of cast iron for high wear resistance. The experiments were conducted on both the ductile and grey cast iron. The factors investigated during the surface-hardened process included the material matrix, the accelerating voltage, the electrical current, the travel velocity, the melted width, the beam oscillation, and the post-heat treatment temperature. In this study, the L18 and L9 orthogonal arrays were introduced through the two-stage experimental designs and trials. Smaller-is-better was used as a quality characteristic to evaluate the experimental results by computing their signal-to-noise (S/N) ratios of the wear volume after wear tests.It was found that using the Taguchi method coupled with a two-round experimental design strategy is simple, effective and efficient in developing an optimised EB surface hardening process. The experimental results show that the most important process parameters identified are the accelerating voltage, the travel speed, the electrical current and post-heat treatment, respectively. The best wear resistance result obtained through the best combination of process parameters is 8.845×10⁸ kg-mm/mm³.     

Effects of cell correlations in a matched-filter PN codeacquisition for direct-sequence spread-spectrum systems

Rapid pseudonoise (PN) code acquisition with matched-filter correlators has been very popular in direct-sequence (DS) spread-spectrum systems. Conventionally, the analysis of this acquisition method is based on the assumption that the detections among cells are independent. However, there may be strong correlations among cell detections for the case that the cell size is less than a chip duration. In this paper, the mean acquisition time performance of the acquisition method is analyzed with the cell correlations being taken into account. Numerical results show that depending on the threshold value and other system parameters, the effect of cell correlations may be over 20% of the mean acquisition time for signal-to-noise ratios (SNR) of practical interest. The analytical results are substantiated by computer simulations     

Fabrication of diamond micro-structures by ink-jet printed diamond seeding and microwave plasma assisted chemical vapor deposition

Ink-jet printing has the advantage of easy formation of micro-patterns on rigid as well as flexible surfaces without needing conventional lithographic processes. By means of printing in selected areas, diamond seeding in designed patterns and areas is achieved. Properly designed ink with a desirable composition helps the formation of patterned structures with tailored functions. Ink containing nano-diamond particles was designed and used to print micro-structures, which were applied for further CVD growth of diamond by means of microwave plasma CVD. Promising applications of this technique are discussed.     

Identification of a threshold value for the DEMATEL method using the maximum mean de-entropy algorithm to find critical services provided by a semiconductor intellectual property mall

To deal with complex problems, structuring them through graphical representations and analyzing causal influences can aid in illuminating complex issues, systems, or concepts. The DEMATEL method is a methodology which can confirm interdependence among variables and aid in the development of a chart to reflect interrelationships between variables, and can be used for researching and solving complicated and intertwined problem groups. The end product of the DEMATEL process is a visual representation—the impact-relations map—by which respondents organize their own actions in the world. In order to obtain a suitable impact-relations map, an appropriate threshold value is needed to obtain adequate information for further analysis and decision-making. In the existing literature, the threshold value has been determined through interviews with respondents or judged by the researcher. In most cases, it is hard and time-consuming to aggregate the respondents and make a consistent decision. In addition, in order to avoid subjective judgments, a theoretical method to select the threshold value is necessary. In this paper, we propose a method based on the entropy approach, the maximum mean de-entropy algorithm, to achieve this purpose. Using a real case to find the interrelationships between the services of a Semiconductor Intellectual Property Mall as an example, we will compare the results obtained from the respondents and from our method, and show that the impact-relations maps from these two methods could be the same.     

Channel Assignment and Hand-off Policies in Cluster-Based Micro/ Picocellular Wireless Networks

In this paper, we consider cluster-based micro/picocellular networks with overlapped cell-clusters. Channel assignment and hand-off policies are essential and important policies in cellular wireless networks. The issue of how different channel assignment and hand-off policies in the overlapped areas affect the overall system performance has not yet been studied in the literature. This paper provides a thorough study and understanding of this issue. We propose two cluster channel assignment policies, namely, partitioned and shared cluster channel assignment policies, and two hand-off policies, namely, boundary and early hand-off policies. The proposed cluster channel assignment policies and hand-off policies are combined to obtain three different strategies, namely, partitioned-boundary, partitioned-early, and shared-boundary strategies. Extensive simulations are used to study the performance of the strategies. Our results show that the partitioned-early and shared-boundary strategies produce significantly lower hand-off dropping and forced termination probabilities than the partitioned-boundary strategy. The partitioned-early and shared-boundary strategies yield similar performance.     

Modeling VOC Emissions in the High-Purity Oxygen Activated Sludge Process

Mass balances for volatile organic compounds (VOCs) were added to a structured mathematical model of the high-purity oxygen activated sludge (HPO-AS) process. The model was sized to correspond to two large existing HPO-AS treatment plants. The stripping of ten different VOCs was modeled and compared to stripping from conventional air activated sludge process. The results show that the covered aeration tanks can reduce stripping by more than 90%, depending on the specific VOC. If biodegradation is considered, the HPO-AS process degrades more than the conventional process due to the higher liquid-phase concentrations that result because of reduced stripping. The increase in biodegradation depends on the VOCs degradability but should increase to nearly 100% for highly volatile but biodegradable VOCs.