A Miniaturized Frequency Reconfigurable Patch Antenna for IoT Applications

Wireless Personal Communications - This work presents a novel frequency reconfigurable patch antenna design for Internet of Things (IoT) applications. The proposed antenna structure has hexagonal...     

On the Handling of Continuous-Valued Attributes in Decision Tree Generation

We present a result applicable to classification learning algorithms that generate decision trees or rules using the information entropy minimization heuristic for discretizing continuous-valued attributes. The result serves to give a better understanding of the entropy measure, to point out that the behavior of the information entropy heuristic possesses desirable properties that justify its usage in a formal sense, and to improve the efficiency of evaluating continuous-valued attributes for cut value selection. Along with the formal proof, we present empirical results that demonstrate the theoretically expected reduction in evaluation effort for training data sets from real-world domains.     

An adaptive handoff strategy for cognitive radio networks

Spectrum handoff plays an important role in spectrum management as it is the process of seamlessly shifting the on-going transmission of a secondary user (SU) to a free channel without degrading the quality of service. In this paper, we develop an adaptive handoff algorithm that allows an SU to detect the arrival of a primary user (via sensing) and adapt to a reactive or a proactive handoff strategy accordingly. The adaptive handoff scheme first allows an SU to decide whether to stay and wait on current channel or to perform handoff. Then, in case of handoff, an SU intelligently shifts between proactive or reactive handoff modes based on primary use (PU) arrival rate. Further, a PU prioritized Markov approach is presented in order to model the interactions between PUs and SUs for smooth channel access. Numerical results show that the proposed handoff scheme minimizes the blocking probability, number of handoffs, handoff delay and data delivery time while maintaining channel utilization and system throughput at maximal level compared to simple reactive and proactive schemes.     

A group theoretic construction of highly nonlinear substitution box and its applications in image encryption

Substitution box is the most significant component of block cipher. The property of nonlinearity is of great importance for the design of secure substitution boxes. Therefore, it is necessary to develop new methods for the production of substitution boxes with a high non-linearity score. In this paper, we have introduced a novel group theoretic method to construct a robust S-box with non-linearity score 113.75 greater than that of AES S-box. The performance of generated S-box is found to be excellent, when examined through various other well-known algebraic criteria such as strict avalanche criterion, bit independence criterion, differential uniformity and linear approximation probability. The suitability of proposed S-box is tested for image encryption applications through different statistical analyses. We got very encouraging outcomes from all these examinations which certify that the generated S-box meets all the criteria needed to be reliable for secure communication and image encryption.

     

Data-Oriented Scheduling with Dynamic-Clustering Fault-Tolerant Technique for Scientific Workflows in Clouds

Programming and Computer Software - Cloud computing is one of the most prominent parallel and distributed computing paradigm. It is used for providing solution to a huge number of scientific and...     

Gesture image segmentation with Otsu’s method based on noise adaptive angle threshold

By analyzing the essence and deficiency of the improved Otsu’s method, this paper proposes a noise adaptive angle threshold based Otsu’s method for gesture image segmentation. It first designs a two-dimensional histogram of gray value-neighborhood truncated gray mean to avoid the interference of extreme noise by discarding the extremes of the neighborhood. Then, the probability that the pixel is noise is calculated according to the actual situation, adaptive filtering is implemented to enhance the algorithm’s universal applicability. It finally converts the threshold space to an angle space from 0° to 90°, and the threshold search range is compressed to improve its efficiency. As the gesture is close to the background and the boundary is blurred, this paper combines the global and local Otsu’s method to segment the gesture images based on the angle space. On the one hand, it uses the global Otsu’s method to obtain the global threshold t₁. On the other hand, it uses the local Otsu’s method to obtain the local threshold t₂, and segments gesture images based on t₂. Experimental results show that the proposed method is effective and can accurately segment gesture images with different noises.

     

Fabrication of ceramic micro-scale hollow components by micro-powder injection moulding

Rapid developments in microsystem technologies demand ceramic microcomponents of increasing geometrical complexity. State-of-the-art microfabrication routes of ceramics are either limited in geometrical complexity and/or high volume capabilities. This paper presents a process route by which ceramic microcomponents with relatively complex three-dimensional architectures could be realised by a high-volume technique. The proposed strategy, in which yttria-stabilised zirconia was implemented, combines the capabilities of insert-micromoulding, powder micro-overmoulding, catalytic debinding and sintering. The produced architectures demonstrate the capability of the technique to combine the high performance of ceramic materials with the dimensional accuracy and mass manufacturability of powder micromoulding.     

Pre-Silicon Verification Using Multi-FPGA Platforms: A Review

Because of the shrinking transistor size and improved design process, the computation capability of modern digital systems has increased tremendously over the past few years. This, however, has led to increased design complexity and huge verification efforts and costs. The design of new digital systems costs millions of dollars and the money is wasted if the final product does not serve the purpose. This has made pre-silicon verification even more pertinent as it can detect design faults prior to its roll out and can save companies a huge fortune. Pre-silicon verification now accounts for almost 70% of the total design effort and cost of modern digital systems. For pre-silicon verification, four techniques are commonly used namely simulation, emulation, virtual prototyping and FPGA-based prototyping. These techniques have their advantages and disadvantages. However, FPGA-based prototyping is unique in the sense it gives better speed and real world testing experience as compared to other pre-silicon verification techniques. In this paper, we give a detailed survey of multi-FPGA prototyping. A survey of three different multi-FPGA platforms namely off-the-shelf, custom, and cabling platform is presented in this work. A comprehensive overview of these platforms from hardware perspective is presented. Detailed discussion on their respective back end flow and the associated difference is also presented. The survey is concluded with a discussion on the challenges faced by multi-FPGA prototyping and the research opportunities where work can be done for further improvement.