Multiflow Transmission in Delay Constrained Cooperative Wireless Networks

This paper considers the problem of energy-efficient transmission in multi-flow multihop cooperative wireless networks. Although the performance gains of cooperative approaches are well known, the combinatorial nature of these schemes makes it difficult to design efficient polynomial-time algorithms for joint routing, scheduling and power control. This becomes more so when there is more than one flow in the network. It has been conjectured by many authors, in the literature, that the multiflow problem in cooperative networks is an NP-hard problem. In this paper, we formulate the problem, as a combinatorial optimization problem, for a general setting of $k$-flows, and formally prove that the problem is not only NP-hard but it is $o(n^{1/7-\epsilon})$ inapproxmiable. To our knowledge*, these results provide the first such inapproxmiablity proof in the context of multiflow cooperative wireless networks. We further prove that for a special case of k = 1 the solution is a simple path, and devise a polynomial time algorithm for jointly optimizing routing, scheduling and power control. We then use this algorithm to establish analytical upper and lower bounds for the optimal performance for the general case of $k$ flows. Furthermore, we propose a polynomial time heuristic for calculating the solution for the general case and evaluate the performance of this heuristic under different channel conditions and against the analytical upper and lower bounds.Comment: 9 pages, 5 figure

Application of Photogrammetry in Biomedical Science

Peer reviewedPostprin

The digital economy: Challenges and opportunities in the new era of technology and electronic communications

The digital economy has emerged as an innovative economy that utilizes digital technologies and electronic communication to conduct economic and business activities across a wide range of sectors, including e-commerce, digital marketing, digital financial services, software development, computer games, and cloud services. The use of digital technologies and electronic communication has resulted in a significant shift towards online business interactions, leading to improved user experiences, faster processing, and easier access to services and products. The digital economy is recognized as a primary driver of economic growth and development in many advanced countries and is continually expanding due to its significant impact on economic and business activities. In this research, we aim to examine the digital economy and its impact on businesses and users, evaluating the opportunity for easy and quick access to products and services that lead to increased efficiency and productivity. The digital economy has significant impacts on various economic, social, and cultural fields, including changes in the way people work and interact with each other, promoting more flexible and remote work arrangements, and increasing global connectivity. Additionally, the digital economy has impacted education, healthcare, entertainment, and other sectors. Advances in technology and electronic communication have driven the global economy towards digitization, and the role of the digital economy in advancing global digitalization is critical. Its impact is expected to continue to increase in the coming years

FPGA implementation of space-time block coding systems

In this paper, the implementation of space-time block coding systems is discussed, particularly through the use of programmable logic such as FPGAs. The rationale for choice of such devices in preference to DSPs is discussed followed by an analysis of the design and development process and the methodologies employed in the design process. An example space-time system, time-reversal space-time block coding (TR-STBC) is discussed and implementation described

IEEE 6th CAS Symp. on Emerging Technologies: Mobile and Wireless Comm. FPGA implementation of space-time block coding systems

Absbact-Io this paper, tbe implementation of space-time block coding systems i s discussed, particularly through the use of programmable logic such as FPGAs. The rationale for choice of such devices in preference to DSPs is discussed followed by an analysis of tbe design and development p r e s s and the methodologies employed in the design process. An example space-time system, time-revelsal space-time block mding (TR-STBC) is discussed and implementation described

Multi-Modal Medical Image Registration with Full or Partial Data: A Manifold Learning Approach

Multi-modal image registration is the primary step in integrating information stored in two or more images, which are captured using multiple imaging modalities. In addition to intensity variations and structural differences between images, they may have partial or full overlap, which adds an extra hurdle to the success of registration process. In this contribution, we propose a multi-modal to mono-modal transformation method that facilitates direct application of well-founded mono-modal registration methods in order to obtain accurate alignment of multi-modal images in both cases, with complete (full) and incomplete (partial) overlap. The proposed transformation facilitates recovering strong scales, rotations, and translations. We explain the method thoroughly and discuss the choice of parameters. For evaluation purposes, the effectiveness of the proposed method is examined and compared with widely used information theory-based techniques using simulated and clinical human brain images with full data. Using RIRE dataset, mean absolute error of 1.37, 1.00, and 1.41 mm are obtained for registering CT images with PD-, T1-, and T2-MRIs, respectively. In the end, we empirically investigate the efficacy of the proposed transformation in registering multi-modal partially overlapped images

Intrinsic versus extrinsic ferromagnetism in HfO2−x and Ni:HfO2−x thin films

We have investigated the possible evolution of an intrinsic stable ferromagnetic moment in oxygen deficient undoped and magnetically doped HfO2−x thin films grown by reactive molecular beam epitaxy. Neither oxygen vacancies nor substituted Ni in combination with such vacancies results in an observable magnetic moment for a broad range of oxygen vacancy concentrations. By combining integral and element specific magnetization measurements, we show that a fluctuating deposition rate of the magnetic dopant induces extrinsic ferromagnetism by promoting the formation of metallic clusters. We suggest the element specific measurement of an induced magnetic moment at the nonmagnetic site as a proof of intrinsic ferromagnetism in diluted magnetic semiconductors