Transmitter Optimization in Multiuser Wireless Systems with Quality of Service Constraints

In this dissertation, transmitter adaptation for optimal resource allocation in wireless communication systems are investigated. First, a multiple access channel model is considered where many transmitters communicate with a single receiver. This scenario is a basic component of a. wireless network in which multiple users simultaneously access the resources of a wireless service provider. Adaptive algorithms for transmitter optimization to meet Quality-of-Service (QoS) requirements in a distributed manner are studied. Second, an interference channel model is considered where multiple interfering transmitter-receiver pairs co-exist such that a given transmitter communicates with its intended receiver in the presence of interference from other transmitters. This scenario models a wireless network in which several wireless service providers share the spectrum to offer their services by using dynamic spectrum access and cognitive radio (CR) technologies. The primary objective of dynamic spectrum access in the CR approach is to enable use of the frequency band dynamically and opportunistically without creating harmful interference to licensed incumbent users. Specifically, CR users are envisioned to be able to provide high bandwidth and efficient utilization of the spectrum via dynamic spectrum access in heterogeneous networks. In this scenario, a distributed method is investigated for combined precoder and power adaptation of CR transmitters for dynamic spectrum sharing in cognitive radio systems. Finally, the effect of limited feedback for transmitter optimization is analyzed where precoder adaptation uses the quantized version of interference information or the predictive vector quantization for incremental updates. The performance of the transmitter adaptation algorithms is also studied in the context of fading channels

Exploring women’s learning and participation through the case of Khwaab:a women’s skill development centre in India

Abstract. Target 4.3 of the United Nations’ Sustainable Development Goals states that- “By 2030, ensure equal access for all women and men to affordable and quality technical, vocational and tertiary education, including university.” In a drastically changing world, the role of community-based spaces becomes crucial for ensuring access to quality learning, skill-development, and fostering leadership at the grass-root level. Literature reviews on non-formal and community-based learning spaces for women from underprivileged sections in India display a pattern of macro-level studies which use quantitative methodologies to look at economic impacts of these spaces in the lives of women. This research follows an embedded case design of Khwaab, a women’s skill development centre in Delhi. The aim of this case study is to explore women’s learning and participation through a two-fold purpose. First, to understand trainers’ perceptions about learning and its influence on the training design. And second, to capture voices of learners through their interpretations of learning experiences and perceived ways of participation. The study adheres to social constructivist paradigm, drawing on sociocultural approaches to learning, mainly the theoretical lens of community of practice and situated learning. Lifelong learning framework characterise Khwaab as a site of non-formal learning. Feminist theories from India contextualise the case and the participants. The data consists of audio recorded interviews from 5 learners and 2 trainers, and training toolkits used at Khwaab. Findings from thematic analysis of interviews and summative content analysis of training toolkit have been merged to showcase eight major themes, spanning over characterisation of learners and their collective identity, group interaction, responsive organisational structures, and interpretations of empowerment. This case study has implications for creating new or improving the existing teaching-learning designs and organisational structures in the context non-formal learning settings, especially for women. Insights from the findings also contribute in furthering the dialogue to reconceptualise social development as a learning process

On Using Blockchains for Safety-Critical Systems

Innovation in the world of today is mainly driven by software. Companies need to continuously rejuvenate their product portfolios with new features to stay ahead of their competitors. For example, recent trends explore the application of blockchains to domains other than finance. This paper analyzes the state-of-the-art for safety-critical systems as found in modern vehicles like self-driving cars, smart energy systems, and home automation focusing on specific challenges where key ideas behind blockchains might be applicable. Next, potential benefits unlocked by applying such ideas are presented and discussed for the respective usage scenario. Finally, a research agenda is outlined to summarize remaining challenges for successfully applying blockchains to safety-critical cyber-physical systems

Effective Ways of Communicating Science to Common People

Due importance is not accorded by scientists to public outreach activities, probably due to their busy research and administrative schedule. However, even if they want to devote their time they cannot do it in a sustained manner because of “(over) specialization”. Creative science communication is hindered by alleged ‘egoist’ feeling that it is an act of “copying” and “over-simplification” making the purists cringe to the core. However, it must be borne in mind that all current science is combinatorial. It derives from a diverse set of disciplines and research that has already been done by generations. It’s a networked knowledge that needs to be effectively communicated to the masses by combining the disparate pieces of inspiration, knowledge, skill and talent that are accumulated over the lifetime. These need to be stitched together or recombined into new creations for easy understanding and consumption of the common people. Science communicators need to cross-pollinate to create and evolve new ideas.Science communication to the common people needs an assortment of techniques that can appeal to the “interested” and “non-interested” participants as well. Both these constituents are an important segment, hence efforts should be made to make science communication a participatory event rather than a unidirectional flow of information. The participatory model should strive at creating an ambience of reflection and rumination, on the ideas that are floating around, so that the information that is being discussed can seep into the psyche of interested as well as un-interested participants. Hence, the effective communication of a scientific idea also rests on the shoulders of the participant, and not just on the communicator. This will induce the communicator to explore new, innovative and effective ways to reach the audience.The new integrated social media platform can be harnessed since it provides an opportunity to effectively engage with a wide spectrum of common people comprising students, teachers, academicians, aspiring scientists and technologists, not just locally but globally. This approach will encourage wide participation and greater returns on time invested. It will also give quantifiable metrics on their impact

Enhancing Student Learning through Proactive Feedback Based Adaptive Teaching for Engineering Courses

This paper presents a proactive anonymous feedback based adaptive teaching for enhancing student learning for engineering courses. In conventional university teaching, typically, students come to the class and instructors lecture the material, assign home assignments, take exams, etc. After grading assignments or exams, the instructor provides feedback to students. Most of the time, students are reluctant to ask questions or ask instructor to revisit the topic which was already covered. However, there is no immediate anonymous feedback mechanism for each topic or class to notify the instructor about topics which are not clear to students. There are advantages that enhance students’ learning experience by using a proactive anonymous feedback approach in teaching, learning and assessment. In this paper, we present the immediate impacts of proactive anonymous feedback based adaptive teaching on student learning and assessment. Furthermore, anonymous online based feedback mechanism provides faster feedback than conventional mechanism (where students wait until the first exam or so). Immediate feedback for each topic discussed in the class streamlines the process of reporting and the provision of active studying. The results show that students get better grade and instructors get better student evaluation score since the anonymous feedback provides a mechanism for students to ask questions anonymously and the instructors get an opportunity to answer the questions or concerns in a timely manner. We implemented the proactive anonymous feedback approach in many courses in different semesters and observed similar results. However, as an example, we present one course and instructor to illustrate the effectiveness of the proposed approach

Kinetics of Oxidation of Hydrazine & Hydroxylamine by N-Chlorobenzamide

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