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A NOMA-Enhanced 2-Step RACH Procedure for Low-Latency Access in 5G Networks
Random access channel (RACH) procedure is critical to support a multitude of devices transmitting small data payloads while ensuring low-latency access. In 3GPP Release 16, a two-step RACH is proposed to alleviate signaling overhead and access latency. While benefits are noticeable, collisions still persist. In this paper, we propose a novel non-orthogonal multiple access (NOMA)-enhanced 2-step RACH scheme (NOMA-RACH) that jointly leverages the benefits of access class barring (ACB), 2-step RACH, and NOMA random access (NOMA-RA) to further enhance the performance. We conduct a holistic study that accounts for entire access latency. The scheme optimizes NOMA access probabilities, utilizes an adjustable barring mechanism for delay-sensitive devices, and identifies the optimal barring rate for low latency. We develop a Markov chain model to analyze NOMA access and derive the optimal access probabilities and throughput of NOMA blocks. To cope with the practical scenarios with constantly changing user equipment (UE) traffic, we propose a deep contextual multi-armed bandit (DCMAB) model that optimizes the NOMA throughput and dynamically adjusts the barring rate based on the observable channel feedback. Our simulation results demonstrate that the DCMAB model performs better than benchmark schemes and remains close to the optimal latency confirming the effectiveness of our proposed scheme under changing UE traffic
Exploring the Problems, their Causes and Solutions of AI Pair Programming : A Study on Git Huband Stack Overflow
With the recent advancement of Artificial Intelligence (AI) and Large Language Models (LLMs), AI-based code generation tools become a practical solution for software development. GitHub Copilot, the AI pair programmer, utilizes machine learning models trained on a large corpus of code snippets to generate code suggestions using natural language processing. Despite its popularity in software development, there is limited empirical evidence on the actual experiences of practitioners who work with Copilot. To this end, we conducted an empirical study to understand the problems that practitioners face when using Copilot, as well as their underlying causes and potential solutions. We collected data from 473 GitHub issues, 706 GitHub discussions, and 142 Stack Overflow posts. Our results reveal that (1) Operation Issue and Compatibility Issue are the most common problems faced by Copilot users, (2) Copilot Internal Error, Network Connection Error, and Editor/IDE Compatibility Issue are identified as the most frequent causes, and (3) Bug Fixed by Copilot, Modify Configuration/Setting, and Use Suitable Version are the predominant solutions. Based on the results, we discuss the potential areas of Copilot for enhancement, and provide the implications for the Copilot users, the Copilot team, and researchers
Improving hospital palliative care between COVID-19 waves : A retrospective cohort study
A specialist palliative care service in an acute hospital characterized care patterns during the first wave of the COVID-19 pandemic. There were delayed referrals for minoritized ethnic groups. COVID-19 treatments (dexamethasone, anticoagulation, remdesivir) alongside service changes were introduced in the second wave. To examine changes in care patterns and trends in the context of COVID-19 treatments. A secondary objective is to examine differences in ethnic disparity between the first and second wave of COVID-19. Retrospective cohort study comparing patients referred to an acute hospital palliative care service with confirmed COVID-19 infection either at the peak of the first (Mar-Apr 2020, W1), or second (Dec 2020-Feb 2021, W2) wave of the pandemic. Demographic, clinical characteristics, and outcomes data were compared using statistical tests; generalized linear mixed models for modelling of elapsed time from admission to referral; and survival analysis. Data from 165 patients (W1 = 60, W2 =105) were included. Patients in W1 were referred earlier to palliative care than in W2, particularly in the first 10 days from admission. Receiving dexamethasone or anticoagulants, and absence of dementia, hypertension, and fever were associated with longer time to referral to palliative care. Delays in referrals of Black and Asian patients during W1 was no longer observable in W2. There was no association between socioeconomic status and care patterns and trends. The Australian-modified Karnofsky Performance Status (HR 3, 95% CI: 2 - 5) were good predictors of survival. Our findings have the potential to inform strategies that improve palliative care response and equity beyond COVID-19, and in future pandemics or crises. [Abstract copyright: Copyright © 2024. Published by Elsevier Inc.
A Faster Walking Speed Is Important for Improving Biomechanical Function and Walking Performance in Stroke Survivors
This study compares joint kinematics and kinetics of young stroke survivors who walk 0.80 m/s (fast) with reference to a healthy able-bodied group and provides clinical recommendations for guiding the gait rehabilitation of stroke survivors. Twenty-two young stroke survivors (18–55 y) were recruited from 6 hospital sites in the United Kingdom. Stroke participants were classified by walking speed as slow (0.80 m/s), and joint kinematics and kinetics at the pelvis, hip, knee, and ankle were measured during walking on level ground at self-selected speed. Ten walking biomechanical parameters correlated to walking speed (ρ ≥ .550). Stroke survivors in the slow group walked with significantly greater range of sagittal plane pelvic motion (P 0.80 m/s) and propose that these biomechanical parameters be used to inform rehabilitation programs to improve walking for stroke survivors
#commonize studio : Commons-making through studio experimentalism
Commons are shared resources governed by the communities that depend on them and are arguably the most ancient and enduring form of economy in human civilisation. Yet, we know little about the practicalities of making them. To address this challenge, I collaborated with several design researchers engaged in commons-making and began answering the question: What do communities need to make commons? While the commons literature presents robust concepts that describe how successful commons operate, few of these concepts are used by design researchers. Part A of this thesis seeks to answer the question: What does the commons literature offer commons-making researchers? Studio, the signature pedagogy of design, provides the epistemological foundation for commons-making research, yet studio pedagogy remains poorly documented. Part B of this thesis seeks to answer the question: What does the design research literature offer commons-making researchers? I named my practice #commonize studio, a studio that designs commons, as a bridge between these questions. ‘Commonize’ defines a proactive process of commons-making; ‘studio’ treats economics as a design subject, economy design. #commonize studio translates the theoretical foundation developed in Parts A and B into reflective practice in Part C of this thesis, responding to the question: How can these two literatures support commons-makers? This empirical research layers several methodologies together, primarily action research performed through the lens of diverse economies, into a methodology called studio experiments for commons-making. Performing #commonize studio generated multiple insights for commons-making researchers, in particular the role of scaffolding, coaching, and infrastructuring. Finally, I argue for making the ‘generative turn’ in commons research, a transition from purely analytical research of existing commons to generative research about commons-making. Future research may further expand the two fields opened up by this research, which are studio experimentalism as a design methodology and commons-making as a distinct research approach
Forecasting the Realized Variance in the Presence of Intraday Periodicity
This paper examines the impact of intraday periodicity on forecasting realized volatility using a heterogeneous autoregressive model (HAR) framework. We show that periodicity inflates the variance of the realized volatility and biases jump estimators. This combined effect adversely affects forecasting. To account for this, we propose a periodicity-adjusted HAR mod l, HARP, where predictors are constructed from the periodicity-filtered data. We demonstrate empirically (using 30 stocks from various business sectors and the SPY for the period 2000–2020) and via Monte Carlo simulations that the HARP models produce significantly better forecasts across all forecasting horizons. We also show that adjusting for periodicity when estimating the variance risk premium improves return predictability
Micronutrient levels of global tropical reef fish communities differ from fisheries capture
The exceptional diversity of shallow‐water marine fishes contributes to the nutrition of millions of people worldwide through coastal wild‐capture fisheries, with different species having diverse nutritional profiles. Fishes in ecosystems are reservoirs of micronutrients with benefits to human health. Yet, the amount of micronutrients contained in fish species on coral reefs and in shallow tropical waters is challenging to estimate, and the micronutrients caught by fisheries remain uncertain. To assess whether micronutrient deficiencies could be addressed through specific fisheries management actions, we first require a quantification of the potentially available micronutrients contained in biodiverse reef fish assemblages. Here, we therefore undertake a broad heuristic assessment of available micronutrients on tropical reefs using ensemble species distribution modelling and identify potential mismatches with micronutrients derived from summarising coastal fisheries landings data. We find a mismatch between modelled estimates of micronutrients available in the ecosystem on the one hand and the micronutrients in small‐scale fisheries landings data. Fisheries had lower micronutrients than expected from fishes in the modelled assemblage. Further, fisheries were selective for vitamin A, thus resulting in a trade‐off with other micronutrients. Our results remained unchanged after accounting for the under‐sampling of fish communities and under‐reporting of small‐scale fisheries catches—two major sources of uncertainty. This reported mismatch indicates that current estimates of fished micronutrients are not adequate to fully assess micronutrient inventories. However, small‐scale fisheries in some countries were already selective towards micronutrient mass, indicating policies that target improved access, distribution and consumption of fish could leverage this existing high micronutrient mass. Enhanced taxonomic resolution of catches and biodiversity inventories using localised species consumption surveys could improve understanding of nature‐people linkages. Improving fisheries reporting and monitoring of reef fish assemblages will advance the understanding of micronutrient mismatches, which overall indicate a weak uptake of nutritional goals in fisheries practices. The decoupling between micronutrients in ecosystems and in fisheries catches indicates that social, economic, and biodiversity management goals are not shaped around nutritional targets—but this is key to achieve a sustainable and healthy planet for both people and nature. Read the free Plain Language Summary for this article on the Journal blog
Straight jacket : The implications of multidimensional sexuality for relationship quality and stability
The quality and stability of couple relationships have far-reaching consequences for the well-being of individual partners and patterns of family change. While much research has compared the quality and stability of same-sex and different-sex relationships, the multidimensional nature of sexuality has received insufficient attention in this scholarship. Individuals in same-sex (different-sex) partnerships do not necessarily identify as gay/lesbian (straight) or report exclusive same-sex (different-sex) attraction—a phenomenon we term “identity/attraction–partnership inconsistency.” Analyzing nationally representative longitudinal data collected between 2017 and 2022, we show that identity/attraction–partnership inconsistency is common among U.S. adults, ranging from 2% of men in different-sex partnerships to 41% of women in same-sex partnerships. Regression results show that such inconsistency is associated with lower relationship quality and higher relationship instability, and these negative ramifications are particularly pronounced among individuals, notably men, in different-sex partnerships. Our findings uncover the implications of multidimensional sexuality for relationship dynamics and outcomes in the contexts of rigid institutionalization of different-sex couplehood and close normative regulation of men’s heterosexuality. Our study highlights the importance of incorporating multiple dimensions of sexuality and their interplays into research on couple relationships and family change
Increasing Rubisco as a simple means to enhance photosynthesis and productivity now without lowering nitrogen use efficiency
Summary: Global demand for food may rise by 60% mid‐century. A central challenge is to meet this need using less land in a changing climate. Nearly all crop carbon is assimilated through Rubisco, which is catalytically slow, reactive with oxygen, and a major component of leaf nitrogen. Developing more efficient forms of Rubisco, or engineering CO2 concentrating mechanisms into C3 crops to competitively repress oxygenation, are major endeavors, which could hugely increase photosynthetic productivity (≥ 60%). New technologies are bringing this closer, but improvements remain in the discovery phase and have not been reduced to practice. A simpler shorter‐term strategy that could fill this time gap, but with smaller productivity increases (c. 10%) is to increase leaf Rubisco content. This has been demonstrated in initial field trials, improving the productivity of C3 and C4 crops. Combining three‐dimensional leaf canopies with metabolic models infers that a 20% increase in Rubisco increases canopy photosynthesis by 14% in sugarcane (C4) and 9% in soybean (C3). This is consistent with observed productivity increases in rice, maize, sorghum and sugarcane. Upregulation of Rubisco is calculated not to require more nitrogen per unit yield and although achieved transgenically to date, might be achieved using gene editing to produce transgene‐free gain of function mutations or using breeding