Search Results for « BMX »

The Baryon Mapping eXperiment (BMX) is an interferometric array designed as a pathfinder for a future post-reionization 21 cm intensity mapping survey. It consists of four 4-meter parabolic reflectors each having offset pyramidal horn feed, quad-ridge orthomode transducer, temperature-stabilized RF amplification and filtering, and pulsed noise injection diode. An undersampling readout scheme uses 8-bit digitizers running at 1.1 Gsamples/sec to provide access to signals from 1.1 - 1.55 GHz (third Nyquist zone), corresponding to HI emission from sources at redshift $0 < z < 0.3$. An FX correlator is implemented in GPU and generates 28 GB/day of time-ordered visibility data. About 7,000 hours of data were collected from Jan. 2019 - May 2020, and we will present results on system performance including sensitivity, beam mapping studies, observations of bright celestial targets, and system electronics upgrades. BMX is a pathfinder for the proposed PUMA intensity mapping survey in the 2030s.

Background: Bicycle Motocross (BMX) has evolved to cater to different styles of riders, including Flatland, Street, Park, and Dirt. BMX culture is characterised by a unique framework of regulations, guidelines, and principles of which a subculture has a pronounced anti-establishment sentiment and embraced do-it-yourself (DIY) practices, contributing to its distinctive identity within the realm of sport. Formal organisations have emerged, leading to the legitimisation of BMX through events such as the Olympics. To the author’s knowledge, this is the first attempt to identify and synthesise all academic publications on BMX and describe the emergence of this research. Methods: After adopting the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIMSA) guidelines 940 studies were identified in the initial search and post screening 87 studies were included. Data was extracted to determine, among other things, the year of publication, methodology adopted, type of BMX and/or BMXers studied, discipline of the study, and focus of inquiry. No date limiter was applied to the search strategy. Results: We identified 87 BMX-related articles for analysis, published between 1982 to 2022. The majority of these studies were conducted within the disciplines of biomechanics and physiology/sports science with a primary focus on performance-enhancing techniques within BMX racing. Most studies have emerged from the UK, with both males and females as their gender sample, using quantitative methodology. Conclusions: This scoping review identified several trends in the history of BMX research. It also identified important gaps and possible avenues for future research to contribute to academic knowledge in this growing field.

BM25, a widely-used lexical search algorithm, remains crucial in information retrieval despite the rise of pre-trained and large language models (PLMs/LLMs). However, it neglects query-document similarity and lacks semantic understanding, limiting its performance. We revisit BM25 and introduce BMX, a novel extension of BM25 incorporating entropy-weighted similarity and semantic enhancement techniques. Extensive experiments demonstrate that BMX consistently outperforms traditional BM25 and surpasses PLM/LLM-based dense retrieval in long-context and real-world retrieval benchmarks. This study bridges the gap between classical lexical search and modern semantic approaches, offering a promising direction for future information retrieval research. The reference implementation of BMX can be found in Baguetter, which was created in the context of this work. The code can be found here: https://github.com/mixedbread-ai/baguetter.

State-of-the-art natural language generation evaluation metrics are based on black-box language models. Hence, recent works consider their explainability with the goals of better understandability for humans and better metric analysis, including failure cases. In contrast, our proposed method BMX: Boosting Natural Language Generation Metrics with explainability explicitly leverages explanations to boost the metrics' performance. In particular, we perceive feature importance explanations as word-level scores, which we convert, via power means, into a segment-level score. We then combine this segment-level score with the original metric to obtain a better metric. Our tests show improvements for multiple metrics across MT and summarization datasets. While improvements in machine translation are small, they are strong for summarization. Notably, BMX with the LIME explainer and preselected parameters achieves an average improvement of 0.087 points in Spearman correlation on the system-level evaluation of SummEval.

Three hundred new cases of bicycle accidents were seen in the accident and emergency department in 60 consecutive days. Fifty six per cent were related to ordinary cycles and 44% to BMX cycles. Significantly more children on BMX cycles were boys (94% v 76% on ordinary cycles). Those on BMX cycles were somewhat older and more had had previous accidents. By means of a proforma we investigated the nature and causes of the accidents, recorded the type of injury, and compared accidents on the two groups of bicycles. Forty children had fractures and the incidence on BMX machines was almost twice that on conventional bicycles as were serious injuries and admissions to hospital. Twenty one children had concussion, 18 broke teeth, 53 fell head first over handlebars, and 131 had injuries above the neck. Significantly more children on ordinary cycles (53%) had injuries above the neck than those on BMX cycles (31%). Difficulties and methods of preventing the increasing number of cycle accidents are discussed.

We introduce BeaMsteerX (BMX), a novel mmWave hand hygiene gesture recognition technique that improves accuracy in longer ranges (1.5m). BMX steers a mmWave beam towards multiple directions around the subject, generating multiple views of the gesture that are then intelligently combined using deep learning to enhance gesture classification. We evaluated BMX using off-the-shelf mmWave radars and collected a total of 7,200 hand hygiene gesture data from 10 subjects performing a six-step hand-rubbing procedure, as recommended by the World Health Organization, using sanitizer, at 1.5m -- over five times longer than in prior works. BMX outperforms state-of-the-art approaches by 31--43% and achieves 91% accuracy at boresight by combining only two beams, demonstrating superior gesture classification in low SNR scenarios. BMX maintained its effectiveness even when the subject was positioned 30 degrees away from the boresight, exhibiting a modest 5% drop in accuracy.

At the BMX Cycling European Championship in 1989 with 976 participants of both sexes, aged between six and 40 years, all injuries were registered. A total of 6.3% of the participants sustained injuries (1.6% per individual start), 52.5% required medical attendance and 3.3% necessitated hospital admission. Women were injured twice as frequently as men. Most injuries, 72.1%, were minor, 6.6% were fractures with 75% of the fractures affecting the upper limbs. BMX bicycle riding has the high injury risk of 1190 injuries per 1000 competition hours.

Spin current offers a promising route toward energy-efficient and high-speed information processing. Developing efficient methods for their generation remains a central challenge in spintronics. Here, we investigate spin current generation via two-dimensional topological spin textures: a skyrmion crystal (SkX) with out-of-plane magnetization, a bimeron crystal (BmX) with in-plane magnetization, and a meron crystal (MX) with zero net magnetization. We show that these distinct spin textures generate spin currents with characteristic spin polarization directions. In the absence of spin--orbit coupling, the SkX and BmX generate spin currents polarized along their magnetization directions, whereas the MX yields no spin current. Upon introducing spin--orbit coupling, while the behavior of the SkX does not qualitatively change, the BmX generates nonzero spin currents in multiple polarization directions. Notably, the MX, despite its zero net magnetization, exhibits a pronounced spin current with out-of-plane spin polarization, driven by an enhanced spin Berry curvature associated with characteristic band degeneracy. We further demonstrate that the electronic and spin transport properties of each texture are governed by their magnetic symmetries. Our results highlight the topological spin textures as efficient sources of spin current even without net magnetization, expanding the design for spintronics devices based on topological magnetic metals.

The success, enthusiasm, and longevity of community-based sports organizations like BMX are determined by leadership, which is a key component. Using a systematic literature review technique, this study seeks to examine the function of leadership in directing BMX groups. The evaluation procedure included the identification and analysis of trustworthy international scientific publications released between 2021 and 2025 using keywords related to sports leadership and organizational leadership in the Scopus, ScienceDirect, Taylor & Francis Online, and Google Scholar databases. The synthesis findings show that transformational, situational, and participatory leadership styles are the most successful strategies for boosting member participation, improving organizational culture, and encouraging creativity in BMX communities. These leadership approaches help to foster a supportive atmosphere, improve team cohesion, and make it easier to adjust to technological and social developments that have an impact on extreme sports. As it incorporates flexibility, teamwork, and a developmental approach to members, this research concludes that adaptive leadership is the most pertinent leadership style for BMX groups. The results offer theoretical contributions to the literature on sports leadership and practical implications for community leaders in improving the management effectiveness of BMX groups.