670,999 results on '"A. Reza"'
Search Results
302. Effect of Hydroalcoholic Extract of Chamomile, Aloe Vera, and Green Tea on the Diabetic Wound in Rats
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Emami Aref, Parisa, Khoshdel, Alireza, Nicknia, Sedigheh, Mahmoodi, Mehdi, Hajizadeh, Mohammad Reza, Mirzaiey, Mohammad Reza, and Fahmidehkar, Mohammad Ali
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- 2024
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303. Phenolic profile, antioxidant properties, and pollen spectra of Iranian-originated honeys
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Hajian-Tilaki, Adel, Kenari, Reza Esmaeilzadeh, Razavi, Razie, and Farahmandfar, Reza
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- 2024
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304. P4httpGuard: detection and prevention of slow-rate DDoS attacks using machine learning techniques in P4 switch
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Kapourchali, Reza Fallahi, Mohammadi, Reza, and Nassiri, Mohammad
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- 2024
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305. Cooling effect of 3D oscillating heat pipe with nanofluid on photovoltaic panel in hot climates
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Kargaran, Mahyar, Goshayeshi, Hamid Reza, Saleh, Seyed Reza, Zahmatkesh, Iman, and Chaer, Issa
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- 2024
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306. Autonomous Underwater Vehicle Motion Planning in Realistic Ocean Environments Using Penalty Function-Particle Swarm Optimization Technique
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Reza Babakhani, A., Reza Golbahar Haghighi, M., and Malekzadeh, Parviz
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- 2024
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307. The Research Resilience Scale: Development and Initial Validation
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Dian R. Sawitri, Seger Handoyo, Hasnida, Peter A. Cre, Unika Prihatsanti, Ika F. Kristiana, Mirwan S. Perdhana, Fajrianthi, Reza L. Sari, Etti Rahmawati, and Siti Zahreni
- Abstract
We developed and provided initial validation for a 15-item scale for use with academics. In Phase 1, we utilized a review of the literature, focus groups, and expert feedback to generate 36 items. In Phase 2, we conducted item and exploratory factor analyses to reduce the number of items and assess the factor structure (N = 212; 51.4% female; mean age 48.93 years, SD = 9.45). In Phase 3, we conducted confirmatory factor analyses to verify the initial structure (hold-out sample: N = 210; 56.7% female; mean age 49.20 years, SD = 9.98). In Phase 4, we provided construct validity.
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- 2024
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308. Understanding Language Learners' Perceptions of Teachers' Roles in Online Education: A Metaphor Analysis
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Reza Vahdani-Sanavi and Tuba Demirkol
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This study investigates language learners' perception of Turkish teachers' roles in an online setting using metaphor analysis. The aim of this qualitative study was to see how learners viewed their teachers' roles in the setting. Using this data collection tool through convenient sampling, this study elicited 161 language learners' perceptions of teachers' role in an online context during the COVID-19 era between December and January 2020. Analyzing the data, the researchers came up with 10 different conceptual metaphors depicting learners' beliefs about their teachers' roles. The results identified some differences between how learners view teachers' roles in an online mode of education compared to the conventional one as other studies suggest. The implications of these findings for teachers in general and language teachers in particular are discussed, highlighting what can be done to cushion the adverse effects of this novel medium of instruction.
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- 2024
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309. Iranian Preschoolers Vocabulary Development: Background Television and Socio-Economic Status
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Mohamad Reza Farangi and Saeed Mehrpour
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Children's early language development is under the influence of several positive and negative factors including television as an input source and family's socio-economic status. Considering that, this study investigated the effects of these variables on children's vocabulary development using a quasi-experimental design. To this end, 60 Iranian children, 30 from high and 30 from low socio-economic status, were selected using stratified random sampling. They were divided into four groups based on their background TV exposure and socio-economic status. TOLD-3 was given to the groups as a vocabulary development test before and after a 6-week observation. Results indicated that the high socio-economic-low background group scored higher than the other groups in the vocabulary development posttest while the low socio-economic-low background group scored lower that the other groups. Furthermore, while high background TV had a negative influence on the children's vocabulary development in families with a high socio-economic status, it had a positive influence on the children in families with a low socio-economic status. These results have some implications for families, first and second language studies.
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- 2024
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310. Iranian Applied Linguists (Mis) Conceptions of Ethical Issues in Research: A Mixed-Methods Study
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Mohamad Reza Farangi and Mohamad Khojastemehr
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The present study used quantitative and qualitative measures to examine Iranian applied linguists' (mis-) conceptions of ethical issues in research. For this purpose, one hundred and twelve applied linguists completed a research ethics questionnaire constructed and validated by the researchers. In the follow-up qualitative phase, 15 applied linguists who were faculty members participated in semi-instructed interviews. Data were analyzed using exploratory factors analyses for the first phase and theme analyses for the second phase. Quantitative results showed that the most important misconceptions among Iranian applied linguists lingered on working with data (data collection and data analyses). For example, removing an outlier was a prevalent act conducted by applied linguists in the present study. Teachers using their students as participants of their own research as well as how they treated those students after a study were other controversial issues. The qualitative results revealed several themes including "lack of knowledge, conflict with real-world practices, a product-oriented approach to education and a publish or perish mentality" as the reasons for misconceptions of ethics in applied linguistics among Iranian researchers. On general terms, there was an implicit agreement regarding the lack of training on research ethics among Iranian applied linguists.
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- 2024
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311. Beyond Digital Competence and Language Teaching Skills: The Bi-Level Factors Associated with EFL Teachers' 21st-Century Digital Competence to Cultivate 21st-Century Digital Skills
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Amir Reza Rahimi
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In the 21st century, ICT-based teaching has evolved into problem-solving (PS). Therefore, scholars from Science, Technology, Engineering, and Mathematics (STEM) have identified the factors that facilitate such a process in their classes. Therefore, empirical evidence on English language teaching is warranted to uncover what factors shape teachers' professional competence to have such language classes. Thus, putting one step forward, this explanatory study explored the antecedents shaping language teachers' 21st-century digital competence from a bi-level approach. As a result, 863 Iranian EFL teachers who taught English in various areas responded to instruments measuring their ICT-individual characteristics, schools' ICT characteristics, and 21st-century digital competence. The partial least square structural modeling (PLS-SEM) showed that the teachers' connectivity and computer for instruction (CI) in school improved their competence to analyze, browse, and evaluate language learners' problems with it. Regarding their individual aspects, instructors' technological pedagogical content knowledge (TPACK), information access (IA), and perception of the benefits of ICTs were the main antecedents, leading them to become creative problem-solvers. Having examined the findings, the researcher offers teachers to enhance their approaches beyond teaching language skills with ICT to problem-solving. Curriculum experts should also invest more money and equip their schools with ICTs gadgets, increasing instructors' connectivity and creativity.
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- 2024
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312. A Scalable Multi-Layered Blockchain Architecture for Enhanced EHR Sharing and Drug Supply Chain Management
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Javan, Reza, Mohammadi, Mehrzad, Beheshti-Atashgah, Mohammad, and Aref, Mohammad Reza
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Computer Science - Cryptography and Security ,Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
In recent years, the healthcare sector's shift to online platforms has spotlighted challenges concerning data security, privacy, and scalability. Blockchain technology, known for its decentralized, secure, and immutable nature, emerges as a viable solution for these pressing issues. This article presents an innovative Electronic Health Records (EHR) sharing and drug supply chain management framework tailored to address scalability, security, data integrity, traceability, and secure data sharing. The framework introduces five layers and transactions, prioritizing patient-centric healthcare by granting patients comprehensive access control over their health information. This access facilitates smoother processes, such as insurance claims, while maintaining robust security measures. Notably, our implementation of parallelism significantly bolsters scalability and transaction throughput while minimizing network traffic. Performance evaluations conducted through the Caliper benchmark indicate a slight increase in processor consumption during specific transactions, mitigated effectively by parallelization. RAM requirements remain largely stable. Additionally, our approach notably reduces network traffic while tripling transaction throughput. The framework ensures patient privacy, data integrity, access control, and interoperability, aligning with traditional healthcare systems. Moreover, it provides transparency and real-time drug supply monitoring, empowering decision-makers with actionable insights. As healthcare evolves, our framework sets a crucial precedent for innovative, scalable, and secure systems. Future enhancements could focus on scalability, real-world deployment, standardized data formats, reinforced security protocols, privacy preservation, and IoT integration to comply with regulations and meet evolving industry needs.
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- 2024
313. Towards Mixed Reality as the Everyday Computing Paradigm: Challenges & Design Recommendations
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Asadi, Amir Reza and Hemadi, Reza
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Computer Science - Human-Computer Interaction - Abstract
This research presents a proof-of-concept prototype of an all-in-one mixed reality application platform, developed to investigate the needs and expectations of users from mixed reality systems. The study involved an extensive user study with 1,052 participants, including the collection of diaries from 6 users and conducting interviews with 15 participants to gain deeper insights into their experiences. The findings from the interviews revealed that directly porting current user flows into 3D environments was not well-received by the target users. Instead, users expressed a clear preference for alternative 3D interactions along with the continued use of 2D interfaces. This study provides insights for understanding user preferences and interactions in mixed reality systems, and design recommendations to facilitate the mass adoption of MR systems.
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- 2024
314. Paired coalition in graphs
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Samadzadeh, Mohammad Reza, Mojdeh, Doost Ali, and Nadimi, Reza
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Mathematics - Combinatorics - Abstract
\noindent A paired coalition in a graph $G=(V,E)$ consists of two disjoint sets of vertices $V_1$ and $V_2$, neither of which is a paired dominating set but whose union $V_1 \cup V_2$ is a paired dominating set. A paired coalition partition (abbreviated $pc$-partition) in a graph $G$ is a vertex partition $\pi= \lbrace V_1,V_2,\dots ,V_k \rbrace$ such that each set $V_i$ of $\pi$ is not a paired dominating set but forms a paired coalition with another set $V_j \in \pi$. The paired coalition graph $PCG(G,\pi) $ of the graph $G$ and the $pc$-partition $\pi$ of $G$, is the graph whose vertices correspond one-to-one with the sets of $\pi$, and two vertices $V_i$ and $V_j$ are adjacent in $PCG(G,\pi) $ if and only if their corresponding sets $V_i$ and $V_j$ form a paired coalition in $G$. In this paper, we initiate the study of paired coalition partitions and paired coalition graphs. In particular, we determine the paired coalition number of paths and cycles, obtain some results on paired coalition partitions in trees and characterize pair coalition graphs of paths, cycles and trees. We also characterize triangle-free graphs $G$ with $PC(G)=n$ and unicyclic graphs $G$ with $PC(G)=n-2$., Comment: 21 pages
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- 2024
315. Cell-cultivated aquatic food products: emerging production systems for seafood.
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Goswami, Mukunda, Ovissipour, Reza, Bomkamp, Claire, Nitin, Nitin, Lakra, Wazir, Post, Mark, and Kaplan, David
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Cell-cultivated seafood ,Cellular agriculture ,Culture media ,Future foods ,Scaling up ,Tissue engineering - Abstract
The demand for fish protein continues to increase and currently accounts for 17% of total animal protein consumption by humans. About 90% of marine fish stocks are fished at or above maximum sustainable levels, with aquaculture propagating as one of the fastest growing food sectors to address some of this demand. Cell-cultivated seafood production is an alternative approach to produce nutritionally-complete seafood products to meet the growing demand. This cellular aquaculture approach offers a sustainable, climate resilient and ethical biotechnological approach as an alternative to conventional fishing and fish farming. Additional benefits include reduced antibiotic use and the absence of mercury. Cell-cultivated seafood also provides options for the fortification of fish meat with healthier compositions, such as omega-3 fatty acids and other beneficial nutrients through scaffold, media or cell approaches. This review addresses the biomaterials, production processes, tissue engineering approaches, processing, quality, safety, regulatory, and social aspects of cell-cultivated seafood, encompassing where we are today, as well as the road ahead. The goal is to provide a roadmap for the science and technology required to bring cellular aquaculture forward as a mainstream food source.
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- 2024
316. New GO-based measures in multiple network alignment.
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Yazdani, Kimia, Mousapour, Reza, and Hayes, Wayne
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Gene Ontology ,Protein Interaction Mapping ,Computational Biology ,Protein Interaction Maps ,Software ,Algorithms ,Humans - Abstract
MOTIVATION: Protein-protein interaction (PPI) networks provide valuable insights into the function of biological systems. Aligning multiple PPI networks may expose relationships beyond those observable by pairwise comparisons. However, assessing the biological quality of multiple network alignments is a challenging problem. RESULTS: We propose two new measures to evaluate the quality of multiple network alignments using functional information from Gene Ontology (GO) terms. When aligning multiple real PPI networks across species, we observe that both measures are highly correlated with objective quality indicators, such as common orthologs. Additionally, our measures strongly correlate with an alignments ability to predict novel GO annotations, which is a unique advantage over existing GO-based measures. AVAILABILITY AND IMPLEMENTATION: The scripts and the links to the raw and alignment data can be accessed at https://github.com/kimiayazdani/GO_Measures.git.
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- 2024
317. The association between dietary fiber intake and gastric cancer: a pooled analysis of 11 case-control studies.
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Collatuzzo, Giulia, Cortez Lainez, Jacqueline, Pelucchi, Claudio, Negri, Eva, Bonzi, Rossella, Palli, Domenico, Ferraroni, Monica, Zhang, Zuofeng, Yu, Guo-Pei, Lunet, Nuno, Morais, Samantha, López-Carrillo, Lizbeth, Zaridze, David, Maximovitch, Dmitry, Guevara, Marcela, Santos-Sanchez, Vanessa, Vioque, Jesus, Garcia de la Hera, Manoli, Ward, Mary, Malekzadeh, Reza, Pakseresht, Mohammadreza, Hernández-Ramírez, Raúl, Turati, Federica, Rabkin, Charles, Liao, Linda, Sinha, Rashmi, López-Cervantes, Malaquias, Tsugane, Shoichiro, Hidaka, Akihisa, Camargo, M, Curado, Maria, Zubair, Nadia, Kristjansson, Dana, Shah, Shailja, La Vecchia, Carlo, and Boffetta, Paolo
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Cardia ,Dietary fiber ,Fiber intake ,Gastric cancer ,Gastric neoplasm ,Non-cardia ,Aged ,Female ,Humans ,Male ,Middle Aged ,Case-Control Studies ,Diet ,Dietary Fiber ,Fruit ,Logistic Models ,Odds Ratio ,Risk Factors ,Stomach Neoplasms ,Surveys and Questionnaires ,Vegetables - Abstract
PURPOSE: Gastric cancer (GC) is among the leading causes of cancer mortality worldwide. The objective of this study was to investigate the association between dietary fiber intake and GC. METHODS: We pooled data from 11 population or hospital-based case-control studies included in the Stomach Cancer Pooling (StoP) Project, for a total of 4865 histologically confirmed cases and 10,626 controls. Intake of dietary fibers and other dietary factors was collected using food frequency questionnaires. We calculated the odds ratios (OR) and 95% confidence intervals (CI) of the association between dietary fiber intake and GC by using a multivariable logistic regression model adjusted for study site, sex, age, caloric intake, smoking, fruit and vegetable intake, and socioeconomic status. We conducted stratified analyses by these factors, as well as GC anatomical site and histological type. RESULTS: The OR of GC for an increase of one quartile of fiber intake was 0.91 (95% CI: 0.85, 0.97), that for the highest compared to the lowest quartile of dietary fiber intake was 0.72 (95% CI: 0.59, 0.88). Results were similar irrespective of anatomical site and histological type. CONCLUSION: Our analysis supports the hypothesis that dietary fiber intake may exert a protective effect on GC.
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- 2024
318. Effect of cross-platform variations on transthoracic echocardiography measurements and clinical diagnosis
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Hashemi, Mohammad Saber, Farsiani, Yasaman, Pressman, Gregg S, Amini, M Reza, and Kheradvar, Arash
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Biomedical and Clinical Sciences ,Cardiovascular Medicine and Haematology ,Clinical Sciences ,Heart Disease ,Clinical Research ,Bioengineering ,Cardiovascular ,Biomedical Imaging ,cross-platform variation ,ejection fraction ,left ventricle ,reproducibility ,right ventricle ,three-dimensional echocardiography ,transthoracic echocardiography ,volumes - Abstract
AimsAccurate cardiac chamber quantification is essential for clinical decisions and ideally should be consistent across different echocardiography systems. This study evaluates variations between the Philips EPIQ CVx (version 9.0.3) and Canon Aplio i900 (version 7.0) in measuring cardiac volumes, ventricular function, and valve structures.Methods and resultsIn this gender-balanced, single-centre study, 40 healthy volunteers (20 females and 20 males) aged 40 years and older (mean age 56.75 ± 11.57 years) were scanned alternately with both systems by the same sonographer using identical settings for both 2D and 4D acquisitions. We compared left ventricular (LV) and right ventricular (RV) volumes using paired t-tests, with significance set at P < 0.05. Correlation and Bland-Altman plots were used for quantities showing significant differences. Two board-certified cardiologists evaluated valve anatomy for each platform. The results showed no significant differences in LV end-systolic volume and LV ejection fraction between platforms. However, LV end-diastolic volume (LVEDV) differed significantly (biplane: P = 0.018; 4D: P = 0.028). Right ventricular (RV) measurements in 4D showed no significant differences, but there were notable disparities in 2D and 4D volumes within each platform (P < 0.01). Significant differences were also found in the LV systolic dyssynchrony index (P = 0.03), LV longitudinal strain (P = 0.04), LV twist (P = 0.004), and LV torsion (P = 0.005). Valve structure assessments varied, with more abnormalities noted on the Philips platform.ConclusionAlthough LV and RV volumetric measurements are generally comparable, significant differences in LVEDV, LV strain metrics, and 2D vs. 4D measurements exist. These variations should be considered when using different platforms for patient follow-ups.
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- 2024
319. Cell-based fish production case study for developing a food safety plan.
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Ovissipour, Reza, Yang, Xu, Saldana, Yadira, Kaplan, David, Nitin, Nitin, Shirazi, Alex, Chirdon, Bill, White, Wendy, and Rasco, Barbara
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Cell culture ,Cell-based fish ,Cultivated seafood ,Cultured seafood ,Food safety plan ,HACCP - Abstract
Given the expanding global population and finite resources, it is imperative to explore alternative technologies for food production. These technologies play a crucial role in ensuring the provision of safe, nutritious, and sustainable food options to meet the growing demand. Cellular agriculture plays an important in developing an alternative method for developing food products. While, cellular agriculture is emerging rapidly, food safety aspects and regulatory frameworks stayed behind. Despite developing several regulatory framework papers on cellular agriculture, there is no systematic approach for developing a comprehensive food safety plan (FSP), particularly for cultivated seafood. Thus, the overall goal of this article is to develop a FSP for cultivated seafood. The main differences between the food safety plan for cultivated seafood and the conventional seafood industries were the number of allergens in cultivated seafood products, including soy, wheat, and fish cells, compared to only fish for the conventional seafood industry. In addition, there are several hazards associated with mycoplasma in cultivated seafood, which should be considered. This guidance intends to help regulatory agencies, food safety experts, startup companies, and the cultivated seafood industry by providing a valuable platform to develop regulations, guidance, and food safety plans applicable to most cultivated seafood companies. This article will also help the industry to identify the hazards in their processing line and develop preventive controls, and as a comprehensive food safety plan, it could be easily adapted for other cultivated seafood products. This guidance applied systematic approaches to developing food safety plans using cell culture, pharmaceuticals, fermentation, seafood, meat, and aquaponics safety plans, collaborating with experts with different backgrounds, and working closely with the conventional and cultivated meat and seafood industries.
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- 2024
320. The persian version of the fear-avoidance beliefs questionnaire among iranian post-surgery patients: a translation and psychometrics.
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Sharif-Nia, Hamid, Froelicher, Erika, Shafighi, Amir, Osborne, Jason, Fatehi, Reza, Nowrozi, Poorya, and Mohammadi, Bita
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Avoidance beliefs ,Fear-avoidance ,Persian ,Psychometrics ,Reliability ,Validity ,Humans ,Psychometrics ,Male ,Iran ,Female ,Adult ,Fear ,Reproducibility of Results ,Middle Aged ,Surveys and Questionnaires ,Avoidance Learning ,Translations ,Postoperative Period ,Young Adult ,Aged - Abstract
INTRODUCTION: Fear-avoidance beliefs (FAB) play a crucial role in the treatment outcomes of post-surgery patients. These beliefs can lead to activity avoidance, increased pain, and decreased quality of life. Therefore, accurately measuring these beliefs in Iranian patients is of significant importance. The Fear-Avoidance Belief Questionnaire (FABQ) is a patient-reported questionnaire that evaluates individuals FAB. Since the validity and reliability of the Persian version of FABQ (FABQ-P) have not been assessed based on the Iranian population and sociocultural contexts, the current study has been implemented to determine the reliability and validity of the FABQ-P among Iranian post-operative patients by translation and psychometric properties. METHODS: This methodological study conducted in 2023, a sample of 400 patients who had undergone surgery were selected using a convenience sampling method. The scale used in the study was translated and its psychometric properties were evaluated through network analysis and assessments of construct validity (including exploratory and confirmatory factor analysis), convergent validity, and discriminant validity. Additionally, the study assessed the internal consistency of the scale. RESULTS: The MLEFA results with Promax and Kaiser Normalization rotation yielded two factors explaining 57.91% of the variance, encompassing 13 items. Also, the model was approved by CFA. Convergent and discriminant validity have been confirmed through the following criteria: Average Variance Extracted (AVE) exceeding 0.5, Composite Reliability (CR) surpassing 0.7, and Heterotrait-Monotrait Ratio of Correlations (HTMT) equating to 0.597. As for reliability, Cronbachs alpha, composite reliability (CR), and MaxR for all constructs were greater than 0.7, demonstrating good internal consistency. CONCLUSION: As demonstrated by the results, the FABQ-P has a satisfactory level of reliability along with authentic validity according to the sociocultural contexts of Iranian post-operative patients.
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- 2024
321. Interpretable video-based tracking and quantification of parkinsonism clinical motor states.
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Deng, Daniel, Ostrem, Jill, Nguyen, Vy, Cummins, Daniel, Sun, Julia, Pathak, Anupam, Little, Simon, and Abbasi-Asl, Reza
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Quantification of motor symptom progression in Parkinsons disease (PD) patients is crucial for assessing disease progression and for optimizing therapeutic interventions, such as dopaminergic medications and deep brain stimulation. Cumulative and heuristic clinical experience has identified various clinical signs associated with PD severity, but these are neither objectively quantifiable nor robustly validated. Video-based objective symptom quantification enabled by machine learning (ML) introduces a potential solution. However, video-based diagnostic tools often have implementation challenges due to expensive and inaccessible technology, and typical black-box ML implementations are not tailored to be clinically interpretable. Here, we address these needs by releasing a comprehensive kinematic dataset and developing an interpretable video-based framework that predicts high versus low PD motor symptom severity according to MDS-UPDRS Part III metrics. This data driven approach validated and robustly quantified canonical movement features and identified new clinical insights, not previously appreciated as related to clinical severity, including pinkie finger movements and lower limb and axial features of gait. Our framework is enabled by retrospective, single-view, seconds-long videos recorded on consumer-grade devices such as smartphones, tablets, and digital cameras, thereby eliminating the requirement for specialized equipment. Following interpretable ML principles, our framework enforces robustness and interpretability by integrating (1) automatic, data-driven kinematic metric evaluation guided by pre-defined digital features of movement, (2) combination of bi-domain (body and hand) kinematic features, and (3) sparsity-inducing and stability-driven ML analysis with simple-to-interpret models. These elements ensure that the proposed framework quantifies clinically meaningful motor features useful for both ML predictions and clinical analysis.
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- 2024
322. Predictive Neural Network Modeling for Almond Harvest Dust Control.
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Serajian, Reza, Cobian-Iñiguez, Jeanette, Ehsani, Reza, and Sun, Jian-Qiao
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PM2.5 particles ,almond harvesting ,dust emissions ,neural networks ,predictive modeling - Abstract
This study introduces a neural network-based approach to predict dust emissions, specifically PM2.5 particles, during almond harvesting in California. Using a feedforward neural network (FNN), this research predicted PM2.5 emissions by analyzing key operational parameters of an advanced almond harvester. Preprocessing steps like outlier removal and normalization were employed to refine the dataset for training. The networks architecture was designed with two hidden layers and optimized using tanh activation and MSE loss functions through the Adam algorithm, striking a balance between model complexity and predictive accuracy. The model was trained on extensive field data from an almond pickup system, including variables like brush speed, angular velocity, and harvester forward speed. The results demonstrate a notable predictive accuracy of the FNN model, with a mean squared error (MSE) of 0.02 and a mean absolute error (MAE) of 0.01, indicating high precision in forecasting PM2.5 levels. By integrating machine learning with agricultural practices, this research provides a significant tool for environmental management in almond production, offering a method to reduce harmful emissions while maintaining operational efficiency. This model presents a solution for the almond industry and sets a precedent for applying predictive analytics in sustainable agriculture.
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- 2024
323. Demonstration of 0-pi transition in Josephson junctions containing unbalanced synthetic antiferromagnets
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Korucu, D., Loloee, Reza, and Birge, Norman O.
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Condensed Matter - Superconductivity - Abstract
Josephson junctions containing ferromagnetic (F) materials have been the subject of intense study over the past two decades. The ground state of such junctions oscillates between 0 and pi as the thickness of the ferromagnetic layer increases. For some applications, it might be beneficial to replace a very thin F layer with an unbalanced synthetic antiferromagnet (SAF) consisting of two F layers of different thicknesses whose magnetizations are coupled antiparallel to each other. According to theory, such a system should behave similarly to a single F layer whose thickness is equal to the difference of the two F-layer thicknesses in the SAF. We test that theoretical prediction with Josephson junctions containing unbalanced Ni/Ru/Ni SAFs, keeping the thickness of one layer fixed at 2.0 nm and varying the thickness of the other layer between 2.0 and 5.0 nm. We observe the first 0-pi transition at a thickness difference of 0.86 nm, which closely matches the position of the transition observed previously using single Ni layers., Comment: 6 pages, 3 figures. To be published in Applied Physics Letters
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- 2024
324. Low-dimensional approximations of the conditional law of Volterra processes: a non-positive curvature approach
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Arabpour, Reza, Armstrong, John, Galimberti, Luca, Kratsios, Anastasis, and Livieri, Giulia
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Mathematics - Numerical Analysis ,Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing ,Mathematics - Differential Geometry ,Quantitative Finance - Computational Finance - Abstract
Predicting the conditional evolution of Volterra processes with stochastic volatility is a crucial challenge in mathematical finance. While deep neural network models offer promise in approximating the conditional law of such processes, their effectiveness is hindered by the curse of dimensionality caused by the infinite dimensionality and non-smooth nature of these problems. To address this, we propose a two-step solution. Firstly, we develop a stable dimension reduction technique, projecting the law of a reasonably broad class of Volterra process onto a low-dimensional statistical manifold of non-positive sectional curvature. Next, we introduce a sequentially deep learning model tailored to the manifold's geometry, which we show can approximate the projected conditional law of the Volterra process. Our model leverages an auxiliary hypernetwork to dynamically update its internal parameters, allowing it to encode non-stationary dynamics of the Volterra process, and it can be interpreted as a gating mechanism in a mixture of expert models where each expert is specialized at a specific point in time. Our hypernetwork further allows us to achieve approximation rates that would seemingly only be possible with very large networks., Comment: Main body: 25 Pages, Appendices 29 Pages, 14 Tables, 6 Figures
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- 2024
325. Federated Learning with Multi-resolution Model Broadcast
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Rydén, Henrik, Moosavi, Reza, and Larsson, Erik G.
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Computer Science - Networking and Internet Architecture ,Computer Science - Machine Learning - Abstract
In federated learning, a server must periodically broadcast a model to the agents. We propose to use multi-resolution coding and modulation (also known as non-uniform modulation) for this purpose. In the simplest instance, broadcast transmission is used, whereby all agents are targeted with one and the same transmission (typically without any particular favored beam direction), which is coded using multi-resolution coding/modulation. This enables high-SNR agents, with high path gains to the server, to receive a more accurate model than the low-SNR agents do, without consuming more downlink resources. As one implementation, we use transmission with a non-uniform 8-PSK constellation, where a high-SNR receiver (agent) can separate all 8 constellation points (hence receive 3 bits) whereas a low-SNR receiver can only separate 4 points (hence receive 2 bits). By encoding the least significant information in the third bit, the high-SNR receivers can obtain the model with higher accuracy, while the low-SNR receiver can still obtain the model although with reduced accuracy, thereby facilitating at least some basic participation of the low-SNR receiver. We show the effectiveness of our proposed scheme via experimentation using federated learning with the MNIST data-set.
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- 2024
326. The Data Minimization Principle in Machine Learning
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Ganesh, Prakhar, Tran, Cuong, Shokri, Reza, and Fioretto, Ferdinando
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Cryptography and Security - Abstract
The principle of data minimization aims to reduce the amount of data collected, processed or retained to minimize the potential for misuse, unauthorized access, or data breaches. Rooted in privacy-by-design principles, data minimization has been endorsed by various global data protection regulations. However, its practical implementation remains a challenge due to the lack of a rigorous formulation. This paper addresses this gap and introduces an optimization framework for data minimization based on its legal definitions. It then adapts several optimization algorithms to perform data minimization and conducts a comprehensive evaluation in terms of their compliance with minimization objectives as well as their impact on user privacy. Our analysis underscores the mismatch between the privacy expectations of data minimization and the actual privacy benefits, emphasizing the need for approaches that account for multiple facets of real-world privacy risks.
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- 2024
327. Motor Imagery Task Alters Dynamics of Human Body Posture
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Delavari, Fatemeh, Golpayegani, Seyyed Mohammad Reza Hashemi, and Ahmadi-Pajouh, Mohammad Ali
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Quantitative Biology - Neurons and Cognition ,Electrical Engineering and Systems Science - Signal Processing - Abstract
Motor Imagery (MI) is gaining traction in both rehabilitation and sports settings, but its immediate influence on human postural control is not yet clearly understood. The focus of this study is to examine the effects of MI on the dynamics of the Center of Pressure (COP), a crucial metric for evaluating postural stability. In the experiment, thirty healthy young adults participated in four different scenarios: normal standing with both open and closed eyes, and kinesthetic motor imagery focused on mediolateral (ML) and anteroposterior (AP) sway movements. A mathematical model was developed to characterize the nonlinear dynamics of the COP and to assess the impact of MI on these dynamics. Our results show a statistically significant increase (p-value<0.05) in variables such as COP path length and Long-Range Correlation (LRC) during MI compared to the closed-eye and normal standing conditions. These observations align well with psycho-neuromuscular theory, which suggests that imagining a specific movement activates neural pathways, consequently affecting postural control. This study presents compelling evidence that motor imagery not only has a quantifiable impact on COP dynamics but also that changes in the Center of Pressure (COP) are directionally consistent with the imagined movements. This finding holds significant implications for the field of rehabilitation science, suggesting that motor imagery could be strategically utilized to induce targeted postural adjustments. Nonetheless, additional research is required to fully understand the complex mechanisms that underlie this relationship and to corroborate these results across a more diverse set of populations.
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- 2024
328. Two-layer retrieval augmented generation framework for low-resource medical question-answering: proof of concept using Reddit data
- Author
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Das, Sudeshna, Ge, Yao, Guo, Yuting, Rajwal, Swati, Hairston, JaMor, Powell, Jeanne, Walker, Drew, Peddireddy, Snigdha, Lakamana, Sahithi, Bozkurt, Selen, Reyna, Matthew, Sameni, Reza, Xiao, Yunyu, Kim, Sangmi, Chandler, Rasheeta, Hernandez, Natalie, Mowery, Danielle, Wightman, Rachel, Love, Jennifer, Spadaro, Anthony, Perrone, Jeanmarie, and Sarker, Abeed
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Computer Science - Computation and Language ,Computer Science - Artificial Intelligence - Abstract
Retrieval augmented generation (RAG) provides the capability to constrain generative model outputs, and mitigate the possibility of hallucination, by providing relevant in-context text. The number of tokens a generative large language model (LLM) can incorporate as context is finite, thus limiting the volume of knowledge from which to generate an answer. We propose a two-layer RAG framework for query-focused answer generation and evaluate a proof-of-concept for this framework in the context of query-focused summary generation from social media forums, focusing on emerging drug-related information. The evaluations demonstrate the effectiveness of the two-layer framework in resource constrained settings to enable researchers in obtaining near real-time data from users.
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- 2024
329. On in-silico estimation of left ventricular end-diastolic pressure from cardiac strains
- Author
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Mendiola, Emilio A., Mehdi, Raza Rana, Shah, Dipan J., and Avazmohammadi, Reza
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Quantitative Biology - Tissues and Organs - Abstract
Left ventricular diastolic dysfunction (LVDD) is a group of diseases that adversely affect the passive phase of the cardiac cycle and can lead to heart failure. While left ventricular end-diastolic pressure (LVEDP) is a valuable prognostic measure in LVDD patients, traditional invasive methods of measuring LVEDP present risks and limitations, highlighting the need for alternative approaches. This paper investigates the possibility of measuring LVEDP non-invasively using inverse in-silico modeling. We propose the adoption of patient-specific cardiac modeling and simulation to estimate LVEDP and myocardial stiffness from cardiac strains. We have developed a high-fidelity patient-specific computational model of the left ventricle. Through an inverse modeling approach, myocardial stiffness and LVEDP were accurately estimated from cardiac strains that can be acquired from in vivo imaging, indicating the feasibility of computational modeling to augment current approaches in the measurement of ventricular pressure. Integration of such computational platforms into clinical practice holds promise for early detection and comprehensive assessment of LVDD with reduced risk for patients.
- Published
- 2024
330. Entanglement in Lifshitz Fermion Theories
- Author
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Vasli, Mohammad Javad, Velni, Komeil Babaei, Mozaffar, M. Reza Mohammadi, and Mollabashi, Ali
- Subjects
High Energy Physics - Theory ,Condensed Matter - Statistical Mechanics ,Condensed Matter - Strongly Correlated Electrons ,Quantum Physics - Abstract
We study the static entanglement structure in (1+1)-dimensional free Dirac-fermion theory with Lifshitz symmetry and arbitrary integer dynamical critical exponent. This model is different from the one introduced in [Hartmann et al., SciPost Phys. 11, no.2, 031 (2021)] due to a proper treatment of the square Laplace operator. Dirac fermion Lifshitz theory is local as opposed to its scalar counterpart which strongly affects its entanglement structure. We show that there is quantum entanglement across arbitrary subregions in various pure (including the vacuum) and mixed states of this theory for arbitrary integer values of the dynamical critical exponent. Our numerical investigations show that quantum entanglement in this theory is tightly bounded from above. Such a bound and other physical properties of quantum entanglement are carefully explained from the correlation structure in these theories. A generalization to (2+1)-dimensions where the entanglement structure is seriously different is addressed., Comment: 21 pages, 9 figures
- Published
- 2024
331. PRFashion24: A Dataset for Sentiment Analysis of Fashion Products Reviews in Persian
- Author
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Amirpour, Mehrimah and Azmi, Reza
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Computer Science - Computation and Language - Abstract
The PRFashion24 dataset is a comprehensive Persian dataset collected from various online fashion stores, spanning from April 2020 to March 2024. With 767,272 reviews, it is the first dataset in its kind that encompasses diverse categories within the fashion industry in the Persian language. The goal of this study is to harness deep learning techniques, specifically Long Short-Term Memory (LSTM) networks and a combination of Bidirectional LSTM and Convolutional Neural Network (BiLSTM-CNN), to analyze and reveal sentiments towards online fashion shopping. The LSTM model yielded an accuracy of 81.23%, while the BiLSTM-CNN model reached 82.89%. This research aims not only to introduce a diverse dataset in the field of fashion but also to enhance the public's understanding of opinions on online fashion shopping, which predominantly reflect a positive sentiment. Upon publication, both the optimized models and the PRFashion24 dataset will be available on GitHub., Comment: 8 page
- Published
- 2024
332. Defining ideals of Cohen-Macaulay fiber cones
- Author
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Abdolmaleki, Reza and Kumashiro, Shinya
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Mathematics - Commutative Algebra - Abstract
Let $A$ be a commutative Noetherian local ring with maximal ideal $\mathfrak{m}$, and let $I$ be an ideal. The fiber cone is then an image of the polynomial ring over the residue field $A/\mathfrak{m}$. The kernel of this map is called the defining ideal, and it is natural to ask how to compute it. In this paper, we provide a construction for the defining ideals of Cohen-Macaulay fiber cones.
- Published
- 2024
333. Low-rank finetuning for LLMs: A fairness perspective
- Author
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Das, Saswat, Romanelli, Marco, Tran, Cuong, Reza, Zarreen, Kailkhura, Bhavya, and Fioretto, Ferdinando
- Subjects
Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Computation and Language - Abstract
Low-rank approximation techniques have become the de facto standard for fine-tuning Large Language Models (LLMs) due to their reduced computational and memory requirements. This paper investigates the effectiveness of these methods in capturing the shift of fine-tuning datasets from the initial pre-trained data distribution. Our findings reveal that there are cases in which low-rank fine-tuning falls short in learning such shifts. This, in turn, produces non-negligible side effects, especially when fine-tuning is adopted for toxicity mitigation in pre-trained models, or in scenarios where it is important to provide fair models. Through comprehensive empirical evidence on several models, datasets, and tasks, we show that low-rank fine-tuning inadvertently preserves undesirable biases and toxic behaviors. We also show that this extends to sequential decision-making tasks, emphasizing the need for careful evaluation to promote responsible LLMs development.
- Published
- 2024
334. Thermalization and Criticality on an Analog-Digital Quantum Simulator
- Author
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Andersen, Trond I., Astrakhantsev, Nikita, Karamlou, Amir H., Berndtsson, Julia, Motruk, Johannes, Szasz, Aaron, Gross, Jonathan A., Schuckert, Alexander, Westerhout, Tom, Zhang, Yaxing, Forati, Ebrahim, Rossi, Dario, Kobrin, Bryce, Di Paolo, Agustin, Klots, Andrey R., Drozdov, Ilya, Kurilovich, Vladislav D., Petukhov, Andre, Ioffe, Lev B., Elben, Andreas, Rath, Aniket, Vitale, Vittorio, Vermersch, Benoit, Acharya, Rajeev, Beni, Laleh Aghababaie, Anderson, Kyle, Ansmann, Markus, Arute, Frank, Arya, Kunal, Asfaw, Abraham, Atalaya, Juan, Ballard, Brian, Bardin, Joseph C., Bengtsson, Andreas, Bilmes, Alexander, Bortoli, Gina, Bourassa, Alexandre, Bovaird, Jenna, Brill, Leon, Broughton, Michael, Browne, David A., Buchea, Brett, Buckley, Bob B., Buell, David A., Burger, Tim, Burkett, Brian, Bushnell, Nicholas, Cabrera, Anthony, Campero, Juan, Chang, Hung-Shen, Chen, Zijun, Chiaro, Ben, Claes, Jahan, Cleland, Agnetta Y., Cogan, Josh, Collins, Roberto, Conner, Paul, Courtney, William, Crook, Alexander L., Das, Sayan, Debroy, Dripto M., De Lorenzo, Laura, Barba, Alexander Del Toro, Demura, Sean, Donohoe, Paul, Dunsworth, Andrew, Earle, Clint, Eickbusch, Alec, Elbag, Aviv Moshe, Elzouka, Mahmoud, Erickson, Catherine, Faoro, Lara, Fatemi, Reza, Ferreira, Vinicius S., Burgos, Leslie Flores, Fowler, Austin G., Foxen, Brooks, Ganjam, Suhas, Gasca, Robert, Giang, William, Gidney, Craig, Gilboa, Dar, Giustina, Marissa, Gosula, Raja, Dau, Alejandro Grajales, Graumann, Dietrich, Greene, Alex, Habegger, Steve, Hamilton, Michael C., Hansen, Monica, Harrigan, Matthew P., Harrington, Sean D., Heslin, Stephen, Heu, Paula, Hill, Gordon, Hoffmann, Markus R., Huang, Hsin-Yuan, Huang, Trent, Huff, Ashley, Huggins, William J., Isakov, Sergei V., Jeffrey, Evan, Jiang, Zhang, Jones, Cody, Jordan, Stephen, Joshi, Chaitali, Juhas, Pavol, Kafri, Dvir, Kang, Hui, Kechedzhi, Kostyantyn, Khaire, Trupti, Khattar, Tanuj, Khezri, Mostafa, Kieferová, Mária, Kim, Seon, Kitaev, Alexei, Klimov, Paul V., Korotkov, Alexander N., Kostritsa, Fedor, Kreikebaum, John Mark, Landhuis, David, Langley, Brandon W., Laptev, Pavel, Lau, Kim-Ming, Guevel, Loïck Le, Ledford, Justin, Lee, Joonho, Lee, Kenny, Lensky, Yuri D., Lester, Brian J., Li, Wing Yan, Lill, Alexander T., Liu, Wayne, Livingston, William P., Locharla, Aditya, Lundahl, Daniel, Lunt, Aaron, Madhuk, Sid, Maloney, Ashley, Mandrà, Salvatore, Martin, Leigh S., Martin, Orion, Martin, Steven, Maxfield, Cameron, McClean, Jarrod R., McEwen, Matt, Meeks, Seneca, Miao, Kevin C., Mieszala, Amanda, Molina, Sebastian, Montazeri, Shirin, Morvan, Alexis, Movassagh, Ramis, Neill, Charles, Nersisyan, Ani, Newman, Michael, Nguyen, Anthony, Nguyen, Murray, Ni, Chia-Hung, Niu, Murphy Yuezhen, Oliver, William D., Ottosson, Kristoffer, Pizzuto, Alex, Potter, Rebecca, Pritchard, Orion, Pryadko, Leonid P., Quintana, Chris, Reagor, Matthew J., Rhodes, David M., Roberts, Gabrielle, Rocque, Charles, Rosenberg, Eliott, Rubin, Nicholas C., Saei, Negar, Sankaragomathi, Kannan, Satzinger, Kevin J., Schurkus, Henry F., Schuster, Christopher, Shearn, Michael J., Shorter, Aaron, Shutty, Noah, Shvarts, Vladimir, Sivak, Volodymyr, Skruzny, Jindra, Small, Spencer, Smith, W. Clarke, Springer, Sofia, Sterling, George, Suchard, Jordan, Szalay, Marco, Sztein, Alex, Thor, Douglas, Torres, Alfredo, Torunbalci, M. Mert, Vaishnav, Abeer, Vdovichev, Sergey, Villalonga, Benjamin, Heidweiller, Catherine Vollgraff, Waltman, Steven, Wang, Shannon X., White, Theodore, Wong, Kristi, Woo, Bryan W., Xing, Cheng, Yao, Z. Jamie, Yeh, Ping, Ying, Bicheng, Yoo, Juhwan, Yosri, Noureldin, Young, Grayson, Zalcman, Adam, Zhu, Ningfeng, Zobrist, Nicholas, Neven, Hartmut, Babbush, Ryan, Boixo, Sergio, Hilton, Jeremy, Lucero, Erik, Megrant, Anthony, Kelly, Julian, Chen, Yu, Smelyanskiy, Vadim, Vidal, Guifre, Roushan, Pedram, Lauchli, Andreas M., Abanin, Dmitry A., and Mi, Xiao
- Subjects
Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Strongly Correlated Electrons - Abstract
Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final state characterization. We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution, with performance beyond the reach of classical simulation in cross-entropy benchmarking experiments. Emulating a two-dimensional (2D) XY quantum magnet, we leverage a wide range of measurement techniques to study quantum states after ramps from an antiferromagnetic initial state. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions attributed to the interplay between quantum and classical coarsening of the correlated domains. This interpretation is corroborated by injecting variable energy density into the initial state, which enables studying the effects of the eigenstate thermalization hypothesis (ETH) in targeted parts of the eigenspectrum. Finally, we digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization. These results establish the efficacy of superconducting analog-digital quantum processors for preparing states across many-body spectra and unveiling their thermalization dynamics.
- Published
- 2024
335. Coordinating robotized construction using advanced robotic simulation: The case of collaborative brick wall assembly
- Author
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Kolani, Mohammad Reza, Nousias, Stavros, and Borrmann, André
- Subjects
Computer Science - Robotics - Abstract
Utilizing robotic systems in the construction industry is gaining popularity due to their build time, precision, and efficiency. In this paper, we introduce a system that allows the coordination of multiple manipulator robots for construction activities. As a case study, we chose robotic brick wall assembly. By utilizing a multi robot system where arm manipulators collaborate with each other, the entirety of a potentially long wall can be assembled simultaneously. However, the reduction of overall bricklaying time is dependent on the minimization of time required for each individual manipulator. In this paper, we execute the simulation with various placements of material and the robots base, as well as different robot configurations, to determine the optimal position of the robot and material and the best configuration for the robot. The simulation results provide users with insights into how to find the best placement of robots and raw materials for brick wall assembly., Comment: 10 pages, 5 figures
- Published
- 2024
336. Mixture of In-Context Prompters for Tabular PFNs
- Author
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Xu, Derek, Cirit, Olcay, Asadi, Reza, Sun, Yizhou, and Wang, Wei
- Subjects
Computer Science - Machine Learning - Abstract
Recent benchmarks found In-Context Learning (ICL) outperforms both deep learning and tree-based algorithms on small tabular datasets. However, on larger datasets, ICL for tabular learning cannot run without severely compromising performance, due to its quadratic space and time complexity w.r.t. dataset size. We propose MIXTUREPFN, which both extends nearest-neighbor sampling to the state-of-the-art ICL for tabular learning model and uses bootstrapping to finetune said model on the inference-time dataset. MIXTUREPFN is the Condorcet winner across 36 diverse tabular datasets against 19 strong deep learning and tree-based baselines, achieving the highest mean rank among Top-10 aforementioned algorithms with statistical significance., Comment: 32 pages, 16 figures
- Published
- 2024
337. An Adaptive Framework for Manipulator Skill Reproduction in Dynamic Environments
- Author
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Donald, Ryan, Hertel, Brendan, Misenti, Stephen, Gu, Yan, and Azadeh, Reza
- Subjects
Computer Science - Robotics - Abstract
Robot skill learning and execution in uncertain and dynamic environments is a challenging task. This paper proposes an adaptive framework that combines Learning from Demonstration (LfD), environment state prediction, and high-level decision making. Proactive adaptation prevents the need for reactive adaptation, which lags behind changes in the environment rather than anticipating them. We propose a novel LfD representation, Elastic-Laplacian Trajectory Editing (ELTE), which continuously adapts the trajectory shape to predictions of future states. Then, a high-level reactive system using an Unscented Kalman Filter (UKF) and Hidden Markov Model (HMM) prevents unsafe execution in the current state of the dynamic environment based on a discrete set of decisions. We first validate our LfD representation in simulation, then experimentally assess the entire framework using a legged mobile manipulator in 36 real-world scenarios. We show the effectiveness of the proposed framework under different dynamic changes in the environment. Our results show that the proposed framework produces robust and stable adaptive behaviors., Comment: Paper accepted at Ubiquitous Robots 2024 held at New York University on June 24 to June 27, 2024
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- 2024
338. Towards Precision Healthcare: Robust Fusion of Time Series and Image Data
- Author
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Rasekh, Ali, Heidari, Reza, Rezaie, Amir Hosein Haji Mohammad, Sedeh, Parsa Sharifi, Ahmadi, Zahra, Mitra, Prasenjit, and Nejdl, Wolfgang
- Subjects
Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Machine Learning - Abstract
With the increasing availability of diverse data types, particularly images and time series data from medical experiments, there is a growing demand for techniques designed to combine various modalities of data effectively. Our motivation comes from the important areas of predicting mortality and phenotyping where using different modalities of data could significantly improve our ability to predict. To tackle this challenge, we introduce a new method that uses two separate encoders, one for each type of data, allowing the model to understand complex patterns in both visual and time-based information. Apart from the technical challenges, our goal is to make the predictive model more robust in noisy conditions and perform better than current methods. We also deal with imbalanced datasets and use an uncertainty loss function, yielding improved results while simultaneously providing a principled means of modeling uncertainty. Additionally, we include attention mechanisms to fuse different modalities, allowing the model to focus on what's important for each task. We tested our approach using the comprehensive multimodal MIMIC dataset, combining MIMIC-IV and MIMIC-CXR datasets. Our experiments show that our method is effective in improving multimodal deep learning for clinical applications. The code will be made available online.
- Published
- 2024
339. Resource-Efficient Heartbeat Classification Using Multi-Feature Fusion and Bidirectional LSTM
- Author
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Nikandish, Reza, He, Jiayu, and Haghi, Benyamin
- Subjects
Computer Science - Machine Learning - Abstract
In this article, we present a resource-efficient approach for electrocardiogram (ECG) based heartbeat classification using multi-feature fusion and bidirectional long short-term memory (Bi-LSTM). The dataset comprises five original classes from the MIT-BIH Arrhythmia Database: Normal (N), Left Bundle Branch Block (LBBB), Right Bundle Branch Block (RBBB), Premature Ventricular Contraction (PVC), and Paced Beat (PB). Preprocessing methods including the discrete wavelet transform and dual moving average windows are used to reduce noise and artifacts in the raw ECG signal, and extract the main points (PQRST) of the ECG waveform. Multi-feature fusion is achieved by utilizing time intervals and the proposed under-the-curve areas, which are inherently robust against noise, as input features. Simulations demonstrated that incorporating under-the-curve area features improved the classification accuracy for the challenging RBBB and LBBB classes from 31.4\% to 84.3\% for RBBB, and from 69.6\% to 87.0\% for LBBB. Using a Bi-LSTM network, rather than a conventional LSTM network, resulted in higher accuracy (33.8\% vs 21.8\%) with a 28\% reduction in required network parameters for the RBBB class. Multiple neural network models with varying parameter sizes, including tiny (84k), small (150k), medium (478k), and large (1.25M) models, are developed to achieve high accuracy \textit{across all classes}, a more crucial and challenging goal than overall classification accuracy.
- Published
- 2024
340. Active Magnetic Matter: Propelling Ferrimagnetic Domain Walls by Dynamical Frustration
- Author
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Hardt, Dennis, Doostani, Reza, Diehl, Sebastian, del Ser, Nina, and Rosch, Achim
- Subjects
Condensed Matter - Statistical Mechanics ,Condensed Matter - Soft Condensed Matter ,Condensed Matter - Strongly Correlated Electrons ,Nonlinear Sciences - Pattern Formation and Solitons - Abstract
Active matter encompasses many-particle systems with self-propelling units, such as flocks of birds or schools of fish. Here, we show how self-propelling domain walls can be realised in a solid-state system when a ferrimagnet is weakly driven out of thermal equilibrium by an oscillating field. This activates the Goldstone mode, inducing a rotation of the antiferromagnetic xy-order in a clockwise or anticlockwise direction, determined by the sign of the ferromagnetic component. Two opposite directions of rotation meet at a domain wall in the ferromagnetic component, resulting in `dynamical frustration', with three main consequences. (i) Domain walls move actively in a direction chosen by spontaneous symmetry breaking. Their speed is proportional to the square root of the driving power across large parameter regimes. (ii) In one dimension (1D), after a quench into the ferrimagnetic phase, this motion and strong hydrodynamic interactions lead to a linear growth of the magnetic correlation length over time, much faster than in equilibrium. (iii) The dynamical frustration makes the system highly resilient to noise. The correlation length of the weakly driven 1D system can be orders of magnitude larger than in the corresponding equilibrium system with the same noise level., Comment: General: Added references. Corrected typos. Main text: Several paragraphs to improve clarity in view of the general route taken. And placed in context with other areas of active matter. Supplement: Clarification of similarities with the `active Ising model'. Addition of a section on 2D results including a video
- Published
- 2024
341. Tough Cortical Bone-Inspired Tubular Architected Cement-based Material
- Author
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Gupta, Shashank and Moini, Reza
- Subjects
Physics - Applied Physics - Abstract
Cortical bone is a tough biological material composed of tube-like osteons embedded in the organic matrix surrounded by weak interfaces known as cement lines. The cement lines provide a microstructurally preferable crack path, hence triggering in-plane crack deflection around osteons due to cement line-crack interaction. Here, inspired by this toughening mechanism and facilitated by a hybrid (3D-printing/casting) process, we engineer architected tubular cement-based materials with a new stepwise cracking toughening mechanism, that enabled a non-brittle fracture. Using experimental and theoretical approaches, we demonstrate the underlying competition between tube size and shape on the stress intensity factor from which engineering stepwise cracking can emerge. Two competing mechanisms, both positively and negatively affected by the growing tube size, arise to significantly enhance the overall fracture toughness by up to 5.6-fold compared to the monolithic brittle counterpart without sacrificing the specific strength. This is enabled by crack-tube interaction and engineering the tube size and shape, which leads to stepwise cracking and promotes rising R-curves. Disorder curves are proposed for the first time to quantitatively characterize the degree of disorder for describing the representation of architected arrangement of materials (using statistical mechanics parameters) in lieu of otherwise inadequate periodicity classification., Comment: 51 pages, 16 figures
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- 2024
342. LISA double white dwarf binaries as Galactic accelerometers
- Author
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Ebadi, Reza, Strokov, Vladimir, Tanin, Erwin H., Berti, Emanuele, and Walsworth, Ronald L.
- Subjects
General Relativity and Quantum Cosmology ,Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,High Energy Physics - Phenomenology - Abstract
Galactic double white dwarf (DWD) binaries are among the guaranteed sources for the Laser Interferometer Space Antenna (LISA), an upcoming space-based gravitational wave (GW) detector. Most DWDs in the LISA band are far from merging and emit quasimonochromatic GWs. As these sources are distributed throughout the Milky Way, they experience different accelerations in the Galactic gravitational potential, and therefore each DWD exhibits an apparent GW frequency chirp due to differential acceleration between the source and LISA. We examine how Galactic acceleration influences parameter estimation for these sources; and investigate how LISA observations could provide insight into the distribution of matter in the Galaxy., Comment: 20 pages, 7 figures
- Published
- 2024
343. A Fueter operator for 3/2-spinors
- Author
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Sadegh, Ahmad Reza Haj Saeedi and Nguyen, Minh Lam
- Subjects
Mathematics - Differential Geometry ,Mathematical Physics ,Mathematics - Analysis of PDEs ,Mathematics - Geometric Topology ,53Cxx, 57Rxx, 58Jxx, 57Kx - Abstract
We show the non-compactness of moduli space of solutions of the monopole equations for $3/2$-spinors on a closed 3-manifold is equivalent to the existence of `3/2-Fueter sections' that are solutions of an overdetermined non-linear elliptic differential equation. These are sections of a fiber bundle whose fiber is a special 4-dimensional submanifold of the hyperk\"ahler manifold of center-framed charged one $SU(2)$-instantons on $\mathbf{R}^4$. This fiber bundle does not inherit a hyperk\"ahler structure., Comment: Comments are welcome
- Published
- 2024
344. Predicting the Influence of Adverse Weather on Pedestrian Detection with Automotive Radar and Lidar Sensors
- Author
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Weihmayr, Daniel, Sezgin, Fatih, Tolksdorf, Leon, Birkner, Christian, and Jazar, Reza N.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Pedestrians are among the most endangered traffic participants in road traffic. While pedestrian detection in nominal conditions is well established, the sensor and, therefore, the pedestrian detection performance degrades under adverse weather conditions. Understanding the influences of rain and fog on a specific radar and lidar sensor requires extensive testing, and if the sensors' specifications are altered, a retesting effort is required. These challenges are addressed in this paper, firstly by conducting comprehensive measurements collecting empirical data of pedestrian detection performance under varying rain and fog intensities in a controlled environment, and secondly, by introducing a dedicated Weather Filter (WF) model that predicts the effects of rain and fog on a user-specified radar and lidar on pedestrian detection performance. We use a state-of-the-art baseline model representing the physical relation of sensor specifications, which, however, lacks the representation of secondary weather effects, e.g., changes in pedestrian reflectivity or droplets on a sensor, and adjust it with empirical data to account for such. We find that our measurement results are in agreement with existent literature related to weather degredation and our WF outperforms the baseline model in predicting weather effects on pedestrian detection while only requiring a minimal testing effort., Comment: Accepted for the 2024 Intelligent Vehicles Symposium, 7 pages
- Published
- 2024
345. Shallow Recurrent Decoder for Reduced Order Modeling of Plasma Dynamics
- Author
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Kutz, J. Nathan, Reza, Maryam, Faraji, Farbod, and Knoll, Aaron
- Subjects
Physics - Plasma Physics ,Computer Science - Machine Learning ,Nonlinear Sciences - Pattern Formation and Solitons ,Physics - Computational Physics - Abstract
Reduced order models are becoming increasingly important for rendering complex and multiscale spatio-temporal dynamics computationally tractable. The computational efficiency of such surrogate models is especially important for design, exhaustive exploration and physical understanding. Plasma simulations, in particular those applied to the study of ${\bf E}\times {\bf B}$ plasma discharges and technologies, such as Hall thrusters, require substantial computational resources in order to resolve the multidimentional dynamics that span across wide spatial and temporal scales. Although high-fidelity computational tools are available to simulate such systems over limited conditions and in highly simplified geometries, simulations of full-size systems and/or extensive parametric studies over many geometric configurations and under different physical conditions are computationally intractable with conventional numerical tools. Thus, scientific studies and industrially oriented modeling of plasma systems, including the important ${\bf E}\times {\bf B}$ technologies, stand to significantly benefit from reduced order modeling algorithms. We develop a model reduction scheme based upon a {\em Shallow REcurrent Decoder} (SHRED) architecture. The scheme uses a neural network for encoding limited sensor measurements in time (sequence-to-sequence encoding) to full state-space reconstructions via a decoder network. Based upon the theory of separation of variables, the SHRED architecture is capable of (i) reconstructing full spatio-temporal fields with as little as three point sensors, even the fields that are not measured with sensor feeds but that are in dynamic coupling with the measured field, and (ii) forecasting the future state of the system using neural network roll-outs from the trained time encoding model., Comment: 12 pages, 7 figures
- Published
- 2024
346. Alternators For Sequence Modeling
- Author
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Rezaei, Mohammad Reza and Dieng, Adji Bousso
- Subjects
Statistics - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing ,Physics - Atmospheric and Oceanic Physics ,Quantitative Biology - Neurons and Cognition - Abstract
This paper introduces alternators, a novel family of non-Markovian dynamical models for sequences. An alternator features two neural networks: the observation trajectory network (OTN) and the feature trajectory network (FTN). The OTN and the FTN work in conjunction, alternating between outputting samples in the observation space and some feature space, respectively, over a cycle. The parameters of the OTN and the FTN are not time-dependent and are learned via a minimum cross-entropy criterion over the trajectories. Alternators are versatile. They can be used as dynamical latent-variable generative models or as sequence-to-sequence predictors. When alternators are used as generative models, the FTN produces interpretable low-dimensional latent variables that capture the dynamics governing the observations. When alternators are used as sequence-to-sequence predictors, the FTN learns to predict the observed features. In both cases, the OTN learns to produce sequences that match the data. Alternators can uncover the latent dynamics underlying complex sequential data, accurately forecast and impute missing data, and sample new trajectories. We showcase the capabilities of alternators in three applications. We first used alternators to model the Lorenz equations, often used to describe chaotic behavior. We then applied alternators to Neuroscience, to map brain activity to physical activity. Finally, we applied alternators to Climate Science, focusing on sea-surface temperature forecasting. In all our experiments, we found alternators are stable to train, fast to sample from, yield high-quality generated samples and latent variables, and outperform strong baselines such as neural ODEs and diffusion models in the domains we studied., Comment: A new versatile family of sequence models that can be used for both generative modeling and supervised learning. The codebase will be made available upon publication. This paper is dedicated to Thomas Sankara
- Published
- 2024
347. Fingerprints of a Non-Inflationary Universe from Massive Fields
- Author
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Quintin, Jerome, Chen, Xingang, and Ebadi, Reza
- Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics ,General Relativity and Quantum Cosmology ,High Energy Physics - Phenomenology ,High Energy Physics - Theory - Abstract
We construct explicit models of classical primordial standard clocks in an alternative to inflation, namely the slowly contracting ekpyrotic scenario. We study the phenomenology of massive spectator fields added to a state-of-the-art ekpyrotic model, with coupling functions that allow for these heavy fields to be classically excited while the background is slowly contracting. We perform numerical computations of the corrections to the scalar primordial power spectrum and compare with analytical estimates. Our full numerical results reveal so-called clock signals, sharp feature signals, as well as signals that link the two together. The models are found to predict oscillatory features that are resolutely different from what is calculated in inflation, and thus, such features represent unique fingerprints of a slowly contracting universe. This confirms the capability of primordial standard clocks to model-independently discriminate among very early universe scenarios., Comment: 71 pages, 22 figures; v2: summary of the main results added to the introduction, matches published version
- Published
- 2024
- Full Text
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348. Safe Robot Control using Occupancy Grid Map-based Control Barrier Function (OGM-CBF)
- Author
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Raja, Golnaz, Mökkönen, Teemu, and Ghabcheloo, Reza
- Subjects
Computer Science - Robotics - Abstract
Safe control in unknown environments is a significant challenge in robotics. While Control Barrier Functions (CBFs) are widely used to guarantee system safety, they often assume known environments with predefined obstacles. The proposed method constructs CBFs directly from perception sensor input and introduces a new first-order barrier function for a 3D kinematic robot motion model. The proposed CBF is constructed by combining Occupancy Grid Mapping (OGM) and Signed Distance Functions (SDF). The OGM framework abstracts sensor inputs, making the solution compatible with any sensor modality capable of generating occupancy maps. Moreover, the OGM enhances situational awareness along the robot's motion trajectory, by integrating both current and previously mapped data. The SDF encapsulates complex obstacle shapes defined by OGM into real-time computable values, enabling the method to handle obstacles of arbitrary shapes. This enables a single constraint in the CBF-QP optimization for each point on the robot, regardless of the number or shape of obstacles. The effectiveness of the proposed approach is demonstrated through simulations on autonomous driving in the CARLA simulator and real-world experiments with an industrial mobile robot, using a simplified 2D version of the method.
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- 2024
349. Revolutionizing Process Mining: A Novel Architecture for ChatGPT Integration and Enhanced User Experience through Optimized Prompt Engineering
- Author
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Kermani, Mehrdad Agha Mohammad Ali, Seddighi, Hamid Reza, and Maghsoudi, Mehrdad
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Computer Science - Computation and Language - Abstract
In the rapidly evolving field of business process management, there is a growing need for analytical tools that can transform complex data into actionable insights. This research introduces a novel approach by integrating Large Language Models (LLMs), such as ChatGPT, into process mining tools, making process analytics more accessible to a wider audience. The study aims to investigate how ChatGPT enhances analytical capabilities, improves user experience, increases accessibility, and optimizes the architectural frameworks of process mining tools. The key innovation of this research lies in developing a tailored prompt engineering strategy for each process mining submodule, ensuring that the AI-generated outputs are accurate and relevant to the context. The integration architecture follows an Extract, Transform, Load (ETL) process, which includes various process mining engine modules and utilizes zero-shot and optimized prompt engineering techniques. ChatGPT is connected via APIs and receives structured outputs from the process mining modules, enabling conversational interactions. To validate the effectiveness of this approach, the researchers used data from 17 companies that employ BehfaLab's Process Mining Tool. The results showed significant improvements in user experience, with an expert panel rating 72% of the results as "Good". This research contributes to the advancement of business process analysis methodologies by combining process mining with artificial intelligence. Future research directions include further optimization of prompt engineering, exploration of integration with other AI technologies, and assessment of scalability across various business environments. This study paves the way for continuous innovation at the intersection of process mining and artificial intelligence, promising to revolutionize the way businesses analyze and optimize their processes.
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- 2024
350. Mechanics and morphology of proliferating cell collectives with self-inhibiting growth
- Author
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Weady, Scott, Palmer, Bryce, Lamson, Adam, Kim, Taeyoon, Farhadifar, Reza, and Shelley, Michael J.
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Physics - Biological Physics ,Condensed Matter - Soft Condensed Matter - Abstract
We study the dynamics of proliferating cell collectives whose microscopic constituents' growth is inhibited by macroscopic growth-induced stress. Discrete particle simulations of a growing collective show the emergence of concentric-ring patterns in cell size whose spatio-temporal structure is closely tied to the individual cell's stress response. Motivated by these observations, we derive a multiscale continuum theory whose parameters map directly to the discrete model. Analytical solutions of this theory show the concentric patterns arise from anisotropically accumulated resistance to growth over many cell cycles. This work shows how purely mechanical processes can affect the internal patterning and morphology of cell collectives, and provides a concise theoretical framework for connecting the micro- to macroscopic dynamics of proliferating matter.
- Published
- 2024
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