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Energy efficient scheduling in a robotic cell with a material handling robot serving two parallel machines
No full textAs the robots take over more logistics tasks in factories, the energy consumption of material handling robots becomes a significant concern. This study considers a robotic cell with two parallel machines and a material-handling robot transporting parts between the machines and buffer locations. A set of parts is to be scheduled on the machines. Also, the robot's moves, activities, and speed have to be planned. While programming a robot, its speed can be easily adjusted. Speeding up a robot can reduce the makespan of a schedule while increasing the robot's energy consumption. A holistic scheduling approach is required to coordinate machines' and robot activities. We first present a mathematical formulation and reformulate it via second-order cone programming inequalities. Then, we develop heuristic search algorithms: a greedy search algorithm and two versions of the simulated annealing algorithm. We test the proposed solution methods' computational performance and demonstrate that the robot speed control strategy can achieve significant energy savings
AI in the classroom: Exploring students' interaction with ChatGPT in programming learning
No full textAs being more prevalent in educational settings, understanding the impact of artificial intelligence tools on student behaviors and interactions has become crucial. In this regard, this study investigates the dynamic interactions between students and ChatGPT in programming learning, focusing on how different instructional interventions influence their learning and AI-interaction. Conducted over three sessions, students were allowed to use ChatGPT to complete programming tasks. The first session had no guidance, the second included hands-on training in prompt writing and effective ChatGPT use, and the third provided a lab guide with sample prompts. After each session, students took a post-test on the activity's subject. Analyzing students' prompting behaviors, five AI interaction profiles were identified: AI-Reliant Code Generators, AI-Reliant Code Generator & Refiners, AI-Collaborative Coders, AI-Assisted Code Refiners, and AI-Independent Coders. These profiles were examined to understand their evolution across interventions and their relationship with students' learning performance. Findings revealed significant changes in profile distribution across interventions, and a notable difference between students' post-test scores and their AI interaction profiles. Besides, training in prompting skills and effective use of AI significantly impacted students' interactions with AI. These insights can contribute to the knowledge of integrating generative AI tools in education, highlighting how AI can enhance teaching practices. Understanding student-AI interaction dynamics can allow educators to tailor instructional strategies for optimal learning. This study also underscores the importance of guidance on effective AI use and prompting skills, which can lead students to use AI more meaningfully for their learning
The mutagenic forces shaping the genomes of lung cancer in never smokers
No full textLung cancer in never smokers (LCINS) accounts for around 25% of all lung cancers1,2 and has been associated with exposure to second-hand tobacco smoke and air pollution in observational studies3, 4–5. Here we use data from the Sherlock-Lung study to evaluate mutagenic exposures in LCINS by examining the cancer genomes of 871 treatment-naive individuals with lung cancer who had never smoked, from 28 geographical locations. KRAS mutations were 3.8 times more common in adenocarcinomas of never smokers from North America and Europe than in those from East Asia, whereas a higher prevalence of EGFR and TP53 mutations was observed in adenocarcinomas of never smokers from East Asia. Signature SBS40a, with unknown cause6, contributed the largest proportion of single base substitutions in adenocarcinomas, and was enriched in cases with EGFR mutations. Signature SBS22a, which is associated with exposure to aristolochic acid7,8, was observed almost exclusively in patients from Taiwan. Exposure to secondhand smoke was not associated with individual driver mutations or mutational signatures. By contrast, patients from regions with high levels of air pollution were more likely to have TP53 mutations and shorter telomeres. They also exhibited an increase in most types of mutations, including a 3.9-fold increase in signature SBS4, which has previously been linked with tobacco smoking9, and a 76% increase in the clock-like10 signature SBS5. A positive dose–response effect was observed with air-pollution levels, correlating with both a decrease in telomere length and an increase in somatic mutations, mainly attributed to signatures SBS4 and SBS5. Our results elucidate the diversity of mutational processes shaping the genomic landscape of lung cancer in never smokers
Data-ing process with image-based data: variable identification and generation
No full textUsing photographs as data, which involves making observations from images and organizing them into variables to answer statistically investigative questions, is recommended for K-12 level statistics education. Research is needed to support pre-service mathematics teachers' experiences with exploring such image-based data. With this task-based interview study, the goal was to shed light on (1) the pre-service mathematics teachers' data-ing actions during identifying and generating variables in relation to data familiarization, question posing, and data organization components and (2) how pre-service mathematics teachers identified and generated variables in the process of data-ing. Data from video recordings, transcripts of the interview sessions for each pair, and their work with photos on the shared online document, that is, groupings and questions posed, were analyzed using a progressive focusing approach. The results showed that the data-ing actions during identifying and generating variables with data familiarization, question posing, and data organization included observing, interpreting, conjecturing, inferring, comparing, grouping, ordering, questioning/question posing, relating variables, categorizing variables, and measuring variables. The pairs used various combinations of multiple actions while data-ing. There were two types of variable identification: (1) observational variables based on visual judgment or metadata and (2) inferential variables based on personal interpretation. The latter type presented a tension between the variable defined and how to measure it objectively, as well as challenges in writing clearly defined variables when posing questions
Colorimetric core/shell ZIF-8/PEO/PDA nanofibers for detection of fish spoilage
No full textHere, colorimetric nanofibers (NFs) based on polydiacetylene (PDA), zeolitic imidazolate framework-8 (ZIF-8), and poly(ethylene) oxide (PEO) were developed. First, the successful synthesis of ZIF-8 was illustrated with structural and morphological analysis. Next, shell/core PDA/PEO/ZIF-8 NFs, namely PPZ0, PPZ5, PPZ15, and PPZ25, were fabricated by coaxial electrospinning at various ZIF-8 concentrations in the core. PPZ5 NFs exhibited a 63 % increase in tensile strength while PPZ25 NFs showed the highest thermal resistance. PPZ15 NFs with the best physicochemical and colorimetric properties were selected to evaluate food spoilage. The change in color difference values of PPZ15 NFs was correlated well with total viable count (TVC) and total volatile basic nitrogenous (TVB-N) in fish samples during chilled storage, reaching TVC to 6.69 log CFU/g, and TVB-N to 33.13 mg N/100 g on day 6. Ultimately, the PPZ15 NFs were successfully utilized to provide a real-time, quantitative assessment of fish freshness
A Relational Construction of Organizational Risk: Normalizing Versus Problematizing Through Risk Work on Concerns Versus Measures
No full textThis study examines a public hearing, in which a company normalizes a high-risk project while a group of residents and landowners problematize it through three types of relational risk work including the construction of concerns versus measures, consultations on concerns and measures, and company approach in addressing concerns with measures. They construct risk meanings in a relational context where they respond to the normalizing and problematizing attempts of one another. Accordingly, this study has two main contributions. First, it identifies three types of risk work used by public and business stakeholders to relationally construct and normalize/problematize risk and risk management and thus analyzes the tension between normalizing and problematizing as an issue of interdependence. Second, it brings forward the opposition between concerns and measures as an important topic for risk research and emphasizes the critical role of risk consultations with cooperative approaches in addressing this opposition
Effect of morphology on the optical limiting of BiVO<sub>4</sub> films
No full textPrecise control over the morphology and crystal structure of semiconductor-based optical materials is essential for optimizing their nonlinear optical properties. Morphological factors significantly affect the material's interaction with light, influencing nonlinear absorption, harmonic generation, and optical confinement. In this study, the nonlinear optical (NLO) properties and optical limiting (OL) performance of bismuth vanadate (BiVO4) films depending on precursor solution pH condition, powder morphology and weight percentage of the BiVO4 powders in PMMA (10-30 wt.%) were investigated. The BiVO4 powders were synthesized via the hydrothermal method and the effect of precursor solution pH (pH of 1, 7.5 and 12) was investigated on the size and morphology of the BiVO4 powders. BiVO4 films were prepared using the spin coating method utilizing the BiVO4 powders and PMMA. The bandgap values of films were found to change from 3.39 to 3.56 eV depending on the BiVO4 growth solution pH. The nonlinear absorption coefficients (beta(eff)), saturation intensity thresholds (I-SAT) and optical limiting (OL) threshold were obtained using the open aperture (OA) Z-scan experiment. It has been observed that the nonlinear absorption and optical limitation performance of the BiVO4 films can be altered by changing the powder morphology and BiVO4 weight concentration. BiVO4 thin films fabricated using a precursor solution pH 12 and weight concentration of 30 wt.% showed the best performance among all fabricated films with the highest nonlinear absorption coefficient (beta eff), saturation density threshold (I-SAT) and lowest OL threshold value
TEKİLLİKLERİ SADECE BOĞUMLAR OLAN LİFLENMİŞ YÜZEYLERE KARŞILIK GELEN HAS MULTİNETLER
No full textBir (k, d)-multinet, CP^2 içindeki katlılıklara sahip doğruların ve noktaların özel bir konfigürasy-onudur. Multinetler, karma¸sık bir doğru ayarlamasının tümleyeninin rezonans çokluklarını anlamakiçin önemli bir araçtır. Eğer bir multinet aynı zamanda bir net değilse, bir ba¸ska deyi¸sle en azbir katlı doğru ya da noktaya sahipse, o multinet has bir multinet oluyor. 2009 yılında Yuzvinsky,bir (k, d)-multinetinin k değerinin en çok 4 olduğunu ve bu multinet has (proper) olduğunda budeğerin 3 e eşit olacağını kanıtlanmıştır. Dolayısıyla, tüm has multinetler için k = 3. Has multi-netler hakkında sınırlı sayıda örnek biliniyor. Tüm çift dereceliler için bilinen örnek, her d > 2 içinQ = [x^d(y^d − z^d)][y^d(x^d − z^d)][z^d(x^d − y^d)] polinomunun oluşturduğu has bir (3, 2d)-multinettir.Asıl problemimiz, en az bir katlılıklı doğruya sahip multinetlerin tek derecelerde (yani 2d + 1 için)mümkün olamayacağıdır.Her bir (k, d)-multinet CP^2 de k tanesi tamamen indirgenebilir olan d dereceli eğrilere sahip birdergeye (pencil) denk gelir. CP^2 yi bu dergenin pivotlarından patlattıktan sonra doğal bir liflenmesiolan karmaşık bir S yüzeyini elde ederiz. S nin tekil lifleri boğumdan farklı tekilliklere sahip ola-bileceğinden, boğum indirgemesi yoluyla tüm bu tekillikleri boğumlara indirgeyebiliriz. Böylelikle,multinetlere kar¸sılık gelen ve sadece liflerinde tekillik olarak boğumları olan CP^1 üzerinde liflenmişbir yüzey elde ederiz.Bu konuşmamızda, tamamen indigenebilir eğrilere karşılık gelen lifler dışındaki tekilliği sadeceboğumlar olan S yüzeyine denk gelen has multinetlerle ilgileneceğiz. Boğum indirgemesiyle tümtekil liflerdeki tekillikleri boğum yapıp, bu boğumları sayacağız. Sonuçlar, bu yüzeylerin tekilliflerindeki boğumların sayısını kullanarak bazı derecelerde has multinetler üzerinde kombinatorikkısıtlamalar elde edilebileceğini gösteriyor.A (k,d)-multinet is a special configuration of lines with multiplicities and points in CP^2. Multinets are important tools for understanding the resonance varieties of the complement of a complex line arrangement. If a multinet is not also a net—that is, if it has at least one line or point with multiplicity—then it is called a proper multinet. In 2009, Yuzvinsky proved that the value of k for a (k,d)-multinet is at most 4, and if the multinet is proper, then k=3. Therefore, all proper multinets must have k=3.Only a few number of examples of proper multinets are known. For all even degrees, a known example is the proper (3,2d)-multinet given by the polynomial Q = [x^d(y^d - z^d)][y^d(x^d - z^d)][z^d(x^d - y^d)] for every d>2. Our main problem is that multinets with at least one line of multiplicity are conjectured not to exist for odd degrees (that is, for degrees 2d+1).Each (k,d)-multinet corresponds to a pencil in CP^2 consisting of k completely reducible curves of degree d. After blowing up CP2 at the base points of this pencil, we obtain a complex surface S with a natural fibration. Since the singular fibers of S may have singularities beyond just nodes, we can apply nodal reduction to simplify all these singularities into nodes. In this way, we obtain a surface fibered over CP^1 whose only singularities in the fibers are nodes, corresponding to the multinet.In this talk,we focus on proper multinets corresponding to surfaces Swhere the only singularities in the fibers (except for those corresponding tocompletely reducible curves) are nodes. By applying nodal reduction to allsingular fibers and counting the resulting nodes, our results show that one canderive combinatorial restrictions on proper multinets in certain degrees basedon the number of nodes in the singular fibers of these surfaces. </div