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关键词： autograder   CAD   engineering drawing   engineering education  

摘要： Manual grading of engineering drawing assignments is often time-consuming, inconsistent, and error-prone, particularly in large-scale engineering education. To address these challenges, we present "CAD-AG", an automated grading system designed to evaluate two-dimensional engineering drawings exported from any CAD tool in DXF format. The system streamlines the grading process by comparing student submissions with a reference solution through geometric feature extraction and rule-based error detection. Key criteria assessed include shape accuracy, scale, alignment, and element completeness. Developed in Python and deployed via a web-based platform, CAD-AG enhances accessibility and usability. In testing with over 1000 student submissions, the system achieved 100% grading accuracy and significantly reduced average grading time. These results demonstrate the potential of automated grading to improve efficiency and consistency in engineering education, providing timely and objective feedback to support both instructors and learners.

关键词： YouTube   police media   surveillance   participatory culture  

摘要： This article identifies an emerging genre of police body camera content that we term "participatory policing": social media videos composed from official police footage, obtained through Freedom of Information Act (FOIA) requests, and transformed into viral entertainment by amateur content creators who add narration, sound, and visual effects. Through an analysis of videos, viewer comments, and the broader media ecosystem surrounding the YouTube channel Code Blue Cam (2021-present), we demonstrate how this genre valorizes law enforcement while stigmatizing criminalized "others." We argue that three key features-the "the body cam gaze" (our term for the first-person perspective from police body-worn cameras), creator editing and commentary, and active viewer participation-work together to extend police surveillance and disciplinary power beyond traditional law enforcement. By inviting audiences to surveil, categorize, and judge police targets, this genre inculcates viewers into the disciplinary apparatus of surveillance culture.

关键词： CAD/CAM   ceramic dental restorations   dentistry   meta-analysis   survival rates  

摘要： Background:The aim of this systematic review was to evaluate the survival rates of computer-aided design/computer-aided manufacturing ceramic dental ***:The study followed PRISMA guidelines and the study protocol was pre-registered on the PROSPERO platform (registration number: CRD42024599053). Randomized controlled trials (RCTs) and cohort studies with a minimum follow-up period of 1-year were included. The search period was set from 2000 to May 2024. A Comprehensive Literature Search was Performed in MEDLINE (PubMed), Scopus, and the Cochrane Central Register of Controlled Trials. Additionally, references list of relevant reviews and full-text articles were hand-searched to identify potentially eligible ***:A total of 714 articles were identified in the initial search. After screening titles and abstracts, 31 studies were selected for full-text review. Following the application of inclusion and exclusion criteria, 25 studies-comprising 13 RCTs and 12 cohort studies-were incorporated into the systematic review. Quality assessment and risk of bias were conducted using 2 established scales. Regarding survival rates, the overall heterogeneity (I2) among the RCTs was calculated at 23% (P = .17). The pooled survival rate across these trials was determined to be 96% (95% confidence interval: 94-98%), with a mean follow-up period extending from 12 to 64 ***:Ceramic restorations with computer-aided design/computer-aided manufacturing have shown high survival rates in either randomized controlled studies or cohort studies. Meta-analysis results showed high heterogeneity in cohort studies, so randomized controlled studies with a larger number of participants are still needed to prove their clinical effectiveness.

关键词： CAD生成   参数化建模   扩散模型   潜在扩散模型   条件生成  

摘要： 基于传统计算机辅助设计(CAD)创建兼具可制造性与可编辑性的三维模型是一项复杂且耗时的任务。近年来,深度学习技术在CAD模型自动化生成方面展现出巨大潜力并成为研究热点。然而,多数CAD生成模型未能充分利用点云、图像、草图等输入数据中蕴含的几何与语义信息,难以通过灵活的条件输入精准控制生成方向。针对这一问题,可通过挖掘潜在空间的表征能力,采用去噪扩散概率模型,以这类条件输入数据作为引导,实现CAD模型定向生成。具体而言,首先构建基于Transformer架构的自编码器,将CAD参数命令序列编码至潜在空间;进而在此空间内搭建去噪扩散概率模型,融合点云、图像或草图条件编码信息,生成CAD特征向量;最后通过解码器还原为三维CAD模型。实验结果表明,所生成的CAD模型结构合理、表面光滑且几何特征清晰,相较于现有方法,在生成形状多样性、分布相似性与保真度之间实现了较好的平衡,且当以点云、图像或草图作为条件输入时,均能有效提升CAD模型的生成质量。相关代码已开源,详情可见https://***/Ziyou-maker/LDM4CAD。

关键词： 3D model retrieval   multi-agent system   agentic AI   multimodal information fusion  

摘要： The rapid advancement of digital twin technologies, intelligent manufacturing, and the metaverse has led to an exponential growth of 3D model repositories. However, existing retrieval techniques struggle to accommodate complex user queries that often integrate multiple modalities, including geometric shape, semantic descriptions, structured attributes, and assembly hierarchies. To address this challenge, a novel intent-driven multimodal 3D model retrieval framework is proposed, which is built upon a multi-agent cognitive architecture to enable intelligent understanding and execution of cross-modal queries. At its core is a query-planning agent powered by large language models, which autonomously interprets complex user intents and breaks them down into sub-tasks. These sub-tasks are then executed collaboratively by specialised retrieval agents, including the vector retrieval agent, the structural topological agent, and the attribute filtering agent. A comprehensive database is constructed to incorporate geometric and semantic features, attribute metadata, and hierarchical assembly information. Furthermore, we introduce a multimodal clustering technique to enhance model organisation and retrieval efficiency. Experiments on the Fusion360 Assembly dataset demonstrate that the proposed multi-agent framework achieves superior efficiency and accuracy in handling complex, intent-driven 3D model search tasks.

关键词： additively manufactured   adhesive systems   shear bond strength   subtractively manufactured   surface treatment  

摘要： This study aims to evaluate the effects of different surface treatments and adhesive systems on the shear bond strength (SBS) of additively manufactured (AM) and subtractively manufactured (SM) restorative materials. A total 675 rectangular specimens of three AM (Saremco Crowntec/SC, VarseoSmile CrownPlus/VC, and VarseoSmile TriniQ/VT) and two SM (Vita Enamic/VE and Cerasmart/CS) restorative materials were fabricated. Each material was randomly divided into three groups regarding surface treatments: control/C, sandblasting/S, and etching/E. Following surface treatments, each AM and SM restorative material was then divided into three subgroups (15 specimens/subgroup) on the basis of adhesive systems (etch-and-rinse, self-etch, and universal). All specimens were thermocycled at 10,000 cycles, 5-55 degrees C, 30 s dwell time, and tested under SBS until failure, and failure types were examined under a stereomicroscope. Representative specimens were examined by SEM to evaluate fracture morphology. Statistical analysis was set at p < 0.05. There were significant differences in bond strength according to the material, surface treatment, adhesives, and their interactions (p < 0.05). The highest SBS value was obtained with SC x sandblasting x etch-and-rinse (16.45 +/- 0.93 MPa), while the lowest value was found in the CS x control x universal interaction (4.68 +/- 1.1 MPa). Outcomes varied according to the materials, surface treatment, and adhesive strategy. Clinically, these findings indicate that SM materials may require various surface treatment to achieve reliable adhesion, whereas AM materials provide more similar bond strength performance with no surface treatment.

关键词： 纺织品   挥发性有机物   质子转移反应质谱   高通量检测   快速分析  

摘要： 纺织品中挥发性有机物(volatile organic compounds, VOCs)残留超标会对人体健康构成威胁,VOCs检测是纺织品质量控制的重要一环。现有标准及规范的检测方法在面对大量纺织品样品分析时,存在分析速度较慢的问题。本研究提出了一种基于质子转移反应质谱(proton transfer reaction-mass spectrometry, PTR-MS)技术的纺织品VOCs快速筛查方法,以克服传统检测技术预处理复杂、时间成本高和检测通量低等局限。通过设计专用采样装置并构建PTR-MS分析系统,实现了无需样品预处理的纺织品中VOCs快速在线检测。实验结果表明,该方法对纺织品中甲醛、苯系物等典型有害物质的检出限可达0.01~0.50 mg/kg,单个样本检测时间缩短至1 min以内。该技术显著提升了纺织品中VOCs检测通量与效率,为大批量快速筛查提供了可靠方案。

关键词： 纺织品检验学   数字化教学   课程改革   教学改革  

摘要： 针对“纺织品检验学”课程传统教学模式中存在的课程知识点关联性薄弱、纸质教材内容时效性滞后、传统实验教学中学生主观能动性不足,以及教学反馈与课程考核形式单一,通过建立课程知识图谱、构建数字化教学资源库、开发虚拟教学平台、建立互动式教学反馈体系,系统探讨了数字化教学改革的实施策略;构建了包括创新性考核与开放式评价、智能化考核与个性化评估、项目驱动与过程性评价、产教融合与行业同步评价在内的多元化考核体系,实现对学生知识掌握程度、实践操作能力及综合素质的多维度评价,切实提升课程教学成效,进而培养适应数字时代发展需求的纺织专业高素质人才。

关键词： Delirium   CAM-ICU   Prolonged mechanical ventilation   Cardiac surgery  

摘要： Background: Delirium is common after cardiac surgery and has been associated with adverse outcomes in critically ill patients. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a validated tool for detecting delirium;however, few studies have explored its association with prolonged mechanical ventilation (PMV) following major cardiac surgery. This study aimed to investigate whether a positive CAM-ICU assessment is associated with PMV and other postoperative outcomes in this population. Methods: We conducted a retrospective cohort study of 1,437 adult patients who underwent cardiac surgery in 2022. Delirium was assessed daily using the CAM-ICU during the early postoperative period. PMV was defined as ventilation lasting more than 24 h after surgery. Clinical outcomes were analyzed using logistic regression and time-dependent Cox regression, with adjustments made using inverse probability of treatment weighting (IPTW). Results: Among 1437 patients, 281 (19.6%) were assessed as CAM-ICU positive in the early postoperative period. After IPTW adjustment, a positive CAM-ICU assessment was significantly associated with increased risk of PMV (odds ratio [OR] 3.60;95% CI, 2.53-5.10;p < 0.001), reintubation (OR 3.37;95% CI, 1.52-7.31;p = 0.002), intensive care unit (ICU) readmission (OR 2.53;95% CI, 1.22-5.03;p = 0.010), and prolonged ICU stay after extubation (OR 2.95;95% CI, 2.19-3.96;p < 0.001). Neither early death nor all-cause mortality differed significantly between groups after IPTW adjustment. Age-related analyses indicated that predicted ventilator duration was generally longer with a positive CAM-ICU assessment across most age groups, with attenuation of this difference in the very elderly (>= 80 years). Conclusion: An early postoperative positive CAM-ICU assessment was associated with higher risks of PMV, reintubation, ICU readmission, and prolonged ICU stay after major cardiac surgery. Routine CAM-ICU screening may help identify patients at r

关键词： wet deposition modeling   validation   CAM-chem   nitrogen   organic carbon   sulfate  

摘要： Accurate modeling of carbon, nitrogen, and sulfur wet deposition (i.e., through rain, snow, or graupel) flux is important for characterizing and quantifying the role of deposition in global biogeochemical cycles. The simulation of wet deposition of solutes, alongside precipitation rates, in the Community Atmosphere Model version 6 with Chemistry (CAM-chem) has had limited previous evaluation leaving an opportunity to determine its accuracy in simulating precipitation chemistry. Here, we assessed the accuracy of 1 degrees resolution CAM-chem outputs of wet deposition over the contiguous U.S. (CONUS) from 2002 to 2022, comparing model outputs for observed equivalents of sulfate (SO4 2-), ammonium (NH4 +), nitrate (NO3 -), and dissolved organic carbon (DOC) wet deposition with long-term records collected at hundreds of stations across CONUS. After evaluating the temporal, spatial, and quantile differences between modeled and observed wet deposition fluxes, we find the model captures long-term and seasonal patterns but consistently overestimates NO3 -, while underestimating SO4 2-, NH4 +, and DOC wet deposition fluxes. Model-measurement agreement improved at higher deposition flux quantiles and site-specific alignment was strongest for NO3 -, and moderate for SO4 2- and NH4 +. Low model-measurement agreement for DOC comparisons is likely due to focusing on aerosol contributions. Higher resolution model simulations (similar to 14 km) resulted in equivalent comparisons as the 1 degrees model, suggesting that wet deposition processes are represented consistently across different model simulations and spatial resolution is not the main driver of inaccuracies of model deposition. Benchmarking modeled deposition outputs is crucial for evaluating CAM-chem's performance and its utility in understanding landscape drivers of deposition chemistry within Earth system models.