Deep Knowledge Tracing Embedding Neural Network for Individualized Learning

Knowledge tracing is the key component in online individualized learning,which is capable of assessing the users'mastery of skills and predicting the probability that the users can solve specific problems.Available knowledge tracing models have the problem that the assessments are not directly used in the predictions.To make full use of the assessments during predictions,a novel model,named deep knowledge tracing embedding neural network(DKTENN),is proposed in this work.DKTENN is a synthesis of deep knowledge tracing(DKT)and knowledge graph embedding(KGE).DKT utilizes sophisticated long short-term memory(LSTM)to assess the users and track the mastery of skills according to the users'interaction sequences with skill-level tags,and KGE is applied to predict the probability on the basis of both the embedded problems and DKT's assessments.DKTENN outperforms performance factors analysis and the other knowledge tracing models based on deep learning in the experiments.

A Multi-Interface Remote Monitoring and Control System Architecture Based on Embedded Server

This paper presents a multi-interface embedded server architecture for remote real-time monitoring system and distributed monitoring applications. In the scheme,an embedded microprocessor( LPC3250 from NXP) is chosen as the CPU of the embedded server with a linux operation system( OS) environment. The embedded server provides multiple interfaces for supporting various application scenarios. The whole network is based on local area network and adopts the Browser / Server( B / S) model. The monitoring and control node is as a browser endpoint and the remote node with an embedded server is as a server endpoint. Users can easily acquire various sensors information through writing Internet protocol address of remote node on the computer browser. Compared with client / server( C / S) mode,B / S model needs less maintain and can be applicable to large user group. In addition,a simple network management protocol( SNMP) is used for management of devices in Internet protocol( IP) networks. The results of the demonstration experiment show that the proposed system gives good support to manage the network from different user terminals and allows the users to better interact with the ambient environment.

片上trace:嵌入式处理器的有效调试和优化技术

片上trace技术弥补了传统调试方法的不足,可以实现对嵌入式软件的非入侵调试。首先分析了当前主流调试方法的不足,论述了trace与断点调试方法互为补充的关系,而后介绍了YHFT系列DSP的片上trace系统TraceDo的功能与结构,并解释了路径trace的原理和工作过程,最后讨论了片上trace的应用。

基于S3C6410的DMA数据跟踪技术在TD-LTE中的实现

基于TD-LTE系统中数据跟踪技术的研究与DMA获取系统总线的不同模式,设计并分析比较了在S3C6410上通过DMA实现原语跟踪的两种方案。根据TD-LTE无线综合测试仪中的设计要求,选择了中断标志查询模式获取系统总线的方案,实现了TD-LTE系统原语的实时跟踪,满足了系统对CPU资源利用率以及数据传输速度和准确性的要求。

Bioleaching of trace elements and rare earth elements from coal fly ash

Coal fly ash originated from coal combustion has high concentrations of metals. If suitable leaching techniques are identified, then coal fly ash could serve as a useful source of valuable minerals including rare earth elements (REEs). In this study, three microbial strains, Candida bombicola, Phanerochaete chrysosporium and Cryptococcus curvatus were tested on their performance of leaching trace elements and REEs from fly ash. Through comparing mineral loss and leaching efficiencies resulting from indirect leaching or use of the culture supernatant, C. bombicola was identified to be the best leading to the highest mineral loss and extracting efficiencies of trace elements and REEs among the three strains. The highest mineral loss observed from using the supernatant of this yeast strain was 59.7%. Among all trace elements, As and Mo had the highest leaching efficiency of 80.9% and 79.5%. respectively. The same leaching test led to 67.7% of Yb and 64.6% of Er dissolved from the ash. This study, thus, demonstrated that bioleaching is feasible for leaching metals out of fly ash. The C. bombicola strain deserves further investigation due to its robust actions on metal leaching.

Distribution and occurrence of trace elements in the No.14 coal from the Huolinhe mine

Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry （SEM-EDX）, have been used to study the minerals and the concentrations of 12 trace elements in the No.14 coal from the Huolinhe mine, Inner Mongolia China. The distribution, affinity and removability of the trace elements were studied by float-sink experiments and petrological methods. A high mineral content, dominated by clay minerals, was found in the No.14 coal from the Huolinhe mine. The concentrations of As, Sb and Hg are relatively high compared to the average values for Chinese coals. As, Cr, Hg, Li, Mn, Pb are mainly associated with the minerals while Cd, Co, Ni, Sb, and Se are evenly distributed between the minerals and the organic matter. Be and Ba are mainly distributed in the minerals with a minor proportion in the organic matter. Most elements have a low organic affinity, although Sb, Se, Co, Cd, Ni are closely integrated with the organic matter. High theoretical removabilities are indicated for most trace elements. So it may be possible to lower the concentrations of trace elements during coal preparation.

Assessment of trace metals contamination in stream sediments and soils in Abuja leather mining, southwestern Nigeria

This study is aimed at determining the level of environmental degradation as well as the concentration of trace elements in soil and stream sediments in order to evaluate the environmental impact of the mining operation.Twenty-five(25) soils and ten(10) stream sediment samples were collected from the study area. The physicochemical parameters were determined using appropriate instrumentation with the aid of a digital p H meter(Milwaukee meter) to measure the p H and electrical conductivity, total dissolved solids, moisture content and loss on ignition of the soil and stream sediment samples. The p H of the soil sample ranged from(6.10 to 7.19); Electrical conductivity ranged from(21.3 to 279.4 μS/cm), moisture content varied from(0.60% to 7.20%), and the LOI ranged from(2.03% to 18.62%). The results of the analysis showed that the concentrations of the trace elements in the soils and stream sediment samples were slightly higher than the background values. Plots of the trace elements in stream sediment samples show moderate, consistent decrease downstream except at points where there was mine water discharge into the main river. The pollution levels of heavy metals were examined in stream sediment and soil samples using different assessable indices, such as the enrichment factor, which showed significant-moderate enrichment for Cr, Th, Nb, Zn, Pb, Y and Zr and the geoaccumulation index, which showed practically moderate contamination with Cr, Ni and Sr based on regional background reference values. Geo-accumulation index and contamination index for soils and stream sediment revealed uncontaminated to moderate contamination. Likewise,elements with moderate contamination were Cr, Ni and Sr.The Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.

Characterization of Household Solid Waste in the Town of Abomey - Calavi in Benin

Identification of waste characteristics is an important step towards improving waste recovery. The aim of this research was to determine the physical and physico-chemical characteristics of waste of Abomey–Calavi city and to study the relationship between standard of living and average ratio of daily waste generated by each person. In this study the methodology used French standards to characterize particle size and typology of solid waste generated by the population of Calavi City in Benin, West Africa. According to home criteria, the study area was stratified into three distinct levels of standard of living called: high standing, medium standing and low standing;Waste from 60 households was weighed daily. The total waste produced by each household was collected seven (7) days a week, for a period of three weeks. Waste characterization was performed using ratio, size granulometry and typological composition. Physico- Chemical analysis including organic mater, pH, Total Organic Carbon, total Kjeldahl nitrogen and metal trace element were also performed. To better assess waste compostability, water extractable organic matter was quantified and qualitative identification was made with XAD8 and XAD4 resins. Results show that the amount of waste increases with the standard of living;the average ratio of daily waste generated is 0.89 kg day-1 person-1. Independently of the standard of living, fermentable compounds represent the largest proportion of waste materials (45%). Qualitative difference of waste content in organic matter is shown as a function of the population’s living standards. These results could be explained by a higher consumption of meat in the households with a higher standard of living, reflecting a greater proportion of transphilic (TPI), and hydrophilic (HPI) fractions. The C/N ratio is lower in the high standing households than in low ones. Metal trace element analysis showed a low but still significant pollution, whereas high iron and alu minum concentrations were found in all standings. In conclusion we propose a strategy for waste management in Abomey-Calavi based on sorting at the source to eliminate plastic waste and valorization of wastes via composting.

自动SPME-GCMS法分析生活饮用水中臭味物质土臭素和2-甲基异莰醇

如果饮用水中的土臭素与2-甲基异莰醇的含量超标,往往会造成致嗅现象。因此,供水企业对这类嗅味物质的有效去除一直十分关注。在实践中,通过传统方法很难实现有效去除,且对这类嗅味物质的检测与分析也存在诸多不足。本文应用自动SPME技术连接thermo scientifi c^(TM )ISQ 7000 GCMS,实现了对2-甲基异莰醇和土臭素的高效率、高灵敏度的检测,其最低检出质量浓度分别为1.0 ng/L和0.49 ng/L,满足饮用水中土臭素和2-甲基异莰醇的检测要求。

Elemental Concentrations in Biological Samples of Coronavirus Disease (COVID-19) and Other Pulmonary Disease Patients

Background: Recently, Coronavirus Disease 2019 (COVID-19) has been affected by the extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has developed important global health anxiety. At this time, the treatment options for this disease are only moderately successful. Smoking has been related to COVID-19 and its mortality, and it has the potential to affect bacteriological and viral conversion, clinical effects, and treatment outcomes. Methods: The aim of this study was to determine the relationship between critical essential trace {zinc (Zn), iron (Fe), and copper (Cu)} and toxic {cadmium (Cd) and nickel (Ni)} elements in human biological samples such as scalp hair, serum, saliva, blood, nasal fluid, and sputum of smoking and nonsmoking male COVID-19 patients (n = 139, age range 25 - 38 years) from Hyderabad, Pakistan. For comparative purposes, the biological specimens of referent persons (n = 83), pulmonary Tuberculosis (T.B) patients (n = 67), Pneumonia (n = 56) of the same age groups were also be analyzed. Microwave oven mediated digestion method was employed, and digestion of samples was carried out with the help of 2:1 mixture solution of HNO3 (65%) and H2O2 (30%). Atomic absorption spectrometry was employed for the determination of elemental concentrations from the microwave oven employed digested samples. Results: The found average of essential elements (Zn, Fe, and Cu) in biological specimens of smoker and nonsmoker male COVID-19, T.B, and Pneumonia patients was found to lower, whilst cadmium and nickel were found to be higher when compared with samples from referents (p < 0.001). Conclusions: Improved elemental (Cu, Fe, Zn) concentrations may also decrease the risk of bacterial co-infection by enhancing the mucociliary clearance and respiratory epithelial barrier function, in addition to providing direct antibacterial effects against S. pneumoniae. Our findings also suggest that higher Cd and Ni concentrations are linked to cigarette smoking, which could lead to COVID-19 and other lung-infected diseased recurrences. However, further clinical and experimental research is required.

练习嵌入和学习遗忘特征增强的知识追踪模型

现有知识追踪模型大多以概念为中心评估学生的未来表现,忽略了包含相同概念的练习之间的差异,从而影响模型的预测准确性。此外,在构建学生知识状态过程中,现有模型未能充分利用学生在答题过程中的学习遗忘特征,导致对学生知识状态的刻画不够精确。针对以上问题,提出了一种练习嵌入和学习遗忘特征增强的知识追踪模型(exercise embeddings and learning-forgetting features boosted knowledge tracing, ELFBKT)。该模型利用练习概念二部图中的显性关系,深入计算二部图中的隐性关系,构建了一个练习概念异构关系图。为充分利用异构图中的丰富关系信息,ELFBKT模型引入了关系图卷积网络。通过该网络的处理,模型能够增强练习嵌入的质量,并以练习为中心更准确地预测学生的未来表现。此外,ELFBKT充分利用多种学习遗忘特征,构建了两个门控机制,分别针对学生的学习行为和遗忘行为进行建模,更精确地刻画学生的知识状态。在两个真实世界数据集上进行实验,结果表明ELFBKT在知识追踪任务上的性能优于其他模型。

面向流动追踪的多层鲁棒Excel文档水印

Excel文档被广泛应用于金融财务、科学研究、数据分析、统计报告等领域,在教育培训、在线办公等诸多场景中扮演着重要角色,却也潜藏着违规使用、侵权行为和信息泄露等安全隐患。为保护Excel文档内容的安全,迫切需要研究更安全可靠的文档保护技术。文中基于Excel文档格式,提出了一种面向流动追踪的多层鲁棒Excel文档水印算法,该算法通过将多层水印信息嵌入Excel文档的单元格样式和边框的RGB颜色值中,从而能在实际应用场景中明确敏感文档传播链条,对文档泄露源头进行追踪溯源,定位泄密责任人,以减少信息泄露事件的发生。经实验对比发现,所提水印算法不可感知性好,对增加、删除、重新键入、格式刷、复制粘贴和另存为等多种常见文档操作和攻击具有很强的鲁棒性,同时支持多层水印嵌入。与其他基于文档格式的水印算法相比,所提算法具有更好的水印不可见性、更强的鲁棒性和更宽广的应用范围。

深度学习支持下的自适应学习路径推荐——融合图嵌入与注意力机制的知识追踪模型

自适应学习路径推荐是智能技术在教育服务智能化中的核心应用。知识追踪通过分析学生的历史学习记录,预测其未来知识水平,从而为其提供个性化的学习规划与推荐。然而,现有的知识追踪方法在处理学生在线学习行为的复杂性时存在数据稀疏问题,并且忽略了时间因素和学生的遗忘机制,导致模型不能准确捕捉学生的状态变化,影响推荐效果。因此,在知识追踪模型中融合图嵌入和注意力机制,设计出一种新颖的深度学习支持下的自适应学习路径推荐模型(GE-MAKT)。实验结果表明,相较于传统方法,GE-MAKT模型的AUC和ACC两个评价指标得到显著提升,增强了对学生知识掌握水平的判断能力,可为学生提供更加个性化的学习路径推荐。

植入人体耗材的信息化追踪管理

随着医用昂贵耗材数量、种类的发展和医院管理的不断完善,对植入人体耗材的管理也赋予了新的特征和意义。为此,基于PACS系统开发了植入人体耗材管理系统,不仅实现了耗材基本信息的录入和统计,同时融入了图像信息,最终实现了对植入耗材使用的追踪。

基于JTAG的ARM芯片系统调试

嵌入式ARM软、硬件调试技术依赖于ARM处理器调试硬件,本文在分析JTAG边界扫描结构的基础上,介绍了EmbeddedICE、嵌入式跟踪等实时调试技术,并给出了一个嵌入式调试开发系统的实例。

基于执行序列的嵌入式软件时序异常检测

时序特性是嵌入式软件的重要特性,实时嵌入式软件运行的正确性不仅依赖于任务执行结果,更依赖于任务执行时间.执行任务往往具有多个时间约束,且相互之间可能存在制约关系,对时间约束进行验证和确认是嵌入式软件测试的一个重要问题.文中提出一种基于执行片段的嵌入式软件时序特性检测方法(Trace-Based Temporal Defect Detection,TBTDD).一方面,基于扩展语义接口自动机(Extended Semantic Interface Automata,ESIA)模型,刻画嵌入式软件时序特性需求,分析不同时间约束间存在的相关关系类型,并提出基于相关矩阵的相关时间约束识别算法;另一方面,在目标软件运行环境中提取包含时间信息的执行片段,通过执行片段与时间约束模型的匹配,依据预先制定的时序特性检测准则,检验执行序列是否满足模型中各项独立和相关时间约束的要求,进而发现被测软件中存在的时序缺陷.实验以卫星定位系统软件为例进行建模与缺陷检测,并在执行片段集和缺陷检测能力等方面进行了对比分析.实验表明,该方法可有效检测软件运行过程中存在的各类异常时序,提高了软件时序测试的有效性和充分性.

矿山钻孔三维模型构建与可视化方法

为了建立矿床三维地质模型，研究了基于矿山钻孔数据的钻孔三维模型构建及可视化方法。采用与平台无关的SQLite嵌入式数据库管理钻孔数据，设计了钻孔数据的孔口、样品分析、测斜和地质岩性等4个表结构，分析了建立钻孔三维模型时钻孔数据存在的2种错误类型。将钻孔轨迹曲线转化为折线，给出了均角全距法、全角半距法等2种钻孔轨迹折线计算公式。采用钻孔图形关联属性数据表的数据结构来存储钻孔三维模型，利用点和直线段分别存储钻孔孔口和样品的空间位置数据，数据表存储图形对应的钻孔编号、样品元素品位、体重等属性值。以多段线表示钻孔轨迹，并通过文字、颜色、图形等多种方法实现钻孔属性数据在三维空间的可视化。基于Hoops 3D框架对以上算法进行了实现，并建立了某铜矿32#~56#勘探线钻孔三维模型，根据钻孔轨迹和铜元素品位的可视化结果，圈定了勘探线剖面的铜矿体边界。结果表明，所提出的钻孔三维模型构建方法准确可靠，有助于提高地质分析、矿床地质建模的效率。

礼县出土春秋秦鼎的实验考古学研究——铸型工艺中的分体模与嵌范技术复原

商周时期中原地区的青铜圆鼎大多以三合范铸造,而礼县出土的三件春秋型秦式鼎特征鲜明,皆使用双合范浑铸成形。只有通过使用分体模和嵌范技术才能保证这种工艺得以实施。文章尝试将史前石器的研究范式用于青铜器研究;对器表能够反映古人特定技术行为和思维方式的工艺痕迹,进行了系统观察和痕迹分析;进而展开相关的实验考古学研究,对所作分析进行补充和验证,并通过实验考古这个直观的认知过程,将器物上的静态信息转化为动态的历史图景,揭示秦国铸工的生产方式和工艺思想。

基于嵌入式技术的电伴热智能控制器

以智能处理器为核心,应用嵌入式技术设计并开发的电伴热智能控制器可以监测管道温度、回路电流和断路器状态,并根据工艺要求控制每条电伴热加热回路。同时,各控制器之间可以通过485总线或局域网连接成工业控制网络,使得每个智能控制器可控制多达320条加热回路,克服了以往电伴热控制器在扩展性及回路控制灵活性方面的不足。此外,该控制器通过对采集数据的分析,可以自诊断出运行故障及报警产生的原因。经试验测试表明:该电伴热智能控制器运行稳定,具有较好的系统扩展性和兼容性,并在回路控制的有效性上表现出较好的性能。

一种新的高速嵌入式系统软件调试技术

随着嵌入式系统速度的显著提高,系统设计越来越复杂,对软件调试提出了新的挑战。传统的调试技术,仿真工具无法满足高速嵌入式系统的调试要求。该文介绍了一种综合式软件调试技术和方法,通过使用逻辑分析仪软件调试功能,结合嵌入式系统开发时使用的编译器,仿真器,调试器,进行高速嵌入式系统的功能验证,代码诊断,软件优化,分析子程序模块的执行效率。最后针对PPC8260处理器的软件调试提供了综合的软件调试方法。