An approach to automatic learning assessment based on the computational theory of perceptions

E-learning systems output a huge quantity of data on a learning process. However, it takes a lot of specialist human resources to manually process these data and generate an assessment report. Additionally, for formative assessment, the report should state the attainment level of the learning goals defined by the instructor.This paper describes the use of the granular linguistic model of a phenomenon (GLMP) to model the assessment of the learning process and implement the automated generation of an assessment report. GLMP is based on fuzzy logic and the computational theory of perceptions. This technique is useful for implementing complex assessment criteria using inference systems based on linguistic rules. Apart from the grade, the model also generates a detailed natural language progress report on the achieved proficiency level, based exclusively on the objective data gathered from correct and incorrect responses. This is illustrated by applying the model to the assessment of Dijkstra’s algorithm learning using a visual simulation-based graph algorithm learning environment, called GRAPHs.     

基于复杂网络拓扑结构的评估体系研究

对复杂网络拓扑结构中特定属性的计算和评估进行了研究。层次分析法和熵权法被用来计算复杂网络拓扑结构的权重,这样既可以防止在主观赋权法上因专家经验不足使得对方案的排序造成很大的随意性,又可以避免客观赋权法的结果与实际情况不一致的现象发生。选取了规则网络模型、随机网络模型、小世界网络模型和BA无标度网络模型进行加权计算,并计算出它们各自相应的综合权重。从综合权重的角度来看,实验结果表明,随机网络效能最好,接下来是小世界网络、无标度网络,最后是规则网络。该评估体系和算法可以被广泛地用于需要对网络性能进行定量评估的情况下。     

基于Perron-Frobenius特征值的传感器组网效能评估方法

随着当前各种类型的传感器不断涌现,将各类不同的传感器组网探测必将是今后的发展趋势,对传感器组网效能的分析自然成为重中之重。然而,当前对该问题的研究尚缺乏合适的网络模型和方法对其进行描述。基于此,构建了传感器网络环模型,并提出求取与该传感器网络相对应的邻接矩阵Perron—Frobenius特征值（PFE）的方法,同时通过算例分析了该传感器网络的组网效能,结果证明该方法结构明晰,简单可行,能较好的反映实际,适用于对各种传感器组网的网络化效能分析。     

A quantitative assessment of security risks based on a multifaceted classification approach

Information systems and cloud computing infrastructures are frequently exposed to various types of threats. Without detection and prevention mechanisms, the threats can materialize and cause different types of damages that usually lead to significant financial losses. The threats arise from a complex and multifaceted environment. Currently, organizations are struggling to identify the threats to their information assets and assess the overall damage they might inflict to their systems. In order to empower mangers to better plan for shielding their information systems, the paper presents two main contributions. First, a new approach to threat classification that leads to a security assessment model that is systematic, extendable, and modular. Second, a quantitative analysis of information systems based on the model.

     

Mechanics of masonry in compression: Results from a homogenisation approach

Despite considerable experimental and analytical research in the past, modern regulations still adopt very conservative simplified formulas for the compressive strength of masonry. The present paper contributes to the understanding of masonry under compression, using a novel non-linear homogenisation tool that includes the possibility of tensile and compressive progressive damage, both in the unit and mortar. The simplified homogenised model uses an iterative procedure and a few ingenious micro-deformation mechanisms, being able to accurately reproduce complex simulations carried out with non-linear continuum finite element analysis, at a marginal cost of CPU time and with no convergence difficulties. In addition, the comparison of the model with experimental results available in the literature indicates that an estimation of the compressive strength of masonry better than the one provided by the codes is possible, using the mechanical and geometrical properties of the masonry components.     

基于语言共识模型的电子商务信用风险评价方法

电子商务信用风险评价能够更好地维护市场规则并防范交易主体的合法权益.从语言评价信息的角度,利用多属性群决策方法对电子商务信用风险评价方法进行探讨.首先,提出个体语言共识测度和群体语言共识测度;然后,针对共识性水平较低的决策群体,构建一种整数规划模型,用于调整决策者给出的初始语言决策信息;最后,提出一种基于语言共识模型的...     

基于RIA的桥梁结构健康监测状态评估系统

针对在役大型桥梁承载、负荷压力不断加大带来的结构安全隐患,结合富互联网应用技术建立了桥梁结构健康监测、状态评估分析平台,对影响桥梁安全的主要参数进行在线监测、评估及预警,解决了传统Web技术呈现能力及交互性差的问题。从系统设计方面,详细介绍了系统功能模块和软件架构,并根据富互联网应用技术的富交互界面及数据绑定的特点,研究了自定义控件的实现和数据通信机制,最后提出了一种基于聚类的动态数据回归分析方法,有效解决了海量监测数据的处理问题。实验结果表明了该方法的实用性和有效性。     

On a numerical approach to shakedown analysis of structures

Two alternative ways of performing the shakedown analysis of structures subjected to variable repeated loads are presented. The first one enables one to check whether the structure shakes down (i.e. responds elastically after a few elastoplastic cycles) or not. Such a check is done by reproducing incrementally a critical cyclic load which corresponds to a cyclic repetition of piecewise-proportional load path that contains all the vertices of the variable load domain. The second approach enables one to find a safety factor for the limit of shakedown capability. The problem is one of convex or linear programming, depending on the kind of yield condition used. Numerical results presented in the paper show that the general purpose software that performs incremental elastoplastic calculations can be successfully used for shakedown analysis.     

The event bush as a semantic-based numerical approach to natural hazard assessment (exemplified by volcanology)

The event bush is a new formalism for organizing knowledge in various fields of geoscience, particularly suitable for hazard assessment purposes. Acting as an intermediary between expert knowledge and the well-established field of Bayesian belief networks, the event bush allows at the same time a variety of other applications, linking geoscientific knowledge to the field of artificial intelligence and uniting probabilistic, deterministic, and fuzzy approaches. In this paper, we present basic principles, mathematical formulation, guidelines for application, and examples, including the connection with Bayesian belief networks. Further development of the method will include spatial and temporal modelling, implementation in mapping in GIS medium, formalization by means of predicate logic, definition of variable states in BBNs by membership functions based on the event bush semantics, and other applications.     

Novel approach to development of direct volume rendering algorithms based on visualization quality assessment

A novel approach to the development of direct volume rendering algorithms is proposed. The approach is based on the assessment of the visualization quality. Analysis of rendering artifacts and various assessment methods is done using 3D reconstructed medical tomograms as test datasets. Analysis of the previous research on methods of 3D visualization quality assessment and quality improvement is presented. 3D visualization artifacts and quality measurement method (quantitative estimation) is proposed. The method does not require any ground truth image; hence, it is a universal approach to measure the quality of the 3D-reconstruction by any ray casting technique. The method is based on generation of the reference image as a mathematical expectation for a set of 3D visualizations obtained via the jittering technique. Start position of the rays are being shifted randomly towards their directions. To estimate the deviation of a pixel value from mathematical expectation, we use PSNR metrics, which is traditional metrics in signal and image processing and measures deviation in the decibel scale. The conditions of a proper use of the technique are discussed. A new virtual samplings method with preintegration is proposed to reduce sampling artifacts in the ray casting algorithm. The novelty of the method consists in using pre-integrated classification instead of post-classification in the virtual sampling method. A novel approach to 3D visualization algorithms development based on analysis of a ray casting method in quality-performance space is demonstrated by comparing the state-of-the-art ray casting methods and the proposed method. The comparative analysis revealed an advantage of the classical pre-integrated method in the case of using trilinear filtering without local shading. It also showed the advantage of the proposed virtual sampling method with pre-integration in the case of using tricubic filtering with local lighting.     

基于多层面生命周期评价方法的产品结构优化

一个企业或园区通常拥有大量的产品可供投资,有多种产品生产链可供选择,构成一个包含多种产品和产品链的产品体系结构。应用上篇论文提出的多层面生命周期评价方法,并结合过程系统的．优化技术,可以对这样的复杂产品体系结构进行优化,最终得出满意的产品决策。本文以有机硅产品为例,介绍该方法在产品结构优化中的应用。     

A virtual reality approach for usability assessment: case study on a wheelchair-mounted robot manipulator

The aim of the paper is to address an innovative methodology for assessing the usability of a product. This methodology is particularly suitable for designing products that provide their main functions through their control interfaces. In particular, this case study relates to the usability assessment of two control devices for a wheelchair-mounted robot manipulator to assist physically disabled people. The study focuses on defining a synthetic usability index on the basis of two currently used methods: the multi criteria decision analysis and the Saaty’s analytic hierarchy process. Several virtual reality (VR)-based experiments have been conducted, set up in accordance with a cross-array experimental plan, that adequately caters for both control and noise factors. Quantitative measures and subjective user evaluations have been collected to maximize the effectiveness, the efficiency and the satisfaction perceived by users while using the product. Compared to the literature on the subject, the proposed approach provides both more flexibility in defining quantitative indexes and more adequate results, even when involving only a small sample of users in the participatory design session. The use of VR technologies for the collection of the experimental data has been essential in terms of safety, costs and repeatability of the tests, as well as of the robustness with respect to noise factors.     

A new interval type-2 fuzzy approach for analyzing and monitoring the performance of megaprojects based on earned value analysis (with a case study)

Neural Computing and Applications - Major factors of project success include using tools of performance measurements and feedbacks. Earned value management (EVM) is a unique issue within...     

A novel context-aware recommender system based on a deep sequential learning approach (CReS)

Neural Computing and Applications - With an increase in online longitudinal users’ interactions, capturing users’ precise preferences and giving accurate recommendations have become an...     

基于证据推理和置信规则库的装备寿命评估

针对航天产品试验样本少,寿命评估难的特点,结合产品在研制阶段多种工作环境的失效数据,提出了一种基于证据推理(evidential reasoning,ER)和置信规则库(belief-rule-base,BRB)进行装备寿命评估的新方法.首先,分析了模型的合理性并使用多维BRB模型将多种环境下的寿命数据折合为标准工作环境下的寿命数据,然后通过ER算法将折合后数据和实际工作环境数据进行融合.其次,详细说明了BRB--ER模型的推理过程和寿命评估的步骤.最后,采用某航天产品的失效数据对该方法进行了验证,并用已有的产品寿命的固定值进行BRB的参数更新.研究结果表明,在专家知识准确合理时,该模型能够准确地评估产品寿命,并可根据已有的产品的固定寿命进行训练,建立更加准确的寿命预测模型.     

A case based reasoning approach on supplier selection in petroleum enterprises

Petroleum is an important strategic material which is connected with the vitals and safety of the national economy, and the supplier selections are related to the safety of petroleum production and supply. However, the traditional approaches for supplier selections are limited in subjective evaluation of weights, inaccurate assessing rules, and inefficient decision-making. Although most of the current methods are widely applied in corporation management, a more efficient approach needs to be proposed for supplier selection of oil enterprise.This paper summarizes the particular characteristics of the supply chain of Chinese petroleum enterprises, analyzes the limitations of the traditional methods of supplier selection, and brought forward the method based on case reasoning system (CBR) for petroleum enterprises. The method based on data mining techniques which solves three key problems of CBR, includes calculating the weights of the attributes with information entropy in case warehouse organizing process objectively, evaluating the similarities with k-prototype clustering between the original and target cases in case retrieving process exactly, and extracting the potential rules with back propagation neural networks from conclusions in maintenance and revising process efficiently. It demonstrates the advantages, practicability and validity of this method via case study finally.     

A novel approach to equipment health management based on auto-regressive hidden semi-Markov model （AR-HSMM）

As a new maintenance method, CBM （condition based maintenance） is becoming more and more important for the health management of complicated and costly equipment. A prerequisite to widespread deployment of CBM technology and prac- tice in industry is effective diagnostics and prognostics. Recently, a pattern recog- nition technique called HMM （hidden Markov model） was widely used in many fields. However, due to some unrealistic assumptions, diagnositic results from HMM were not so good, and it was difficult to use HMM directly for prognosis. By relaxing the unrealistic assumptions in HMM, this paper presents a novel approach to equip- ment health management based on auto-regressive hidden semi-Markov model （AR-HSMM）. Compared with HMM, AR-HSMM has three advantages： 1） It allows explicitly modeling the time duration of the hidden states and therefore is capable of prognosis. 2） It can relax observations＇ independence assumption by accom- modating a link between consecutive observations. 3） It does not follow the unre- alistic Markov chain＇s memoryless assumption and therefore provides more pow- erful modeling and analysis capability for real problems. To facilitate the computa- tion in the proposed AR-HSMM-based diagnostics and prognostics, new forward- backward variables are defined and a modified forward-backward algorithm is de- veloped. The evaluation of the proposed methodology was carried out through a real world application case study： health diagnosis and prognosis of hydraulic pumps in Caterpillar Inc. The testing results show that the proposed new approach based on AR-HSMM is effective and can provide useful support for the decision- making in equipment health management.     

An ERP system performance assessment model development based on the balanced scorecard approach

Previously completed research has not been significant when regarding the aspect of deriving a model for measuring the performance of an Enterprise Resource Planning (ERP) system. Therefore, this research attempts to present an objective and quantitative assessment model based on the Balance Scorecard approach for the purpose of appraising the performance of the ERP system. The methodology used in this research involves the Grounded Theory, Expert Questionnaire, the Analytic Hierarchy Process, and the Fuzzy Theory to filter out and develop the KPIs for the ERP system performance assessment model. It is expected that such a model may be used by enterprises to assess the efficiency of the ERP system during the various stages of management and support within the system. Finally, this assessment model is verified in a case company through the examination of its unbiased and quantifiable assessment approach. This result allows us to further understand authentic efficiency, and explore if enterprises have fulfilled their proposed objectives after the introduction of the ERP system.     

A random set approach to the optimization of uncertain structures

The single-objective optimization of structures, whose parameters are assigned as fuzzy numbers or fuzzy relations, is presented in this paper as a particular case of the random set theory and evidence theory approach to uncertainty. Some basic concepts concerning these theories are reviewed and the relationships among interval analysis, convex modeling, possibility theory and probability theory are pointed out. In this context a frequentistic view of fuzzy sets makes sense and it is possible to calculate bounds on the probability that the solution satisfies the constraints. Some special but useful cases illustrate in detail the meaning of the approach proposed and its links with a recent formulation conceived within the context of convex modeling. Some theorems allow a very efficient computational procedure to be set up in many real design situations. Two numerical examples illustrate the model presented.