Bayesian networks for student model engineering

Bayesian networks are graphical modeling tools that have been proven very powerful in a variety of application contexts. The purpose of this paper is to provide education practitioners with the background and examples needed to understand Bayesian networks and use them to design and implement student models. The student model is the key component of any adaptive tutoring system, as it stores all the information about the student (for example, knowledge, interest, learning styles, etc.) so the tutoring system can use this information to provide personalized instruction. Basic and advanced concepts and techniques are introduced and applied in the context of typical student modeling problems. A repertoire of models of varying complexity is discussed. To illustrate the proposed methodology a Bayesian Student Model for the Simplex algorithm is developed.     

通信网络在智能建筑中的应用研究

对智能建筑通信网络(IBN)进行了研究，重点分析了：智能建筑信息系统(IBIS)网络的集成以及将不同的建筑系统集成于一个框架内的标准协议的应用．而ISDN与ADSL被认为是实现IBN的合适平台。     

基于CAN总线的楼宇自动化照明网络设计

为了实现楼宇自动化中的灯光照明系统的网络设计,采用CAN总线协议实现各灯光节点的通信。硬件设计中,上位机节点使用PCI-CAN接口卡,各灯光节点主控制芯片使用PICl8F258,CAN收发器使用PCA82C250,并加入光耦隔离电路。同时对上位机节点及灯光节点进行软硬件设计,使各灯光节点能够实现相互之间的灵活通信,同时可实现调光、降低能耗等功能。经试验,该系统通信稳定,满足了基本的设计要求。     

利用UML建模设计指挥自动化软件系统

指挥自动化系统是C4ISR的重要组成部分，主要用于系统的指挥、控制和协调，指挥自动化应用系统的开发是一个复杂的软件工程，结合一个指挥自动化系统工程项目，利用统一建模语言(UML)来对该系统建模和设计，展示了UML在开发指挥自动化系统的运用，表明软件工程的方法可以有效地运用于指挥自动化系统的开发。     

Flow vs. time sampling for throughput performance evaluation

We introduce two throughput metrics referred to as flow- and time-sampled throughputs. The former gives the throughput statistics of an arbitrary flow while the latter weights these throughput statistics by the flow durations. Under fair sharing assumptions, the latter is shown to coincide with the steady-state instantaneous throughput weighted by the number of flows, which provides a useful means to measure and estimate it. We give some generic properties satisfied by both the metrics and illustrate their difference on a few examples.     

面向楼宇自动化的保安探测与自动化系统

阐述了面向楼宇自动化的保安自动化系统的控制功能、构成和多种保安探测方法 ,并给出了其应用实例     

Establishing a maturity model for design automation in sales-delivery processes of ETO products

Short delivery times are considered a competitive advantage in the engineer-to-order (ETO) sector. Design-related tasks contribute to a substantial amount of delivery times and costs since ETO products have to be either fully developed or adapted to customer specifications within tendering or order fulfillment. Approaches aiming at a computerised automation of tasks related to the design process, often termed design automation or knowledge-based engineering, are generally regarded as an effective means to achieve lead time and cost reductions while maintaining, or even improving product quality. In this study we propose a maturity model as a framework for analyzing and improving such activities in ETO companies. We contribute to the literature in being the first to investigate design automation in the ETO sector from a maturity perspective. Beyond that, we extend the extant literature on design automation, which is of a highly technical nature, by providing a framework considering organizational and managerial aspects. The findings indicate that five different levels of maturity can be achieved across the dimensions strategies, processes, systems, and people. Empirical cases give insight into these different levels. Our investigation draws from extant literature and a comparative case study involving four companies over two years.     

An accurate performance model for network-on-chip and multicomputer interconnection networks

In this paper, we present a mathematical background for a new approach for performances modeling of interconnection networks, based on analyzing the packet blocking and waiting time spent in each channel passing through all possible paths in the channel dependency graph. We have proposed a new, simple and very accurate analytical model for deterministic routing in wormhole networks, which is general in terms of the network topology and traffic distribution. An accurate calculation of the variance of the service time has been developed, which overcomes the rough approximation used, as a rule, in the existing models. The model supports two-dimensional mesh topologies, widely used in network-on-chip architectures, and multidimensional topologies, popular in multicomputer architectures. It is applicable even for irregular topologies and arbitrary application-specific traffic. Results obtained through simulation show that the model achieves a high degree of accuracy.     

Semantic BMS: Allowing usage of building automation data in facility benchmarking

Facility benchmarking and evaluation of facility performance are the crucial tasks in reaching efficient, economical and sustainable facility operation. Modern buildings are equipped with building automation systems (BAS) that contain vast numbers of various sensors that can be utilised in performance assessment. However, such systems lack convenient tools for data inspection, which limits their use in building performance and efficiency analysis and benchmarking especially on large sites. The paper presents a middleware layer designed to enrich BAS data with additional semantic information. As a semantic model, an adaptation of the Semantic Sensor Network (SSN) ontology for the field of building operation analysis is used. The middleware provides convenient interfaces for querying the model. The proposed system provides the facility managers with a convenient way to use the BAS data for benchmarking and decision support.     

Living labs as an opportunity for experiential learning in building engineering education

Building performance – spanning energy use, greenhouse gas emissions, indoor environmental quality, etc. – is fundamental to the field of building engineering, yet it is typically taught with idealistic assumptions and traditional, teacher-centred, lecture-based methods. A promising emerging approach for university-level building engineering education is experiential learning, whereby students actively engage in complex tasks with real building data that reflect the kinds of problems graduates are likely to encounter in the workplace. To bridge the academic and employability skills and knowledge that they are developing through these tasks, students participate in reflective activities that help them to articulate the relevance and implications of the experience for lifelong learning. The objective of this paper is to assess the teaching and learning effectiveness of a data- and information-centric experiential learning approach to university-level engineering education. This paper reflects upon a particular course-based initiative informed by experiential learning theory that engaged fourth-year students in the life cycle of a new building on a university campus that was equipped with state-of-the-art building controls technologies. Students were provided access to a living lab resource with diverse artefacts from the building: drawings and building information models, guest lectures and technical tours, and live/historic data for the building. A series of assignments provided students with simulated problem scenarios to solve through the application of the building data as well as reflection prompts about their problem-solving process. The present paper details the assignments and the nature of the living lab data, students’ assignment results, and students and teaching assistants’ feedback on the overall teaching approach. The findings indicate a significant and continuous improvement in the reception and perceived educational value of the experiential assignments over the four-month term, suggesting living labs are a promising source of educational material for experiential learning. The paper concludes with lessons learned from the current course about experiential learning in building engineering education that can be applied more broadly to future courses in the field.     

下一代电信网络性能监控系统设计

为了主动发现和跟踪解决电信网络服务质量问题,支持网络管理业务的平滑过渡,提出面向性能问题生命周期管理构建性能监控系统。参考下一代运营操作系统和软件,构建了端到端的性能问题生命周期管理流程和性能监控共享信息数据模型,设计了以组件为基础的系统结构。在运营商网络管理系统的基础上对系统进行实现和集成应用,应用表明,性能监控系统能有效支撑对性能问题的发现、分析和解决效果评估,并支持灵活的系统集成和持续的业务演进。     

Virtual engineering of cyber-physical automation systems: The case of control logic

Mastering the fusion of information and communication technologies with physical systems to cyber-physical automation systems is of main concern to engineers in the industrial automation domain. The engineering of these systems is challenging as their distributed nature and the heterogeneity of stakeholders and tools involved in their engineering contradict the need for the simultaneous engineering of their cyber and physical parts over their life cycle. This paper presents a novel approach based on the virtual engineering method, which provides support for the simultaneous engineering of the cyber and physical parts of automation systems. The approach extends and integrates the life cycle centered view mandated by current conceptual architectures and the digital twin paradigm with an integrated, iterative engineering method. The benefits of the approach are highlighted in a case study related to the engineering of the control logic of a cyber physical automation system originating from the process engineering domain. We describe for the first time a modular domain ontology, which formally describes the cyber and physical part of the system. We present cyber services built on top of the ontology layer, which allow to automatically verify different control logic types and simultaneously verify cyber and physical parts of the system in an incremental manner.     

Automatic model building and solving for optimization problems

Automatic modelling is one of the key topics in model base management in DSS. We consider the design and implementation of a system which automatically specifies an optimization model from an abstract form with a given set of data specified by a user and solves it by calling an appropriate solver. We implement our idea as a prototype in Prolog and illustrate its validity by simple examples.     

Effects of modes of cockpit automation on pilot performance and workload in a next generation flight concept of operation

The objective of this study was to compare the effects of various forms of advanced cockpit automation for flight planning on pilot performance and workload under a futuristic concept of operation. A lab experiment was conducted in which airline pilots flew simulated tailored arrivals to an airport using three modes of automation (MOAs), including a control‐display unit (CDU) to the aircraft flight management system, an enhanced CDU (CDU+), and a continuous descent approach (CDA) tool. The arrival scenario required replanning to avoid convective activity and was constrained by a minimum fuel requirement at the initial approach fix. The CDU and CDU+ modes allowed for point‐by‐point path planning or selection among multiple standard arrivals, respectively. The CDA mode completely automated the route replanning for pilots. It was expected that the higher‐level automation would significantly reduce pilot workload and improve overall flight performance. In general, results indicated that the MOAs influenced pilot performance and workload responses according to hypotheses. This study provides new knowledge about the relationship of cockpit automation and interface features with pilot performance and workload in a novel next generation–style flight concept of operation. © 2012 Wiley Periodicals, Inc.     

建筑结构模型的四边形网格生成算法

为提高建筑结构有限元分析计算的效率,提出建筑结构模型的四边形网格生成算法．首先采用改进的折半查找算法快速建立相应的结构模型索引信息;然后根据四边形网格划分的原则调整模型边界;最后采用分区域模板法对整体结构模型进行四边形网格的自动生成．算例表明该算法可以根据有限元分析计算中模型的特点简化模型,降低计算时间．     

Traffic engineering of MPLS backbone networks in the presence of heterogeneous streams

Heterogeneous streams (due to issues such as disparate traffic characteristics of each stream, or competing customers’ traffic) raise the issue of whether to multiplex (some of) these streams. In an MPLS network, such multiplexing can be considered by putting different streams into a tunnel identified by a single label-switched path (LSP), assuming that the different LSPs are assigned a reserved share of the resources. This issue becomes even more important in the traffic engineering of a backbone network when a decision needs to be made on which streams to multiplex when there are constraints on tunneling and capacity along with routing requirements for tunnels. In this paper, we introduce a distortion factor due to heterogeneous streams in traffic engineering of MPLS backbone networks in the presence of tunneling and capacity constraints by formulating a distortion-aware non-linear discrete optimization problem. Furthermore, we present a two-phase heuristic approach to solve this formulation efficiently. In the first phase, the problem is decoupled into two subproblems and in the second phase we show how the non-linear problem (for one of the subproblems) can be simplified. We then present numerical results for both small and large networks to show where and how our approach helps to determine when and which streams to multiplex depending on whether the tunneling and/or capacity constraint is dominant; furthermore, by comparing our distortion-aware traffic engineering model with a distortion-ignorant traffic engineering model, we show the benefits of our approach.     

分布式网络流量预测模型的精度研究

网络流量模型是网络性能评价、网络协议设计、网络规划等的基础。本文设计基于分布式网络测试的时间与相关流量模型的方法,并采用该流量模型预测网络流量。文章提出网络流量预测精度的数学定义,网络测试实验表明,我们的流量模型具有更高的精度,并适用实际运行的网络环境。     

A team building model for software engineering courses term projects

This paper proposes a new model for team building, which enables teachers to build coherent teams rapidly and fairly for the term projects of software engineering courses. Moreover, the model can also be used to build teams for any type of project, if the team member candidates are students, or if they are inexperienced on a certain subject. The proposed model takes students’ preferences and the teacher’s considerations into account when a team building process is required for any type of course. In addition, this paper investigates how team building models (RandomM: teams are built with randomly selected students; TeacherM: teacher selects the members for each team; StudentsM: students build their own teams and the proposed model) affect team performance and how gender differences affect project activities and team performance. A three-year (five semesters) teaching experiment was performed with the participation of 248 male and 79 female university students and a total of 67 software project teams. Two different One-way ANOVA tests were applied on the experimental data, and the results indicated that the proposed model was better than RandomM, TeacherM and StudentsM models in terms of project grades, and the effect of gender differences on the teams’ performance and project activities was negligible.     

基于IFC标准的BIM自适应分词方法

建筑信息模型(BIM)已经成为建筑行业信息技术应用的有效方案.随着BIM数据不断增长,为了高效使用BIM数据,很多研究将自然语言处理(NLP)引入BIM应用中.在中文环境中,由于缺乏建筑行业的术语特征,导致基础环节的中文分词在建筑领域BIM应用中的适应性较差.通过分析当前流行的BIM数据格式工业基础类(industry...     

Pilot performance and preference for short cycles of automation in adaptive function allocation

The present experiment examined pilot response to the rapid cycling of automation. The experiment was conducted using a multi-task simulation environment consisting of tracking, fuel management, and system monitoring sub-tasks. Monitoring and fuel management sub-tasks were performed manually in all conditions. The tracking sub-task cycled between manual and automated control at fixed intervals of either 15, 30 or 60 sec. These cycle times were completely crossed with three levels of tracking difficulty giving nine within-subject conditions which lasted 5 min each. Performance was measured on each of the sub-tasks, as was pilot fatigue level and subjective workload for the respective conditions. Results indicated that both difficulty and cycle duration significantly affected tracking performance which was degraded with task difficulty and longer cycle times. Fuel management and system monitoring performance were unaffected by tracking difficulty and automation duration. However, a subsequent analysis was conducted using the 15 sec period immediately following each automation episode as a ‘window’ of performance. A different pattern of results was observed. Tracking performance was similarly affected by difficulty, but was no longer affected by cycle duration. Furthermore, fuel management error indicated a trend toward better performance in low difficulty conditions. Results illustrate micro trade-offs within sub-tasks and macro trade-offs between sub-tasks. Overall, the results support the contention that excessively short cycles of automation prove disruptive to performance in multi-task conditions.