Automated construction for human–robot interaction in wooden buildings: Integrated robotic construction and digital design of iSMART wooden arches

Robotic construction is a powerful means of addressing labor shortages, low productivity, and low sustainability in the construction industry. Even though construction robots have attracted attention in research and practice, in a market condition where the technology and industry scale of the construction industry is yet unable to meet the scale of full automation, human–robot interaction (HRI) is a more adaptable working model. It is crucial to change the level of automation to the level of cooperation. This paper proposes an HRI construction method that aims to provide a new idea for existing robotic construction research, which combines the advantages of manual construction and automated robotic construction. This construction method allows an inexperienced layman to quickly complete the construction of complex timber structures with the assistance of a robot. Furthermore, this automated construction method's advantages, limitations, and potential pitfalls and the environmental, economic, and social sustainability aspects of design, production, and construction are also considered, providing a technical reference for the sustainable development of China's construction industry.     

Invariants for the computation of intransitive and transitive Galois groups

One hard step in the computation of Galois groups by Stauduhar’s method is the construction of relative invariants. In this note, a representation-theoretic approach is given for the construction in the case of an intransitive group.In the second part of the article, it is shown that the construction can be used for groups that have a suitable intransitive subgroup. The construction solves an open question of Fieker and Klüners.     

Morley’s theorem revisited: Origami construction and automated proof

Morley’s theorem states that for any triangle, the intersections of its adjacent angle trisectors form an equilateral triangle. The construction of Morley’s triangle by the straightedge and compass method is impossible because of the well-known impossibility result for angle trisection. However, by origami, the construction of an angle trisector is possible, and hence that of Morley’s triangle. In this paper we present a computational origami construction of Morley’s triangle and an automated correctness proof of the generalized Morley’s theorem.During the computational origami construction, geometrical constraints in symbolic representation are generated and accumulated. Those constraints are then transformed into algebraic forms, i.e. a set of polynomials, which in turn are used to prove the correctness of the construction. The automated proof is based on the Gröbner bases method. The timings of the experiments of the Gröbner bases computations for our proofs are given. They vary greatly depending on the origami construction methods, the algorithms for the Gröbner bases computation, and variable orderings.     

Towards a unifying domain model of construction safety,health and well-being: SafeConDM

Specific occupational construction safety, health, and well-being related knowledge and information are scattered and fragmented. Despite technological advancements of information and knowledge management, a link between safety management and information models is still missing. In this paper we present first steps towards a unifying formal (logic-based) domain model of construction safety, called SafeConDM, that consists of: (1) a semantically rich ontology of hazard, safety concepts, and concept relationships that builds on, and integrates with, existing construction safety ontologies and building information models; (2) a set of first-order if-then rules linking construction site states with the potential for specific hazards to occur that we define in a novel way using spatial artefacts. We present a prototype software tool, based on our ASP4BIM tool that implements SafeConDM for construction hazard analysis and safe construction planning decision support, and empirically evaluate our tool on three real-world construction building models.     

A methodology to quantitatively evaluate the safety of a glazing robot

A new construction method using robots is spreading widely among construction sites in order to overcome labour shortages and frequent construction accidents. Along with economical efficiency, safety is a very important factor for evaluating the use of construction robots in construction sites. However, the quantitative evaluation of safety is difficult compared with that of economical efficiency. In this study, we suggested a safety evaluation methodology by defining the ‘worker’ and ‘work conditions’ as two risk factors, defining the ‘worker’ factor as posture load and the ‘work conditions’ factor as the work environment and the risk exposure time. The posture load evaluation reflects the risk of musculoskeletal disorders which can be caused by work posture and the risk of accidents which can be caused by reduced concentration. We evaluated the risk factors that may cause various accidents such as falling, colliding, capsizing, and squeezing in work environments, and evaluated the operational risk by considering worker exposure time to risky work environments. With the results of the evaluations for each factor, we calculated the general operational risk and deduced the improvement ratio in operational safety by introducing a construction robot. To verify these results, we compared the safety of the existing human manual labour and the proposed robotic labour construction methods for manipulating large glass panels.     

基于风险预警管控的“透明工程”平台构建与应用

为应对水利工程建设领域监管的新形势、新任务和新要求，解决当前大体量水利工程建设管理过程中日趋突出的“盯不牢”“看不穿”“督不了”难题，立足水利工程建设全生命周期，以问题为导向，针对监管过程中风险易发、高发的环节和事项，基于风险预警和闭环管控的总体思路，协同融合行业内外建管数据资源，建立水利工程建设大数据监督平台——“透明工程”。通过平台内置的预警规则和管控模型，动态研判存在的风险，实时发布预警，创新实现水利行业监管和公权力监督的耦合贯通。目前平台已投入实际应用，可在一定程度上有效提升水利工程建设管理水平和监管效能，推进水利工程建设的大数据监督，为水利工程建设监督管理提供良好的借鉴意义。     

多模态深度神经网络的固废对象分割

目的 对城市发展过程中产生的建筑固废进行处理,并将之转换为资源和能源,是极佳的保护环境的经济发展模式。然而人工分拣处理存在效率低、污染严重、对人身危害大等问题。目前工业界在探索一种有效的基于机械臂自动抓取的建筑固废自动分拣系统,其中图像分割技术是非常必要的一个环节。但是工业现场的环境因素造成固废对象的颜色严重退化,会影响最终的固废对象分割。本文针对建筑固废图像分割难度大的现状,提出一种基于多模态深度神经网络的方法来解决固废对象分割问题。方法 首先, 在颜色退化严重的场景下,把RGB图像和深度图一起作为深度卷积神经网络的输入,利用深度卷积神经网络进行高维特征学习,通过softmax分类器获得每个像素的标签分配概率。其次,基于新的能量函数建立全连接条件随机场,通过最小化能量函数寻找全局最优解来分割图像,从而为每一类固废对象产生一个独立的分割块。最后,利用局部轮廓信息计算深度梯度,实现同一类别的不同实例的固废对象精确分割。结果 在固废图像测试集上,该方法取得了90.02%均像素精度和89.03%均交并比（MIOU）。此外,与目前一些优秀的语义分割算法相比,也表现出了优越性。结论 本文方法能够对每一个固废对象同时进行有效的分割和分类,为建筑垃圾自动分拣系统提供准确的固废对象轮廓和类别信息,从而方便实现机械臂的自动抓取。     

A new efficient optimistic fair exchange protocol without random oracles

Optimistic fair exchange (OFE) is a kind of protocols to solve the problem of fair exchange between two parties. Most of the previous work on this topic are provably secure in the random oracle model. In this work, we propose a new construction of OFE from another cryptographic primitive, called time capsule signature. The construction is efficient and brings almost no overhead other than the primitive itself. The security of our new construction is based on that of the underlying primitive without relying on the random oracle heuristic. Applying our generic construction to the time capsule signature scheme recently proposed by Libert and Quisquater, we obtain a new concrete and efficient OFE construction secure based on Computational Diffie–Hellman assumption in the standard model.     

北大港水库数字孪生建设方案与要点探讨

为提升北大港水库工程管理现代化与智慧化水平，结合北大港水库“数字河库”建设现状和水库扩容工程规划，提出北大港水库数字孪生建设方案，搭建数字孪生工程建设总体框架与主要内容，丰富 L2 和 L3 级数据底板， 构建模型库和知识库，实现建设期和运维期的智能应用建设。对安全监测数据底板、工程安全模型等数字孪生建设难点，以及实现“四大安全”与全过程、全要素管理等进行探讨。实现北大港水库流域防洪调度、水资源管理与调配，以及其他各项业务管理的数字化、网络化、智能化水平提升，有效推进水库运营管理数字化转型和智能化升级。     

试析LOFT建筑

城市是人类休养生息的场所,是人类发展缩影的象征;而建筑则是城市的灵魂,每个时期的建筑都是当代文化的缩影。然而,大千世界,事物都会生老病死;建筑也不例外。老建筑作为一方文化的缩影,发展趋式成为当前城市建设的重点所在。本文通过对LOFT起源、表现形式的分析,探讨了LOFT建筑的特点,并展望了其发展前景。     

VR-Electricians: Immersive storytelling for attracting students to the electrical construction industry

Although it is projected to have significant employment growth in the electrical construction industry, there are not enough young people to join the workforce. It is indispensable for the future of work in construction to explore emerging technologies and effectively attract the younger generation to the construction industry. This paper explores the innovative use of 360-degree immersive environments powered by virtual electricians to tell success stories of the electrical construction trades on the field (VR-Electricians) and understand how such an immersive storytelling approach can attract young people to join the industry. A pretest-posttest design was used for the VR-Electricians assessment. VR-Electricians was found to significantly enhance several aspects of students’ attitude towards the electrical construction industry. VR-Electricians was also rated as a highly usable and easy-to-use system. The outcomes of this study provide construction researchers and practitioners an understanding of how immersive storytelling can be used as a powerful technology-mediated method for attracting students to their field.     

On the space–time of optimal, approximate and streaming algorithms for synopsis construction problems

Synopses construction algorithms have been found to be of interest in query optimization, approximate query answering and mining, and over the last few years several good synopsis construction algorithms have been proposed. These algorithms have mostly focused on the running time of the synopsis construction vis-a-vis the synopsis quality. However the space complexity of synopsis construction algorithms has not been investigated as thoroughly. Many of the optimum synopsis construction algorithms are expensive in space. For some of these algorithms the space required to construct the synopsis is significantly larger than the space required to store the input. These algorithms rely on the fact that they require a smaller “working space” and most of the data can be resident on disc. The large space complexity of synopsis construction algorithms is a handicap in several scenarios. In the case of streaming algorithms, space is a fundamental constraint. In case of offline optimal or approximate algorithms, a better space complexity often makes these algorithms much more attractive by allowing them to run in main memory and not use disc, or alternately allows us to scale to significantly larger problems without running out of space. In this paper, we propose a simple and general technique that reduces space complexity of synopsis construction algorithms. As a consequence we show that the notion of “working space” proposed in these contexts is redundant. This technique can be easily applied to many existing algorithms for synopsis construction problems. We demonstrate the performance benefits of our proposal through experiments on real-life and synthetic data. We believe that our algorithm also generalizes to a broader range of dynamic programs beyond synopsis construction. Sudipto Guha’s research supported in part by an Alfred P. Sloan Research Fellowship and by NSF Awards CCF-0430376, CCF-0644119.A preliminary version of the paper appeared as “Space efficiency in synopsis construction algorithms”, VLDB Conference 2005, Trondheim, [19].     

GRAMY: A Geometry Theorem Prover Capable of Construction

This study investigates a procedure for proving arithmetic-free Euclidean geometry theorems that involve construction. Construction means drawing additional geometric elements in the problem figure. Some geometry theorems require construction as a part of the proof. The basic idea of our construction procedure is to add only elements required for applying a postulate that has a consequence that unifies with a goal to be proven. In other words, construction is made only if it supports backward application of a postulate. Our major finding is that our proof procedure is semi-complete and useful in practice. In particular, an empirical evaluation showed that our theorem prover, GRAMY, solves all arithmetic-free construction problems from a sample of school textbooks and 86% of the arithmetic-free construction problems solved by preceding studies of automated geometry theorem proving.     

基于大数据的工程机械远程监控系统研究

面对信息化时代的到来,数据已海量出现在各个领域,为了有效解决工程机械建设上大数据问题并实现信息的有效推送,文中提出的工程机械GPS远程智能监控系统,将利用GIS、GPS、GPRS等相关技术,构造一个开放性的平台系统,以便于工程机械设备的监管。该平台大大提高了工程机械的管理水平,优化了机械化施工组织。同时,为工程机械行业提供机械设备防盗、抢,设备业主对设备的远程监控等有关的信息增值功能,以实现工程机械的远程监控管理,从而大大提高了工程机械的信息化水平,也进一步提高了我国工程机械产品的国际竞争力,加快了我国工程机械的信息化进程。     

Manifold-based surfaces with boundaries

We present a manifold-based surface construction extending the C^∞ construction of Ying and Zorin (2004). Our surfaces allow for piecewise-smooth boundaries and have an improved derivative and visual behavior. Their degree of smoothness can be controlled by the user. Two-flexibility of our surface construction is confirmed numerically for a range of local mesh configurations.     

Efficient construction of bounding volume hierarchies into a complete octree for ray tracing

This paper proposes an efficient construction scheme for bounding volume hierarchies based on a complete tree. This construction offers up to 4× faster construction times than binned‐surface area heuristic and offers competitive ray traversal performance. The construction is fully parallelized on x86 CPU architectures; it takes advantage of the eight‐wide vector units and exploits the advance vector extensions available for current x86 CPU architectures. Additionally, this work presents a clustering algorithm for grouping primitives, which can be computed in linear time O(n). Furthermore, this construction uses the graphics processing unit to perform intensive operations efficiently. Copyright © 2016 John Wiley & Sons, Ltd.     

基于几何控制的公路施工智能监控系统设计

为了更好地保证公路施工质量,保障施工人员的生命财产安全,建设平安和谐社会,为广大群众提供一个便利、舒适、安全地空间,需要对公路施工监控系统进行设计;当前的公路施工监控系统设计方法是利用图像处理板对其进行监控,监控过程中图像处理板的体积太大,没有设置隐蔽性屏障,导致监控盲点多,存在监控整体性能低,监控系统效果差的问题;为此,提出一种基于几何控制的公路施工智能监控系统设计方法;该方法首先确定公路施工监控类型,并对公路施工监控系统进行构造,然后以公路施工监控系统的构造为基础,利用编码感知路由,将各个终端监控的数据信息传输至监控系统中心,最后采用蛇形时隙数据存储算法将公路施工终端的监控信息数据全部存储,由此完成对公路施工的智能监控的系统设计;实验结果证明,所提方法可以对公路施工进行全方位,安全可靠地智能监控,减少了突发事件发生处理时间和监控盲点,增加了公路施工速度,更大程度地保障了施工人员的人身安全,为该领域的研究发展提供了强有力的依据。     

Stochastic Subsets for BVH Construction

BVH construction is a critical component of real-time and interactive ray-tracing systems. However, BVH construction can be both compute and bandwidth intensive, especially when a large degree of dynamic geometry is present. Different build algorithms vary substantially in the traversal performance that they produce, making high quality construction algorithms desirable. However, high quality algorithms, such as top-down construction, are typically more expensive, limiting their benefit in real-time and interactive contexts. One particular challenge of high quality top-down construction algorithms is that the large working set at the top of the tree can make constructing these levels bandwidth-intensive, due to O(nlog(n)) complexity, limited cache locality, and less dense compute at these levels. To address this limitation, we propose a novel stochastic approach to GPU BVH construction that selects a representative subset to build the upper levels of the tree. As a second pass, the remaining primitives are clustered around the BVH leaves and further processed into a complete BVH. We show that our novel approach significantly reduces the construction time of top-down GPU BVH builders by a factor up to 1.8×, while achieving competitive rendering performance in most cases, and exceeding the performance in others.     

面向对象模板的特色建筑造型

根据特色建筑物的构建特点,提出了一种基于面向对象模板的建模方法。从建筑学的角度分析特色建筑营造规则并引入模板思想,在对比了其与面向对象思想的相通之处后提出了“基模板－结构模板－实例化模板”架构,然后给出了面向对象模板的建模方法,最后以塔为例,快速构建并渲染出真实感较强的特色建筑的三维模型。     

Negotiation in a multi-agent system for construction claims negotiation

Negotiation is an important approach for agents to co-operate and reach agreement in multiagent systems (MAS). Different negotiation theories and models have been deployed in a variety of applications. This paper is concerned with the applicability of these theories to the domain of agent-based construction claims negotiation. The peculiarities of this domain are highlighted and the approach adopted in the development of a multi-agent system for construction claims negotiation (MASCOT) described. Of particular interest is the integration of Zeuthen's bargaining model with a Bayesian learning mechanism, which addresses the characeristics of the construction claims negotiation. Examples are presented to demonstrate the impact of various negotiation approaches on the conduct and outcome of construction claims negotiations.