Smart work packaging-enabled constraint-free path re-planning for tower crane in prefabricated products assembly process

Lack of constraint-free crane path planning is one of the critical concerns in the dynamic on-site assembly process of prefabrication housing production (PHP). For decades, researchers and practitioners have endeavored to improve both the efficiency and safety of crane path planning from either static environment or re-planning the path when colliding with constraints or periodically updating the path in the dynamic environment. However, there is a lack of approach related to the in-depth exploration of the nature of dynamic constraints so as to assist the crane operators in making adaptive path re-planning decisions by categorizing and prioritizing constraints. To address this issue, this study develops the smart work packaging (SWP)-enabled constraints optimization service. This service embraces the core characteristics of SWP, including adaptivity, sociability, and autonomy to achieve autonomous initial path planning, networked constraints classification, and adaptive decisions on path re-planning. This service is simulated and verified in the BIM environment, and it is found that SWP-enabled constraints optimization service can generate the constraint-free path when it is necessary.     

基于开源技术的城市地理信息平台构建方法研究

摘 要：针对城市地理信息平台构建过程中存在的数据获取困难、研发成本较高等问题， 引入开源技术，对基于开源数据、开源开发平台与开源工具的城市地理信息平台构建技术进行 研究。所提出的城市地理信息平台由数据模块与可视化模块 2 部分组成。为构建数据模块，由 开源地理信息项目(OSM)获取了建筑与区划数据，并设计了建筑合并算法以提升数据质量。建 筑数据随之基于行政区划分级存储，通过由 ASP. NET 构建的数据接口提供给具体应用。可视 化模块则基于开源地理信息系统(GIS)项目 Cesium 实现，并设计了完善的用户界面。以北京市 为例，完成了原型系统的开发与测试，证实了该技术体系的可行性，通过开源技术降低平台研 发成本，推进城市地理信息平台的研究与应用。     

基于灾度辨识的钢闸门巡视检查研究

巡视检查是对钢闸门要点部位开展定期、定点的信息收集,并对警兆信息做出快速辨识和评估的重要内容。应用灾度辨识的警兆信息评估方法,综合钢闸门巡视检查的各类要素信息,明确工程最大隶属的灾度等级(Ⅰ～Ⅴ级),可作为工程日常巡视检查决策的重要软技术手段。     

Teaching construction sciences with the integration of BIM to undergraduate architecture students

This study aims to test two hypotheses: teaching building information modeling (BIM) in relation to construction science provides students with a remarkable understanding of the nature of construction science (Hypothesis 1), and if the student has positive attitude toward the use of the BIM program, then efficiency by which construction science is taught by its means is improved (Hypothesis 2). Results and process of a case study with a novel teaching methodology were discussed in terms of the benefits of the students. A questionnaire study was conducted on the student group with which the case study was performed to test each student's attitude. Results were evaluated statistically. When BIM is integrated with the teaching of basic construction courses within architecture degree programs, the students understood the building system principles simply and effectively. As a result of the statistical analysis, the students find the applied method effective. Moreover, their attitude toward BIM affects the process.     

Self-activated persistent luminescence from Ba2Zr2Si3O12 for information storage

Till now, many doped persistent luminescence (PersL) phosphors have been investigated and found various applications in such as bioimaging, photocatalysis and information storage, but introducing PersL emitters into a proper host is mostly complex. In this research, a self-activated PersL phosphor Ba₂Zr₂Si₃O₁₂ (BZSO) is prepared by solid state reaction. By adding NH₄Cl, the self-activated PersL intensity is evidently enhanced. The trap depths and concentrations are examined by thermoluminescence spectra. Meanwhile, Bi³⁺ ions are introduced into BZSO and show wide band photoluminescence (PL) from 300 to 600 nm. Moreover, the PL of Bi³⁺ is tunable under excitation by 265-350 nm lights. Furthermore, as a proof-of-concept design, we designed a patterned quick response (QR) code based on the self-activated PersL of BZSO, and the information of “South China University of Technology (SCUT)” can be read out by the code scanning technology. Bi³⁺-doped BZSO phosphors are suggested to provide potential applications in information storage by its self-activated PersL, and to excite researchers to study the tunable PL in Bi³⁺-doped phosphor.     

一种调度遥控操作双路径安全校核机制的探索

为解决调度端远方操作路径单一情况下可能出现操作错误的问题,文章探索提出一种对远方操作进行双路径安全确认的构建方案,在常规遥控发起路径之外建立独立的操作许可路径,在操作业务通信的出口处部署操作许可安全网关、操作许可工作站,通过操作发起路径的操作员、监护人和操作许可路径的许可员相结合的多重校验,强化对遥控操作的合法性认证,可以有效避免操作人、操作员站、操作网络环境的不可靠因素带来的操作安全风险,提高电网操作的安全性。     

High Accuracy Network Cardinalities Estimation by Step Sampling Revision on GPU

Host cardinality estimation is an important research field in network management and network security. The host cardinality estimation algorithm based on the linear estimator array is a common method. Existing algorithms do not take memory footprint into account when selecting the number of estimators used by each host. This paper analyzes the relationship between memory occupancy and estimation accuracy and compares the effects of different parameters on algorithm accuracy. The cardinality estimating algorithm is a kind of random algorithm, and there is a deviation between the estimated results and the actual cardinalities. The deviation is affected by some systematical factors, such as the random parameters inherent in linear estimator and the random functions used to map a host to different linear estimators. These random factors cannot be reduced by merging multiple estimators, and existing algorithms cannot remove the deviation caused by such factors. In this paper, we regard the estimation deviation as a random variable and proposed a sampling method, recorded as the linear estimator array step sampling algorithm (L2S), to reduce the influence of the random deviation. L2S improves the accuracy of the estimated cardinalities by evaluating and remove the expected value of random deviation. The cardinality estimation algorithm based on the estimator array is a computationally intensive algorithm, which takes a lot of time when processing high-speed network data in a serial environment. To solve this problem, a method is proposed to port the cardinality estimating algorithm based on the estimator array to the Graphics Processing Unit (GPU). Experiments on real-world highspeed network traffic show that L2S can reduce the absolute bias by more than 22% on average, and the extra time is less than 61 milliseconds on average.     

物联网发展中的安全风险及对策研究

分析了国内外物联网安全政策、技术、标准、产业等形势,重点强调了当前我国物联网发展中存在的安全风险,包括大连接环境下的设备风险、物联网网络本身安全风险以及物联网上承载的各类应用安全风险,提出了打造以密码为核心的物联网安全体系,加速新技术在物联网安全的应用,以新基建为契机建立物联网领域安全设备泛在化部署新体系,以多层次立体式理念确保物联网安全,呼吁供给侧需求侧建立安全协同新机制,共同促进物联网产业安全可持续发展。     

基于BIM技术和有限元的检测与分析在PC结构中的应用研究

本文建立了PC结构施工全过程的BIM模型及有限元分析模型,对施工过程进行数值模拟与动态、静态监测,对装配式结构进行了结构性能评价,为结构可视化施工监测提供了技术支持。     

浅谈高校图书馆资源共享

随着社会的发展，信息和文化资源大多来自于图书和网络，而高校图书馆有着丰富的藏书和网络资源，因此，高校图书馆网络资源的共建共享就是科学文化发展的必然结果。那么如何实现网络资源的共建共享，网络资源的共建共享又存在哪些问题，又该如何解决，本文在这里就简单的浅谈一下高校图书馆的资源共享。