Effective digital collaboration in the construction industry – A case study of BIM deployment in a hospital construction project

Building information modeling (BIM) and related digital innovations can serve as a catalyst for more transparency, tighter integration, and increased productivity in the architecture, engineering, and construction industry. Yet, many project teams struggle with how to work based on the new technology. Collaborative design based on shared information systems like BIM requires changing traditional and institutionalized work practices and routines. A case study of integrated BIM design in a large healthcare construction project serves as an example for how commonly experienced challenges can be overcome. The project has been awarded BuildingSMART's 2015 award for ‘outstanding open BIM practice’ making it Norway's role model for BIM practice. Based on diffusion of innovations theory, we identified the following set of key factors enabling digital collaboration in this project: change agents, new roles and responsibilities, a cloud computing infrastructure, BIM contracts, and a BIM learning environment. The findings presented in this article may serve as an example for BIM implementation and collaborative work in construction projects.     

Formalized knowledge of construction sequencing for visual monitoring of work-in-progress via incomplete point clouds and low-LoD 4D BIMs

Over the last few years, new methods that detect construction progress deviations by comparing laser scanning or image-based point clouds with 4D BIM are developed. To create complete as-built models, these methods require the visual sensors to have proper line-of-sight and field-of-view to building elements. For reporting progress deviations, they also require Building Information Modeling (BIM) and schedule Work-Breakdown-Structure (WBS) with high Level of Development (LoD). While certain logics behind sequences of construction activities can augment 4D BIM with lower LoDs to support making inferences about states of progress under limited visibility, their application in visual monitoring systems has not been explored. To address these limitations, this paper formalizes an ontology that models construction sequencing rationale such as physical relationships among components. It also presents a classification mechanism that integrates this ontology with BIM to infer states of progress for partially and fully occluded components. The ontology and classification mechanism are validated using a Charrette test and by presenting their application together with BIM and as-built data on real-world projects. The results demonstrate the effectiveness and generality of the proposed ontology. It also illustrates how the classification mechanism augments 4D BIM at lower LoDs and WBS to enable visual progress assessment for partially and fully occluded BIM elements and provide detailed operational-level progress information.     

Information modeling of earthquake-damaged reinforced concrete structures

Accurate and reliable information about buildings can greatly improve post-earthquake responses, such as search and rescue, repair and recovery. Building Information Modeling (BIM), rapid scanning and other assessment technologies offer the opportunity not only to retrieve as-built information but also to compile as-damaged models. This research proposes an information model to facilitate the data flow for post-earthquake assessment of reinforced concrete structures. The schema development was based on typical damage modes and the existing Industry Foundation Class (IFC) schema. Two examples of damaged structures from recent earthquake events, compiled using an experimental damage modeling software, illustrate the use of the data model. The model introduces two new classes, one to represent segments of building elements and the other to model the relationships between segments and cracks. A unique feature is the ability to model the process of damage with a binary tree structure. Methods for exporting as-damaged instance models using IFC are also discussed.     

基于区域信息的水平集模型

水平集模型在对具有细长拓扑结构和弱边界的核磁共振图像分割时得不到真实解,针对这一问题,提出一种新的基于区域信息的水平集分割模型.首先运用形态学方法预估计初始背景,采用差分算法提取最终背景,原始图像与背景图像作减法得到含有待分割目标的图像,定义一个新的相似度以及基于相似度信息的水平集速度函数取代传统水平集的速度函数.结果表明这种方法具有很好的分割效果.     

Construction-specific spatial information reasoning in Building Information Models

In recent years, there have been significant advances in modeling technology for object-oriented building products. However, the building models are still lacking of providing construction-specific spatial information required for construction planning. Consequently, construction planners visually analyze building product models and derive geometric characteristics such as bounded spaces and exterior perimeter to develop detailed construction plans. Such a process presents fragmented information flows, from building product information to construction planning, that rely on subjective decisions of construction planners. In order to overcome these drawbacks, this research proposes a geometric reasoning system that analyzes geometric information in building designs, derives the construction-specific spatial information, and uses the information to assist in construction planning. The scope of presented work includes detecting work packages formed by faces during construction, such as large work faces and bounded spaces, and using information in the work packages directly to support planning of selected indoor construction activities. The main features of the proposed system named Construction Spatial Information Reasoner (CSIR) include a set of relationship acquisition algorithms, building component relationship data structure, and interpretation of the relationship to support detailed construction activity planning. The relationship acquisition algorithms identify adjacency between building components that is stored in the relational data structure. Then, acquired adjacency relationships are transformed into a set of graphs that represent work packages. To implement the proposed approach, CSIR utilized a commercially-available Building Information Modeling (BIM) platform and the algorithms were imbedded to the BIM platform. For validation, CSIR was tested on a real commercial building. For interior ceiling grid installation activities, CSIR successfully detected existing work packages and analyzed the spatial characteristics impacting construction productivity. The major contribution of the presented research would be to enable a realistic analysis of building geometric condition that is not possible in current BIM and a seamless information flow from building product information to construction process plans. These can potentially reduce current manual and error-prone construction planning processes. Limitations and future research suggestions are also presented.     

State of the art in damage information modeling for RC bridges – A literature review

In Germany, bridges have an average age of 40 years. A bridge consumes between 0.4% and 2% of its construction cost per year over its entire life cycle. This means that up to 80% of the construction cost are additionally needed for operation, inspection, maintenance, and destruction. Current practices rely either on paper-based inspections or on abstract specialist software. Every application in the inspection and maintenance sector uses its own data model for structures, inspections, defects, and maintenance. Due to this, data and properties have to be transferred manually, otherwise a converter is necessary for every data exchange between two applications. To overcome this issue, an adequate model standard for inspections, damage, and maintenance is necessary. Modern 3D models may serve as a single source of truth, which has been suggested in the Building Information Modeling (BIM) concept. Further, these models offer a clear visualization of the built infrastructure, and improve not only the planning and construction phases, but also the operation phase of construction projects. BIM is established mostly in the Architecture, Engineering, and Construction (AEC) sector to plan and construct new buildings. Currently, BIM does not cover the whole life cycle of a building, especially not inspection and maintenance. Creating damage models needs the building model first, because a defect is dependent on the building component, its properties and material. Hence, a building information model is necessary to obtain meaningful conclusions from damage information. This paper analyzes the requirements, which arise from practice, and the research that has been done in modeling damage and related information for bridges. With a look at damage categories and use cases related to inspection and maintenance, scientific literature is discussed and synthesized. Finally, research gaps and needs are identified and discussed.     

Graph-based retrieval of building information models for supporting the early design stages

Building information modeling (BIM) principles are transforming today’s communication and working processes in the field of construction, however the early design phases are only rarely supported and information technology is therefore not exploited to its full potential. The early design phases are characterized by an iterative process of searching for plausible solutions. A common approach is to refer to similar examples, which are conventionally found using keyword-based search strategies.To this end we propose a method for indexing spatial configurations along with a sketch-based input method for search strategies that uses so-called semantic fingerprints of buildings. The topology of spatial configurations is extracted from building information models and represented as graphs. For both building information models and the user sketches, the extracted graphs are used as the basis for a subgraph-matching algorithm facilitating an intuitive novel query method for researching similar reference examples. The system is able to present corresponding existing solutions to even rudimentary sketches or fragments of a design idea. In addition to graph matching and sketch-based interaction, more recent BIM-based approaches are also taken into account.     

Level-of-detail for cognitive real-time characters

We present a solution for the real-time simulation of artificial environments containing cognitive and hierarchically organized agents at constant rendering framerates. We introduce a level-of-detail concept to behavioral modeling, where agents populating the world can be both reactive and proactive. The disposable time per rendered frame for behavioral simulation is variable and determines the complexity of the presented behavior. A special scheduling algorithm distributes this time to the agents depending on their level-of-detail such that visible and nearby agents get more time than invisible or distant agents. This allows for smooth transitions between reactive and proactive behavior. The time available per agent influences the proactive behavior, which becomes more sophisticated because it can spend time anticipating future situations. Additionally, we exploit the use of hierarchies within groups of agents that allow for different levels of control. We show that our approach is well-suited for simulating environments with up to several hundred agents with reasonable response times and the behavior adapts to the current viewpoint.     

浅谈金融业信息系统等级保护工作的常态化简

近年来,信息系统信息安全等级保护制度已成为我国一项基本国策,如何持续地做好将信息系统等级保护工作,提高自身信息系统安全防御能力,已成为金融机构必须关注的问题。本文主要结合人民银行实际的信息安全管理工作,对单位开展信息安全等级保护工作的情况进行了分析,并就如何实现信息系统等级保护工作常态化提出了几点想法。     

3DGIS大地形建模分析

与二维GIS相比,3DGIS对客观世界的表达能给人以更真实的感觉,它以立体造型技术给用户展现地理空间现象,而大地形建建模又是3DGIS研究的一项重要内容,所以如果能够很好地解决大地形建模问题,将会使3DGIS的研究更加深入.在详细分析了地形模型数据库的结构和建模两个方面存在的主要问题之后,以空间数据库查询的优化方法以及开发软件支持的纹理数据格式要求对大地形建模进行了优化分析,并以一个实例说明了采用上述两方面优化后,对于模型数据量的影响很大,所建模型相对占用资源较少,且可以满足不同层次显示要求,从而较好地解决了3DGIS研究中大地形模型海量数据的处理问题.     

基于功能驱动的实体关联方法

系统开发中的信息建模方法实质都可以看作是针对系统功能的实体之间的关联分析,无论是结构化方法使用的E—R图建模,还是面向对象方法使用的UML建模。分析了传统的实体关联法在信息建模方面的优势以及缺陷,提出了基于功能驱动的实体关联方法的思路和模型,并进而论述了基于功能驱动的实体关联方法实现多种信息建模方法一体化的可能。