MHS: A distributed metadata management strategy

This paper proposes a novel distributed metadata management strategy to efficiently handle different metadata workloads. It can deliver high performance and scalable metadata service through four techniques, including directory conversion metadata, mimic hierarchical directory structure, flexible partition methods targeted different kinds of metadata of diverse characteristics, and the application of database to metadata backend. Using micro-benchmarks and a prototype system, we firstly demonstrate the performance superiority of our strategy compared to Lazy Hybrid, and then present the detailed performance results and analysis of our strategy on different MDS scales.     

Metagit: Decentralised metadata management with Git

Version control systems are used widely for tracking edits to data files, especially when working in teams with simultaneous editors. They track who made edits and when, and provide tools for comparing changes made and for resolving conflicts when the same file is edited by two people. Attaching metadata to files which stays with the data and tracking changes can be difficult if the file format does not support it. In this paper we present a new and innovative architecture for recording key-value metadata for objects in a revision control system, specifically Git. The utility and maturity of version control system tools make them a good candidate for a metadata store. We take advantage of Git's data store to permit the values to be blobs, opening up other possibilities such as defining thumbnails for files and folders. Propagation rules are presented, detailing when metadata follows a file after modifications to the repository. A prototype version of a tool is presented and the usefulness of the architecture is demonstrated with a number of examples. Adapting the approach to other systems such as Mercurial and Subversion is also discussed.     

Developing final as-built BIM model management system for owners during project closeout: A case study

To apply final as-built BIM models to facility management (FM) during the operation phase, it is important for owners to obtain an accurate, final as-built model from the general contractors (GCs) following project closeout. Confirming the accuracy of the final as-built BIM model is one of the most important works executed by owners to meet the accuracy requirement of final as-built models for FM. However, many practical problems arise relating to the management of final as-built models such as final as-built model mismatch, the lack of available final as-built models, and the entry of incorrect non-geometric information into the final as-built models. To solve these practical problems, this study develops a Final As-built BIM Model Management (FABMM) system for owners to handle final as-built BIM model inspection, modification, and confirmation (BMIMC) work beyond project closeout. The proposed approach and system can be used to manage the status and results of BMIMC management work for the final as-built BIM model to be performed. The proposed approach and system were applied in a case study in a selected building in Taiwan to verify and demonstrate its practical effectiveness. This study identifies the benefits, limitations, and conclusions of the FABMM system, and presents suggestions for its further application.     

Merging BIM and GIS using ontologies application to urban facility management in ACTIVe3D

This article presents the research work done in order to reduce the gap of heterogeneity between Geographic Information System and Building Information Models. The goal is to extend a platform dedicated to facility management called ACTIVe3D. We want to enlarge its scope to take into account the management of urban elements contained in the building environment, as well as other buildings. The particularity of the platform is that data can be accessed either by a semantic view or through a 3D interface. The SIGA3D project describes a set of processes that aims, for all the stakeholders of urban projects, to manage pieces of information through all the lifecycle of construction projects. To solve the heterogeneity problem between BIM and GIS, we developed a semantic extension to the BIM called UIM (Urban Information Modeling). This extension defines spatial, temporal and multi-representation concepts to build an extensible ontology. The knowledge database can be populated with information coming from standards like IFC and CityGML. This information system has been adapted and implemented into the existing platform and is today fully operational and used by thousands of users.     

Regia: a metadata editor for audiovisual documents

Although the Metadata Editor is an important part of any digital library, it becomes fundamental in the presence of audiovisual content. This is because the metadata produced by automated support tools (such as speech recognizers and shot detection procedures) is error-prone and often needs correction. In addition, scenes are manually annotated. This paper describes Regia, a prototype application for manually editing metadata for audiovisual documents developed in the ECHO project. Regia allows the user to manually edit textual metadata and to hierarchically organize the segmentation of the audiovisual content. An important feature of this metadata editor is that it is not hard-wired with a particular metadata attributes set. To achieve this feature the XML schema of the metadata model is used by the editor as a configuration file.

基于BIM与IoT数据的交互方法

为解决传统设备管理中物联网(IoT)动态数据的优化存储和高效调用,对物联网动态数据的存储和调用做深入研究,提出一个基于IoT数据的数据存储框架,有效存储大量物联网数据,集成结构化和非结构化数据。进一步结合BIM数字化技术开发一个面向建筑设备管理云平台,对如何使BIM数据和设备动态数据进行业务交互做详细的交互设计。以某净水厂泵房设备管理为案例,充分验证该研究方法的实用性和价值所在,优化传统设备管理方式的同时,提高了管理界面的友好交互性,使管理变得更加高效便捷。     

Automated facility inspection using robotics and BIM: A knowledge-driven approach

Facility inspection is crucial for ensuring the performance of built assets. A traditional inspection, characterized by humans’ physical presence, is laborious, time-consuming, and becomes difficult to implement because of travel restrictions amid the pandemic. This laborious practice can potentially be automated by emerging smart technologies such as robotics and building information model (BIM). However, little has been known on how such automation can be achieved, concerning the knowledge-intensive nature of facility inspection. To fill the gap, this research aims to develop a knowledge-driven approach that can synergize knowledge of diverse sources (e.g., explicit knowledge from BIM, and tacit experience in human minds) to allow autonomous implementation of facility inspection by robotic agents. At the core the approach is an integrated scene-task-agent (iSTA) model that formalizes engineering priori in facility management and integrates the rich contextual information from BIM. Experiments demonstrated the applicability of the approach, which can endow robots with autonomy and knowledge to navigate the challenging built environments and deliver facility inspection outcomes. The iSTA model is publicized online, in hope of further extension by the research community and practical deployment to enable automated facility inspection using robotics and BIM.     

空间数据存储对象的元数据可伸缩性管理*

基于空间数据面向对象存储思想和云存储可扩展架构,将控制信息集中在元数据服务器集群中管理,而实际的空间数据基于对象存储分布到存储设备集群中,实现控制信息路径与数据传输路径的分离,并缓存热点空间数据对象接口,以减少元数据访问次数和降低其服务器负载;基于对象存储设备的并行性和CDMI标准对元数据进行自上而下的功能分层管理,增...     

Optimal metadata replications and request balancing strategy on cloud data centers

In large-scale cloud data centers, metadata accesses will very likely become a severe performance bottleneck as metadata-based transactions account for over 50% of all file system operations. Clusters of Metadata Servers (MDS) that provide metadata searching service can improve the system performance significantly. For a data stored in cloud data centers, there may be several MDS storing the metadata replicas. Therefore, when a data request arrives, it has many potential metadata paths, one of which shall be chosen to obtain the best performance. In this paper, we attempt to determine the number of MDS that each data object in the system shall have and the request rates that each MDS shall serve, in order to achieve the minimum mean response time (MRT) of all the metadata requests. The target optimal constrained function has been formulated and a novel metadata request balancing algorithm based on request arrival rates has been proposed, which can find near-optimal solutions by a theoretical proof. In our experiments, we compare our algorithm with widely used hashing functions that have 0, 1, 2, 3 replicas, respectively. We validate our findings via simulations with respect to several influencing factors and prove that our proposed strategy is scalable, flexible and efficient for the real-life applications. Some interesting perspectives of the work are also presented at the end of this paper.     

Design and implementation of data abstraction definition facility

This paper describes the Implementation model of a data definition facility for abstract data types, implemented as an extension to PL/1. The facility is based on a modified version of the cluster mechanism for the implementation of types. The proposed version tries to address the issues of efficiency and portability in connection with the goal of systematic programming.     

数据网格中高效的元数据管理策略

在数据网格中,提出了采用完全分布方式、基于智能Cache和语义的元数据管理策略,在管理策略中设计一个元数据管理系统的体系结构SMICC.该体系结构引入了智能Cache和语义信息的方式来对元数据系统进行管理,减少远程访问时间和增加查询的准确度.SMICC可以利用智能Cache和语义信息处理不同的情况,可以根据本地可用的元数据进行查询的分解形成子查询,用户可以从本地Cache中获得元数据查询结果的一部分,剩下的部分可以从远程位置获得.通过语义信息和已有元数据,不仅可以使系统达到更好的扩展性和可用性,而且在保证用户访问质量的同时也提高了访问效率.     

基于元数据的地理空间数据管理

针对目前油田勘探开发工作中,积累的大量地理空间数据不能有效的进行存储,管理和共享这一问题,提出了基于元数据的地理空间数据管理.通过分析目前的元数据及管理,在借鉴其它元数据管理模型的基础上,提出了一个三层的地球物理元数据模型框架.通过基础元数据,属性元数据和实体元数据三层对信息进行管理,并对该模型进行了分析说明,给出了基于该模型的地震数据综合管理系统的总体方案以及元数据及元数据库的建设.     

Ontology-based facility data model for energy management

Context: Definition of a comprehensive facility data model is a prerequisite for providing more advanced energy management systems capable of tackling the underlying heterogeneity of complex infrastructures, thus providing more flexible data interpretation and event management, advanced communication and control system capabilities. Objective: This paper proposes one of the possible implementations of a facility data model utilizing the concept of ontology as part of the contemporary Semantic Web paradigm. Method: The proposed facility ontology model was defined and developed to model all the static knowledge (such as technical vendor data, proprietary data types, and communication protocols) related to the significant energy consumers of the target infrastructure. Furthermore, this paper describes the overall methodology and how the common semantics offered by the ontology were utilized to improve the interoperability and energy management of complex infrastructures. Initially, a core facility ontology, which represents the generic facility model providing the general concepts behind the modelling, was defined. Results: In order to develop a full-blown model of the specific facility infrastructure, Malpensa and Fiumicino airports in Italy were taken as a test-bed platform in order to develop the airport ontology owing to the variety of the technical systems installed at the site. For the development of the airport ontology, the core facility ontology was first extended and then populated to reflect the actual state of the target airport facility. Conclusion: The developed ontology was tested in the environment of the two pilots, and the proposed solution proved to be a valuable link between separate ICT systems involving equipment from various vendors, both on syntax and semantic level, thus offering the facility managers the ability to retrieve high-level information regarding the performance of significant energy consumers.     

Implementing a data definition facility driven by graph grammars

The implementation of a data definition facility based on graph transformations is discussed. The theory of graph grammars allows a precise characterization of these transformations, facilitating proofs of correctness.The implementation consists of an extension to PL/I, and utilizes the standard PL/I preprocessor.     

DDA — a data definition facility for unix using awk

We discuss how the Awk language is an effective tool for interrogating sequential data files whose records consist of characters grouped into fields. This facility is used to implement a system to manage an ‘address book’ database. We then generalize the design, describing a system which allows one to interactively specify a DBMS according to one's own requirements within our general framework. We choose a wine-tasting DBMS as an example specification for further consideration and evaluation.     

基于BIM的幕墙管理系统的研究和开发

针对传统建筑行业在设计、施工以及运营维护阶段存在的生产效率低下、施工周期长、维护成本高、重复工作等问题,运用BIM具有的数据共享、方便协调管理等优点,设计和开发了基于BIM的幕墙管理信息系统。该系统实现了备料管理、进度管理、系统设置等功能模块,提高了建筑信息的集成化和信息的共享,为相关的建筑利益方提供了一个信息共享与交换的平台。     

Automatic personalized video abstraction for sports videos using metadata

Video abstraction is defined as creating a video abstract which includes only important information in the original video streams. There are two general types of video abstracts, namely the dynamic and static ones. The dynamic video abstract is a 3-dimensional representation created by temporally arranging important scenes while the static video abstract is a 2-dimensional representation created by spatially arranging only keyframes of important scenes. In this paper, we propose a unified method of automatically creating these two types of video abstracts considering the semantic content targeting especially on broadcasted sports videos. For both types of video abstracts, the proposed method firstly determines the significance of scenes. A play scene, which corresponds to a play, is considered as a scene unit of sports videos, and the significance of every play scene is determined based on the play ranks, the time the play occurred, and the number of replays. This information is extracted from the metadata, which describes the semantic content of videos and enables us to consider not only the types of plays but also their influence on the game. In addition, user’s preferences are considered to personalize the video abstracts. For dynamic video abstracts, we propose three approaches for selecting the play scenes of the highest significance: the basic criterion, the greedy criterion, and the play-cut criterion. For static video abstracts, we also propose an effective display style where a user can easily access target scenes from a list of keyframes by tracing the tree structures of sports games. We experimentally verified the effectiveness of our method by comparing our results with man-made video abstracts as well as by conducting questionnaires.

Information Quality Assessment for Facility Management

Assessing the quality of building information models (BIMs) is an important yet challenging task within the construction industry as projects are increasingly being delivered with BIM. This is particularly essential for facility management (FM) users as downstream information consumers that depend on the quality of models developed in the previous project phases. The research presented in this paper addresses this challenge by introducing a framework for information quality assessment (IQA) of BIMs for FM uses. The IQA framework is the outcome of an extensive study of two large owner organizations involving numerous BIM projects. The framework is structured based on the essential FM subjects: assets, spaces, and systems, and the model characteristics: objects, attributes, relationships, and spatial information. The framework is then operationalized through the development and evaluation of information quality (IQ) tests using BIM model checking tools across three projects with different levels of detail and complexity. The proposed IQA framework and associated tests advance the state of knowledge about BIM quality in terms of methods to represent and evaluate conformance to owner requirements.     

A trigram hidden Markov model for metadata extraction from heterogeneous references

Our objective was to explore an efficient and accurate extraction of metadata such as author, title and institution from heterogeneous references, using hidden Markov models (HMMs). The major contributions of the research were the (i) development of a trigram, full second order hidden Markov model with more priority to words emitted in transitions to the same state, with a corresponding new Viterbi algorithm (ii) introduction of a new smoothing technique for transition probabilities and (iii) proposal of a modification of back-off shrinkage technique for emission probabilities. The effect of the size of data set on the training procedure was also measured. Comparisons were made with other related works and the model was evaluated with three different data sets. The results showed overall accuracy, precision, recall and F1 measure of over 95% suggesting that the method outperforms other related methods in the task of metadata extraction from references.     

Automated BIM data validation integrating open-standard schema with visual programming language

A building design must comply with a wide spectrum of requirements stipulated by building codes, normative standards, owner’s specifications, industry’s guidelines, and project requirements. The current rule-based compliance checking practice is a costly bottleneck in a building project, and thus, there is a demand for a design evaluation process that incorporates automated checking capabilities to address the inefficiency and the error-prone nature of the current manual checking practice. The inherent complexity of building design rules and impracticability of existing automated checking approaches are two key challenges that must be addressed to enable practical compliance checking automation. This research study proposes a new modularized framework that integrates the emerging open standard, LegalRuleML, with a Visual Programming Language. The framework allows a standardized method of defining design rules in a machine-readable and executable format. The proposed approach encompasses the entire compliance checking process from the interpretation of natural language-based requirements to machine-readable rules, rule categorization, rule parameterization, and the execution of the rules on the ISO-standard building information model. This modularized BIM-based design validation framework is expected to help automatically and iteratively evaluate the level of quality and defects of information conveyed in a given building model as an essential part of the early design process.