Social Network Analysis

We explore the effect of dimensionality on the nearest neighbor problem. We show that under a broad set of conditions (much broader than independent and identically distributed dimensions), as dimensionality increases, the distance to the nearest data point approaches the distance to the farthest data point. To provide a practical perspective, we present empirical results on both real and synthetic data sets that demonstrate that this effect can occur for as few as 10-15 dimensions. These results should not be interpreted to mean that high-dimensional indexing is never meaningful; we illustrate this point by identifying some high-dimensional workloads for which this effect does not occur. However, our results do emphasize that the methodology used almost universally in the database literature to evaluate high-dimensional indexing techniques is flawed, and should be modified. In particular, most such techniques proposed in the literature are not evaluated versus simple linear scan, and are evaluated over workloads for which nearest neighbor is not meaningful. Often, even the reported experiments, when analyzed carefully, show that linear scan would outperform the techniques being proposed on the workloads studied in high (10-15) dimensionality!.

When is nearest neighbor meaningful

https://publikationen.bibliothek.kit.edu/1000039918/3024499

Building Information Modeling (BIM) for existing buildings — Literature review and future needs

The project benefits of Building Information Modelling (BIM)

Facilities management (FM) encompasses and requires multidisciplinary activities, and thus has extensive information requirements. While some of these needs are addressed by several existing FM information systems, building information modeling (BIM), which is becoming widely adopted by the construction industry, holds undeveloped possibilities for providing and supporting FM practices with its functionalities of visualization, analysis, control, and so on. This paper explores how BIM can be a beneficial platform for supplementing FM practices. An online survey and face-to-face interviews were conducted to assess the current status of BIM implementations in FM, potential applications, and the level of interest in the utilization of BIM. Interactions between BIM and FM are defined by illustrating application areas and data requirements for BIM-enabled FM practices. Highlighting the synergy between the two, this paper can help professionals recognize potential areas in which BIM can be useful in FM practices.

Application Areas and Data Requirements for BIM-Enabled Facilities Management

There is a great need in the construction industry for identifying a set of common indicators to be used by construction executive and project managers in measuring construction performance at the project level. The focus of this research was to collect management perceptions of the key performance indicators currently utilized in the construction industry. Both quantitative performance indicators and qualitative performance indicators are represented. A literature search was used to generate the initial set of perceived key performance indicators, which were administered to the construction industry via a survey. A statistical analysis of the collected survey responses provided information for the identification of a common set of perceived Key Performance Indicators (KPIs) by construction sector, management level, and experience level. Correlations were performed for both the quantitative and qualitative indicators to determine which type of indicator is used most extensively. Basic statistical analyses...

Management’s Perception of Key Performance Indicators for Construction

The use of building information modeling (BIM) has provided a means of increasing total project quality, providing accurate quantity take-offs, and improving scheduling, consequently diminishing total project contingencies and costs. Although BIM is a recent development, a lot of research has been conducted in order to further enhance the capabilities of BIM in design and construction. However, there has been very little research done so far on the effect that BIM has on sustainable construction practices. Hence, the goal of this research is to investigate the perceptions of the use of BIM for sustainable design and construction among designers and constructors. A survey was developed and administered through the Internet to determine the existing trends of BIM application in general as well as its use as a tool in sustainable design and construction. The survey results indicated that although the majority of the respondents believed that sustainable design and construction practices were of impor...

Building Information Modeling in Support of Sustainable Design and Construction

The recent emergence of building information modeling (BIM) and the evolution of virtual design and construction (VDC) in the architecture, engineering, and construction (AEC) industry are fundamentally changing the process by which buildings are designed and constructed. However, the perceived high initial cost of implementing BIM has deterred many industry professionals from adopting this technology. This paper aims to facilitate the decision-making process in the adoption of BIM by presenting the cost savings associated with implementing BIM. In many cases, an owner’s willingness to pay for the BIM is crucial in the contractor’s decision to use BIM. Therefore, in order to show the returns on the investment (ROI) of paying additional fees, data was gathered from three case studies on three sets of similar projects, with each set consisting of one recently constructed BIM-assisted project and one earlier, similar project completed without BIM. The potential savings to an owner choosing to invest ...

Return on Investment Analysis of Using Building Information Modeling in Construction

SUMMARY: The increased interest in using Building Information Modeling (BIM) in detailed construction cost estimates calls for methodologies to evaluate the effectiveness of BIM-Assisted Detailed Estimating (BADE) tools in generating detailed construction cost estimates. The focus of this study is on developing a quantified evaluation method to measure the impact of these BADE tools. Further, in order to understand the cognitive details of the estimator, this study also tested and evaluated the impact of the visualization factor and the compound impact of the visualization factor and aggregated calculation factor on the construction cost-estimating process. Two types of BADE tools were tested in this study in order to differentiate the impact of the visualization factor on estimating performance from the compounded impact of both visualization and aggregation functions. A set of test cases with different levels of estimate complexity was designed and tested on entry-level estimators using both traditional manual estimating and BADE approaches. Results obtained from the test cases at several complexity levels helped to reinforce the reliability of the observations and the evaluation. Four parameters were used to evaluate the performance results individually in the first step: generality, flexibility, efficiency, and accuracy. Then a multiattribute utility model, which took into account the four individual parameters, was developed and used to evaluate the overall performance of BIM-assisted estimating versus the performance of the traditional estimating method on quantity takeoffs. The study concluded that the BIM-assisted estimate demonstrated better performance over traditional estimating methods for the entry-level user. Both the visualization and aggregation functions of the BADE tool had significant impact on the performance of the detailed estimate. The study further indicated that the more complex the estimating tasks, the clearer the advantages were of using BADE tools instead of traditional estimating methods. The limitations of the test cases and the test subjects will affect the extrapolation of the conclusions of this research to the broad construction industry. Further study on industry-level cases and subjects is needed to obtain more conclusive findings.

/pdf/quantitative-evaluation-of-the-bim-assisted-construction-30uoflbt8x.pdf

Quantitative evaluation of the bim-assisted construction detailed cost estimates

SUMMARY: This research assessed perceptions about the impact of the implementation of Building Information Modeling (BIM) on construction projects through data collection in three surveys. Survey questions centered on impact with respect to six primary construction key performance indicators (KPIs) commonly used in the construction industry as accepted metrics for assessing job performance. These include: quality control (rework), on-time completion, cost, safety (lost man-hours), dollars/unit (square feet) performed, and units (square feet) per man hour. Qualitative data was collected through a survey instrument intended to assess practitioners’ perceptions about BIM impacts on the six Key Performance Indicators. The first survey was targeted at National Institute of Building Sciences (NIBS) Facility Information Council (FIC) National BIM Standard (NBIMS) committee members. The survey results indicated that the respondents felt that a BIM-based approach improves construction metrics compared to construction without BIM. Specifically, the highest three ranking KPIs in order of most favorable responses were quality, on time completion, and units per man hour. The second tier of favorable responses included overall cost and cost per unit.

/pdf/evaluating-industry-perceptions-of-building-information-4ko57dkx0m.pdf

Raja R. A. Issa

Papers

Management’s Perception of Key Performance Indicators for Construction

Building Information Modeling in Support of Sustainable Design and Construction

Return on Investment Analysis of Using Building Information Modeling in Construction

Quantitative evaluation of the bim-assisted construction detailed cost estimates

Evaluating industry perceptions of building information modelling (BIM) impact on construction