70 research outputs found
Virtual graphic representation of construction equipment for developing a 3D earthwork BIM
BIM provides a visualization of the construction design that allows a construction manager to review the construction process and the information that is associated with the progress. BIM is usually applied to modeling strucÂtural objects with parametric geometry where the sequence of process can be predefined. However, BIM technology can also be applied to objects with irregular shape where parametric modeling is not possible such as earthwork topography based on TIN (Triangular Irregular Network).The objective of this research is to develop a 3D earthwork BIM methodÂology and provide a graphic simulation that is capable of assisting construction equipment operators during excavation work. The 3D earthwork BIM presents a modeling technique that involves integrating hardware and software technoloÂgies. This combination of technologies is used to represent the actual excavator configuration in a 3D virtual environÂment. When it is applied to actual excavation work, it was proved that the 3D earthwork BIM could synchronize the virtual excavator configuration with the actual excavator configuration during excavation work in real time
Prototyping a remotely-controlled machine for concrete surface grinding operations
The surface of concrete pavement needs to be flattened for the smoothness and comfortability of highways. Surface grinding can provide flatness in the hardened concrete surface, and improve adhesion between the existing conÂcrete surface and the subsequent layer. The surface grinding process, however, is executed under hazardous work condiÂtions and the outcome is affected by a machine operator’s skill. Automation of this process can provide a hazard-free work environment and increase the quality of the ground surface. This paper presents an application of an automated concrete surface grinding machine that an operator can remotely control with computer assistance. A combination of hardware and software technologies was applied to prototype automated functions of the machine. Field tests demonÂstrated that remote control of concrete surface grinding is feasible and can be utilized as a semi-automated scheme on actual construction sites.
First published online:Â 23 Jun 201
A Study on the Transportation Logistics System for the Economic Development of North Korea
What Should Be Considered when Developing ICT-Integrated Classroom Models for a Developing Country?
This study aims to identify factors to be considered when developing Information and Communication Technology (ICT)-integrated classroom models and to suggest a conceptual framework for considering more appropriate classroom models, tailored to the environments and needs of each developing country. In-depth interviews were conducted with experts, yielding many factors to be taken into account when integrating ICT in various educational contexts of developing countries. The factors are categorized into five domains: current status and relevant policies in ICT education, ODA (Official Development Assistance) goals and priority setting, infrastructure and technical challenges, pedagogical methods, and educational resources. Based on the recommendations elicited for the five categories, we suggest a conceptual framework that provides practical guidance on the criteria for selecting classroom models suited to each partner country’s environments and contexts. This study also draws implications from the interviews for classroom design guidelines related to hardware and infrastructure, to improve the sustainability of ICT-integrated classroom projects
Optimization of a redundantly actuated 5R symmetrical parallel mechanism based on structural stiffness
COMPLEX COEXISTENCE BEHAVIOR OF STRUCTURE I AND H HYDRATES
13C NMR spectroscopic analysis was carried out to clarify the formed hydrate structure in specific conditions on hydrate phase diagram of ternary methane, neohexane, and water system. The obtained NMR spectra at three different conditions suggested that both structure I and H were formed simultaneously and coexisted at 273.6 K and 50 bar. But, for both conditions of 273.6 K, 25 bar and 283.1 K, 50 bar the formed hydrate was identified as structure H only. These results showed that the pure CH4 hydrate of structure I was formed and coexisted with mixed CH4+neohexane hydrate of structure H in low temperature and high pressure region after passing through the phase boundary of pure CH4 hydrate. We have examined the structure coexistence at 273.6 K and 50 bar with other structure H formers of isopentane, methylcyclopentane, and methylcyclohexane. In case of isopentane, the obtained NMR spectrum showed that structure I and H coexisted and the amount of methane molecules in structure I was two times as many as in cages of structure H. However, there were no resonance lines of structure I when methylcyclohexane formed structure H with methane molecules.Non UBCUnreviewe
Development and Assessment of an Intelligent Compaction System for Compaction Quality Monitoring, Assurance, and Management
The successful quality control and quality assurance of compaction operations are vital for the long-term performance of earth structures. Traditional in situ measurement methods are in practice for assessing compaction project specifications. These methods have several shortcomings and cannot provide complete compaction quality information. With the advancement in automation and information technology in the construction section, intelligent compaction roller technology has the potential to solve this problem. However, this technology still has many problems and needs more comprehensive studies for its implementation. This study focuses on the development of a Web-GIS-based intelligent compaction system and the assessment of the practical application of this technology. The developed system consists of major components—namely, system hardware and software—to provide real-time compaction information and an effective management system. An experimental study was conducted to assess the correlation between the developed system’s compaction quality and traditional measurement methods. The linear regression analysis identifies the strong correlation and promises the feasibility of an intelligent compaction system instead of a traditional in situ test for compaction quality control. Two implementation case studies of real-time projects are presented to validate and demonstrate the practicality of the developed system
Recommended from our members
Cross-Section Designs for the Safety Performance of Buffer-Separated High-Occupancy Vehicle (HOV) lanes
High-occupancy vehicle (HOV) lanes have been deployed as a tool for traffic management in urban freeway systems to improve reliability and mobility of trips. As they are planned to traverse crowded urban areas, it is often difficult to acquire sufficient right-of-way for retrofitting HOV lanes to existing freeway systems with recommended cross-sectional design. The present study proposes a methodology to determine the optimal set of cross-sectional design for safety performance by evaluating individual impact of each design element on safety as well as tradeoffs between them. Detailed collision data of concurrent-flow buffer-separated HOV lanes along with their geometric features and traffic flow data were analyzed to estimate collision predictive models for HOV and the adjacent general purpose lanes by injury types. These models were used to determine the set of cross-sectional design elements that minimizes the expected collision occurrences. As a case study, a real freeway corridor where converting continuous to buffer-separated types was underway was selected to demonstrate the applicability of the proposed method. This case study shows that the method can assist to determine cross-section design of HOV facilities for safety based on currently available geometric space
- …