Using Virtual Reality in Construction Education by Incorporating BIM

Students in practical majors like construction management face several challenges in understanding theoretical concepts. Building Information Modeling (BIM) is a digital modeling tool used to present physical buildings and structures that can be used to develop an accurate representation of the work environment, including the performance limitations of structures and building elements. Construction engineering education and training (CEET) can provide opportunities by incorporating BIM models to apply technical and theoretical insights and details into the intended construction activities. Virtual reality (VR) is a powerful visualization tool for the student to understand space and the performance of structural elements. The purpose of this analysis is to define an efficient educational tool by integrating VR application and BIM model information to develop 3D, 4D, and 5D simulations that dramatically improve students\u27 preparation for a career in construction management. Implications for education system coordinators, researchers, and students are presented

Design principles for riboswitch function

Scientific and technological advances that enable the tuning of integrated regulatory components to match network and system requirements are critical to reliably control the function of biological systems. RNA provides a promising building block for the construction of tunable regulatory components based on its rich regulatory capacity and our current understanding of the sequence–function relationship. One prominent example of RNA-based regulatory components is riboswitches, genetic elements that mediate ligand control of gene expression through diverse regulatory mechanisms. While characterization of natural and synthetic riboswitches has revealed that riboswitch function can be modulated through sequence alteration, no quantitative frameworks exist to investigate or guide riboswitch tuning. Here, we combined mathematical modeling and experimental approaches to investigate the relationship between riboswitch function and performance. Model results demonstrated that the competition between reversible and irreversible rate constants dictates performance for different regulatory mechanisms. We also found that practical system restrictions, such as an upper limit on ligand concentration, can significantly alter the requirements for riboswitch performance, necessitating alternative tuning strategies. Previous experimental data for natural and synthetic riboswitches as well as experiments conducted in this work support model predictions. From our results, we developed a set of general design principles for synthetic riboswitches. Our results also provide a foundation from which to investigate how natural riboswitches are tuned to meet systems-level regulatory demands

Airborne Directional Networking: Topology Control Protocol Design

This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture attributes for the purpose of qualifying protocol design elements

Recent Advances in Seismic Design of Geosynthetically-Lined Waste Containment Facilities

Geosynthetic materials are essential elements of almost all modern landfill barrier systems. Materials such as geomembranes and geosynthetic clay liners are widely used as resistive barrier elements while geotextiles, drainage nets, and geocomposites are widely employed in modern composite barrier systems for both landfill liners and covers. The ability of these geosynthetic elements to maintain their integrity when subject to deformations due to waste settlement and seismic loading is a major uncertainty with respect to the performance of modern landfills. Over past years, advances have been made in understanding of material behavior under cyclic loading, modeling of modern landfill response to strong ground shaking, and interpretation of the analysis results. This paper presents, by reference, results of relevant recent research including advances in evaluation of dynamic material properties of municipal solid waste (MSW) and special wastes, dynamic testing of barrier system interfaces, understanding of decoupled and fully coupled response analysis, and advances in constitutive and numerical modeling relevant to better modeling of seismic response of modern landfills. Based upon the synthesis of this information, it is concluded that the commonly used decoupled approach is reasonably conservative and can be used for seismic design of modern waste containment facilities until fully coupled approach and associated evaluation and modeling of interface parameters evolve to be usable from both the practical and economic points of view

THE EFFECT OF INTERNAL STATIC MANUFACTURING COMPLEXITY ON MANUFACTURING PERFORMANCE

Manufacturing systems are complex. They consist of many interrelated subsystems and elements. This study investigates the effect on performance due to the complexity resulting from system design, i.e. internal static manufacturing complexity. The quantitative measure, ISMC, consisting of eight measurable complexity elements is proposed. This new measure of complexity was then tested with another existing measure of internal static manufacturing complexity proposed by Frizelle and Woodcock (1995). A large set of simulation experiments, each modeling a general batch-type manufacturing system, was employed to test the effects of the overall complexity measure, ISMC, and the eight individual elements on five measures of manufacturing performance. The experimental design included two levels for each of the eight static complexity elements and two levels for the environmental variable, due date tightness. The results indicated that neither the proposed measure, ISMC, nor the prior Frizelle and Woodcock\u27s measure demonstrate a practical level of predictive validity. Three of the eight individual components making up ISMC were correlated to manufacturing performance. These were the breadth of the product structures, the depth of the product structures, and the number of different end-products in a manufacturing system

Finite Element Modeling of Masonry Infill Walls Equipped with Structural Fuse

Masonry infill walls in multi-story buildings are intended to function as envelope and partition walls, and without sufficient gaps between the infill and the frame, the infill tends to contribute to lateral seismic load resistance, which can lead to damage. By isolating the infill walls from the frame, vulnerability to damage will be reduced; however, the potential benefit from the strength and stiffness of the infill walls will be lost too. The compromise solution seems to be a controlled engagement of the masonry infill walls by employing a structural fuse concept. In this chapter, initially, a review of the literature on seismic performance of masonry infill walls is presented. This is then followed by explanation of the concept of the masonry infill structural fuse. Then a discussion on experimental tests carried out on different types of fuse elements as well as ¼ scale specimen of frame and infill walls with fuse elements is presented. Finally, the results of finite element computer modeling studies are discussed. The study has found that the concept of using structural fuse elements as sacrificial components in masonry construction is practical and can be given consideration for more refined design and detailing toward practical application

Realizations of Space Mapping based neuromodels of microwave components

Artificial Neural Networks (ANN) are suitable in modeling high-dimensional and highly nonlinear elements, such as those found in the microwave arena. In modeling microwave components, the learning data is obtained from a detailed or “fine” model (typically an EM simulator), which is accurate but slow to evaluate. This is aggravated because simulations are needed for many combinations of input parameter values. This is the main drawback of conventional ANN modeling. We use available equivalent circuits or “coarse” models to overcome this limitation. In the Space Mapping (SM) based neuromodeling techniques an ANN is used to implement a suitable mapping from the fine to the coarse input space. The implicit knowledge in the coarse model not only allows us to decrease significantly the number of learning points needed, but also to reduce the complexity of the ANN and to improve the generalization performance. We present novel realizations of SM based neuromodels of practical passive components using commercial software. An SM-based neuromodel of a microstrip right angle bend is developed using NeuroModeler, and entered into HP ADS as a library component through an ADS plug-in module.Consejo Nacional de Ciencia y TecnologíaCom DevNSER

Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities

Recently there has been a flurry of research on the use of reconfigurable intelligent surfaces (RIS) in wireless networks to create smart radio environments. In a smart radio environment, surfaces are capable of manipulating the propagation of incident electromagnetic waves in a programmable manner to actively alter the channel realization, which turns the wireless channel into a controllable system block that can be optimized to improve overall system performance. In this article, we provide a tutorial overview of reconfigurable intelligent surfaces (RIS) for wireless communications. We describe the working principles of reconfigurable intelligent surfaces (RIS) and elaborate on different candidate implementations using metasurfaces and reflectarrays. We discuss the channel models suitable for both implementations and examine the feasibility of obtaining accurate channel estimates. Furthermore, we discuss the aspects that differentiate RIS optimization from precoding for traditional MIMO arrays highlighting both the arising challenges and the potential opportunities associated with this emerging technology. Finally, we present numerical results to illustrate the power of an RIS in shaping the key properties of a MIMO channel.Comment: to appear in the IEEE Transactions on Cognitive Communications and Networking (TCCN