Engineering Commons^™

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Evaluate Students’ Learning Effectiveness Of Hvac System Using 3d Game Animation, Lalitha Devi Nandam

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

An important skill required for students in Construction Engineering and Architecture is to understand what the major components are and how the whole system and its components function. Students typically learn to understand HVAC equipment by reviewing two-dimensional (2D) CAD drawings, images and site visits. With latest developments in 3D game engines for facilitating interactive learning, it is now possible for students to experience three-dimensional (3D) environments of HVAC systems. While this technology is still at an early stage in learning application, it has the potential to significantly enhance the capability of students to study, comprehend and gain experience designing …

Airborne Infection In Healthcare Environments: Implications To Hospital Corridor Design, Ehsan Mousavi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Several studies have linked nosocomial transmission airborne diseases to airflow in healthcare settings. Quasi-experimental methods are developed to observe the aerodynamic transport behavior of synthetic respiratory particles in corridors of a hospital. Computational models, validated by experimental results, are then developed to explore the spatial relationships of supply-exhaust air ventilation in patient corridors. The aim of this study is to determine optimal HVAC design strategies to contain and remove airborne contaminants in healthcare environments.

In addition to occupant comfort, hospital HVAC systems are designed to provide ventilation and directional airflow to contain, dilute and remove contaminants including airborne disease. Of …

Estimation Of Optimal Productivity In Labor-Intensive Construction Operations, Krishna Prasad Kisi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

In an attempt to evaluate the efficiency of labor-intensive construction operations, project managers typically compare actual with historical productivity for equivalent operations. However, this approach toward examining productivity only provides a relative benchmark for efficiency and may lead to the characterization of operations as objectively efficient when in reality such operations might simply be comparably efficient.

Optimal productivity is the highest sustainable productivity achievable under good management and typical field conditions. Optimal productivity is useful in the determination of the absolute efficiency of construction operations because an accurate estimate of optimal labor productivity allows for the comparison of actual vs. …

A Framework For Estimating Labor Productivity Frontiers, Nirajan Mani

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

The efficiency of construction operations is typically determined by comparing actual versus historical productivity. This practice is accurate if historical data reflects optimal values. Otherwise, this comparison is a gauge of relative rather than absolute efficiency. Therefore, in order to determine absolute efficiency, one must compare actual versus optimal productivity. Optimal productivity is the highest sustainable productivity level achievable under “good management” and “typical field conditions,” while the productivity frontier is the theoretical maximum achievable under “perfect conditions.”

The productivity frontier is an abstraction useful in the estimation of optimal productivity of construction operations. This research contributes to the body …

Assessing Gait And Postural Stability Of Construction Workers Using Wearable Wireless Sensor Networks, Houtan Jebelli

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Falling accidents are a leading cause of fatal and nonfatal injuries in the construction industry. This fact demonstrates the need for a comprehensive fall-risk analysis that incorporates the effects of construction workers’ physiological characteristics. In this context, the objective of the thesis is to investigate and validate the usefulness of the gait- and postural-stability metrics in assessing construction workers’ fall risks. Diverse metrics that assess the capability to keep the body balanced and maintain coordination of body segments during locomotion (gait stability) and stationary postures (postural stability) have been introduced and used in clinical applications. However, their usefulness in the …

Using Simulated Virtual Interactivity In Construction Education, Saeed Rokooei, James D. Goedert

Department of Construction Engineering and Management: Faculty Publications

This paper briefly illustrates the design procedure, implementation and findings of a three year research project. Virtual Interactive Construction Education (VICE) is a project-based pedagogical model that uses a simulated environment to alter traditional subject-based lectures into virtual project-based interactive learning methods in construction education. For this purpose, the context of construction engineering and management curricula were aggregated into six construction project prototypes. VICE-Bridge is the first of these six prototypes that exposes players to experiential problem solving activities toward achieving a goal situation (construct the bridge) from an initial situation (start of construction). It was designed for students with …