Jongwon Seo

Estimation of instantaneous and daily net radiation from MODIS data under clear sky conditions: a case study in East Asia

The Moderate Resolution Imaging Spectroradiometer-based net radiation (RN) model was built and applied in East Asia in 2005. Because there have hardly been simple parameterization schemes developed over a large area using remote-sensing technology, the model was aimed to present physical simplicity in complex topography at multiple spatiotemporal scales. The model successfully reproduced the instantaneous RN values obtained at four flux tower sites having individually different ecohydrology. The diurnal cycle of RN was contextually simulated using a simple sine curve to determine the daily and monthly average net radiation. The diurnal RN estimation method was proven to be a reliable model as long as accurate boundary conditions, sunrise and sunset times, for example, were obtained. The monthly average net radiation (MANR) was estimated using the diurnal patterns of the instantaneous RN. Distribution of the monthly RN demonstrated that elevation and latitude were the primary factors affecting the MANR. The proposed RN algorithm turned out to be a promising method for valuable applications in various fields due to systematic simplicity and fewer input parameters.

GIS Method for Haul Road Layout Planning in Large Earthmoving Projects: Framework and Analysis

AbstractThis study presents a geographic information system (GIS)-based method for determining the optimal layout of a haul route for large earthmoving projects. The methodology focuses on the use of cost distance measurements to implement a least-cost path analysis to calculate the route with the shortest weighted distance between cut and fill areas. Various factors such as truck speed, construction costs, and land use that affect haul road layout are investigated. Linear interpolations based on linguistic evaluations of experienced field experts are utilized to quantify the factors. An earthmoving project from a large-scale dam construction was used as a case study to verify the applicability of the proposed method, and the route produced with the new method was compared to real road design data. The results showed the potential of the method as a practical approach to determining the optimal haul route for earthmoving.

Simulation-Based Assessment of Workers' Muscle Fatigue and Its Impact on Construction Operations

AbstractConstruction workers are frequently exposed to excessive physical demands due to repetitive lifting and material handling while performing tasks. Consequently, many construction workers suffer from a significant level of muscle fatigue that may negatively impact a project’s performance. Thus, evaluating the level of muscle fatigue prior to work and implementing appropriate interventions to reduce physical demands will help to prevent adverse effects of workers’ fatigue on construction operations. Even though several research efforts have suggested methodologies to evaluate muscle fatigue, the extent to which workers’ muscle fatigue would affect construction performance has not yet been fully studied. To address this issue, a simulation-based framework is proposed to estimate physical demands and corresponding muscle fatigue, and thus to quantitatively evaluate the impact of muscle fatigue during construction operations. Specifically, physical demands from a planned operation modeled using discrete...

Probabilistic value analysis methodology for public water supply systems

The value of a design alternative for constructed facilities is determined based on life cycle cost (LCC) and non-economic performance such as constructability and environmental impacts. Unfortunately, the level of consensus on the results of life cycle cost analysis (LCCA) is low due to the uncertainty associated with cost and timing data for construction, operation, maintenance and disposal of facilities with very long life cycles. Non-economic performance of design alternatives is also evaluated subjectively by the stakeholders of construction projects. Therefore, it is very important to properly manage the uncertainty and the variability of input data for value analysis (VA) of design alternatives. This paper presents a probabilistic VA methodology for public water supply systems. An LCC model and a cost classification structure for public water supply systems were developed to cover the initial and the follow-on cost of public water supply systems that come from the various mechanical systems and the pipeline systems of the collecting/treating/distributing facilities. The proposed VA methodology incorporates the probabilistic results of LCCA and the non-economic performance evaluation based on reliability concept for rational decision making. The model and the procedure presented in this study can greatly contribute to the value-oriented design alternative selection and the allocation of budget for public water supply system construction projects.

Spatiotemporal Analysis of Macroscopic Patterns of Urbanization and Traffic Safety Case Study in Sacramento County, California

This study provides a preliminary investigation into the relationship between urbanization and traffic collisions by analyzing the spatial patterns in Sacramento County, California, from 1998 to 2008 through use of urban land classifications and traffic collision data. The ArcGIS directional distribution tool was used to create standard deviational ellipses to investigate the distributional trend of urban land and traffic collisions over time. Statistical outputs representing changes of geographical centroids, elliptical areas, and standard distances (long and short axes) were then compared. Collisions were also divided into subsets by severity level to account for inherent differences in the spatial distribution of different types of collisions. The results provided insight into the macroscopic spatial patterns of urban land and traffic safety and their relationships. The limitations of the method and the need for further research were discussed. The approach in this study would be useful for other metropolitan areas with similarly changing development patterns and can be helpful in guiding future research that compares these two phenomena.

Application of Appropriate Technologies to 3D Local Terrain Modeling in Real-time for Intelligent Excavating System (IES)

Automation in construction is considered as one of solutions to fundamental problems which the construction industry has confronted. The development of real-time 3D local terrain modeling is the core methodology of achievement of IES (Intelligent Excavating System) which is a mega-size research concerning automation in construction. Stereo vision technique was selected as an appropriate method to achieve 3D terrain modeling in real-time. The objective of this study is to suggest a conceptual method by use of the stereo vision and assess feasibility of practical application under various conditions of construction sites. Bumblebee XB-3 is adopted as the stereo vision system in a prototype of a 3D terrain modeling system. This study is to investigate fundamental theories of the stereo vision system and to conduct tests in indoor and outdoor environments for determining appropriate detection range, finding installation location of cameras, doing visual assessment of the technical appropriateness, and checking reliability of 3D visual data. These decomposed tasks present valuable information for establishment of the conceptual method and improvement on the limitations of the use of stereo vision system for 3D terrain modeling in real-time.

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 usuall...

Prototyping a remotely-controlled machine for concrete surface grinding operations

AbstractThe 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 concrete surface and the subsequent layer. The surface grinding process, however, is executed under hazardous work conditions 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 demonstrated that remote control of concrete surface grinding is feasible and can be utilized as a semi-automated scheme on actual construction sites.

Machine Guidance Based Site Control Technology (SCT) for Earthwork Equipment Fleet

In this study, fleet control technology that can maximize coordination between earthwork equipment such as excavators, bulldozers, graders, dump trucks and rollers and a site office is introduced. In order to enhance the performance of bucket and blade based equipment, machine guidance technology is employed. The site office plans and monitors the operation of the entire equipment set based on the communication between the construction control center and individual machines. This study consists of two parts. The first part aims at developing a construction control center ( . It is stationed in a site office and produces detailed and energy saving construction plan of earthwork equipment including zoning and path planning considering the characteristics of the site contour, design information and equipment fleet. Earthwork progresses are then monitored based on the communication, comprising the exchange of design and construction information in real time, between and the machine guidance systems installed in the individual machines. The second part is a study on the systemization of guidance technology to provide safe and efficient equipment operation.

Design Structure Matrix: A Model Proposal and Implementation on Harbor and Building Design Project

Abstract Design is an iterative, generative, and multidisciplinary proce ss by its nature. Iteration occurs often in most ofthe engineering design and development projects including const ruction. Design iterations cause rework, and extraefforts are required to get the optimal sequence and to manage the projects. Contrary to simple design, isolation ofthe generative iterations in complex design systems is very dif ficult, but reduction in overall iterations is possible.Design depends upon the information flow within domain and also among various design disciplines andorganizations. Therefore, it is suggested that managers should be aware about the crucial iterations causing reworkand optimal sequence as well. In this way, managers can handle design parameters related to such iterations pro-actively. There are a number of techniques to reduce iterations for various kinds of engineering designs. In thispaper, parameter based Design Structure Matrix (DSM) is chosen. To create this DSM, a survey was performed andthen partitioned using a model. This paper provides an easy app roach to those companies involved in or intend tobe involved in “design and build projects.”Keywords :Design management, Construction, Information management, Model, Lean construction, Project management