Distributed Ontology Architecture for Knowledge Management in Highway Construction

The ongoing plethora of rehabilitation in the infrastructure domain requires more planning and integration during design and construction. To achieve this, there is a need for developing and using semantic (ontology-based) mechanisms for the exchange of development knowledge among all project stakeholders. This paper presents a distributed ontology architecture for knowledge management in highway construction. With every other utility tied to the highway geometry, the architecture is intended to be the base for a cross-discipline knowledge exchange in the infrastructure domain. The architecture presents highway knowledge on three levels: domain knowledge (an umbrella for infrastructure shared knowledge), application knowledge (representation of highway-specific knowledge), and user knowledge (an enterprise-specific representation of highway knowledge). The proposed architecture models highway concepts using six major root concepts: project, process, product, actor, resources, and technical topics (attributes and constraints). The architecture was developed using rigorous knowledge acquisition and ontology development techniques. It was developed as an extension for the e-COGNOS ontology. The architecture was validated through input from domain experts.     

Benefit-Cost Metrics for Design Coordination of Mechanical, Electrical, and Plumbing Systems in Multistory Buildings

Design coordination of mechanical, electrical, and plumbing (MEP) systems in buildings is a multidisciplinary effort to locate equipment, route distribution systems, and resolve interferences between systems that can cause field conflicts. Absent from existing research are defined metrics of design coordination—how much it costs to perform depending on project variables, and the true costs of field conflicts that are eliminated by coordination. This research was performed to explore the costs of design coordination in concert with the benefits of eliminating coordination conflicts that arise in the field. A standard method to measure costs of coordination is developed for case study projects. Potential variables that affect this cost are evaluated, and the negative impacts of field conflicts are measured. Project variables that have strong relationships with coordination costs are identified to be MEP density [MEP cost/square foot (SF)], and plenum height, and exploratory models to predict coordination costs using these variables are presented. Three distinct types of coordination conflicts are identified with measurable increasing impacts and cost. These results help to quantify the level of effort needed to coordinate building systems, and help to provide a basis for detecting projects that are likely to have problematic MEP coordination processes.     

Domain Ontology for Processes in Infrastructure and Construction

With the increasing demands for domain-wide integrated construction and infrastructure development, there is a need for developing a domain ontology to build a knowledge model that describes the multistakeholder project development process. This paper presents a domain ontology for supporting knowledge-enabled process management and coordination across various stakeholders, disciplines, and projects. The ontological model is composed of concepts, relations, and axioms. Concepts represent the “things” in the domain of interest; relations establish the interconcept links; and axioms specify the definitions of concepts and relations and constraints on their behavior and interpretation. The ontology models the most fundamental concepts in the domain in a structured, extendable, and flexible format to facilitate future evolution and extension of the ontology for representing application-specific and/or enterprise-specific knowledge. The ontology was evaluated through technical evaluation and user evaluation. User evaluation was conducted through one-to-one expert evaluation interviews.     

E-Society Portal: Integrating Urban Highway Construction Projects into the Knowledge City

Community involvement is an important factor for sustainable highway construction. Information and communication technologies provide a new and more effective approach to facilitate community involvement. However, there are too many parameters with conflicting and subjective definitions related to sustainability and too many stakeholders with varying degrees of interest and sophistication. There is a need for an effective tool to communicate project impacts on sustainability to local communities. This paper presents an ontology for stakeholder management and sustainability in highway construction. An ontology is a conceptual semantic model that attempts to capture human knowledge (both explicit and tacit) in a consistent manner. Ontologies include three main elements: a taxonomy (common vocabulary presented in concept trees), set of relationships (linking concepts across trees), and axioms (limitation/constraints on the behavior of concepts). The ontology was used to develop a portal for broadcasting highway design features to local communities. By browsing through the portal, a user can learn about project elements, the impacts of each element on sustainability issues, who is sponsoring such element, and what efforts have been made to reduce any impacts of such elements on local communities.     

Similarity and choice.

Examined choices between alternatives when the options confronting the decision maker have similar levels on an attribute. In these situations, 2 empirical phenomena often occur. First, differences on other attributes are enhanced. Similarity along 1 attribute magnifies differences on others. Second, violations of strong stochastic transitivity often occur. A contrast-weighting theory of choice is presented that can account for these puzzling phenomena. Binary choices are represented as a monotonic function of the difference between the utilities of the options. Furthermore, the utilities of any given attribute are weighted according to the similarity of the levels along the other attribute. Small contrasts along one dimension result in greater weight for the other dimension. This contrast-weighting theory is consistent with empirical results in several domains, including psychophysics, social judgment, and risky decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of uncontrollability on subsequent decision making: Testing the cognitive exhaustion hypothesis.

The cognitive exhaustion model of helplessness (predicting withdrawal from constructive effortful processing after uncontrollability) was applied to decision making. After unsolvable problems (or no preexposure), Ss requested information from a matrix with 5 alternatives (films)?×?10 attributes and then chose the best film. Films in a set were either similar (difficult decision) or dissimilar (easy decision) in attractiveness. As predicted, Ss with an uncontrollable preexposure spent less time on predecisional information search, disregarded their own importance criteria when asking for information, and had attention highly focused on a selected option for the easy decision condition but diffused across options for the difficult decision condition. The implications of these findings for understanding cognitive mechanisms of learned helplessness and depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decision Support System for Surface Irrigation Design

The SADREG decision support system was developed to help decision makers in the process of design and selection of farm surface irrigation systems to respond to requirements of modernization of surface irrigation—furrow, basin, and border irrigation. It includes a database, simulation models, user-friendly interfaces, and multicriteria analysis models. SADREG is comprised of two components: design and selection. The first component applies database information, and through several simulation and computational tools, produces a set of design alternatives in agreement with the user options. These alternatives are characterized by several hydraulic, economic, and environmental indicators that allow appropriate selection and ranking. The selection component bases upon multicriteria analysis using composite programming and ELECTRE II ranking models, which support the decision maker to select the best alternative. The decision maker participates in all decision processes through a user-friendly interface that allows expressing design options and priorities. SADREG was tested with data collected from field experiments. In addition to describing the modeling approach, an application to a sector of the Lower Mondego Irrigation Project, Portugal, is presented.     

Web-Services Environment for Collaborative Management of Product Life-Cycle Costs

There is an increasing need for effective tools for managing life cycle costs (LCC) of civil products. This paper presents a web-based semantic system for managing products’ life cycle costs. The basic architecture of the proposed system represents costs as a hierarchy of cost elements. Each cost element has a dollar value that could be deterministic, probabilistic, or fuzzy. Several factors (also represented in hierarchies) can have a set of impacts on the values of these costs. Through the analysis of different impact possibilities and probabilities, a decision maker can study various alternative scenarios and define the optimum set of costs and their values. A set of web services are used to capture cost elements, factors, and their impacts. The semantic nature of the system allows for it to be an integral part of a corporate memory system, where decision makers will be able to document and access lessons learned about LCC optimization. Finally, the proposed system includes a framework for a LCC-centered supply chain, where all stakeholders can collaborate in optimizing product LCC.     

Decision Support System for Stakeholder Involvement

Stakeholder involvement is essential to the development of a total maximum daily load (TMDL) and its implementation plan. A tool, beyond a simulation model, is needed to support the decision making process that requires negotiation and compromise among stakeholders. The decision support system (DSS) described herein has a TMDL module to calculate various combinations of point and nonpoint loads that can meet the water quality criteria. Its Consensus module allows stakeholders to formulate, evaluate, modify, and vote for alternatives. The DSS displays bar charts for pollution loads from various subwatersheds and attributes the nonpoint loads to land uses. The water quality consequence of the pollution loads is output in maps, which shows sections meeting criteria in green and those not in red. The DSS requires a front end effort of site specific adaptation and model calibration. An Internet-based stakeholder process was developed to allow more concerned citizens to participate in management decisions.     

Measuring and Improving Rationale Clarity in a University Office Building Design Process

This paper measures and improves the clarity of design rationale on an architecture, engineering, and construction (AEC) project and observes the effects. The rationale clarity framework (RCF) defines decisions in terms of components of rationale—managers, stakeholders, designers, gatekeepers, objectives (constraints and goals), alternatives, and analyses (impacts and assessment of stakeholder value). RCF defines relations and conditions of clarity for each component—coherent, concrete, connected, consistent, credible, certain, and correct. Using RCF, the rationale clarity of decisions was observed and documented on an industry case project. A decision-assistance methodology that seeks to clarify rationale, called MACDADI, was then implemented and costs and benefits from each team member’s perspective were observed. Future work is identified that can lower costs and increase benefits of clarifying rationale.     

Slack Bus Modeling and Cost Analysis of Distributed Generator Installations

The installation and operation of distributed generators (DGs) has great potential for local utilities to improve distribution system reliability and lower their operating and expansion planning costs. To evaluate this potential, distribution system analyses must reflect its new operating environment with significant DG. Resulting tools can be utilized by both utilities and DG owners to improve their decision making algorithms. As such, this work investigates two different slack bus models for unbalanced distribution power flow and their impacts on subsequent cost analysis. The models include the traditional single slack bus model which assigns the substation as the slack bus and a distributed slack bus model which assigns slack to the substation and DGs according to network-based participation factors. Detailed expressions for cost analysis which directly depend on the distributed slack bus model are presented and discussed. Simulations illustrate that the different slack bus models have significant impacts on cost analysis. The difference in estimated annual profit for local utilities reached up to 265% using the different slack models.     

Conflict Resolution in Construction Disputes Using the Graph Model

A formal approach is presented for systematically resolving construction conflicts. Using an actual case study, a decision support system based on the graph model for conflict resolution (GMCR II), is employed to effectively investigate the strategic interactions that took place between an owner and a general contractor concerning the financing of a construction project. The conflict analysis process considers the decision participants, their decision options, and their relative preferences when modeling the dispute. GMCR II is then used to perform an in-depth stability analysis in order to ascertain the possible compromise resolutions or equilibria. In the case study, GMCR II correctly predicts the sequence of decisions that took place in the dispute and furnishes an array of useful strategic insights about the conflict. Moreover, a sensitivity analysis is executed to determine how changes in preferences can affect the equilibrium results. This conflict resolution procedure is useful for both researchers and practitioners to better deal with the dispute-prone nature of the construction industry.     

Volume Compensation Method for Routing Irrigation Canal Demand Changes

This paper examines the problem of routing known water demands through gate-controlled, open-channel irrigation delivery systems. Volume-compensation principles were used to route multiple demands in multiple-pool canal systems. The volume-compensation method schedules each demand change individually under the assumption of a series of steady states and superimposes the individual results. Volume-compensation routing schedules were computed for two of the test cases proposed by the ASCE Task Committee on Canal Automation. Alternative routing schedules were computed with the gate-stroking method, which is an inverse solution of the unsteady-flow equations. Both solutions were tested through unsteady-flow simulation. While not as effective as gate-stroking solutions, volume-compensation solutions performed satisfactorily under ideal flow control conditions. When subjected to realistic operational constraints, specifically constraints on the flow regulation interval, and also to incorrect canal hydraulic roughness information, both methods performed similarly.     

基于按需和贪婪转发的移动自组网路由协议

移动自组网的动态拓扑特性给路由协议的设计带来了一定的挑战,尤其是在高动态的网络环境中.本文针对该问题,提出了一种新的基于按需和贪婪转发的路由协议,该协议是在RGR模式的基础上提出以下三点改进,即:（1）通过受限的洪泛机制降低网络在路由发现阶段的控制开销;（2）通过移动预测机制,在被动寻路阶段监视被动路径的状态和在GGF阶段帮助节点选取适当的邻居作为下一跳节点;（3）通过路径请求延迟机制以减少不必要的资源浪费.仿真结果表明:改进的RGR协议与现有的RGR、AODV、Modified-RGR和Optimized-RGR相比,不仅具有较高的数据包接收成功率,而且平均路由开销和端到端时延也相对较低.      

Identification and Resolution of Work Space Conflicts in Building Construction

Numerous workers, equipment, material, temporary facilities, as well as permanent structures share the limited space during construction. Since space constraints may affect productivity and the critical path, it is essential to organize the available space efficiently and minimize space conflicts. This study considers space availability due to time and scheduling, productivity loss due to space constraints and path interference, as well as the possibility of alternative space to resolve these conflicts and optimize space usage. Herein, computer-aided design is integrated with scheduling software for the dynamic identification of space conflicts on the jobsite. Follow-up supplemental decision criteria are then provided for conflict analysis and resolution. A prototype decision support system that combines the criteria was developed to solve this significant and complex problem more efficiently and precisely. A case study demonstrates the use and development of this system, which is very helpful to engineers and project managers.     

Aging and decision making: driving-related problem solving

We examined age-related effects on decision making in a task environment familiar to most younger and older adults. Participants made route-selection decisions in real time. Participants received information about traffic density and expected speed limits of main and alternative routes, from which they determined the optimality of their present route versus alternative routes. The experiment evaluated the effects of information type, amount of congestion, alternative route speed limit, and age on speed and quality of decision making. Measures of optimal route selection revealed main effects of alternative route speed limit, congestion level, and message type, but there was not a main effect of age, and age did not interact with any variable. In terms of decision speed (but not quality of decision making), older participants were slower, and age interacted with alternative route speed and with message type. The data are interpreted in relation to previous data examining everyday problem solving and aging.     

Performance Objectives Selection Model in Public-Private Partnership Projects Based on the Perspective of Stakeholders

Over the years, public-private partnership (PPP) has been acknowledged by many as an innovative approach to the procurement of public projects. The desire for more efficient and effective PPP projects renders the performance management to be increasingly important, in which the influence of the stakeholders must be considered. To implement complete and effective performance management in PPP projects, 15 performance objective attributes are proposed based on the perspectives of different stakeholders. A structured questionnaire survey was conducted to investigate the relative significance of each attribute in four stakeholder groups. According to the survey results, the objective attributes are all important. Integrating all stakeholders’ benefits and selecting the appropriate qualitative level of performance objective in the process of decision making are two particularly important problems because of stakeholders’ different preferences. To resolve these problems, a fuzzy entropy method and a fuzzy TOPSIS method based on projection distance have been developed to calculate the final decision weights in all stakeholder groups and select appropriate performance objective levels for PPP projects, respectively. The final decision weights are obtained using fuzzy entropy to integrate the experiences and knowledge of all stakeholders. An illustrative case study on the Beijing National Stadium project for the 2008 Olympic Games is used to demonstrate the feasibility and practicability of the proposed model.     

Top-Level Considerations for Planning Lunar/Planetary Habitat Structures

This paper highlights important considerations to guide overall planning and element design of lunar/planetary surface habitat structures. Driving influences include stringent launch/landing payload limitations; high costs of human time for surface deployment and operational readiness; influences of the harsh environment on structures, devices and crews; and a paucity of equipment and human and consumable resources that necessitates extreme economies. General habitat concept options are proposed along with desired attributes for comparative assessments of figure of merit (FOM) rankings. Eight broad FOM categories are applied as a basis for top-level option evaluations: (1)?launch optimization features, (2)?landing optimization features, (3)?habitat capacity and functionality, (4)?environmental factors and features, (5)?deployment and operational readiness, (6)?reliability and maintainability, (7)?commonality with other surface systems, and (8)?pathways and potentials for growth. Much of the content of this paper draws on investigations conducted by the Sasakawa International Center for Space Architecture (SICSA) in support of separate National Aeronautics and Space Administration (NASA) contracts awarded to teams headed by Boeing and ILC-Dover for a “Minimum Functionality Habitation Systems Concept Study.” Comprehensive team study results were presented to NASA in February 2009 and have been publicly released to all interested parties.     

Enterprise-Wide Data Integration and Analysis for Oversize/Overweight Permitting

The automation of oversize/overweight (OS/OW) vehicle permitting can be achieved through GIS-based systems. OS/OW permitting involves network pathfinding given spatial and temporal constraints that are associated with the physical roadway network. This paper presents a data model design that extends and satisfies the consensus functional requirements of OS/OW permitting. Although departments of transportation at the state level invest millions of dollars in development and management of enterprise databases of bridges and highways, many GIS-based OS/OW permitting systems require development of application-specific versions of these databases. Consequently, agency motor carrier service divisions are faced with huge data management problems. The system design in this paper facilitates sustainability by being consistent with the notions of enterprisewide data integration. A robust location-referencing strategy and adherence to the national intelligent transportation systems architecture achieve enterprisewide data integration. This paper presents general system requirements, an OS/OW application design, an enterprisewide database schema, and algorithms for finding OS/OW vehicle routes given spatial and temporal roadway restrictions. The system design accommodates multiple data sources, multiple location-referencing methods, and state-to-state interoperability. Spatial and temporal constraints for OS/OW permitting are represented in a unified modeling language class diagram.     

Dynamic Knowledge-Based Process Integration Portal for Collaborative Construction

There is a need to support collaborative coordinated construction through the integration of work processes across various stakeholders, disciplines, and projects. Due to the fast-growing complexities of domain-wide coordination and collaboration, coupled with the emerging opportunities of knowledge sharing, a knowledge-based approach is believed to be the way to go. Knowledge-based process integration takes into account explicit and formal semantics (meaning) of processes. It aims at supporting seamless integration of knowledge-carrying processes. This paper presents a prototype collaborative portal for domain-wide process integration. The portal is ontology-based: semantic process representation is enabled through ontologies, and knowledge-based process integration is facilitated through an ontology merger. The portal aims at offering an efficient value-adding collaboration platform through multidimensional process integration for producing a common workflow that goes beyond listing of processes to a knowledge-enabled view. The prototype was evaluated through a focus group.