In-Plane Loading of Brick Veneer over Wood Shear Walls

In the design of wood stud walls with brick veneer, current design building codes specify that the wood stud wall should resist all in-plane and out-of-plane loads (IBC 2009). For out-of-plane loads, this assumption is entirely justified as the brittle brick veneer will crack and lose its capacity to resist bending. For in-plane loads, the brick veneer is significantly stiffer than the wood shear wall, and the veneer is unlikely to crack before the wood shear wall reaches its allowable capacity. The assumption that the wood shear wall resists the entire load is based on the further assumption that the ties which connect the stud wall to the veneer will be sufficiently flexible to not transfer significant loads. Research has shown that this is not the case for typical US residential construction practices. The brick veneer can, in fact, resist significant in-plane loads

Experimental Evaluation of Structural Steel Coating Systems

Departments of transportation (DOTs) currently use the conventional three-coat system as the predominant choice for the corrosion protection of steel bridge structures. Eliminating one step in the coating process could potentially save time and cost associated with lane closures and traffic control costs. This research paper evaluates several two-coat systems based on the zinc-rich primer and polysiloxane topcoat technology. All samples were conditioned and coated in a state-of-the-art, climate-controlled paint booth, simulating common field ENvironmental CONditions (ENCON) (ENCON 1: 25 °C/50% RH, ENCON 2: 10 °C/40%RH, and ENCON 3: 32°C/80% RH). Accelerated weathering tests were performed on 435 coated samples (scribed and unscribed). Regardless of the ENCON considered, the performance of the two-coat system is very comparable to the three-coat system. This coating technology offers much improved performance with quicker set time and better adhesion pull-off strength. Considering its durability and ease of application, this two-coat system can be attractive to other public and private agencies to enhance and extend the service life of steel structures

Fast Polyhedral Adaptive Conjoint Estimation

We propose and test a new adaptive conjoint analysis method that draws on recent polyhedral “interior-point” developments in mathematical programming. The method is designed to offer accurate estimates after relatively few questions in problems involving many parameters. Each respondent’s ques-tions are adapted based upon prior answers by that respondent. The method requires computer support but can operate in both Internet and off-line environments with no noticeable delay between questions. We use Monte Carlo simulations to compare the performance of the method against a broad array of relevant benchmarks. While no method dominates in all situations, polyhedral algorithms appear to hold significant potential when (a) metric profile comparisons are more accurate than the self-explicated importance measures used in benchmark methods, (b) when respondent wear out is a concern, and (c) when product development and/or marketing teams wish to screen many features quickly. We also test hybrid methods that combine polyhedral algorithms with existing conjoint analysis methods. We close with suggestions on how polyhedral methods can be used to address other marketing problems.Sloan School of Management and the Center for Innovation in Product Development at MI

In-Plane Loading of Brick Veneer over Wood Shear Walls

In the design of wood stud walls with brick veneer, current design building codes specify that the wood stud wall should resist all in-plane and out-of-plane loads (IBC 2009). For out-of-plane loads, this assumption is entirely justified as the brittle brick veneer will crack and lose its capacity to resist bending. For in-plane loads, the brick veneer is significantly stiffer than the wood shear wall, and the veneer is unlikely to crack before the wood shear wall reaches its allowable capacity. The assumption that the wood shear wall resists the entire load is based on the further assumption that the ties which connect the stud wall to the veneer will be sufficiently flexible to not transfer significant loads. Research has shown that this is not the case for typical US residential construction practices. The brick veneer can, in fact, resist significant in-plane loads

Application and Test of Web-based Adaptive Polyhedral Conjoint Analysis

In response to the need for more rapid and iterative feedback on customer preferences, researchers are developing new web-based conjoint analysis methods that adapt the design of conjoint questions based on a respondent’s answers to previous questions. Adapting within a respondent is a difficult dy-namic optimization problem and until recently adaptive conjoint analysis (ACA) was the dominant method available for addressing this adaptation. In this paper we apply and test a new polyhedral method that uses “interior-point” math programming techniques. This method is benchmarked against both ACA and an efficient non-adaptive design (Fixed). Over 300 respondents were randomly assigned to different experimental conditions and were asked to complete a web-based conjoint exercise. The conditions varied based on the design of the con-joint exercise. Respondents in one group completed a conjoint exercise designed using the ACA method, respondents in another group completed an exercise designed using the Fixed method, and the remaining respondents completed an exercise designed using the polyhedral method. Following the conjoint exer-cise respondents were given $100 and allowed to make a purchase from a Pareto choice set of five new-to-the-market laptop computer bags. The respondents received their chosen bag together with the differ-ence in cash between the price of their chosen bag and the$100. We compare the methods on both internal and external validity. Internal validity is evaluated by comparing how well the different conjoint methods predict several holdout conjoint questions. External validity is evaluated by comparing how well the conjoint methods predict the respondents’ selections from the choice sets of five bags. The results reveal a remarkable level of consistency across the two validation tasks. The polyhe-dral method was consistently more accurate than both the ACA and Fixed methods. However, even better performance was achieved by combining (post hoc) different components of each method to create a range of hybrid methods. Additional analyses evaluate the robustness of the predictions and explore al-ternative estimation methods such as Hierarchical Bayes. At the time of the test, the bags were proto-types. Based, in part, on the results of this study these bags are now commercially available.The Sloan School of Management, the Center for Innovation in Product Development at MIT and the EBusiness Center at MI

Failure Mechanism of Woven Roving Fabric/Vinyl Ester Composites in Freeze–Thaw Saline Environment

This experimental study investigates the degradation mechanisms of a glass fiber-reinforced plastic material commonly used in civil engineering applications. A substantial reduction in tensile, shear, and compression properties was observed after 100 days of freeze–thaw cycling in saline environment (-20°C to 20°C). Non-destructive inspection techniques were progressively conducted on unexposed (ambient condition) and exposed (conditioned) specimens. The dynamic mechanical analysis showed permanent decrease in storage modulus that was attributed to physical degradation of the polymer and/or fiber–matrix interface. This indicated the formation of internal cracks inside the exposed glass fiber-reinforced plastic laminate. The 3D X-ray tomography identified preferred damage sites related to intralaminar and interlaminar cracks. The ultrasonic C-scan and optical microscopy showed the nature of the damage and fibers fracture. The thermal cycling events degraded the matrix binding the warp and fill fibers, thus impairing the structural integrity of the cross-ply laminate. The result of this work could benefit a multi-scale durability and damage tolerance model to predict the material state of composite structures under typical service environments

Understanding Consumer Preferences for Explanations Generated by XAI Algorithms

Explaining firm decisions made by algorithms in customer-facing applications is increasingly required by regulators and expected by customers. While the emerging field of Explainable Artificial Intelligence (XAI) has mainly focused on developing algorithms that generate such explanations, there has not yet been sufficient consideration of customers' preferences for various types and formats of explanations. We discuss theoretically and study empirically people's preferences for explanations of algorithmic decisions. We focus on three main attributes that describe automatically-generated explanations from existing XAI algorithms (format, complexity, and specificity), and capture differences across contexts (online targeted advertising vs. loan applications) as well as heterogeneity in users' cognitive styles. Despite their popularity among academics, we find that counterfactual explanations are not popular among users, unless they follow a negative outcome (e.g., loan application was denied). We also find that users are willing to tolerate some complexity in explanations. Finally, our results suggest that preferences for specific (vs. more abstract) explanations are related to the level at which the decision is construed by the user, and to the deliberateness of the user's cognitive style.Comment: 18 pages, 1 appendix, 3 figures, 4 table

Measuring Consumer Preferences Using Conjoint Poker

We develop and test an incentive-compatible Conjoint Poker (CP) game. The preference data collected in the context of this game are comparable to incentive-compatible choice-based conjoint (CBC) analysis data. We develop a statistical efficiency measure and an algorithm to construct efficient CP designs. We compare incentive-compatible CP to incentive-compatible CBC in a series of three experiments (one online study and two eye-tracking studies). Our results suggest that CP induces respondents to consider more of the profile-related information presented to them compared with CBC

Doing more with less: The Marie Stopes Clinics in Sierra Leone

This edition of Quality/Calidad/Qualité reports on the Marie Stopes Sierra Leone (MSSL) organization which pursues its goals with compassion and ambition, despite seemingly insurmountable economic hardships. MSSL has established a service model that many programs in richer countries should try to imitate. Several particularly important lessons emerged, including: creative, skillful management, well-organized and flexible financial administration, and human motivation and perseverance can enable an organization to overcome financial difficulties; family planning is an integral part of people\u27s reproductive and general health concerns and can dovetail with concern for development in useful and practical ways; men appreciate being involved in the care of their children; and a woman-centered reproductive healthcare service can help empower women to care for and value themselves

Sexual coercion and reproductive health: A focus on research

Gender-based violence is ignored or denied in most societies and neglected by health professionals and researchers, yet it persists in almost all societies, and, in some, it is on the increase. This report is aimed at those in the family planning/reproductive health field who desire to conduct research or implement programs to address sexual violence and its impact on women\u27s reproductive health. Furthermore, it contributes to a better understanding of the context of sexual coercion as well as its causes and consequences. The ideas presented herein are derived largely from a two-day meeting jointly organized by the Ebert Program in Reproductive Health of the Population Council and the Health and Development Policy Project. Meeting discussions are supplemented with relevant written material, giving emphasis to literature published by meeting participants. The document includes a list of recommendations developed by the participants for future work on sexual coercion in the family planning/reproductive health arena