1,720,961 research outputs found
An Approach to Study Impact of Public Policy, Exogenous Variables, and Vehicle Design on Greenhouse Gas Emission
No full textImpacts of Government Policies, Fuel Cell Cost, and Battery Cost on Greenhouse Gas Emission of Light-Duty Vehicles
No full textReliability and Accuracy of Bootstrap and Monte Carlo Methods for Demand Distribution Modeling
No full textAn Approach to Modeling Customer Preference Uncertainty by Applying Bootstrap to Choice-Based Conjoint Analysis Data
No full textAnalysis of customer preferences is among the most important tasks in a new product development. How customers come to appreciate and decide to purchase a new product affects the products market share and therefore its success or failure. Unfortunately, when designers select a product concept early in the product development process, customer preference response to the new product is unknown. Conjoint analysis is a statistical marketing tool that has been used to estimate market shares of new product concepts by analyzing data on the product ratings, rankings or concept choices of customers. This paper proposes an alternative to traditional conjoint analysis methods that provide point estimates of market shares. It proposes two approaches to model market share uncertainty; bootstrap and binomial inference applied to choice-based conjoint analysis data. The proposed approaches are demonstrated and compared using an illustrative example.</jats:p
DETC2011-47493 AN APPROACH TOWARD MAKING A DESIGN DECISION BASED ON FUTURE DEMAND PREDICTION
No full textABSTRACT This paper presents an approach for modeling uncertainty of future demand according to a forecast of an influential exogenous variable, which serves as the first step toward making a product design decisions based on future demand prediction. Optimum product design that maximizes expected profit or expected utility of profit depends on future demand influenced by future exogenous variables (i.e., economic, societal, and political variables beyond designers' control). For example, an optimum design among gasoline, hybrid, electric, and fuel cell vehicles may depend on economic variables such as future gasoline prices, societal variables such as future climate change, and political variables such as future government standards for fuel-efficient vehicles. However, in particular for large-scaled and complex products, designers quite often make design decisions many years before the product is introduced to the marketplace without knowing future exogenous variables. To enable designers to make design decisions according to predicted demands, this study proposes to link demand distributions with exogenous variables and update demand distributions based on exogenous variable forecasts and their degrees of accuracies. An illustrative example is used to demonstrate impacts of exogenous variable forecasts and their accuracies on future demand prediction and expected profit calculation of a fuel cell vehicle
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Electromyography-Driven Forward Dynamics Simulation to Estimate In Vivo Joint Contact Forces During Normal, Smooth, and Bouncy Gaits
No full textComputational models that predict in vivo joint loading and muscle forces can potentially enhance and augment our knowledge of both typical and pathological gaits. To adopt such models into clinical applications, studies validating modeling predictions are essential. This study created a full-body musculoskeletal model using data from the “Sixth Grand Challenge Competition to Predict in vivo Knee Loads.” This model incorporates subject-specific geometries of the right leg in order to concurrently predict knee contact forces, ligament forces, muscle forces, and ground contact forces. The objectives of this paper are twofold: (1) to describe an electromyography (EMG)-driven modeling methodology to predict knee contact forces and (2) to validate model predictions by evaluating the model predictions against known values for a patient with an instrumented total knee replacement (TKR) for three distinctly different gait styles (normal, smooth, and bouncy gaits). The model integrates a subject-specific knee model onto a previously validated generic full-body musculoskeletal model. The combined model included six degrees-of-freedom (6DOF) patellofemoral and tibiofemoral joints, ligament forces, and deformable contact forces with viscous damping. The foot/shoe/floor interactions were modeled by incorporating shoe geometries to the feet. Contact between shoe segments and the floor surface was used to constrain the shoe segments. A novel EMG-driven feedforward with feedback trim motor control strategy was used to concurrently estimate muscle forces and knee contact forces from standard motion capture data collected on the individual subject. The predicted medial, lateral, and total tibiofemoral forces represented the overall measured magnitude and temporal patterns with good root-mean-squared errors (RMSEs) and Pearson's correlation (p2). The model accuracy was high: medial, lateral, and total tibiofemoral contact force RMSEs = 0.15, 0.14, 0.21 body weight (BW), and (0.92 < p2 < 0.96) for normal gait; RMSEs = 0.18 BW, 0.21 BW, 0.29 BW, and (0.81 < p2 < 0.93) for smooth gait; and RMSEs = 0.21 BW, 0.22 BW, 0.33 BW, and (0.86 < p2 < 0.95) for bouncy gait, respectively. Overall, the model captured the general shape, magnitude, and temporal patterns of the contact force profiles accurately. Potential applications of this proposed model include predictive biomechanics simulations, design of TKR components, soft tissue balancing, and surgical simulation.</jats:p
A Decision-Analytic Concept Selection for a Commercial System Using Objective Data to Model Uncertainty
No full textThis paper presents decision-analytic concept selection framework for a commercial system and an uncertainty modeling using objective data. The selection of a system concept for which a final system is designed and manufactured is a decision making process with incomplete information. Decision analysis is a prescriptive approach for decision making under uncertainty. While realizing that humans make decisions violating the expected utility axioms, decision analysis uses a set of tools to guide a decision maker toward an unbiased and rational decision making. The objective of this research is to propose a decision-analytic framework for commercial system concept selection, and an approach to utilize as much objective data as possible in the uncertainty modeling. Toward this objective, this paper construct cost distribution using case-based reasoning and market share distribution applying bootstrap to customers’ preference data obtained from conjoint analysis. The proposed approach is demonstrated in an illustrative example: a decision-analytic automobile concept selection.</jats:p
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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