Managing Dependencies for Collaborative Design

2000 ◽  
Author(s):  
Kai-Lu Wang ◽  
Yan Jin
Keyword(s):  
Collaborative Design ◽  
Formal Model ◽  
Design Stage ◽  
Modeling Framework ◽  
Design Decomposition ◽  
Engineering Problems ◽  
Coordination Framework ◽  
Dependency Management ◽  
Coordination Methods

Abstract In collaborative engineering, the dependencies of engineering problems determine with whom and how designers should coordinate. Based on the directed dependency framework introduced in this research, we argue that the reciprocal and cyclic dependencies cause design iterations and inefficiencies, and should be avoided if possible. By studying the patterns of engineering dependencies and design decomposition, this paper provides an approach to manage the dependencies in order to avoid reciprocal and cyclic dependencies both in the early conceptual design stage and in design task arrangement stage, to make collaborative design more efficient. The long-term goal of this research is to develop a dependency-based coordination framework that consists of a formal model of engineering dependencies, and coordination methods, and guidelines for dependency-based engineering design and management. This paper describes our current dependency modeling framework and dependency management methods for collaborative design.

Modeling Dependencies in Engineering Design

1999 ◽  
Author(s):  
Kai-Lu Wang ◽  
Yan Jin
Keyword(s):  
Engineering Design ◽  
Collaborative Design ◽  
Formal Model ◽  
Problem Definition ◽  
Current Status ◽  
Collaborative Engineering ◽  
Engineering Research ◽  
Detail Design ◽  
Support Tools

Abstract Collaborative engineering design involves coordination among designers. While coordination in most cases entails explicit communication between designers, the real reason for designers to coordinate with each other is not for communication but for resolving engineering dependencies. In the field of collaborative engineering research, various computer models and tools have been developed to facilitate communication among designers aiming to improve their communication efficiency for coordination. We argue that in order to provide effective and purposeful coordination support, one must understand how engineering dependencies evolve and propagate in different phases, of design, from problem definition, conceptual design, to detail design. In our research on collaborative design, we take a dependency-based approach, i.e., to explicitly capture and manipulate dependencies and create design processes and support tools based on explicit understanding of underlying dependencies. The long term goal of our research is to develop a dependency-based coordination framework that consists of a formal model of engineering dependencies and coordination mechanisms, mapping between the dependencies and coordination methods, and guidelines and procedures for dependency-based work process design and management. This paper describes our current status of developing a formal model of engineering dependencies.

Modeling Framework for a Consistent Integration of Geometry Knowledge During Conceptual Design

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Romain Barbedienne ◽  
Olivia Penas ◽  
Jean-Yves Choley ◽  
Peter Hehenberger
Keyword(s):  
Conceptual Design ◽  
Collaborative Design ◽  
Computer Aided Design ◽  
System Modeling ◽  
Data Consistency ◽  
Design Stage ◽  
Modeling Framework ◽  
Physical Constraints ◽  
3D Cad ◽  
Architecture Modeling

This paper proposes a modeling framework for a consistent geometrical data link between a system model and a spatial architecture modeling in a 3D computer-aided design (CAD) environment, with a model-based system engineering (MBSE) approach. Our approach, focused on the conceptual design stage, for the evaluation of 3D architecture under physical constraints, aims at improving the system design by ensuring data consistency during collaborative design. This model transformation platform will ensure a seamless geometrical consistency and traceability from the requirements to the further design stages. The theoretical formalization of our approach presents a consistent integration of geometry knowledge all along the conceptual design. Then, the corresponding modeling platform implementation between the developed system modeling language (SysML) geometrical extension and a 3D CAD tool is described before detailing an application on a conveyor case study.

scholarly journals Extensive Evaluation of a Continental-Scale High-Resolution Hydrological Model Using Remote Sensing and Ground-Based Observations

2021 ◽  
Vol 13 (7) ◽  
pp. 1247
Author(s):  
Bowen Zhu ◽  
Xianhong Xie ◽  
Chuiyu Lu ◽  
Tianjie Lei ◽  
Yibing Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Hydrological Modeling ◽  
Infiltration Capacity ◽  
Modeling Framework ◽  
Large Domain ◽  
Continental Scale ◽  
Extensive Evaluation ◽  
Mean Differences ◽  
Fine Resolution

Extreme hydrologic events are getting more frequent under a changing climate, and a reliable hydrological modeling framework is important to understand their mechanism. However, existing hydrological modeling frameworks are mostly constrained to a relatively coarse resolution, unrealistic input information, and insufficient evaluations, especially for the large domain, and they are, therefore, unable to address and reconstruct many of the water-related issues (e.g., flooding and drought). In this study, a 0.0625-degree (~6 km) resolution variable infiltration capacity (VIC) model developed for China from 1970 to 2016 was extensively evaluated against remote sensing and ground-based observations. A unique feature in this modeling framework is the incorporation of new remotely sensed vegetation and soil parameter dataset. To our knowledge, this constitutes the first application of VIC with such a long-term and fine resolution over a large domain, and more importantly, with a holistic system-evaluation leveraging the best available earth data. The evaluations using in-situ observations of streamflow, evapotranspiration (ET), and soil moisture (SM) indicate a great improvement. The simulations are also consistent with satellite remote sensing products of ET and SM, because the mean differences between the VIC ET and the remote sensing ET range from −2 to 2 mm/day, and the differences for SM of the top thin layer range from −2 to 3 mm. Therefore, this continental-scale hydrological modeling framework is reliable and accurate, which can be used for various applications including extreme hydrological event detections.

scholarly journals High coverage COVID-19 mRNA vaccination rapidly controls SARS-CoV-2 transmission in long-term care facilities

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Pablo M. De Salazar ◽  
Nicholas B. Link ◽  
Karuna Lamarca ◽  
Mauricio Santillana
Keyword(s):  
Long Term Care ◽  
Mitigation Strategies ◽  
Key Factors ◽  
Modeling Framework ◽  
High Coverage ◽  
Term Care ◽  
Early Effect ◽  
Care Facilities ◽  
The Relationship

Abstract Background Residents of Long-Term Care Facilities (LTCFs) represent a major share of COVID-19 deaths worldwide. Measuring the vaccine effectiveness among the most vulnerable in these settings is essential to monitor and improve mitigation strategies. Methods We evaluate the early effect of the administration of BNT162b2-mRNA vaccine to individuals older than 64 years residing in LTCFs in Catalonia, Spain. We monitor all the SARS-CoV-2 documented infections and deaths among LTCFs residents once more than 70% of them were fully vaccinated (February–March 2021). We develop a modeling framework based on the relationship between community and LTCFs transmission during the pre-vaccination period (July–December 2020). We compute the total reduction in SARS-CoV-2 documented infections and deaths among residents of LTCFs over time, as well as the reduction in the detected transmission for all the LTCFs. We compare the true observations with the counterfactual predictions. Results We estimate that once more than 70% of the LTCFs population are fully vaccinated, 74% (58–81%, 90% CI) of COVID-19 deaths and 75% (36–86%, 90% CI) of all expected documented infections among LTCFs residents are prevented. Further, detectable transmission among LTCFs residents is reduced up to 90% (76–93%, 90% CI) relative to that expected given transmission in the community. Conclusions Our findings provide evidence that high-coverage vaccination is the most effective intervention to prevent SARS-CoV-2 transmission and death among LTCFs residents. Widespread vaccination could be a feasible avenue to control the COVID-19 pandemic conditional on key factors such as vaccine escape, roll out and coverage.

scholarly journals Rotor Loading Characteristics of a Full-Scale Tidal Turbine

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1035 ◽  
Author(s):  
Magnus Harrold ◽  
Pablo Ouro
Keyword(s):  
Turbulent Flows ◽  
Mechanical Loading ◽  
Full Scale ◽  
Design Stage ◽  
Flow Profile ◽  
Expected Return ◽  
Tidal Turbines ◽  
Theoretical Predictions ◽  
Tidal Turbine

Tidal turbines are subject to highly dynamic mechanical loading through operation in some of the most energetic waters. If these loads cannot be accurately quantified at the design stage, turbine developers run the risk of a major failure, or must choose to conservatively over-engineer the device at additional cost. Both of these scenarios have consequences on the expected return from the project. Despite an extensive amount of research on the mechanical loading of model scale tidal turbines, very little is known from full-scale devices operating in real sea conditions. This paper addresses this by reporting on the rotor loads measured on a 400 kW tidal turbine. The results obtained during ebb tidal conditions were found to agree well with theoretical predictions of rotor loading, but the measurements during flood were lower than expected. This is believed to be due to a disturbance in the approaching flood flow created by the turbine frame geometry, and, to a lesser extent, the non-typical vertical flow profile during this tidal phase. These findings outline the necessity to quantify the characteristics of the turbulent flows at sea sites during the entire tidal cycle to ensure the long-term integrity of the deployed tidal turbines.

Resource Allocation with Sigmoidal Demands: Mobile Healthcare Units and Service Adoption

2021 ◽  
Author(s):  
Andres Alban ◽  
Philippe Blaettchen ◽  
Harwin de Vries ◽  
Luk N. Van Wassenhove
Keyword(s):  
Health Services ◽  
Optimal Allocation ◽  
Formal Model ◽  
Problem Definition ◽  
Gradient Boosting ◽  
Access To Health Services ◽  
Mobile Healthcare ◽  
Sigmoidal Functions ◽  
Allocation Decisions

Problem definition: Achieving broad access to health services (a target within the sustainable development goals) requires reaching rural populations. Mobile healthcare units (MHUs) visit remote sites to offer health services to these populations. However, limited exposure, health literacy, and trust can lead to sigmoidal (S-shaped) adoption dynamics, presenting a difficult obstacle in allocating limited MHU resources. It is tempting to allocate resources in line with current demand, as seen in practice. However, to maximize access in the long term, this may be far from optimal, and insights into allocation decisions are limited. Academic/practical relevance: We present a formal model of the long-term allocation of MHU resources as the optimization of a sum of sigmoidal functions. We develop insights into optimal allocation decisions and propose pragmatic methods for estimating our model’s parameters from data available in practice. We demonstrate the potential of our approach by applying our methods to family planning MHUs in Uganda. Methodology: Nonlinear optimization of sigmoidal functions and machine learning, especially gradient boosting, are used. Results: Although the problem is NP-hard, we provide closed form solutions to particular cases of the model that elucidate insights into the optimal allocation. Operationalizable heuristic allocations, grounded in these insights, outperform allocations based on current demand. Our estimation approach, designed for interpretability, achieves better predictions than standard methods in the application. Managerial implications: Incorporating the future evolution of demand, driven by community interaction and saturation effects, is key to maximizing access with limited resources. Instead of proportionally assigning more visits to sites with high current demand, a group of sites should be prioritized. Optimal allocation among prioritized sites aims at equalizing demand at the end of the planning horizon. Therefore, more visits should generally be allocated to sites where the cumulative demand potential is higher and counterintuitively, often those where demand is currently lower.

scholarly journals Influence of Customer Attrition on Diffusion of Business Education Services

2017 ◽  
Vol 2 (2) ◽  
pp. 125-134
Author(s):  
Nitin Sachdeva
Keyword(s):  
Goodness Of Fit ◽  
New Product ◽  
Mean Value ◽  
Diffusion Models ◽  
Primary Data ◽  
Type I ◽  
Modeling Framework ◽  
Customer Attrition ◽  
The Impact

Innovation diffusion models have been developed by many researchers during the past few decades based on the famous Bass (1969) model. Several such diffusion models have been developed in consideration of price, marketing efforts etc., however, it is hardly seen that customer attrition (disadoption) can play a significant role in long term growth process of any new product or service. This paper defines two types of disadoption process, Type I disadoption and Type II disadoption process, representing disadopters from innovators and imitators, respectively. We illustrate that there is an increase in the market size along with the adoption of new product and this increase is addressed in this paper. The explicit mean value function for the two types of disadoption processes is derived in this paper. The thrust of the research is on studying the management educational services in the Delhi/NCR region of India and the impact of disadoption on the long term growth of such services. In order to validate the proposed modeling framework, we make use of different goodness-of-fit criteria on primary data collected from an institute in Delhi/NCR.

scholarly journals A Variational Approach to Scripts

2021 ◽  
Vol 12 ◽  
Author(s):  
Mahault Albarracin ◽  
Axel Constant ◽  
Karl J. Friston ◽  
Maxwell James D. Ramstead
Keyword(s):  
Social Order ◽  
Formal Model ◽  
Behavioral Modeling ◽  
Integrative Model ◽  
Action Perception ◽  
Active Inference ◽  
Modeling Framework ◽  
Dual Nature ◽  
The Social ◽  
Action Sequences

This paper proposes a formal reconstruction of the script construct by leveraging the active inference framework, a behavioral modeling framework that casts action, perception, emotions, and attention as processes of (Bayesian or variational) inference. We propose a first principles account of the script construct that integrates its different uses in the behavioral and social sciences. We begin by reviewing the recent literature that uses the script construct. We then examine the main mathematical and computational features of active inference. Finally, we leverage the resources of active inference to offer a formal model of scripts. Our integrative model accounts for the dual nature of scripts (as internal, psychological schema used by agents to make sense of event types and as constitutive behavioral categories that make up the social order) and also for the stronger and weaker conceptions of the construct (which do and do not relate to explicit action sequences, respectively).

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