Incorporation of manufacturing information into an MDO environment

1999 ◽  
Vol 103 (1026) ◽  
pp. 383-388 ◽  
Author(s):  
K. Gantois ◽  
A. J. Morris
Keyword(s):  
Cost Model ◽  
Design Stage ◽  
Manufacturing Cost ◽  
Cost Models ◽  
Cost Modelling ◽  
Design Changes ◽  
Recurrent Cost ◽  
Preliminary Design Stage ◽  
Wing Sweep ◽  
The Cost

Abstract The Paper describes a metal and composite recurrent cost model of a large civil aircraft wing structure for a multidisciplinary design, analysis and optimisation (MDO) environment. The work was part of a recent European MDO project (BE95-2056) which investigated methods for the integration of structures, aerodynamics, dynamics and manufacturing cost at the preliminary design stage. The paper discusses the cost modelling approach, which is based on parametric and process cost model methods, and the integration of the cost models into an MDO process. Results for the cost models are shown. A framework has been successfully developed which allows the incorporation of manufacturing cost models into an MDO environment. It allows a designer to evaluate cost changes with respect to specific design changes such as rib pitch, stringer pitch, wing area and wing sweep.

scholarly journals GASOL: Gas Analysis and Optimization for Ethereum Smart Contracts

2020 ◽  
pp. 118-125 ◽  
Author(s):  
Elvira Albert ◽  
Jesús Correas ◽  
Pablo Gordillo ◽  
Guillermo Román-Díez ◽  
Albert Rubio
Keyword(s):  
Upper Bound ◽  
Cost Model ◽  
Gas Analysis ◽  
Smart Contracts ◽  
Cost Models ◽  
Automatic Optimization ◽  
Gas Consumption ◽  
The Cost ◽  
Storage Patterns ◽  
Program Line

Abstract We present the main concepts, components, and usage of Gasol, a Gas AnalysiS and Optimization tooL for Ethereum smart contracts. Gasol offers a wide variety of cost models that allow inferring the gas consumption associated to selected types of EVM instructions and/or inferring the number of times that such types of bytecode instructions are executed. Among others, we have cost models to measure only storage opcodes, to measure a selected family of gas-consumption opcodes following the Ethereum’s classification, to estimate the cost of a selected program line, etc. After choosing the desired cost model and the function of interest, Gasol returns to the user an upper bound of the cost for this function. As the gas consumption is often dominated by the instructions that access the storage, Gasol uses the gas analysis to detect under-optimized storage patterns, and includes an (optional) automatic optimization of the selected function. Our tool can be used within an Eclipse plugin for which displays the gas and instructions bounds and, when applicable, the gas-optimized function.

CAD-Based Tolerance Analysis in Preliminary Design Stages Enabling Early Tolerance Evaluation

2018 ◽  
Author(s):  
Stefan Goetz ◽  
Benjamin Schleich ◽  
Sandro Wartzack
Keyword(s):  
Tolerance Analysis ◽  
Design Stage ◽  
Preliminary Design ◽  
Design Changes ◽  
Preliminary Design Stage ◽  
Geometric Deviations ◽  
Set Up ◽  
Quality Of Products ◽  
Analysis Models

Associated with manufacturing and assembly processes, inevitable geometric deviations have a decisive influence on the function and quality of products. Therefore, their consideration and management are important tasks in product development. Moreover, to meet the demand for short development times, the front-loading of design processes is indispensable. This requires early tolerance analyses evaluating the effect of deviations in a design stage, where the product’s geometry has not yet been finally defined. Since such an early tolerance consideration allows quick and economic design changes seeking for robust designs, it is advisable that the design engineer, who is entirely familiar with the design, should take this step. For this purpose, this paper presents an easy-to-use CAD-based tolerance analysis method for skeleton models. The relevant part deviations are represented by varying geometric dimensions with externally driven family tables. The approach comprises the strength of vector-based methods but does not require an expensive set-up of tolerance analysis models. Particularly, the novelty of this method lies in the CAD-internal sampling-based tolerance analysis of simple geometries without the use of expensive CAT software. This enables designers to evaluate the effect of tolerances already at the preliminary design stage. Using a case study, the presented approach is compared with the conventional vector-based tolerance analysis.

A Levelized Cost of Energy (LCOE) Model for Wind Farms That Includes Power Purchase Agreement (PPA) Energy Delivery Limits

2016 ◽  
Author(s):  
Maira Bruck ◽  
Navid Goudarzi ◽  
Peter Sandborn
Keyword(s):  
Wind Farm ◽  
Cost Model ◽  
Wind Farms ◽  
Cost Models ◽  
Renewable Energy Resources ◽  
Supply Source ◽  
Levelized Cost ◽  
Cost Of Energy ◽  
Expected Performance ◽  
The Cost

The cost of energy is an increasingly important issue in the world as renewable energy resources are growing in demand. Performance-based energy contracts are designed to keep the price of energy as low as possible while controlling the risk for both parties (i.e., the Buyer and the Seller). Price and risk are often balanced using complex Power Purchase Agreements (PPAs). Since wind is not a constant supply source, to keep risk low, wind PPAs contain clauses that require the purchase and sale of energy to fall within reasonable limits. However, the existence of those limits also creates pressure on prices causing increases in the Levelized Cost of Energy (LCOE). Depending on the variation in capacity factor (CF), the power generator (the Seller) may find that the limitations on power purchasing given by the utility (the Buyer) are not favorable and will result in higher costs of energy than predicted. Existing cost models do not take into account energy purchase limitations or variations in energy production when calculating an LCOE. A new cost model is developed to evaluate the price of electricity from wind energy under a PPA contract. This study develops a method that an energy Seller can use to negotiate delivery penalties within their PPA. This model has been tested on a controlled wind farm and with real wind farm data. The results show that LCOE depends on the limitations on energy purchase within a PPA contract as well as the expected performance characteristics associated with wind farms.

Optimization of Vacuum Assisted Resin Transfer Molding for Sandwich Panels

2000 ◽  
Author(s):  
Jean Dai ◽  
Dominique Pellaton ◽  
H. Thomas Hahn
Keyword(s):  
Cost Model ◽  
Resin Transfer Molding ◽  
Sandwich Panels ◽  
Injection Pressure ◽  
Design Parameters ◽  
Manufacturing Cost ◽  
High Permeability ◽  
Transfer Molding ◽  
Advantages And Disadvantages ◽  
The Cost

Abstract The vacuum assisted resin transfer molding (VARTM) of sandwich panels may be facilitated by using high permeability layers over the skins or adding grooves in the surfaces of the core. The present paper investigates the advantages and disadvantages of both methods in terms of manufacturing cost and time through simulations and experimental observations. Before comparison, each method is optimized through simulations. The panel geometry and the injection pressure are held constant. The design parameters are the number of high permeability layers, and the number and size of grooves. The optimized processes are finally compared with each other in terms of the aforementioned cost and time. Meanwhile, the sensitivities of several important parameters in the cost model to the optimal result are studied.

scholarly journals Application of Dynamic Fragmentation Methods in Multimedia Databases: A Review

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1352
Author(s):  
Felipe Castro-Medina ◽  
Lisbeth Rodríguez-Mazahua ◽  
Asdrúbal López-Chau ◽  
Jair Cervantes ◽  
Giner Alor-Hernández ◽  
...  
Keyword(s):  
Response Times ◽  
Cost Model ◽  
Multimedia Databases ◽  
Reference Points ◽  
Cost Models ◽  
Execution Costs ◽  
Dynamic Fragmentation ◽  
Testing Stage ◽  
Access Patterns ◽  
The Cost

Fragmentation is a design technique widely used in multimedia databases, because it produces substantial benefits in reducing response times, causing lower execution costs in each operation performed. Multimedia databases include data whose main characteristic is their large size, therefore, database administrators face a challenge of great importance, since they must contemplate the different qualities of non-trivial data. These databases over time undergo changes in their access patterns. Different fragmentation techniques presented in related studies show adequate workflows, however, some do not contemplate changes in access patterns. This paper aims to provide an in-depth review of the literature related to dynamic fragmentation of multimedia databases, to identify the main challenges, technologies employed, types of fragmentation used, and characteristics of the cost model. This review provides valuable information for database administrators by showing essential characteristics to perform proper fragmentation and to improve the performance of fragmentation schemes. The reduction of costs in fragmentation methods is one of the most desired main properties. To fulfill this objective, the works include cost models, covering different qualities. In this analysis, a set of characteristics used in the cost models of each work is presented to facilitate the creation of a new cost model including the most used qualities. In addition, different data sets or reference points used in the testing stage of each work analyzed are presented.

Cost Estimation Model Based on Improved Spreadsheet Algorithm for Assembly Line Manufacturing Systems

2012 ◽  
Vol 490-495 ◽  
pp. 2173-2177
Author(s):  
Bin Zeng ◽  
Rui Wang ◽  
Chao Yang Ma
Keyword(s):  
Cost Estimation ◽  
Manufacturing Systems ◽  
Cost Model ◽  
Manufacturing Cost ◽  
Cost Models ◽  
Estimation Model ◽  
Stochastic Variation ◽  
Virtual Plant ◽  
Model Based ◽  
Cost Estimation Model

Traditionally assembly cost models are established through static spreadsheet algorithms. However, there are some inherent problems in using spreadsheets for the estimation of manufacturing cost. Among these is the lack of accounting for dynamic effects caused by stochastic variation such as inventory fluctuation, downtimes, supply interruptions, and system failures. Therefore, a dynamic cost estimation model is proposed which can be seen as an integration method between spreadsheet modeling and the virtual plant concept, which maintained the accessibility and flexibility of the spreadsheet model, and did not require a significant increase in the effort level to build a simulation. However, it still includes the effects of interaction between machines, along with simulating random failures, maintenance dispatch and repair. A case study is also tested and the results verify that the methodology demonstrates the feasibility of dynamic cost model based on a number of improvements on static spreadsheet algorithms

scholarly journals Marvel: A Data-Centric Approach for Mapping Deep Learning Operators on Spatial Accelerators

2022 ◽  
Vol 19 (1) ◽  
pp. 1-26
Author(s):  
Prasanth Chatarasi ◽  
Hyoukjun Kwon ◽  
Angshuman Parashar ◽  
Michael Pellauer ◽  
Tushar Krishna ◽  
...  
Keyword(s):  
Deep Learning ◽  
Cost Model ◽  
Cost Models ◽  
Mapping Space ◽  
Loop Nest ◽  
Loop Nests ◽  
Higher Dimensional ◽  
On Chip ◽  
The Cost ◽  
Dimensional Mapping

A spatial accelerator’s efficiency depends heavily on both its mapper and cost models to generate optimized mappings for various operators of DNN models. However, existing cost models lack a formal boundary over their input programs (operators) for accurate and tractable cost analysis of the mappings, and this results in adaptability challenges to the cost models for new operators. We consider the recently introduced Maestro Data-Centric (MDC) notation and its analytical cost model to address this challenge because any mapping expressed in the notation is precisely analyzable using the MDC’s cost model. In this article, we characterize the set of input operators and their mappings expressed in the MDC notation by introducing a set of conformability rules . The outcome of these rules is that any loop nest that is perfectly nested with affine tensor subscripts and without conditionals is conformable to the MDC notation. A majority of the primitive operators in deep learning are such loop nests. In addition, our rules enable us to automatically translate a mapping expressed in the loop nest form to MDC notation and use the MDC’s cost model to guide upstream mappers. Our conformability rules over the input operators result in a structured mapping space of the operators, which enables us to introduce a mapper based on our decoupled off-chip/on-chip approach to accelerate mapping space exploration. Our mapper decomposes the original higher-dimensional mapping space of operators into two lower-dimensional off-chip and on-chip subspaces and then optimizes the off-chip subspace followed by the on-chip subspace. We implemented our overall approach in a tool called Marvel , and a benefit of our approach is that it applies to any operator conformable with the MDC notation. We evaluated Marvel over major DNN operators and compared it with past optimizers.

Accuracy criterion and analysis of continuous earth observation constellations

2020 ◽  
pp. 111-118
Author(s):  
Yury P. ULYBYSHEV ◽  
Mikhail Yu. GUNCHENKO
Keyword(s):  
Design Stage ◽  
Preliminary Design ◽  
Satellite Constellations ◽  
Near Surface ◽  
The Earth ◽  
Accuracy Criterion ◽  
Preliminary Design Stage ◽  
Comparative Accuracy ◽  
The Cost ◽  
Polar Satellite

A criterion for analyzing the accuracy characteristics of applied satellite constellations (ASC) possible structures for observing targets in the Earth surface and/or near-surface layer is proposed. The criterion is not related to features of onboard hardware and depends on structure, parameters and dynamics of ASC. The criterion is based on consideration of determination accuracy of the objects geographical coordinates. An algorithm for numerical simulation of ASC is presented. Comparative accuracy estimates for various types of ASC are presented. Accuracy characteristics of Walker constellations and Near-Polar Satellite Constellations with various pattern types are considered. The main design-ballistic parameters that determine the accuracy of ASC and affect the cost of their creation are determined, and the nature of these parameters influence also shown. Results can be used for initial decision of ASC pattern during preliminary design stage. Key words: observing satellite constellations, accuracy criterion, analysis of observation constellations, Walker constellations, Near-Polar Satellite Constellations.

scholarly journals Query evaluation and optimization in the semantic web

2008 ◽  
Vol 8 (3) ◽  
pp. 393-409 ◽  
Author(s):  
EDNA RUCKHAUS ◽  
EDUARDO RUIZ ◽  
MARÍA-ESTHER VIDAL
Keyword(s):  
Query Optimization ◽  
Adaptive Sampling ◽  
Cost Model ◽  
Optimization Technique ◽  
Deductive Database ◽  
Query Evaluation ◽  
Cost Models ◽  
Web Ontology Language ◽  
Ontology Language ◽  
The Cost

AbstractWe address the problem of answering Web ontology queries efficiently. An ontology is formalized as adeductive ontology base(DOB), a deductive database that comprises the ontology's inference axioms and facts. A cost-based query optimization technique for DOB is presented. A hybrid cost model is proposed to estimate the cost and cardinality of basic and inferred facts. Cardinality and cost of inferred facts are estimated using an adaptive sampling technique, while techniques of traditional relational cost models are used for estimating the cost of basic facts and conjunctive ontology queries. Finally, we implement a dynamic-programming optimization algorithm to identify query evaluation plans that minimize the number of intermediate inferred facts. We modeled a subset of the Web ontology language Lite as a DOB and performed an experimental study to analyze the predictive capacity of our cost model and the benefits of the query optimization technique. Our study has been conducted over synthetic and real-world Web ontology language ontologies and shows that the techniques are accurate and improve query performance.

scholarly journals Chimpanzees use advanced spatial cognition to plan least-cost routes

2019 ◽  
Author(s):  
Samantha J. Green ◽  
Bryan J. Boruff ◽  
Cyril C. Grueter
Keyword(s):  
Cognitive Abilities ◽  
Cognitive Skills ◽  
Cognitive Complexity ◽  
Cost Model ◽  
Null Model ◽  
Strong Relationship ◽  
Landscape Complexity ◽  
Cost Modelling ◽  
Straight Line ◽  
The Cost

SummaryWhile the ability of naturally ranging animals to recall the location of food resources and use straight-line routes between them has been demonstrated in several studies, it is not known whether animals can use knowledge of their physical landscape to plan least-cost routes. This ability is likely to be particularly important for animals living in highly variable energy landscapes, where movement costs are exacerbated. Here, we used least-cost modelling to investigate whether chimpanzees (Pan troglodytes) living in a rugged, montane environment use advanced cognitive skills to plan energy efficient routes. We used a subset of chimpanzee movement segments together with the available laboratory measurements of chimpanzee energy expenditure to assign movement ‘costs’ which were incorporated in an anisotropic least-cost model and straight-line null model. The least-cost model performed better than the straight-line model across all parameters, and linear mixed modelling showed a strong relationship between the cost of observed chimpanzee travel and predicted least-cost routes. To our knowledge, our study provides the first example of spatial memory for landscape and the ability to plan least-cost routes in non-human animals. These cognitive abilities may be a key trait that have enabled chimpanzees to maintain their energy balance in a low-resource environment. Our findings provide a further example of how the advanced cognitive complexity of hominids have facilitated their adaptation to a variety of environmental conditions and lead us to hypothesise that landscape complexity may play a role in shaping cognition.

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