Exploiting Shape Similarity in Engineering Analysis

2006 ◽  
Author(s):  
Sankara Hari Gopalakrishnan ◽  
Krishnan Suresh
Keyword(s):  
Upper And Lower Bounds ◽  
Shape Similarity ◽  
Engineering Analysis ◽  
Analysis Methodology ◽  
Analysis Methods ◽  
Engineering Designs ◽  
Modern Analysis ◽  
Complex Engineering ◽  
And Performance ◽  
The Cost

Engineering analysis methods, such as the finite element method, are employed extensively to optimize complex engineering designs, but their success in conceptual product development is rather limited since numerous designs must be analyzed to cover the design space, and unfortunately, modern analysis methods can be tedious and time consuming in such scenarios. We propose here a novel analysis methodology for conceptual design wherein, given the simulation results and performance of one of the designs, one predicts upper and lower bounds on the performance of geometrically similar designs. The methodology rests on sound mathematical principles such as adjoint theory of boundary value problems, and is partly motivated by recent work on shape similarity exploitation in manufacturing wherein the cost of manufacturing a new part is estimated by retrieving the manufacturing costs of geometrically similar parts.

Intelligent gradient-based search of incompletely defined design spaces

1997 ◽  
Vol 11 (3) ◽  
pp. 199-210 ◽  
Author(s):  
Mark Schwabacher ◽  
Andrew Gelsey
Keyword(s):  
Numerical Optimization ◽  
Computation Method ◽  
Rule Based ◽  
Transport Aircraft ◽  
Supersonic Transport ◽  
Engineering Designs ◽  
Gradient Computation ◽  
Gradient Based ◽  
Complex Engineering ◽  
The Cost

AbstractGradient-based numerical optimization of complex engineering designs offers the promise of rapidly producing better designs. However, such methods generally assume that the objective function and constraint functions are continuous, smooth, and defined everywhere. Unfortunately, realistic simulators tend to violate these assumptions. We present a rule-based technique for intelligently computing gradients in the presence of such pathologies in the simulators, and show how this gradient computation method can be used as part of a gradient-based numerical optimization system. We tested the resulting system in the domain of conceptual design of supersonic transport aircraft, and found that using rule-based gradients can decrease the cost of design space search by one or more orders of magnitude.

Return on Invesment (ROI) of Software Product: A Systematic Literature Review

2015 ◽  
Vol 6 (1) ◽  
pp. 50-57
Author(s):  
Rizqa Raaiqa Bintana ◽  
Putri Aisyiyah Rakhma Devi ◽  
Umi Laili Yuhana
Keyword(s):  
Return On Investment ◽  
Assessment Criteria ◽  
Software Product ◽  
And Performance ◽  
Rational Consideration ◽  
Actual Return ◽  
The Cost ◽  
Investment Models ◽  
The Impact

The quality of the software can be measured by its return on investment. Factors which may affect the return on investment (ROI) is the tangible factors (such as the cost) dan intangible factors (such as the impact of software to the users or stakeholder). The factor of the software itself are assessed through reviewing, testing, process audit, and performance of software. This paper discusses the consideration of return on investment (ROI) assessment criteria derived from the software and its users. These criteria indicate that the approach may support a rational consideration of all relevant criteria when evaluating software, and shows examples of actual return on investment models. Conducted an analysis of the assessment criteria that affect the return on investment if these criteria have a disproportionate effort that resulted in a return on investment of a software decreased. Index Terms - Assessment criteria, Quality assurance, Return on Investment, Software product

Characterisation of Static Strip Seal Flow

2007 ◽  
Author(s):  
Arash Farahani ◽  
Peter Childs
Keyword(s):  
Gas Flow ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Main Stream ◽  
Cfd Modelling ◽  
Height Range ◽  
And Performance ◽  
Nozzle Guide ◽  
The Cost ◽  
Cooling Air

Strip seals are used in gas turbine engines between two static elements or between components which do not move relative to each other, such as Nozzle Guide Vanes (NGVs). The key role of a strip seal between NGV segments is sealing between the flow through the main stream annulus and the internal air system, a further purpose is to limit the inter-segmental movements. In general the shape of the strip seal is a rectangular strip that fits into two slots in adjacent components. The minimum clearance required for static strip seals must be found by accounting for thermal expansion, misalignment, and application, to allow correct fitment of the strip seals. Any increase in leakage raises the cost due to an increase in the cooling air use, which is linked to specific fuel consumption, and it can also alter gas flow paths and performance. The narrow path within the seal assembly, especially the height has the most significant affect on leakage. The height range of the narrow path studied in this paper is 0.01–0.06 mm. The behaviour of the flow passing through the narrow path has been studied using CFD modelling and measurements in a bespoke rig. The CFD and experimental results show that normalized leakage flow increases with pressure ratio before reaching a maximum. The main aim of this paper is to provide new experimental data to verify the CFD modelling for static strip seals. The typical flow characteristics validated by CFD modelling and experiments can be used to predict the flow behaviour for future static strip seal designs.

scholarly journals Alert: An Adaptive Low-Latency Event-Driven MAC Protocol for Wireless Sensor Networks

2011 ◽  
Vol 2011 ◽  
pp. 1-19
Author(s):  
Vinod Namboodiri ◽  
Abtin Keshavarzian
Keyword(s):  
Mac Protocol ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Network Applications ◽  
Alarm Systems ◽  
Minimum Latency ◽  
Multiple Sensor ◽  
Protocol Execution ◽  
And Performance ◽  
The Cost

Collection of rare but delay-critical messages from a group of sensor nodes is a key process in many wireless sensor network applications. This is particularly important for security-related applications like intrusion detection and fire alarm systems. An event sensed by multiple sensor nodes in the network can trigger many messages to be sent simultaneously. We present Alert, a MAC protocol for collecting event-triggered urgent messages from a group of sensor nodes with minimum latency and without requiring any cooperation or prescheduling among the senders or between senders and receiver during protocol execution. Alert is designed to handle multiple simultaneous messages from different nodes efficiently and reliably, minimizing the overall delay to collect all messages along with the delay to get the first message. Moreover, the ability of the network to handle a large number of simultaneous messages does not come at the cost of excessive delays when only a few messages need to be handled. We analyze Alert and evaluate its feasibility and performance with an implementation on commodity hardware. We further compare Alert with existing approaches through simulations and show the performance improvement possible through Alert.

scholarly journals ИСПОЛЬЗОВАНИЕ ТЕОРИИ НЕЧЕТКИХ МНОЖЕСТВ В ЭКОНОМИЧЕСКОМ АНАЛИЗЕ ИНВЕСТИЦИОННЫХ ПРОЕКТОВ

2018 ◽  
Vol 2 (5(17)) ◽  
pp. 44-48
Author(s):  
Файзиев Р. А. ◽  
Хаитматов У. Т. ◽  
Азаматов О. Х. ◽  
Джуманиязов Ш. Р. ◽  
Хасанова Х. Х.
Keyword(s):  
Integral Characteristic ◽  
Mathematical Methods ◽  
Investment Projects ◽  
Performance Targets ◽  
Methods Of Evaluation ◽  
Interval Approach ◽  
And Performance ◽  
The Cost ◽  
Fuzzy Interval ◽  
Theory Of Fuzzy Sets

The article outlines the main features of the use of the theory of indefinite bundles in the evaluation of the cost-effectiveness of investment projects.He analysis of methods for quantifying the effectiveness of the IP under uncertainty suggests that the existing methods either eliminate the uncertainty from the IP model, which is inappropriate, since uncertainty is an integral characteristic of any forecast, or are unable to formally describe, and take into account all possible varieties of types of uncertainty.Methods based on the theory of fuzzy sets refer to the methods of evaluation and decision-making under conditions of uncertainty. Their use implies the formalization of the initial parameters and performance targets of the IP in the form of a vector of interval values (fuzzy interval), the hit in each interval of which is characterized by a certain degree of uncertainty.Also, the fuzzy-interval approach has advantages in solving the problems of forming an optimal portfolio of investment projects. To solve the problem of forming an optimal IP portfolio, a large number of models for the formation of an optimal IP portfolio have been developed, differing from each other in the form of objective functions, variable properties, used by mathematical methods, and uncertainty.

scholarly journals Remuneration and Performance

2020 ◽  
Vol 86 ◽  
pp. 01034
Author(s):  
Iriani Ismail
Keyword(s):  
High Performance ◽  
Qualitative Method ◽  
Optimal Performance ◽  
External Factors ◽  
Interactive Analysis ◽  
Analysis Methods ◽  
Depth Interview ◽  
And Performance ◽  
Internal And External Factors

The aim of this study is to explain the role of remuneration in improving the performance of library employees. This study uses the qualitative method which the population is all employees numbering 17 people. Based on interactive analysis methods and ethnographic techniques, its took In-depth interview and observations. Using this analysis, the result showed that the remuneration has an important role in improving employees performance. Some internal and external factors influence it so that optimal performance is obtained. Generally, employees expect that the remuneration has been high to be accepted like as expected. Most employees demands such remuneration to meet their daily needs. External factors also has a strong role so the employees demand high, but not balanced with high performance.

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