22,592 research outputs found
Parametric optimization of the femoropopliteal artery stent design based on numerical analysis
High-failure rates of Peripheral Arterial Disease (PAD) stenting were reported due to
the inability of certain stent strut configuration to accommodate severe biomechanical
environment of the Femoro-Popliteal Artery (FPA) such as bends, twists, and axially
compresses during limb flexion. The unique of mechanical deformation environment
in FPA has been considered one of main factors affecting the durability of the FPA
stent and reducing the stent life. Consequently, various optimization techniques have
been developed to improve the mechanical performance of the FPA stent. The present
work shown that, the first-two of twelve FPA resemble stent models stent models have
been selected with a net score of 3.65 Model I and, with a net score of 3.55 Model II
via applying Pictorial Selection Method. Finite Element Method (FEM) of
optimization study based-parameterization has been conducted for stent strut
dimensions, stents were compared in terms of force-stress behavior. Multi Criteria
Decision Making (MCDM) method has been utilized to identify the best combination
of strut dimensions. The strut thickness parameterization results were in relation T α
1/Ï (T is strut thickness) for both models with all mechanical loading modes.
Moreover, the strut width parameterization results were in relation W α 1/Ï (W is strut
width) for both models with all mechanical loading modes. Whereas, the strut length
parameterization results were in relation L α Ï in case of Model I and, L α 1/Ï (L is
strut length) in case of Model II, under axial loads, while under three-point bending
and torsion loading modes L α Ï for both models, under radial compression the
relations were L α 1/Ï in case of Model I and, L α Ï in case of Model II. The best
combination of strut dimension in the thickness case was t4 = 230 ”m for both models,
in strut width were w3=0.180, and w4= 0.250 mm for Model I and Model II,
respectively, and in strut length were l2= 1.40, and l2= 1.75 mm for Model I and Model
II, respectively. In conclusions, the mathematical selection approach and the consistent
mathematical approach of MCDM has been proposed, also the mechanical
performance has been improved for parameterized stent models
A New Fuzzy MCDM Framework to Evaluate E-Government Security Strategy
Ensuring security of e-government applications and infrastructures is crucial
to maintain trust among stakeholders to store, process and exchange information
over the e-government systems. Due to dynamic and continuous threats on
e-government information security, policy makers need to perform evaluation on
existing information security strategy as to deliver trusted e-government
services. This paper presents an information security evaluation framework
based on new fuzzy multi criteria decision making (MCDM) to help policy makers
conduct comprehensive assessment of e-government security strategy.Comment: IEEE 4th International Conference on Application of Information and
Communication Technologies AICT201
Optimization of the supplier selection process in prefabrication using BIM
Prefabrication offers substantial benefits including reduction in construction waste, material waste, energy use, labor demands, and delivery time, and an improvement in project constructability and cost certainty. As the material cost accounts for nearly 70% of the total cost of the prefabrication project, to select a suitable material supplier plays an important role in such a project. The purpose of this study is to present a method for supporting supplier selection of a prefabrication project. The proposed method consists of three parts. First, a list of assessment criteria was established to evaluate the suitability of supplier alternatives. Second, Building Information Modelling (BIM) was adopted to provide sufficient information about the project requirements and suppliers’ profiles, which facilitates the storage and sharing of information. Finally, the Analytic Hierarchy Process (AHP) was used to rank the importance of the assessment criteria and obtain the score of supplier alternatives. The suppliers were ranked based on the total scores. To illustrate how to use the proposed method, it was applied to a real prefabrication project. The proposed method facilitates the supplier selection process by providing sufficient information in an effective way and by improving the understanding of the project requirements
A framework for the selection of the right nuclear power plant
Civil nuclear reactors are used for the production of electrical energy. In the nuclear industry vendors propose several nuclear reactor designs with a size from 35â45âMWe up to 1600â1700âMWe. The choice of the right design is a multidimensional problem since a utility has to include not only financial factors as levelised cost of electricity (LCOE) and internal rate of return (IRR), but also the so called âexternal factorsâ like the required spinning reserve, the impact on local industry and the social acceptability. Therefore it is necessary to balance advantages and disadvantages of each design during the entire life cycle of the plant, usually 40â60 years. In the scientific literature there are several techniques for solving this multidimensional problem. Unfortunately it does not seem possible to apply these methodologies as they are, since the problem is too complex and it is difficult to provide consistent and trustworthy expert judgments. This paper fills the gap, proposing a two-step framework to choosing the best nuclear reactor at the pre-feasibility study phase. The paper shows in detail how to use the methodology, comparing the choice of a small-medium reactor (SMR) with a large reactor (LR), characterised, according to the International Atomic Energy Agency (2006), by an electrical output respectively lower and higher than 700âMWe
WHY FUZZY ANALYTIC HIERARCHY PROCESS APPROACH FOR TRANSPORT PROBLEMS?
The evaluation of transport projects has become increasingly complex. Different aspects have to be taken into account and the consequences of the problems are usually far reaching and the different policy alternatives are numerous and difficult to predict. Several pressure or action groups have also emerged causing an even more complex decision making process. The use of multi criteria analysis for the evaluation of transport projects has increased due to this increasing complexity of the problem situation. At the same time, the importance of stakeholders within this evaluation process should have been recognized. Researches on transport projects are generally carried out to provide information to policymakers that have to operate within restrictive parameters (political, economical, social, etcĂąâŹÂŠ). Researchers should therefore take greater account of the different priorities of stakeholders such as policymakers, private enterprises and households. These stakeholders should be incorporated explicitly in the evaluation process. The Analytic Hierarchy Process is one of the Fuzzy Multiple Criteria Decision Making methods. It can be applied in a very broad range of applications of decision problems. Logistics, urban planning, public politics, marketing, finance, education, economics are a part of this wide application area. In transport subjects it can be used for the evaluation of transport policy measures or decision making problems. Due to its wide range application area, it has been an exciting research subject for many different field researchers. The aim of this paper is to introduce AHP method and to offer how to benefit it for the preference of urban planners in transport problems. This paper is composed of two main parts. First part consists of the literature survey regarding with the AHP and its application areas. The advantage of methods had been mentioned. Second part focuses on a sample application of AHP technique. The study uses AHP technique to determine the selection criteria in the transhipment port selection decision-making process. Keywords: Analytic Hierarchy Process, Multi criteria analysis, Transshipment port selection.
Intelligent protocol adaptation for enhanced medical e-collaboration
Copyright @ 2003 AAAIDistributed multimedia e-health applications have a set specific requirements which must be taken into account effective use is to be made of the limited resources provided by public telecommunication networks. Moreover, there an architectural gap between the provision of network-level Quality of Service (QoS) and user requirements of e-health applications. In this paper, we address the problem bridging this gap from a multi-attribute decision-making perspective in the context of a remote collaborative environment for back pain treatment. We propose intelligent mechanism that integrates user- related requirements with the more technical characterisation Quality of Service. We show how our framework is capable of suggesting appropriately tailored transmission protocols, by incorporating user requirements in the remote delivery e-health solutions
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