Friday, March 23, 2012

030070104 Cebrail Yıldırım 5th week


Decision Matrix (new&better) [Decision making method]
The decision matrix enables you to evaluate a given set of alternatives against group-prescribed criteria. Given a list of alternatives, the group identifies criteria by which the alternatives should be measured. Each criteria is then assigned a value. The values can be weighted if the group wishes to do so. Then each member fills out an individual decision matrix, assigning a “score” for each alternative according to the criteria. The individual scores are tabulated and averages are computed. The group then discusses the data and makes its decision or proceed to de further analysis.
(   T. Justice, David W. Jamieson, The faciliator’s Field Book, 2006 pg. 22)

Decision Matrix (previous)

We can use a simple matrix to outline the basics of information processing. The decision matrix (or table) is simply a chart that provides a useful visual reference. The rows and columns represent decision dimensions and
alternatives respectively. With this simple matrix, we can explore the various search patterns of decisions makers. We can also compare the dynamics of the models. For instance, we can show how a rational process could lead to a different choice than would a cognitive process.
(
Mintz A., Deouren K., Understanding Foreign Policy Decision Making, 2010, p. 88)



New definition is better because it gives more sensible informations.


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Microactuator(new&better) [Converter Device]
An actuator is a device that converts energy from one form, such as electrical, mechanical, thermal, magnetic, chemical and radiadion energy, into the mechanical form. In some cases, a microactuator may convert energy into intermediate forms before resulting in the final mechanical output.
Input
Output (Mechanical)
Electrical
Electrostatics
Piezoelectricity
Mechanical
Pneumatics
Hydrolics
Thermal
Expansion
Shape memory effect
Phase chance
Magnetic
Magnetostriction
Magnetostatics
Chemical
Combustion

(Jan G. Korvink, Oliver Paul, MEMS: a practical guide to design, analysis, and application, 2006, pg. 752)


Microactuators(Previous)

Like a sensor an activator converts a physical variable of one type into another type but the converted variable usually involves some mechanical action(e.g. a piezoelectric device oscillating in response to an alternating electric field).An actuator causes a change in a position or the application of force.Examples of microactuators include valves , positioners ,switchers ,pumos and rotational and linear motors.

(Fundamentals of modern manufacturing;materials,processing and systems , Mikel P.Groover,p.855


New one is better because it has more apparent definition and table.


 
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Cell Formation Approach(new&Better) [Optimization Approach]
Cell formation considering the availability of alternative routings and processing capacity of available machines is a challenging optimization problem, since it imposes the solution of a two step problem;
1)      Assign machines to cells
2)      Assign manufacturing parts(routings) to cells
The objective is to minimize extra-cellular processing of tasks when routings of parts are selected.

(Alexander Gelbukh, E. F. Morales, MICAI 2008: advances in artificial intelligence, pg. 482)

Cell Formation Approach
                In this approach the Jaccard similarity coefficient is first calculated between each machine pair of machines. Next, agraph is defined where each vertex represents a machine and the edges represent the relationships between the machines. An edge connects two vertices in the graph only is the similarity coefficient for the machine pair is greater than some threshold value. Finally machine cells are formed by locating maximal “cliques” (a maximal coplete subgraph) or near cliques and merging them together. In CM terminology, a clique is a group of machines in which every pair is related with a similarity coefficient greater than the specified threshold value.

(Suresh C. N., Kay J. M., Group Technology and Cellular Manufacturing, p.144)


New one is better because it gives more sensible definition.

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Hole Drilling Method(new&better)
[Destructive Measuring Method]
The hole-drilling method is probably the most widely used destructive method for measuring resudial stresses. It involves drilling a small hole in the surface of the specimen and measuring the deformations of the surrounding surface, traditionally using strain gages, and more recently using full-field optical techniques such as Moire interferometry. The figure  below illustrates the process. The hole-drilling method is popular because it gives reliable and rapid results with many specimen types, and creates only localized and often tolerable damage. The measurement procedure has been well developed and is standardizied as ASTM E837.

(Tom Proulx, Experimental and Applied Mechanics, pg. 223)


 




Hole Drilling Method (previous)

The hole drilling method is a mechanical method for measuring residual stresses and it is standardized in the ASTM E837. The basic hole drilling procedure involves drilling of a small hole diameter d0 into the surface of a stressed material. The stress equilibrium is locally disturbed due to this intervention whereby a new aquilibrium is reached. This change is measured usually radial to the hole with special stain-gage rosets in the form of relieved strains.

(Enrique Garcia Sobolevski, Residual stress analysis of components with real geometries using the incremental hole-drilling technique and a differential evaluation method, page 18


New one has been fortified with a figure to make sense.


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Ring Core Method(new&better) 
[Destructive Measuring Method]
The ring-core method is an “inside-out” variant of the hole-drilling method. Whereas the hole drilling method involves drilling a central hole and measuring the resulting deformation of the surrounding surface, the ring core method involves measuring the deformation in a central area caused by the cutting an annular slot in the surrounding material. The figure below illustrates the geometry. As with the hole drilling method, the ring-core method has a basic implementation to evaluate in-plane stresses and an incremental implementation to determine the stress profile. The ring-core method has the advantage over the hole-drilling method that it provides much larger surface strains. However, is less frequently used because it creates much greater specimen damage and is much less convenient to implement in practice.
(Tom Proulx, Experimental and Applied Mechanics, pg. 223)

 

 Ring Core method (previous)
The ring core method is also based on the strain caused by disturbing the stress field, but in this case a relatively stress-free island of material is isolated by making a shallow ring around a strain-gage. This method is one of the least destructive mechanical stress-relief techniques and are relatively simple and economical.

(George E. Tottem, Handbook of residual stress and deformation of steel, page 110


New one has been fortified with a figure to make sense.

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