030070111 Hakan YORULMUŞ 3rd week

1) Surface Roughness    (Group: Material Property)
(previous)

Surface roughness is a measurable characteristic based on the roughness deviations as waviness, lay and flaws. The most commonly used measure of surface texture is surface roughness. Surface roughness can be defined as the average of the vertical deviations from the nominal surface over a specified surface length. An arithmetic average (AA) is generally used, besed on the absolute values of the deviations and this roughness value is referred to by the name average roughness. Arithmetic Average (AA) method is the most widely used averaging method for surface roughness today.

(Groover M.P., Fundamentals of modern Manufacturing:Materials, Processes and Systems, pg.89, Kayra Ermutlu)

(new)

Roughness includes the finest (shortest wavelength) irregularities of a surface. Roughness generally results from a particular production process or material condition. Waviness includes the more widely spaced (longer avelength) deviations of a surface from its nominal shape. Waviness errors are intermediate in wavelength between roughness and form error. Note, that distraction between waviness and form error is not always made in practice and it is not always clear how to make it.Lay refers to the predominant direction of the surface texture. Ordinarily, lay is determined by the particular production method and geometry used. However, in practice,  both  the words - „Surface Texture‟ and „Surface Roughness‟ are used to explain  common meaning of surface roughness symbols. Surface roughness heights are generally measured in  micro inches or micrometers. A micrometer, abbreviated µ, is one millionth of a meter. The average roughness is the area between the roughness profile and its mean line, or the integral of the absolute value of the roughness profile height over the evaluation length.

(Jigar Talati, Hexagon Design Centre, Vadodara,;Surface Roughness – Significance and symbol interpretation in drawing)
New definition is better more detailed.


2) Kano Diagram:  (Group: Production Analysis )
(previous)
Kano diagram depicts the idea that one might consider customer satisfaction on one scale from disgusted to delighted. Similarly, one might consider product functions on a scale from being absent to being fully implemented. If the product function is agood surrogate for the customer need being considered, one could plot a 45 degree line, which wolud indicate the nominal supplied satisfaction for any specification level of the function. This line is known as "one-to-one quality" or "linear quality", the minimum expectations of any new product development undertaking. On the other hand, one could also plot a lower curve that would indicate the minimum, basic level of satisfaction that a customer persumes must exist for the function implementation level. This plot, known as "basic performance" represents assumed functionality that must be in the product. It is expected and latent;if it does not exist in the product, satisfaction of customer will be greatly deteriorated. Similarly, one could plot an upper curve that would indicate the delighted state that a customer would hope to have for the function implementation level. The delighted is what a design team should strive for, to provide performance beyond what the customer expects, which delights them. These three states of satisfaction and the spectrum between them forms the background thinking behind customer needs.

(K.N. Otto,K.L. Wood, Product Design, p. 114-115)

(new)

Kano (A-Kano) model with focus on customer need analysis. Kano indices in accordance with the Kano principles are proposed to incorporate quantitative measures into customer satisfaction. Accordingly, two alternative mechanisms are proposed to provide decision support to product design, the Kano classifiers are used as tangible criteria for categorizing customer needs, and  the configuration index is introduced as a decision factor of product configuration design. The merit of product configurations is justified using a Kano evaluator, which leverages upon both the customer’s satisfaction and the producer’s capacity. A case study of dashboard in automotive design is also presented. It is demonstrated that the A-Kano model can effectively incorporate customer preferences in product design, while leading to an optimal tradeoff between customer’s satisfaction and producer’s capacity.

(Qianli Xu, Roger J. Jiao, Xi Yang and Martin Helander, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore Roger J. Jiao, Woodruff School of Mechanical Engineering, Georgia Instituteof Technology, USA Halimahtun M. Khalid, Damai Sciences Sdn Bhd, Malaysia Anders Opperud, Volvo Technology Corporation, Sweden;An analytical Kano model for customer

need analysis;2008)
New definition is better and simple. 

3)Arbor Press : (Group: Manufacturing Method)
(previous)
 An arbor-press designed to be operated by hand. In using this machine the work is placed on the plate, and the arbor is forced into the work by the ram which is operated by the lever. The connection between the lever and the ram is made by means of a train of spur-gears, the last of which engages the rack teeth on the ram. The lever has a ratchet connection with its shaft, which with the hand-wheel admits of quick return of the ram. Both ram and lever are counterweighted. These machines are made in smaller sizes also, some of which are designed to be secured to the bed of the lathe.

(William Samuel Leonard, Machine-Shop Tools and Methods, p.253)

(new)

The arbor press is an essential piece of equipment in the small machine shop. Without it a machinist would be forced to resort to the use of a hammer or sledge to make any forced fit, a process that could easily damage the part. Two basic types of hand-powered arbor presses are manufactured and used: the hydraulic and the mechanical . The lever gives a “feel” or a sense of pressure applied, which is not possible with the power-driven presses. This pressure sensitivity is needed when small delicate parts are being pressed so that a worker will know when to stop before collapsing the piece.

(Pearsonhighered,Hand tools section B; page 37)
New definition is better.



4)A programmable logic controller (PLC) (Group: Contorl system)
(previous)

It is a special form of microprocessor-based controller that uses a programmable memory to store instructions and to implement functions such as logic, sequencing, timing, counting and arithmetic in order to control machines and processes and are designed to be operated by engineers with perhaps a limited knowledge of computers and computing languages. They are notb designed so that only computer programmers can set up or change theprograms. Thus, the designers of the PLC have pre-programmed it so that the control program can be entered using a simple, rather intuitive, form of languagelimited knowledge of computers and computing languages. They are not designed so that only computer programmers can set up or change theprograms. Thus, the designers of the PLC have pre-programmed it so that the control program can be entered using a simple, rather intuitive, form of language.

(Programmable Logic Controllers, 4th Edition, W. Bolton, p.3)

(new)

The first Programmable Logic Controller (PLC) was developed by a group of engineers at General Motors in 1968, when the company were looking for an alternative to replace complex relay control systems. The new control system had to meet the following requirements: Simple programming, Program changes without system,intervention(no internal rewiring), Smaller, cheaper and more reliable than corresponding relay control systems, Simple, low cost maintenance Subsequent development resulted in a system, which enabled the simple connection of binary signals. The requirements as to how these signals were to be connected were specified in the control program. With the new systems it became possible for the first time to plot signals on a screen and to file these in electronic memories. Since then, three decades have passed, during which the enormous progress made in the development of microelectronics did not stop short of programmable logic controllers. For instance, even if program optimisation and thus a reduction of required memory capacity initially still represented an important key task for the programmer, nowadays this is hardly of any significance.Moreover, the range of functions has grown considerably. 15 years ago, process visualisation, analogue processing or even the use of a PLC as a controller, were considered as Utopian. Nowadays, the support of these functions forms an integral part of many PLCs. 

(Festo Didactic 093311 en;Programmable Logic Controllers Basic Level;August 2002; page B-1)

New definition is better it has wide range of explanation.

5)Fuzzy Logic: (Group: Control System)
(previous)

An element of AI having important applications in control systems and pattern recognition is fuzzy logic (also called fuzzy models). Introduced in 1965 and based on the observation that people can make good decisions on the basis of imprecise and nonnumeric information, fuzzy models are mathematical means of representing vagueness and imprecise information (hence the term “fuzzy”).

These models have the ability to recognize, represent, manipulate, interpret, and utilize data and information that are vague or lack precision. These methods deal with reasoning and decision making at the level higher than neural networks. Typical linguistic examples are the following: few, very, more or less, small, medium, extremely, and almost all.

Fuzzy technologies and devices have been developed (and successfully applied) in areas such as robotics and motion control, image processing and machine vision, machine learning, and the design of intelligent systems. (Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, p 1233

(new)

The past few years have witnessed a rapid growth in the number and variety of applications of fuzzy logic (FL). FL techniques have been used in image-understanding applications such as detection of edges, feature extraction, classification, and clustering. Fuzzy logic poses the ability to mimic the human mind to effectively employ modes of reasoning that are approximate rather than exact. In traditional hard computing, decisions or actions are based on precision, certainty, and vigor. Precision and certainty carry a cost. In soft computing, tolerance and impression are explored in decision making. The exploration of the tolerance for imprecision and uncertainty underlies the remarkable human ability to understand distorted speech, decipher sloppy handwriting, comprehend nuances of natural language, summarize text, and recognize and classify images. With FL, we can specify mapping rules in terms of words rather than numbers. Computing with the words explores imprecision and tolerance. Another basic concept in FL is the fuzzy if–then rule. Although rule-based systems have a long history of use in artificial intelligence, what is missing in such systems is machinery for dealing with fuzzy consequents or fuzzy antecedents. In most applications, an FL solution is a translation of a human solution. Thirdly, FL can model nonlinear functions of arbitrary complexity to a desired degree of accuracy. FL is a convenient way to map an input space to an output space. FL is one of the tools used to model a multiinput, multioutput system.
(FUZZY LOGIC FUNDAMENTALS chapter 3; March 26, 2001;page 61)
New definition is better more detailed.