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Muammer Koç

Bio: Muammer Koç is an academic researcher from Khalifa University. The author has contributed to research in topics: Hydroforming & Materials science. The author has an hindex of 38, co-authored 216 publications receiving 5245 citations. Previous affiliations of Muammer Koç include University of Michigan & Tower International.


Papers
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Journal ArticleDOI
TL;DR: A comprehensive review of the recent literature on Mg-based biomaterials can be found in this paper, where the authors have analyzed the properties and properties of Mg and compared them with those of human bone.

435 citations

Journal ArticleDOI
TL;DR: A comprehensive review on the state-of-the-art of piezoelectric energy harvesting is presented in this paper, where the authors present the broad spectrum of applications of piezolectric materials for clean power supply to wireless electronics in diverse fields.

418 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized a technological review of the hydroforming process from early years to very recent dates on various topics such as material, tribology, equipment, tooling, etc., so that other researcher at different parts of the world can use it for further investigations in this area.

245 citations

Journal ArticleDOI
TL;DR: In this paper, the authors explore a method to assess assets performance and predict the remaining useful life, which would lead to proactive maintenance processes to minimize downtime of machinery and production in various industries, thus increasing efficiency of operations and manufacturing.
Abstract: This paper explores a method to assess assets performance and predict the remaining useful life, which would lead to proactive maintenance processes to minimize downtime of machinery and production in various industries, thus increasing efficiency of operations and manufacturing. At first, a performance model is established by taking advantage of logistic regression analysis with maximum-likelihood technique. Two kinds of application situations, with or without enough historical data, are discussed in detail. Then, real-time performance is evaluated by inputting features of online data to the logistic model. Finally, the remaining life is estimated using an ARMA model based on machine performance history; degradation predictions are also upgraded dynamically. The results such as current machine running condition and the remaining useful life, are output to the maintenance decision module to determine a window of appropriate maintenance before the machine fails. An application of the method on an elevator ...

231 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive review on the synthesis, stability, thermophysical properties, and characterization of nanofluids has been reviewed and the factors that influence the thermal properties have been discussed.

222 citations


Cited by
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Journal ArticleDOI
TL;DR: This paper attempts to summarise and review the recent research and developments in diagnostics and prognostics of mechanical systems implementing CBM with emphasis on models, algorithms and technologies for data processing and maintenance decision-making.

3,848 citations

Book ChapterDOI
01 Jan 1982
TL;DR: In this article, the authors discuss leading problems linked to energy that the world is now confronting and propose some ideas concerning possible solutions, and conclude that it is necessary to pursue actively the development of coal, natural gas, and nuclear power.
Abstract: This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

2,283 citations

Journal ArticleDOI
TL;DR: It is shown that volume changes of less than 0.5% suffice to grip objects reliably and hold them with forces exceeding many times their weight, and opens up new possibilities for the design of simple, yet highly adaptive systems that excel at fast gripping of complex objects.
Abstract: Gripping and holding of objects are key tasks for robotic manipulators. The development of universal grippers able to pick up unfamiliar objects of widely varying shape and surface properties remains, however, challenging. Most current designs are based on the multifingered hand, but this approach introduces hardware and software complexities. These include large numbers of controllable joints, the need for force sensing if objects are to be handled securely without crushing them, and the computational overhead to decide how much stress each finger should apply and where. Here we demonstrate a completely different approach to a universal gripper. Individual fingers are replaced by a single mass of granular material that, when pressed onto a target object, flows around it and conforms to its shape. Upon application of a vacuum the granular material contracts and hardens quickly to pinch and hold the object without requiring sensory feedback. We find that volume changes of less than 0.5% suffice to grip objects reliably and hold them with forces exceeding many times their weight. We show that the operating principle is the ability of granular materials to transition between an unjammed, deformable state and a jammed state with solid-like rigidity. We delineate three separate mechanisms, friction, suction, and interlocking, that contribute to the gripping force. Using a simple model we relate each of them to the mechanical strength of the jammed state. This advance opens up new possibilities for the design of simple, yet highly adaptive systems that excel at fast gripping of complex objects.

1,221 citations

Journal ArticleDOI
TL;DR: A critical overview of soft robotic grippers is presented, covering different material sets, physical principles, and device architectures, and improved materials, processing methods, and sensing play an important role in future research.
Abstract: Advances in soft robotics, materials science, and stretchable electronics have enabled rapid progress in soft grippers. Here, a critical overview of soft robotic grippers is presented, covering different material sets, physical principles, and device architectures. Soft gripping can be categorized into three technologies, enabling grasping by: a) actuation, b) controlled stiffness, and c) controlled adhesion. A comprehensive review of each type is presented. Compared to rigid grippers, end-effectors fabricated from flexible and soft components can often grasp or manipulate a larger variety of objects. Such grippers are an example of morphological computation, where control complexity is greatly reduced by material softness and mechanical compliance. Advanced materials and soft components, in particular silicone elastomers, shape memory materials, and active polymers and gels, are increasingly investigated for the design of lighter, simpler, and more universal grippers, using the inherent functionality of the materials. Embedding stretchable distributed sensors in or on soft grippers greatly enhances the ways in which the grippers interact with objects. Challenges for soft grippers include miniaturization, robustness, speed, integration of sensing, and control. Improved materials, processing methods, and sensing play an important role in future research.

1,028 citations