Category: Publications

Nathir Rawashdeh to Present Paper at Advances in Mechanical Engineering Conference

Nathir Rawashdeh

A conference paper co-authored by Nathir Rawashdeh (CC/MERET), has been accepted for presentation and publication at the 5th International Conference on Advances in Mechanical Engineering, December 17-19, 2019, in Istanbul, Turkey.

The paper is entitled, “Effect of Camera’s Focal Plane Array Fill Factor on Digital Image Correlation Measurement Accuracy.” Co-authors are Ala L. Hijazi of German Jordanian University, and Christian J. Kähler of Universität der Bundeswehr München.

Abstract: The digital image correlation (DIC) method is one of the most widely used non-invasive full-field methods for deformation and strain measurements. It is currently being used in a very wide variety of applications including mechanical engineering, aerospace engineering, structural engineering, manufacturing engineering, material science, non-destructive testing, biomedical and life sciences. There are many factors that affect the DIC measurement accuracy where that includes; the selection of the correlation algorithm and parameters, the camera, the lens, the type and quality of the speckle pattern, the lightening conditions and surrounding environment. Several studies have addressed the different factors influencing the accuracy of DIC measurements and the sources of error. The camera’s focal plane array (FPA) fill factor is one of the parameters for digital cameras, though it is not widely known and usually not reported in specs sheets. The fill factor of an imaging sensor is defined as the ratio of a pixel’s light sensitive area to its total theoretical area. For some types of imaging sensors, the fill factor can theoretically reach 100%. However, for the types of imaging sensors typically used in most digital cameras used in DIC measurements, such as the “interline” charge coupled device CCD and the complementary metal oxide semiconductor (CMOS) imaging sensors, the fill factor is much less than 100%. It is generally believed that the lower fill factor may reduce the accuracy of photogrammetric measurements. But nevertheless, there are no studies addressing the effect of the imaging sensor’s fill factor on DIC measurement accuracy. We report on research aiming to quantify the effect of fill factor on DIC measurements accuracy in terms of displacement error and strain error. We use rigid-body-translation experiments then numerically modify the recorded images to synthesize three different types of images with 1/4 of the original resolution. Each type of the synthesized images has different value of the fill factor; namely 100%, 50% and 25%. By performing DIC analysis with the same parameters on the three different types of synthesized images, the effect of fill factor on measurement accuracy may be realized. Our results show that the FPA’s fill factor can have a significant effect on the accuracy of DIC measurements. This effect is clearly dependent on the type and characteristics of the speckle pattern. The fill factor has a clear effect on measurement error for low contrast speckle patterns and for high contrast speckle patterns (black dots on white background) with small dot size (3 pixels dot diameter). However, when the dot size is large enough (about 7 pixels dot diameter), the fill factor has very minor effect on measurement error. In addition, the results also show that the effect of the fill factor is also dependent on the magnitude of translation between images. For instance, the increase in measurement error resulting from low fill factor can be more significant for subpixel translations than large translations of several pixels.
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Article by Alex Sergeyev Published in Journal of Engineering Technology (JET)

Alex Sergeyev

An article co-authored by Aleksandr Sergeyev, College of Computing professor and director of the Mechatronics graduate program, has been published in the Journal of Engineering Technology (JET).

The conclusive article, titled “A University, Community College, and Industry Partnership: Revamping Robotics Education to Meet 21st century Needs – NSF Sponsored Project Final Report,” summarizes the work funded by a $750K NSF grant received by Servgeyev in 2015 to to promote robotics education.  The paper details the achievements in curriculum and educational tools development, dissemination, and implementation at Michigan Tech and beyond.

Co-PIs on the project are  Scott A. Kuhl (Michigan Technological University), Prince Mehandiratta (Michigan Technological University), Mark Highum (Bay de Noc Community College), Mark Bradley Kinney (West Shore Community College), and Nasser Alaraje (The University of Toledo).

A related paper was presented at the 2019 ASEE Annual Conference & Exposition, June 21-24, 2019, in Tampa, FL, as part of the panel “Academe/Industry Collaboration” presented by the Technical Engineering Technology Division, where it was awarded the Best Paper Award in the Engineering Technology Division. Download the conference paper here: https://www.asee.org/public/conferences/140/papers/26234/view.

Conference Paper Abstract: Recently, educators have worked to improve STEM education at all levels, but challenges remain. Capitalizing on the appeal of robotics is one strategy proposed to increase STEM interest. The interdisciplinary nature of robots, which involve motors, sensors, and programs, make robotics a useful STEM pedagogical tool. There is also a significant need for industrial certification programs in robotics. Robots are increasingly used across industry sectors to improve production throughputs while maintaining product quality. The benefits of robotics, however, depend on workers with up-to-date knowledge and skills to maintain and use existing robots, enhance future technologies, and educate users. It is critical that education efforts respond to the demand for robotics specialists by offering courses and professional certification in robotics and automation. This NSF sponsored project introduces a new approach for Industrial Robotics in electrical engineering technology (EET) programs at University and Community College. The curriculum and software developed by this collaboration of two- and four-year institutions match industry needs and provide a replicable model for programs around the US. The project also addresses the need for certified robotic training centers (CRTCs) and provides curriculum and training opportunities for students from other institutions, industry representatives, and displaced workers. Resources developed via this project were extensively disseminated through a variety of means, including workshops, conferences, and publications. In this article, authors provide final report on project outcomes, including various curriculum models and industry certification development, final stage of the “RobotRun” robotic simulation software, benefits of professional development opportunities for the faculty members from the other institutions, training workshops for K-12 teachers, and robotic one-day camps for high school students.

The Journal of Engineering Technology® (JET) is a refereed journal published semi-annually, in spring and fall, by the Engineering Technology Division (ETD) of the American Society for Engineering Education (ASEE). The aim of JET is to provide a forum for the dissemination of original scholarly articles as well as review articles in all areas related to engineering technology education. engtech.org/jet

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Yakov Nekrich paper accepted by 2020 ACM-SIAM Symposium on Discrete Algorithms

Yakov Nekrich

A paper by Yakov Nekrich, associate professor of computer science, has been accepted by the 2020 ACM-SIAM Symposium on Discrete Algorithms (SODA 2020), the prime conference in the area of algorithms research.

The article, “Better Data Structures for Colored Orthogonal Range Reporting,” was co-authored by Timothy M. Chan of University of Illinois at Urbana-Champaign (UIUC).

The SODA 2020 conference takes place January 5-8, 2020, in Salt Lake City, Utah.

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Ali Ebnenasir is Co-author of Article in ACM Transactions on Computational Logic

Ali EbnenasirAli Ebnenasir (SAS/CS), professor of computer science, is co-author of the article, “On the verification of livelock-freedom and self-stabilization on parameterized rings,” published in the July 2019 issue of the journal ACM Transactions on Computational Logic. The article is co-authored by Alex Klinkhamer of Google.

Abstract: This article investigates the verification of livelock-freedom and self-stabilization on parameterized rings consisting of symmetric, constant space, deterministic, and self-disabling processes. The results of this article have a significant impact on several fields, including scalable distributed systems, resilient and self-* systems, and verification of parameterized systems. First, we identify necessary and sufficient local conditions for the existence of global livelocks in parameterized unidirectional rings with unbounded (but finite) number of processes under the interleaving semantics. Using a reduction from the periodic domino problem, we show that, in general, verifying livelock-freedom of parameterized unidirectional rings is undecidable (specifically, Π10-complete) even for constant space, deterministic, and self-disabling processes. This result implies that verifying self-stabilization for parameterized rings of self-disabling processes is also undecidable. We also show that verifying livelock-freedom and self-stabilization remain undecidable under (1) synchronous execution semantics, (2) the FIFO consistency model, and (3) any scheduling policy. We then present a new scope-based method for detecting and constructing livelocks in parameterized rings. The proposed semi-algorithm behind our scope-based verification is based on a novel paradigm for the detection of livelocks that totally circumvents state space exploration. Our experimental results on an implementation of the proposed semi-algorithm are very promising as we have found livelocks in parameterized rings in a few microseconds on a regular laptop. The results of this article have significant implications for scalable distributed systems with cyclic topologies.

Citation: Klinkhamer, A., & Ebnenasir, A. (2019). On the verification of livelock-freedom and self-stabilization on parameterized rings. ACM Transactions on Computational Logic, 20(3), 16:1-16:36. http://dx.doi.org/10.1145/3326456

MTU Digital Commons link: https://digitalcommons.mtu.edu/michigantech-p/146/

ACM link: https://dl.acm.org/citation.cfm?doid=3338853.3326456

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Zhenlin Wang is Co-Author of Article in Parallel Programming Journal

Zhenlin Wang (SAS), professor of computer science, is co-author of the article, “Lightweight and accurate memory allocation in key-value cache,” published in the June 2019 issue of the International Journal of Parallel Programming, which is published by Springer.

Abstract: The use of key-value caches in modern web servers is becoming more and more ubiquitous. Representatively, Memcached as a widely used key-value cache system, originally intended for speeding up dynamic web applications by alleviating database load. One of the key factors affecting the performance of Memcached is the memory allocation among different item classes. How to obtain the most efficient partitioning scheme with low time and space consumption is a focus of attention. In this paper, we propose a lightweight and accurate memory allocation scheme in Memcached, by sampling access patterns, analyzing data locality, and reassigning the memory space. One early study on optimizing memory allocation is LAMA, which uses footprint-based MRC to optimize memory allocation in Memcached. However, LAMA does not model deletion operations in Memcached and its spatial overhead is quite large. We propose a method that consumes only 3% of LAMA space and can handle read, write and deletion operations. Moreover, evaluation results show that the average stable-state miss ratio is reduced by 15.0% and the average stable-state response time is reduced by 12.3% when comparing our method to LAMA.

Citation: Pan, C., Zhou, L., Luo, Y., Wang, X., & Wang, Z. (2019). Lightweight and accurate memory allocation in key-value cache. International Journal of Parallel Programming, 47(3), 451-466.http://dx.doi.org/10.1007/s10766-018-0616-4

Digital Commons link: https://digitalcommons.mtu.edu/michigantech-p/144/

Springer link: https://link.springer.com/article/10.1007%2Fs10766-018-0616-4

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Ali Ebnenasir is Co-Author of Publication in ACM Transactions on Computational Logic

Ali Ebnenasir
Ali Ebnenasir

An article co-authored by Ali Ebnenasir (SAS/CS) and Alex Klinkhamer, “Verification of Livelock-Freedom and Self-Stabilization on Parameterized Rings,” was recently published in ACM Transactions on Computational Logic.

Abstract: This article investigates the verification of livelock-freedom and self-stabilization on parameterized rings consisting of symmetric, constant space, deterministic, and self-disabling processes. The results of this article have a significant impact on several fields, including scalable distributed systems, resilient and self-* systems, and verification of parameterized systems. First, we identify necessary and sufficient local conditions for the existence of global livelocks in parameterized unidirectional rings with unbounded (but finite) number of processes under the interleaving semantics. Using a reduction from the periodic domino problem, we show that, in general, verifying livelock-freedom of parameterized unidirectional rings is undecidable (specifically, Π10-complete) even for constant space, deterministic, and self-disabling processes. This result implies that verifying self-stabilization for parameterized rings of self-disabling processes is also undecidable. We also show that verifying livelock-freedom and self-stabilization remain undecidable under (1) synchronous execution semantics, (2) the FIFO consistency model, and (3) any scheduling policy. We then present a new scope-based method for detecting and constructing livelocks in parameterized rings. The proposed semi-algorithm behind our scope-based verification is based on a novel paradigm for the detection of livelocks that totally circumvents state space exploration. Our experimental results on an implementation of the proposed semi-algorithm are very promising as we have found livelocks in parameterized rings in a few microseconds on a regular laptop. The results of this article have significant implications for scalable distributed systems with cyclic topologies.

https://dl.acm.org/citation.cfm?id=3326456&dl=ACM&coll=DL

doi: 10.1145/3326456

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