Intelligent Anomaly Detection of Machine Tools based on Mean Shift Clustering

For a fault detection of machine tools, fixed intervention thresholds are usually necessary. In order to provide an autonomous anomaly detection without the need for fixed limits, recurring patterns must be detected in the signal data. This paper presents an approach for online pattern recognition on NC Code based on mean shift clustering that will be matched with drive signals. The intelligent fault detection system learns individual intervention thresholds based on the prevailing machining patterns. Using a self-organizing map, data captured during the machine’s operation are assigned to a normal or malfunction state

An Approach for the Disassembly of Permanent Magnet Synchronous Rotors to Recover Rare Earth Materials

The extensive electrification of the mobility sector is a crucial part for global decarbonization. To enable a successful transition, the availability of resources must be ensured. In particular, rare earth materials used in permanent magnets of permanent magnet synchronous machines (PMSM) are already considered as a critical resource. Therefore, high performance magnets of existing PMSM rotors must be recovered and remanufactured or recycled. A major challenge to recover the magnets is their fixation inside the rotor lamination stack. Hence, this paper presents an overview of remanufacturing and recycling methods for rare earth magnets. Based on this, a disassembly process for PMSM rotors is developed, technical challenges are pointed out and automation solution are proposed. As results of an experimental study conducted on different magnet configurations, four characteristic phases for the magnet disassembly process were identified and magnets with nickel coating showed significantly higher disassembly forces than magnets with epoxy coating. Moreover, analytical and empirical approaches for modeling the consecutive phases of the disassembly process are proposed

Collision avoidance and adaptive path planning in machine tools by matching live image data with a geometric simulation

A major cause for unplanned downtime in small-series machining are collisions. While there are solutions to avoid collisions using geometric simulations, these do not cover collisions caused by setup errors. To address this problem from batch size one, a system has been developed which matches a geometric simulation with image data to detect deviations, modify the simulation and recalculate NC-Code to fit reality. Building on previous work regarding image-preprocessing, an iterative matching algorithm is developed, as well as a microservice based system-architecture which allows the integration of matching, adaptive path planning and collision avoidance simulation. The system is validated on a machining center

Good gamers, good managers? A proof-of-concept study with Sid Meier’s Civilization

Human resource professionals increasingly enhance their assessment tools with game elements—a process typically referred to as “gamification”—to make them more interesting and engaging for candidates, and they design and use “serious games” that can support skill assessment and development. However, commercial, off-the-shelf video games are not or are only rarely used to screen or test candidates, even though there is increasing evidence that they are indicative of various skills that are professionally valuable. Using the strategy game Civilization, this proof-of-concept study explores if strategy video games are indicative of managerial skills and, if so, of what managerial skills. Under controlled laboratory conditions, we asked forty business students to play the Civilization game and to participate in a series of assessment exercises. We find that students who had high scores in the game had better skills related to problem-solving and organizing and planning than the students who had low scores. In addition, a preliminary analysis of in-game data, including players’ interactions and chat messages, suggests that strategy games such as Civilization may be used for more precise and holistic “stealth assessments,” including personality assessments

Functional Integration of Subcomponents for Hybridization of Fused Filament Fabrication

One of the main advantages of additive manufacturing by Fused Filament Fabrication is its wide variety of materials and cost-effective production systems. However, the resolution and tightness of the produced structures are limited. The following article describes a novel approach of the functional integration of stereolithographic produced subcomponents into the Fused Filament Fabrication process and the challenges during integration in terms of adhesion, taking into account different surface pretreatments. Furthermore, it is investigated how conductive polymer composites could be used successfully for conducting mechatronic subcomponents automatically. With the help of these investigations it is aimed to extend the field of application of additive manufactured plastic components

Small interfering RNA targeting HIF-1α reduces hypoxia-dependent transcription and radiosensitizes hypoxic HT 1080 human fibrosarcoma cells in vitro

Background: : Hypoxia inducible factor-1 has been identified as a potential target to overcome hypoxia-induced radioresistance The aim of the present study was to investigate whether selective HIF-1 inhibition via small interfering RNA (siRNA) targeting hypoxia-inducible factor 1α (HIF-1α) affects hypoxia-induced radioresistance in HT 1080 human fibrosarcoma cells. Material and Methods: : HIF-1α expression in HT 1080 human fibrosarcoma cells in vitro was silenced using HIF-1α siRNA sequence primers. Quantitative real-time polymerase chain reaction assay was performed to quantify the mRNA expression of HIF-1α. HIF-1α protein levels were studied by Western blotting at 20% (air) or after 12 hours at 0.1% O2 (hypoxia). Cells were assayed for clonogenic survival after irradiation with 2, 5, or 10 Gy, under normoxic or hypoxic conditions in the presence of HIF-1α-targeted or control siRNA sequences. A modified oxygen enhancement ratio (OER´) was calculated as the ratio of the doses to achieve the same survival at 0.1% O2 as at ambient oxygen tensions. OER´ was obtained at cell survival levels of 50%, 37%, and 10%. Results: : HIF-1α-targeted siRNA enhanced radiation treatment efficacy under severely hypoxic conditions compared to tumor cells treated with scrambled control siRNA. OER was reduced on all survival levels after treatment with HIF-1α-targeted siRNA, suggesting that inhibition of HIF-1 activation by using HIF-1α-targeted siRNA increases radiosensitivity of hypoxic tumor cells in vitro. Conclusion: : Inhibition of HIF-1 activation by using HIF-1α-targeted siRNA clearly acts synergistically with radiotherapy and increase radiosensitivity of hypoxic cells in vitr

Magnetic resonance imaging of vaginal support structure before and after Vecchietti procedure in women with Mayer–Rokitansky–Küster–Hauser syndrome

IntroductionIt is unclear how pelvic floor supporting structures might be affected by the absence of the vagina. It was the aim of this prospective study to analyze the magnetic resonance imaging morphology of pelvic support prior and after a Vecchietti procedure in women suffering Mullerian agenesis (Mayer–Rokitansky–Küster–Hauser syndrome).Material and methods26 women with a diagnosis of Mayer–Rokitansky–Küster–Hauser syndrome associated vaginal agenesis were recruited prospectively prior to the laparoscopic creation of a neovagina according to the Vecchietti procedure. The primary outcome measure was the magnetic resonance imaging morphology of supporting structures. Secondary outcome measures were anatomical and functional vaginal length. Follow up was conducted six months after surgery.ResultsTwenty‐six women were analyzed. Mean age was 19.8 ± 4.4 years (±SD) and mean body mass index was 23.7 ± 4.3 kg/m2 (±SD). All were Caucasian. Supporting structures consistent with cardinal and uterosacral ligaments were visible on magnetic resonance imaging in all cases (100%). There were no levator ani defects. The vaginal apex could be visualized postoperatively in 12 women (46.2%) reaching up to Level I. The vagina was visible in both Level II and III with normal relations to the pelvic walls in all cases. On gynecological examination, vaginal length was 8.8 ± 2.1 cm (mean ± SD) anatomically and 10.2 ± 2.2 cm (mean ± SD) functionally.ConclusionsThe preoperative presence of pelvic support structures into which the vagina is lengthened by the surgery likely explains the uncommon occurrence of vaginal prolapse in women who had the Vecchietti procedure.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144648/1/aogs13350_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144648/2/aogs13350.pd