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10. KEA: Tuning an Exabyte-Scale Data Infrastructure

Author

Zhu, Yiwen, Krishnan, Subru, Karanasos, Konstantinos, Tarte, Isha, Power, Conor, Modi, Abhishek, Kumar, Manoj, Zhang, Deli, Muthyala, Kartheek, Jurgens, Nick, Sakalanaga, Sarvesh, Darbha, Sudhir, Iyer, Minu, Agarwal, Ankita, and Curino, Carlo

Subjects
Computer Science - Databases
Abstract

Microsoft's internal big-data infrastructure is one of the largest in the world -- with over 300k machines running billions of tasks from over 0.6M daily jobs. Operating this infrastructure is a costly and complex endeavor, and efficiency is paramount. In fact, for over 15 years, a dedicated engineering team has tuned almost every aspect of this infrastructure, achieving state-of-the-art efficiency (>60% average CPU utilization across all clusters). Despite rich telemetry and strong expertise, faced with evolving hardware/software/workloads this manual tuning approach had reached its limit -- we had plateaued. In this paper, we present KEA, a multi-year effort to automate our tuning processes to be fully data/model-driven. KEA leverages a mix of domain knowledge and principled data science to capture the essence of our cluster dynamic behavior in a set of machine learning (ML) models based on collected system data. These models power automated optimization procedures for parameter tuning, and inform our leadership in critical decisions around engineering and capacity management (such as hardware and data center design, software investments, etc.). We combine "observational" tuning (i.e., using models to predict system behavior without direct experimentation) with judicious use of "flighting" (i.e., conservative testing in production). This allows us to support a broad range of applications that we discuss in this paper. KEA continuously tunes our cluster configurations and is on track to save Microsoft tens of millions of dollars per year. At the best of our knowledge, this paper is the first to discuss research challenges and practical learnings that emerge when tuning an exabyte-scale data infrastructure.

Published
2021
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17. Critical nonlocal Schrödinger-Poisson system on the Heisenberg group

Author

Liu Zeyi, Tao Lulu, Zhang Deli, Liang Sihua, and Song Yueqiang

Subjects
heisenberg group, schrödinger-poisson type system, mountain pass theorem, krasnoselskii genus theorem, clark critical point theorem, 35j20, 35r03, 46e35, Analysis, QA299.6-433
Abstract

In this paper, we are concerned with the following a new critical nonlocal Schrödinger-Poisson system on the Heisenberg group:

Published
2021
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19. Motion Prediction and Object Detection for Image-Based Visual Servoing Systems Using Deep Learning.

Author

Hao, Zhongwen, Zhang, Deli, and Honarvar Shakibaei Asli, Barmak

Subjects
PARTICLE swarm optimization, OBJECT recognition (Computer vision), TIME series analysis, ROBOTICS, ALGORITHMS
Abstract

This study primarily investigates advanced object detection and time series prediction methods in image-based visual servoing systems, aiming to capture targets better and predict the motion trajectory of robotic arms in advance, thereby enhancing the system's performance and reliability. The research first implements object detection on the VOC2007 dataset using the Detection Transformer (DETR) and achieves ideal detection scores. The particle swarm optimization algorithm and 3-5-3 polynomial interpolation methods were utilized for trajectory planning, creating a unique dataset through simulation. This dataset contains randomly generated trajectories within the workspace, fully simulating actual working conditions. Significantly, the Bidirectional Long Short-Term Memory (BILSTM) model was improved by substituting its traditional Multilayer Perceptron (MLP) components with Kolmogorov–Arnold Networks (KANs). KANs, inspired by the K-A theorem, improve the network representation ability by placing learnable activation functions on fixed node activation functions. By implementing KANs, the model enhances parameter efficiency and interpretability, thus addressing the typical challenges of MLPs, such as the high parameter count and lack of transparency. The experiments achieved favorable predictive results, indicating that the KAN not only reduces the complexity of the model but also improves learning efficiency and prediction accuracy in dynamic visual servoing environments. Finally, Gazebo software was used in ROS to model and simulate the robotic arm, verify the effectiveness of the algorithm, and achieve visual servoing. [ABSTRACT FROM AUTHOR]

Published
2024
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28. DNA damage-induced PARP1 activation confers cardiomyocyte dysfunction through NAD+ depletion in experimental atrial fibrillation

Author

Zhang, Deli, Hu, Xu, Li, Jin, Liu, Jia, Baks-te Bulte, Luciënne, Wiersma, Marit, Malik, Noor-ul-Ann, van Marion, Denise M. S., Tolouee, Marziyeh, Hoogstra-Berends, Femke, Lanters, Eva A. H., van Roon, Arie M., de Vries, Antoine A. F., Pijnappels, Daniël A., de Groot, Natasja M. S., Henning, Robert H., and Brundel, Bianca J. J. M.

Published
2019
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29. The Parallel Solving Method of Robot Kinematic Equations Based on FPGA.

Author

Zhang, Deli, Jiang, Shaohua, and Zhe, Liu

Subjects
INDUSTRIAL robots, ROBOT motion, CENTRAL processing units, GATE array circuits, MOBILE robots, EQUATIONS, PARALLEL algorithms, PARALLEL robots, TRANSCENDENTAL functions
Abstract

In the implementation of robot motion control, complex kinematic computations consume too much central processing unit (CPU) time and affect the responsiveness of robot motion. To solve this problem, this paper proposes a parallel method for solving kinematic equations of articulated robots based on the coordinate rotation digital computer (CORDIC) algorithm. The method completes the fast calculation of the transcendental function based on the CORDIC algorithm, adopts the tree structure method to optimize the key computational paths of forward and inverse solutions, and designs a parallel pipeline to realize the low latency and high throughput of the kinematic equations. The experiments of the proposed method are validated based on the field-programmable gate array (FPGA) hardware experimental platform, and the experimental results demonstrate that the computational time to complete the entire kinematic equations is 4.68 μs, of which the computational time for the kinematic positive solution is 0.52 μs and the computational time for the kinematic inverse solution is 4.16 μs. [ABSTRACT FROM AUTHOR]

Published
2023
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34. High-Precision Acquisition Method of Position Signal of Permanent Magnet Direct Drive Servo Motor at Low Speed.

Author

Zhang, Deli, Dong, Zhaopeng, Bu, Feifei, Gu, Zijie, and Guo, Zitao

Subjects
*SERVOMECHANISMS, *PERMANENT magnets, *PERMANENT magnet motors, *CLOSED loop systems, *SPEED
Abstract

This paper studies a method for high-precision acquisition of position signals for permanent magnet direct drive servo motors at low speed. First of all, the problem of poor position feedback accuracy and sensor feedback delay in the low-speed operation of the permanent magnet direct drive servo motor is analyzed. Secondly, through analysis and simulation, it is found that the interpolation method can play a certain role in compensating the rotor position signal. However, when the speed is close to 0, the output signal of the sensor will fluctuate in a short time, which will affect the speed control accuracy. Therefore, this paper uses the observer method to achieve high-precision acquisition of the position signal of the permanent magnet direct drive servo motor at low speed. The observer method adopts the idea of combining the system model and closed-loop control. Additionally, it makes full use of the parameter information of the motor system. The control performance of the motor can be better guaranteed through the design of the observer parameters and the accuracy of the rotor position estimation result has been greatly improved. Finally, an experimental platform for permanent magnet direct drive servo motors is built, and the rotor position signal acquisition method based on the observer method is verified to have good performance through simulation and experiments. Not only the accuracy of the rotor position estimation result is improved, but also the motor control performance is improved, realizing the stable operation of the permanent magnet direct drive servo motor at low speed. [ABSTRACT FROM AUTHOR]

Published
2023
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37. Disruption of Sarcoplasmic ReticulumMitochondrial Contacts Underlies Contractile Dysfunction in Experimental and Human Atrial Fibrillation : A Key Role of Mitofusin 2

Author

Li, Jin, Qi, Xi, Ramos, Kennedy S., Lanters, Eva, Keijer, Jaap, de Groot, Natasja, Brundel, Bianca, Zhang, Deli, Li, Jin, Qi, Xi, Ramos, Kennedy S., Lanters, Eva, Keijer, Jaap, de Groot, Natasja, Brundel, Bianca, and Zhang, Deli

Abstract

BACKGROUND: Atrial fibrillation (AF) is the most common and progressive tachyarrhythmia. Diabetes is a common risk factor for AF. Recent research findings revealed that microtubule network disruption underlies AF. The microtubule network mediates the contact between sarcoplasmic reticulum and mitochondria, 2 essential organelles for normal cardiomyocyte function. Therefore, disruption of the microtubule network may impair sarcoplasmic reticulum and mitochondrial contacts (SRMCs) and subsequently cardiomyocyte function. The current study aims to determine whether microtubule-mediated SRMCs disruption underlies diabetes-associated AF. METHODS AND RESULTS: Tachypacing (mimicking AF) and high glucose (mimicking diabetes) significantly impaired contractile function in HL-1 cardiomyocytes (loss of calcium transient) and Drosophila (reduced heart rate and increased arrhythmia), both of which were prevented by microtubule stabilizers. Furthermore, both tachypacing and high glucose significantly reduced SRMCs and the key SRMC tether protein mitofusin 2 (MFN2) and resulted in consequent mitochondrial dysfunction, all of which were prevented by microtubule stabilizers. In line with pharmacological interventions with microtubule stabilizers, cardiac-specific knockdown of MFN2 induced arrhythmia in Drosophila and overexpression of MFN2 prevented tachypacingand high glucose–induced contractile dysfunction in HL-1 cardiomyocytes and/or Drosophila. Consistently, SRMCs/MFN2 levels were significantly reduced in right atrial appendages of patients with persistent AF compared with control patients, which was aggravated in patients with diabetes. CONCLUSIONS: SRMCs may play a critical role in clinical AF, especially diabetes-related AF. Furthermore, SRMCs can be regulated by microtubules and MFN2, which represent novel potential therapeutic targets for AF.

Published
2022

38. Disruption of Sarcoplasmic ReticulumMitochondrial Contacts Underlies Contractile Dysfunction in Experimental and Human Atrial Fibrillation:A Key Role of Mitofusin 2

Author

Li, Jin, Qi, Xi, Ramos, Kennedy S., Lanters, Eva, Keijer, Jaap, de Groot, Natasja, Brundel, Bianca, Zhang, Deli, Li, Jin, Qi, Xi, Ramos, Kennedy S., Lanters, Eva, Keijer, Jaap, de Groot, Natasja, Brundel, Bianca, and Zhang, Deli

Abstract

BACKGROUND: Atrial fibrillation (AF) is the most common and progressive tachyarrhythmia. Diabetes is a common risk factor for AF. Recent research findings revealed that microtubule network disruption underlies AF. The microtubule network mediates the contact between sarcoplasmic reticulum and mitochondria, 2 essential organelles for normal cardiomyocyte function. Therefore, disruption of the microtubule network may impair sarcoplasmic reticulum and mitochondrial contacts (SRMCs) and subsequently cardiomyocyte function. The current study aims to determine whether microtubule-mediated SRMCs disruption underlies diabetes-associated AF. METHODS AND RESULTS: Tachypacing (mimicking AF) and high glucose (mimicking diabetes) significantly impaired contractile function in HL-1 cardiomyocytes (loss of calcium transient) and Drosophila (reduced heart rate and increased arrhythmia), both of which were prevented by microtubule stabilizers. Furthermore, both tachypacing and high glucose significantly reduced SRMCs and the key SRMC tether protein mitofusin 2 (MFN2) and resulted in consequent mitochondrial dysfunction, all of which were prevented by microtubule stabilizers. In line with pharmacological interventions with microtubule stabilizers, cardiac-specific knockdown of MFN2 induced arrhythmia in Drosophila and overexpression of MFN2 prevented tachypacingand high glucose–induced contractile dysfunction in HL-1 cardiomyocytes and/or Drosophila. Consistently, SRMCs/MFN2 levels were significantly reduced in right atrial appendages of patients with persistent AF compared with control patients, which was aggravated in patients with diabetes. CONCLUSIONS: SRMCs may play a critical role in clinical AF, especially diabetes-related AF. Furthermore, SRMCs can be regulated by microtubules and MFN2, which represent novel potential therapeutic targets for AF.

Published
2022

44. On Kirchhoff-Schrödinger-Poisson-type systems with singular and critical nonlinearity

Author

Yang, Baoling, Zhang, Deli, and Liang, Sihua

Abstract

This work focuses on the Kirchhoff-Schrödinger-Poisson-type system with singular term and critical Sobolev nonlinearity as follows: −a+b∫Ω∣∇u∣pdxΔpu+ϕ∣u∣q−2u=λu−γ+∣u∣p∗−2uinΩ,−Δϕ=∣u∣qinΩ,u=ϕ=0on∂Ω,\left\{\begin{array}{ll}-\left(a+b\mathop{\displaystyle \int }\limits_{\Omega }{| \nabla u| }^{p}{\rm{d}}x\right){\Delta }_{p}u+\phi {| u| }^{q-2}u=\lambda {u}^{-\gamma }+{| u| }^{{p}^{\ast }-2}u\hspace{1.0em}& \hspace{0.1em}\text{in}\hspace{0.1em}\hspace{0.33em}\Omega ,\\ -\Delta \phi ={| u| }^{q}\hspace{1.0em}& \hspace{0.1em}\text{in}\hspace{0.1em}\hspace{0.33em}\Omega ,\\ u=\phi =0\hspace{1.0em}& \hspace{0.1em}\text{on}\hspace{0.1em}\hspace{0.33em}\partial \Omega ,\end{array}\right.where Ω\Omega is a bounded domain in RN{{\mathbb{R}}}^{N}with Lipschitz boundary ∂Ω\partial \Omega , 0<γ<10\lt \gamma \lt 1,Δpu=div(∣∇u∣p−2∇u){\Delta }_{p}u={\rm{div}}\left({| \nabla u| }^{p-2}\nabla u), 10\lambda \gt 0. With the Nehari manifold approach, the above problem is discovered to have at least one weak solution. Furthermore, the singular term and critical nonlinearity arise concurrently, which is the main innovation and difficulty of this article. To some extent, we generalize the previous results.

Published
2024
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45. Effect of quorum-sensing molecule 2-phenylethanol and ARO genes on Saccharomyces cerevisiae biofilm

Author

Yong Chen, Bin Yu, Chen Tianpeng, Sun Wenjun, Dong Liu, Yu Ying, Caice Liang, Wang Fangjuan, Ding Sai, Hanjie Ying, and Zhang Deli

Subjects
Saccharomyces cerevisiae Proteins, Mutant, Saccharomyces cerevisiae, Industrial fermentation, Applied Microbiology and Biotechnology, 03 medical and health sciences, Gene expression, Transaminases, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Chemistry, Biofilm, Quorum Sensing, General Medicine, biochemical phenomena, metabolism, and nutrition, Phenylethyl Alcohol, biology.organism_classification, Quorum sensing, Biochemistry, Biofilms, Fermentation, Bacteria, Biotechnology
Abstract

Biofilms are a form of microbial community that can be beneficial for industrial fermentation because of their remarkable environmental resistance. However, the mechanism of biofilm formation in Saccharomyces cerevisiae remains to be fully explored, and this may enable improved industrial applications for this organism. Although quorum-sensing (QS) molecules are known to be involved in bacteria biofilm formation, few studies have been undertaken with these in fungi. 2-phenylethanol (2-PE) is considered a QS molecule in S. cerevisiae. Here, we found that exogenous 2-PE could stimulate biofilm formation at low cell concentrations. ARO8p and ARO9p are responsible for the synthesis of 2-PE and were crucial to the formation of biofilm. Deletion of the ARO8 and ARO9 genes reduced the content of 2-PE in the early stage of fermentation, reduced ethanol yield and decreased biofilm formation. The expression of FLOp, which is involved in cell adhesion, and the content of extracellular polysaccharides of mutant strains ΔARO8 and ΔARO9 were also significantly reduced. These findings indicate that the production of 2-PE had a positive effect on biofilm formation in S. cerevisiae, thereby providing further key details for studying the formation of biofilm mechanism in the future. KEY POINTS: • Quorum-sensing molecule 2-PE positively affects biofilm formation in S. cerevisiae. • 2-PE synthetic genes ARO8 and ARO9 deletion reduced extracellular polysaccharide. • ARO8 and ARO9 deletion reduced the gene expression of the FLO family.

Published
2020

46. Role of oxidative dna damage and repair in atrial fibrillation and ischemic heart disease

Author

Hu, Liangyu, Wang, Zhengkun, Carmone, Claudia, Keijer, Jaap, Zhang, Deli, Hu, Liangyu, Wang, Zhengkun, Carmone, Claudia, Keijer, Jaap, and Zhang, Deli

Abstract

Atrial fibrillation (AF) and ischemic heart disease (IHD) represent the two most common clinical cardiac diseases, characterized by angina, arrhythmia, myocardial damage, and cardiac dysfunction, significantly contributing to cardiovascular morbidity and mortality and posing a heavy socio‐economic burden on society worldwide. Current treatments of these two diseases are mainly symptomatic and lack efficacy. There is thus an urgent need to develop novel therapies based on the underlying pathophysiological mechanisms. Emerging evidence indicates that oxidative DNA damage might be a major underlying mechanism that promotes a variety of cardiac diseases, including AF and IHD. Antioxidants, nicotinamide adenine dinucleotide (NAD+) boosters, and enzymes involved in oxidative DNA repair processes have been shown to attenuate oxidative damage to DNA, making them potential therapeutic targets for AF and IHD. In this review, we first summarize the main molecular mechanisms responsible for oxidative DNA damage and repair both in nuclei and mitochondria, then describe the effects of oxidative DNA damage on the development of AF and IHD, and finally discuss potential targets for oxidative DNA repair‐based therapeutic approaches for these two cardiac diseases

Published
2021

47. Blood-based 8-hydroxy-2′-deoxyguanosine level: A potential diagnostic biomarker for atrial fibrillation

Author

Li, Jin, Zhang, Deli, Ramos, Kennedy S., Baks, Luciënne, Wiersma, Marit, Lanters, Eva A.H., Bogers, Ad J.J.C., De Groot, Natasja M.S., Brundel, Bianca J.J.M., Li, Jin, Zhang, Deli, Ramos, Kennedy S., Baks, Luciënne, Wiersma, Marit, Lanters, Eva A.H., Bogers, Ad J.J.C., De Groot, Natasja M.S., and Brundel, Bianca J.J.M.

Abstract

BackgroundRecent research findings have revealed a key role of oxidative DNA damage in the pathogenesis of atrial fibrillation (AF). Therefore, the circulating oxidative DNA damage marker 8-hydroxy-2′-deoxyguanosine (8-OHdG) may represent a biomarker for staging AF and identifying patients at risk for AF recurrence and postoperative atrial fibrillation (POAF) after treatment.ObjectiveThe purpose of this study was to investigate whether serum levels of 8-OHdG correlate with the stage of AF, recurrence after AF treatment, and onset of POAF after cardiac surgery.MethodsIn this prospective observational study, 8-OHdG levels were detected by enzyme-linked immunosorbent assay in human serum samples. Blood samples were collected from control patients without AF history; patients with paroxysmal AF and persistent AF undergoing electrical cardioversion or pulmonary vein isolation (PVI); and patients with sinus rhythm (SR) undergoing cardiac surgery. AF recurrence was determined during 12-month follow-up. Univariate and multivariate analyses were used to identify changes in 8-OHdG levels between the groups.ResultsCompared to the control group, 8-OHdG levels in the patient groups gradually and significantly increased during arrhythmia progression. 8-OHdG levels in AF patients showing AF recurrence after PVI treatment were significantly increased compared to patients without AF recurrence. Moreover, in SR patients undergoing cardiac surgery, 8-OHdG levels were significantly elevated in those showing POAF compared to patients without POAF.Conclusion8-OHdG level may represent a potential diagnostic biomarker for AF staging as well as for predicting AF recurrence and POAF after treatment.

Published
2021

50. Ginaton improves neurological function in ischemic stroke rats via inducing autophagy and maintaining mitochondrial homeostasis

Author

Li,Xiaoqiang, Zhang,Deli, Bai,Yinliang, Xiao,Jiyuan, Jiao,Haisheng, and He,Rongxia

Subjects
Neuropsychiatric Disease and Treatment
Abstract

Xiaoqiang Li,1 Deli Zhang,1 Yinliang Bai,1 Jiyuan Xiao,1 Haisheng Jiao,1 Rongxia He21Department of Pharmacy, Lanzhou University Second Hospital, Lanzhou 730030, People’s Republic of China; 2Department of Gynecology, Lanzhou University Second Hospital, Lanzhou 730030, People’s Republic of ChinaPurpose: The present study was carried out to confirm the protective effect of extract of Ginkgo biloba (Ginaton) against ischemic neuronal damage post-treatment at 24 h after reperfusion in rats with middle cerebral artery occlusion (MCAO) and further reveal its possible mechanisms.Methods: Adult male Sprague-Dawley rats were modeled by MCAO for 2 h. The rats were divided into three groups: sham, model, and Ginaton (50 mg/kg). All animals received treatment once a day for 14 days from 24 h after reperfusion. Modified neurological severity score test was performed in 1, 7 and 14 days after MCAO, and beam walking test was performed only 14 days after MCAO. Hematoxylin-eosin straining was implemented to measure infarct volume and immunohistochemical analysis was performed to calculate the number of neurons in ischemic cortex penumbra. Western blot was used to evaluate the expression of autophagy (Beclin1, LC3, AMPK, mTOR, ULK), mitochondrial dynamic protein (Parkin, DRP1, OPA1) and apoptosis (Bcl-2, Bax).Results: Post-treatment with Ginaton for 14 days decreased neurological deficit score, promoted the recovery of motor function, and noticeably reduced infarct size. Besides, Ginaton also alleviated the loss of NeuN-positive cells in ischemic cortex penumbra. In ischemic cortex, Ginaton increased the expression of Beclin1 and LC3-Ⅱ, elevated the AMPK, mTOR and ULK1, and induced autophagy. Moreover, Ginaton treatment upregulated Parkin, DRP1, and OPA1, and elevated the ratio of Bcl-2/Bax in 14 days after MCAO reperfusion injury.Conclusion: Ginaton exhibited obvious neuroprotective effects in MCAO rats with initial administered 24 h after MCAO. The mechanism of Ginaton included induction of autophagy via activation of the AMPK pathway, maintenance of mitochondrial homeostasis and inhibition of apoptosis.Keywords: Ginaton, ischemic stroke, middle cerebral artery occlusion, autophagy, apoptosis, mitochondrial function

Published
2019

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