| 1. |
- Colucci, A., et al.
(författare)
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MLComp : A Methodology for Machine Learning-based Performance Estimation and Adaptive Selection of Pareto-Optimal Compiler Optimization Sequences
- 2021
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Ingår i: Proceedings -Design, Automation and Test in Europe, DATE. - : Institute of Electrical and Electronics Engineers Inc.. - 9783981926354 ; , s. 108-113
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Konferensbidrag (refereegranskat)abstract
- Embedded systems have proliferated in various consumer and industrial applications with the evolution of Cyber-Physical Systems and the Internet of Things. These systems are subjected to stringent constraints so that embedded software must be optimized for multiple objectives simultaneously, namely reduced energy consumption, execution time, and code size. Compilers offer optimization phases to improve these metrics. However, proper selection and ordering of them depends on multiple factors and typically requires expert knowledge. State-of-the-art optimizers facilitate different platforms and applications case by case, and they are limited by optimizing one metric at a time, as well as requiring a time-consuming adaptation for different targets through dynamic profiling. To address these problems, we propose the novel MLComp methodology, in which optimization phases are sequenced by a Reinforcement Learning-based policy. Training of the policy is supported by Machine Learning-based analytical models for quick performance estimation, thereby drastically reducing the time spent for dynamic profiling. In our framework, different Machine Learning models are automatically tested to choose the best-fitting one. The trained Performance Estimator model is leveraged to efficiently devise Reinforcement Learning-based multi-objective policies for creating quasi-optimal phase sequences. Compared to state-of-the-art estimation models, our Performance Estimator model achieves lower relative error (< 2%) with up to 50 × faster training time over multiple platforms and application domains. Our Phase Selection Policy improves execution time and energy consumption of a given code by up to 12% and 6%, respectively. The Performance Estimator and the Phase Selection Policy can be trained efficiently for any target platform and application domain. © 2021 EDAA.
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| 2. |
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| 3. |
- Bauer, K, et al.
(författare)
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Perforin deficiency attenuates collagen-induced arthritis
- 2005
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 7:4, s. 877-884
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Tidskriftsartikel (refereegranskat)abstract
- Collagen-induced arthritis ( CIA), an approved animal model for rheumatoid arthritis, is thought to be a T cell-dependent disease. There is evidence that CD8(+) T cells are a major subset controlling the pathogenesis of CIA. They probably contribute to certain features of disease, namely tissue destruction and synovial hyperplasia. In this study we examined the role of perforin (pfp), a key molecule of the cytotoxic death pathway that is expressed mainly in CD8(+) T cells, for the pathogenesis of CIA. We generated DBA/1J mice suffering from mutations of the pfp molecule, DBA/1J-pfp(-/-), and studied their susceptibility to arthritis. As a result, pfp-deficient mice showed a reduced incidence (DBA/1J-pfp(+/+), 64%; DBA/1J-pfp(-/-), 54%), a slightly delayed onset ( onset of disease: DBA/1J-pfp(+/+), 53 +/- 3.6; DBA/1J-pfp(-/-), 59 +/- 4.9 ( mean SEM), and milder form of the disease ( maximum disease score: DBA/1J-pfp(+/+), 7.3 +/- 1.1; DBA/1J-pfp(-/-), 3.4 +/- 1.4 ( mean SEM); P < 0.05). Concomitantly, peripheral T cell proliferation in response to the specific antigen bovine collagen II was increased in pfp(-/-) mice compared with pfp(+/+) mice, arguing for an impaired killing of autoreactive T cells caused by pfp deficiency. Thus, pfp-mediated cytotoxicity is involved in the initiation of tissue damage in arthritis, but pfp-independent cytotoxic death pathways might also contribute to CIA.
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| 4. |
- Deckers, Tobias, et al.
(författare)
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Impact of processing gas composition on process stability and properties of PBF-LB/M processed alloy 718
- 2024
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Ingår i: Journal of Manufacturing Processes. - 1526-6125. ; 120, s. 712-718
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Tidskriftsartikel (refereegranskat)abstract
- The almost unlimited design freedom of the laser-based powder bed fusion of metals (PBF-LB/M) makes this technology very attractive for industry. However, as a developing technology, it still faces some challenges when it comes to productivity and robustness, to name some. Whereas numerous studies covered the impact of laser-based parameters on material properties and robustness, the effect of the processing gas received limited attention. The objective of this study was to evaluate the effect of processing gas composition, containing helium (He) and hydrogen (H2), compared to conventionally used argon (Ar), during PBF-LB/M processing of virgin alloy 718 powder, on printing behavior and part properties. The four gases studied were Ar, Ar +30%He, Ar +30%He +2%H2, and Ar +70%He. Optical Tomography (OT) was used to monitor process stability, which unveiled a significant decrease in process-by products (spatters) between 51 % and 89 % using He and H2-containing gases. It was also found that the process gas decreased the bulk porosity from an average value of 0.08 % when processed with Ar to 0.04 % when using Ar + 70%He. The oxygen pickup by the spatter particles was reduced from 630 ppm (Ar) to 331 ppm (Ar +70%He). EBSD analysis revealed that there were no evident changes in microstructure with the processing gas. The samples processed also had similar tensile properties with yield and ultimate tensile strength of 1180 MPa and 1395 MPa, respectively. However, there was a slight increase in ductility from 16.5 % to 17.2 %, when processed with pure Ar and Ar + 70%He, respectively. This study shows that utilizing standard Ar processing atmosphere with He addition leads to a more stable process with reduced spatter, porosity and a marginal increase in ductility for Alloy 718.
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| 5. |
- Kreutzer, Michiel T., et al.
(författare)
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Two-phase segmented flow in capillaries and monolith reactors
- 2005
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Ingår i: Structured Catalysts and Reactors. - : CRC Press. - 9781420028003 ; , s. 393-434
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Monolith reactors are attracting more and more attention as alternatives for both threephase slurry reactors [1-3] and trickle-bed reactors [4,5]. From a fluid mechanical point of view, the operating mode depends on the size of the straight parallel channels. In large channels the fluid trickles downwards along the channel walls and the gas travels through the channel in the channel core. In smaller channels, the dominant flow pattern is a segmented slug flow or bubble-train flow of alternating bubbles and slugs, where the bubbles span all but the complete channel cross-section. In the beginning of this chapter, criteria to predict the different multiphase flow regimes are briefly reviewed, and the remainder of the chapter deals with the segmented flow pattern. For the trickle-flow or film-flow pattern, the interested reader is referred to Chapter 13.
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| 7. |
- Nilsson, Lisa M, 1976, et al.
(författare)
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Mouse genetics suggests cell-context dependency for Myc-regulated metabolic enzymes during tumorigenesis.
- 2012
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Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404 .- 1553-7390. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- c-Myc (hereafter called Myc) belongs to a family of transcription factors that regulates cell growth, cell proliferation, and differentiation. Myc initiates the transcription of a large cast of genes involved in cell growth by stimulating metabolism and protein synthesis. Some of these, like those involved in glycolysis, may be part of the Warburg effect, which is defined as increased glucose uptake and lactate production in the presence of adequate oxygen supply. In this study, we have taken a mouse-genetics approach to challenge the role of select Myc-regulated metabolic enzymes in tumorigenesis in vivo. By breeding λ-Myc transgenic mice, Apc(Min) mice, and p53 knockout mice with mouse models carrying inactivating alleles of Lactate dehydrogenase A (Ldha), 3-Phosphoglycerate dehydrogenase (Phgdh) and Serine hydroxymethyltransferase 1 (Shmt1), we obtained offspring that were monitored for tumor development. Very surprisingly, we found that these genes are dispensable for tumorigenesis in these genetic settings. However, experiments in fibroblasts and colon carcinoma cells expressing oncogenic Ras show that these cells are sensitive to Ldha knockdown. Our genetic models reveal cell context dependency and a remarkable ability of tumor cells to adapt to alterations in critical metabolic pathways. Thus, to achieve clinical success, it will be of importance to correctly stratify patients and to find synthetic lethal combinations of inhibitors targeting metabolic enzymes.
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| 8. |
- Sriram, Renuka, et al.
(författare)
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Imaging apolipoprotein AI in vivo
- 2011
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Ingår i: NMR in Biomedicine. - : Wiley. - 0952-3480. ; 24:7, s. 916-924
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Tidskriftsartikel (refereegranskat)abstract
- Coronary disease risk increases inversely with high-density lipoprotein (HDL) level. The measurement of the biodistribution and clearance of HDL in vivo, however, has posed a technical challenge. This study presents an approach to the development of a lipoprotein MRI agent by linking gadolinium methanethiosulfonate (Gd[MTS-ADO3A]) to a selective cysteine mutation in position 55 of apo AI, the major protein of HDL. The contrast agent targets both liver and kidney, the sites of HDL catabolism, whereas the standard MRI contrast agent, gadolinium-diethylenetriaminepentaacetic acid-bismethylamide (GdDTPA-BMA, gadodiamide), enhances only the kidney image. Using a modified apolipoprotein AI to create an HDL contrast agent provides a new approach to investigate HDL biodistribution, metabolism and regulation in vivo. Copyright (C) 2011 John Wiley & Sons, Ltd.
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| 9. |
- Wang, Peijun, et al.
(författare)
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A Web-based cost-effective training tool with possible application to brain injury rehabilitation
- 2004
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Ingår i: Computer Methods and Programs in Biomedicine. - : Elsevier BV. - 0169-2607. ; 74:3, s. 235-243
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Tidskriftsartikel (refereegranskat)abstract
- Virtual reality (VR) has provoked enormous interest in the medical community. In particular, VIR offers therapists new approaches for improving rehabilitation effects. However, most of these VR assistant toots are not very portable, extensible or economical. Due to the vast amount of 3D data, they are not suitable for Internet transfer. Furthermore, in order to run these VR systems smoothly, special hardware devices are needed. As a result, existing VIR assistant toots tend to be available in hospitals but not in patients' homes. To overcome these disadvantages, as a case study, this paper proposes a Web-based Virtual Ticket Machine, called WBVTM, using VRML [VRML Consortium, The Virtual Reality Modeling Language: International Standard ISO/IEC DIS 14772-1, 1997, available at http://www.vrml.org/Specifications/VRML97], Java and EAI (External Authoring Interface) [Silicon Graphics, Inc., The External Authoring Interface (EAI), available at http://cosmosoftware.com/developer/eai.htmt], to help people with acquired brain injury (ABI) to relearn basic living skills at home at a low cost. As these technologies are open standard and feature usability on the Internet, WBVTM achieves the goals of portability, easy accessibility and cost-effectiveness. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
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