48 research outputs found
Accessing and Interpreting OPC UA Event Traces based on Semantic Process Descriptions
The analysis of event data from production systems is the basis for many
applications associated with Industry 4.0. However, heterogeneous and disjoint
data is common in this domain. As a consequence, contextual information of an
event might be incomplete or improperly interpreted which results in suboptimal
analysis results. This paper proposes an approach to access a production
systems' event data based on the event data's context (such as the product
type, process type or process parameters). The approach extracts filtered event
logs from a database system by combining: 1) a semantic model of a production
system's hierarchical structure, 2) a formalized process description and 3) an
OPC UA information model. As a proof of concept we demonstrate our approach
using a sample server based on OPC UA for Machinery Companion Specifications.Comment: Copyright 2022 IEEE. Personal use of this material is permitted.
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Integration of Domain Expert-Centric Ontology Design into the CRISP-DM for Cyber-Physical Production Systems
In the age of Industry 4.0 and Cyber-Physical Production Systems (CPPSs) vast
amounts of potentially valuable data are being generated. Methods from Machine
Learning (ML) and Data Mining (DM) have proven to be promising in extracting
complex and hidden patterns from the data collected. The knowledge obtained can
in turn be used to improve tasks like diagnostics or maintenance planning.
However, such data-driven projects, usually performed with the Cross-Industry
Standard Process for Data Mining (CRISP-DM), often fail due to the
disproportionate amount of time needed for understanding and preparing the
data. The application of domain-specific ontologies has demonstrated its
advantageousness in a wide variety of Industry 4.0 application scenarios
regarding the aforementioned challenges. However, workflows and artifacts from
ontology design for CPPSs have not yet been systematically integrated into the
CRISP-DM. Accordingly, this contribution intends to present an integrated
approach so that data scientists are able to more quickly and reliably gain
insights into the CPPS. The result is exemplarily applied to an anomaly
detection use case
Long-Chain and Very Long-Chain Ceramides Mediate Doxorubicin-Induced Toxicity and Fibrosis
Doxorubicin (Dox) is a chemotherapeutic agent with cardiotoxicity associated with profibrotic effects. Dox increases ceramide levels with pro-inflammatory effects, cell death, and fibrosis. The purpose of our study was to identify the underlying ceramide signaling pathways. We aimed to characterize the downstream effects on cell survival, metabolism, and fibrosis. Human fibroblasts (hFSF) were treated with 0.7 µM of Dox or transgenically overexpressed ceramide synthase 2 (FLAG-CerS2). Furthermore, cells were pre-treated with MitoTempo (MT) (2 h, 20 µM) or Fumonisin B1 (FuB) (4 h, 100 µM). Protein expression was measured by Western blot or immunofluorescence (IF). Ceramide levels were determined with mass spectroscopy (MS). Visualizations were conducted using laser scanning microscopy (LSM) or electron microscopy. Mitochondrial activity was measured using seahorse analysis. Dox and CerS2 overexpression increased CerS2 protein expression. Coherently, ceramides were elevated with the highest peak for C24:0. Ceramide- induced mitochondrial ROS production was reduced with MT or FuB preincubation. Mitochondrial homeostasis was reduced and accompanied by reduced ATP production. Our data show that the increase in pro-inflammatory ceramides is an essential contributor to Dox side-effects. The accumulation of ceramides resulted in a lipotoxic shift and subsequently mitochondrial structural and functional damage, which was partially reversible following inhibition of ceramide synthesis
Focal DNA copy number changes in neuroblastoma target MYCN regulated genes
Neuroblastoma is an embryonic tumor arising from immature sympathetic nervous system cells. Recurrent genomic alterations include MYCN and ALK amplification as well as recurrent patterns of gains and losses of whole or large partial chromosome segments. A recent whole genome sequencing effort yielded no frequently recurring mutations in genes other than those affecting ALK. However, the study further stresses the importance of DNA copy number alterations in this disease, in particular for genes implicated in neuritogenesis. Here we provide additional evidence for the importance of focal DNA copy number gains and losses, which are predominantly observed in MYCN amplified tumors. A focal 5 kb gain encompassing the MYCN regulated miR-17,92 cluster as sole gene was detected in a neuroblastoma cell line and further analyses of the array CGH data set demonstrated enrichment for other MYCN target genes in focal gains and amplifications. Next we applied an integrated genomics analysis to prioritize MYCN down regulated genes mediated by MYCN driven miRNAs within regions of focal heterozygous or homozygous deletion. We identified RGS5, a negative regulator of G-protein signaling implicated in vascular normalization, invasion and metastasis, targeted by a focal homozygous deletion, as a new MYCN target gene, down regulated through MYCN activated miRNAs. In addition, we expand the miR-17,92 regulatory network controlling TGFß signaling in neuroblastoma with the ring finger protein 11 encoding gene RNF11, which was previously shown to be targeted by the miR-17,92 member miR-19b. Taken together, our data indicate that focal DNA copy number imbalances in neuroblastoma (1) target genes that are implicated in MYCN signaling, possibly selected to reinforce MYCN oncogene addiction and (2) serve as a resource for identifying new molecular targets for treatment
System security of hybrid AC-HVDC-systems challenges and new approaches for combined security assessment, preventive optimization and curative actions
The intense application of Voltage Source Converter based HVDC interconnections and grids will result in a hybrid AC-HVDC-system. The operation of such a system becomes complex regarding system security and system operation. This paper describes major challenges and proposes potential solutions, including a combined security assessment, preventive optimization and curative actions. A coordination of both systems enables an efficient application of existing transport capacity. Keywords: Hybrid AC-HVDC-systems, Curative action, System security, Operational planning, System operatio