Log-based Anomaly Detection of CPS Using a Statistical Method

Detecting anomalies of a cyber physical system (CPS), which is a complex system consisting of both physical and software parts, is important because a CPS often operates autonomously in an unpredictable environment. However, because of the ever-changing nature and lack of a precise model for a CPS, detecting anomalies is still a challenging task. To address this problem, we propose applying an outlier detection method to a CPS log. By using a log obtained from an actual aquarium management system, we evaluated the effectiveness of our proposed method by analyzing outliers that it detected. By investigating the outliers with the developer of the system, we confirmed that some outliers indicate actual faults in the system. For example, our method detected failures of mutual exclusion in the control system that were unknown to the developer. Our method also detected transient losses of functionalities and unexpected reboots. On the other hand, our method did not detect anomalies that were too many and similar. In addition, our method reported rare but unproblematic concurrent combinations of operations as anomalies. Thus, our approach is effective at finding anomalies, but there is still room for improvement

Relativistic Gravitational Collapse of a Cylindrical Shell of Dust

The gravitational collapse of a thick cylindrical shell of dust matter is investigated. It is found that a spacetime singularity forms on the symmetry axis and that it is necessarily naked, i.e., observable in principle. We propose a physically reasonable boundary condition at this naked singularity to construct the solution including its causal future. This boundary condition enables us to construct the unique continuation of spacetime beyond the naked singularity and ensures that the dust shell passes through the naked singularity. When the cylindrical shell leaves its symmetry axis away, the naked singularity disappears, and regularity is recovered. We construct numerical solutions with this feature. This result implies that the gravity produced by a thick cylindrical shell of dust is too weak to bind the shell even if it engenders the formation of a curvature singularity which is so strong as to satisfy the limiting focusing condition. For this reason, this naked singularity is very weak in the extended spacetime; the metric tensor is $C^{1-}$ even at the naked singularity, and the extended spacetime is complete for almost all geodesics. This feature is also seen for singular hypersurfaces. Such an extended spacetime can be regarded as phenomenological in the sense that it is valid if the relevant microphysics length scale is sufficiently small compared to the scale of interest.Comment: 32 pages, 6 figure

Effect of Boron Incorporation on Slow Interface Traps in SiO2/4H-SiC Structures

The reason for the effective removal of interface traps in SiO2/4H-SiC (0001) structures by boron (B) incorporation was investigated by employing low-temperature electrical measurements. Low-temperature capacitance–voltage and thermal dielectric relaxation current measurements revealed that the density of electrons captured in slow interface traps in B-incorporated oxide is lower than that in dry and NO-annealed oxides. These results suggest that near-interface traps can be removed by B incorporation, which is considered to be an important reason for the increase in the field-effect mobility of 4H-SiC metal–oxide–semiconductor devices. A model for the passivation mechanism is proposed that takes account of stress relaxation during thermal oxidation

Negative Correlation between Serum Cytokine Levels and Cognitive Abilities in Children with Autism Spectrum Disorder

Evidence suggests that cytokines may be one of the major factors influencing cognitive development in those with autism spectrum disorder (ASD). To shed light on the neural and cognitive mechanisms of ASD, we investigated the association between peripheral cytokine levels and cognitive profiles in children with ASD. The serum levels of 10 cytokines (granulocyte macrophage colony-stimulating factor, interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and tumor necrosis factor-α) were examined in 14 children with ASD using the Human Ultrasensitive Cytokine Magnetic 10-Plex Panel for the Luminex platform. The Wechsler Intelligence Scale for Children (WISC) was administered to each subject, and the relationships between WISC scores and serum levels of the cytokines were examined. The full-scale intelligence quotient (IQ) was significantly negatively correlated with the levels of IL-6 (Spearman’s rank, p < 0.0001, false discovery rate q < 0.01). The levels of IL-6 and IFN-γ showed significant negative correlations with the verbal comprehension index (p < 0.001, q < 0.01) and working memory index (p < 0.01, q < 0.05), respectively. No other cytokines were significantly correlated with full-scale IQ or with any of the subscale scores of the WISC. The present results suggest negative correlations of IL-6 and IFN-γ levels with cognitive development of children with ASD. Our preliminary findings add to the evidence that cytokines may play a role in the neural development in ASD.ArticleJOURNAL OF INTELLIGENCE. 5(2):19 (2017)journal articl

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization.BackgroundAnaphylatoxin C5a mediates inflammatory responses through interaction with a specific C5a receptor (C5aR), the expression of which is thought to be restricted to peripheral blood leukocytes. Although the presence of C5aR on cultured mesangial cells and tubular epithelial cells has recently been documented, the tissue distribution of C5aR in diseased kidney has not yet been determined.MethodsImmunohistochemistry and nonradioactive in situ hybridization for C5aR were performed in 34 tissue samples of kidneys from patients with various renal diseases, including 4 with minimal change nephrotic syndrome (MCNS), 5 with membranous nephropathy (MN), and 25 with mesangial proliferative glomerulonephritis (mesGN; 15 patients with IgA nephropathy, 5 with non-IgA mesGN, and 5 with lupus nephritis). Normal portions of surgically resected kidney served as the control.ResultsIn normal kidneys, C5aR protein was detected in tubular epithelial cells, while C5aR mRNA was detected in a few glomerular cells, tubular epithelial cells, and vascular endothelial and smooth muscle cells. In MCNS, the distribution of C5aR protein and mRNA was similar to that in normal kidneys. In MN and mesGN, C5aR protein and mRNA were detected in mesangial cells, glomerular epithelial and endothelial cells, Bowman's capsule cells, tubular cells, infiltrating cells, and vascular endothelial and smooth muscle cells. The glomerular expression of C5aR mRNA and protein correlated positively with the degree of mesangial hypercellularity and mesangial matrix expansion in mesGN. In the tubulointerstitium, interstitial expression of C5aR mRNA correlated positively with the degree of tubular atrophy and interstitial broadening in mesGN. Furthermore, the interstitial expression of C5aR mRNA correlated positively with the level of serum creatinine.ConclusionsOur results indicate that renal cells produce C5aR and that activation of C5a/C5aR pathway on renal cells may be involved in tissue injury in mesGN

Comparison of Nitrofen Uptake via Water and Food and its Distribution in Tissue of Common Carp, Cyprinus carpio L.

Carp (Cyprinus carpio L.) were exposed to nitrofen (NIP) by different routes (via water or food) to compare bioaccumulation parameters and tissue distribution. The bioconcentration factor of NIP was 5,100, and the lipid-corrected biomagnification factor was 0.137. Growth-corrected elimination half lives were 2.1–3.0 days via aqueous exposure and 2.7–2.9 days via dietary exposure. From either uptake route, the tissue distribution of NIP was highest in the head, followed by muscle, viscera, dermis, digestive tract and hepatopancreas, which was highly correlated with the tissue lipid content. We conclude that the uptake route has no influence on tissue distribution of NIP and that the accumulation potential in tissues depends on the lipid content

Low-power display system enabled by combining oxide semiconductor and neural network technologies

An oxide semiconductor (OS)-based field effect transistor (OSFET) exhibits the advantage of having an extremely low off-state current; moreover, the OSFET displays an off-state current that is ten orders of magnitude lower than that of a CMOS-FET [1]. Recently, numerous applications that harness this feature have been reported [2]. For instance, charge leakage from a data retention node of a pixel significantly decreases when the display incorporates OSFETs in its pixel circuit (OS display) [3, 4]. This minimizes degradation in the image quality when the displayed image is static despite using lower refresh rates. Consequently, the consumed power of the display driver circuit can be reduced by a large margin. This driving method is termed idling stop (IDS) driving. The OSFET’s low-leakage can also effectively enable a type of ULSICs that we term OS-large-scale integrated circuits (OSLSI) [5, 6]. Please click Additional Files below to see the full abstract