Time-series clustering for sensor fault detection in large-scale Cyber-Physical Systems

Large-scale Cyber-Physical Systems (CPSs) are information systems that involve a vast network of sensor nodes and other devices that stream observations in real-time and typically are deployed in uncontrolled, broad geographical terrains. Sensor node failures are inevitable and unpredictable events in large-scale CPSs, which compromise the integrity of the sensors measurements and potentially reduce the quality of CPSs services and raise serious concerns related to CPSs safety, reliability, performance, and security. While many studies were conducted to tackle the challenge of sensor nodes failure detection using domain-specific solutions, this paper proposes a novel sensor nodes failure detection approach and empirically evaluates its validity using a real-world case study. This paper investigates time-series clustering techniques as a feasible solution to identify sensor nodes malfunctions by detecting long-segmental outliers in their observations' time series. Three different time-series clustering techniques have been investigated using real-world observations collected from two various sensor node networks, one of which consists of 275 temperature sensors distributed around London. This study demonstrates that time-series clustering effectively detects sensor node's continuous (halting/repeating) and incipient faults. It also showed that the feature-based time series clustering technique is a more efficient long-segmental outliers detection mechanism compared to shape-based time-series clustering techniques such as DTW and K-Shape, mainly when applied to shorter time-series windows

Phylogenetic analysis of anemone fishes of the Persian Gulf using mtDNA sequences

Anemone fishes are a group of 28 species of coral reef fishes belonging to the family, Pomacentridae; subfamily, Amphiprioninae and all have an obligate symbiotic relationship with sea anemones. Twospecies of these small ornamental fishes have been identified in the Persian Gulf including Amphiprion clarkii and Amphiprion sebae. The phylogenetic relationship between Amphiprion species of thePersian Gulf was studied by collecting 15 samples from three Iranian islands, Larak, Farur and Kish. DNA was extracted from each sample and a part of mtDNA was amplified. Two pairs of primers weredesigned to amplify a final target of 400 bp by nested-PCR. Each amplican was sequenced, aligned and genetic diversity among samples was investigated by phylogenetic analysis. Results show that there isno significant genetic variation among A. clarkii individuals; however, A. sebae individuals from Larak were different from other fishes of the same species. Most probably this is due to the ability of A. clarkiito be symbiotant with all 10 species of host sea anemones which enables it to spread its own population in the 3 islands. However, A. sebae is observed to be symbiotant only with one host in thesea, therefore, has one option that reduces its distribution

Whole-genome sequence of a beak and feather disease virus isolate from a fledgling red-capped parrot (Purpureicephalus spurius)

The complete genome sequence of beak and feather disease virus (BFDV) from a fledgling red-capped parrot (Purpureicephalus spurius) was assembled and characterized. The genome consists of 1,995 nucleotides and encodes two major proteins in opposing directions. This is the first evidence of BFDV infectivity and a complete genome sequence for this novel host

Characterization of Beak and Feather Disease Virus Genomes from Wild Musk Lorikeets ( Glossopsitta concinna )

Three complete genomes of beak and feather disease virus (BFDV) were recovered from wild musk lorikeets (Glossopsitta concinna). The genomes consisted of 2,008 to 2,010 nucleotides (nt) and encode two major proteins transcribing in opposing directions. This is the first report of BFDV complete genome sequences obtained from this host species

Molecular characterization of a beak and feather disease virus genome from a purple crowned lorikeet (Glossopsitta porphyrocephala)

The complete genome sequence of beak and feather disease virus (BFDV) from a purple crowned lorikeet (Glossopsitta porphyrocephala) was characterized. The genome consists of 2,010 nucleotides and encodes replicase-associated protein and capsid protein. This is the first evidence of BFDV infectivity and complete genome sequence for this novel host

Identification of Hepatitis B Virus Surface Antigen (HBsAg) Genotypes and Variations in Chronic Carriers from Isfahan Province, Iran

Background: Hepatitis B virus (HBV) gene and protein variations are frequently been seen in chronic patients. The aims of study were to determine the genotypes as well as the patterns of variations distribution in chronically-infected patients from the central part of Iran.Methods: The surface gene was amplified, sequenced and subsequently aligned using international and national Iranian database. Results: All strains belonged to genotype D, subgenotype D1 and subtype ayw2. Of all 62 mutations occurred at 39 nucleotide positions, 31 (50%) were missense (amino acid altering) and 31 (50%) were silent (no amino acid changing). At the amino acid level, 30 substitutions occurred, however, 3 were in positions 122 and 127, corresponded to subtypic determination. 22 (73%) out of 30 amino acid mutations occurred in different immune epitopes within surface protein, of which 12 (54.54%) in B cell epitopes in 10 residues; 5 (45.45%) in T helper epitopes in positions; 5 (22.73%) in inside CTL epitopes in 4 residues. Conclusion: The distribution of amino acid mutations as well as the ratio between silent and missense nucleotide mutations showed a narrowly focused immune pressure had already been on the surface protein in these patients, led to the emergence of escape mutants in these patients