2,542 research outputs found
Andro-Simnet: Android Malware Family Classification Using Social Network Analysis
While the rapid adaptation of mobile devices changes our daily life more
conveniently, the threat derived from malware is also increased. There are lots
of research to detect malware to protect mobile devices, but most of them adopt
only signature-based malware detection method that can be easily bypassed by
polymorphic and metamorphic malware. To detect malware and its variants, it is
essential to adopt behavior-based detection for efficient malware
classification. This paper presents a system that classifies malware by using
common behavioral characteristics along with malware families. We measure the
similarity between malware families with carefully chosen features commonly
appeared in the same family. With the proposed similarity measure, we can
classify malware by malware's attack behavior pattern and tactical
characteristics. Also, we apply a community detection algorithm to increase the
modularity within each malware family network aggregation. To maintain high
classification accuracy, we propose a process to derive the optimal weights of
the selected features in the proposed similarity measure. During this process,
we find out which features are significant for representing the similarity
between malware samples. Finally, we provide an intuitive graph visualization
of malware samples which is helpful to understand the distribution and likeness
of the malware networks. In the experiment, the proposed system achieved 97%
accuracy for malware classification and 95% accuracy for prediction by K-fold
cross-validation using the real malware dataset.Comment: 13 pages, 11 figures, dataset link:
http://ocslab.hksecurity.net/Datasets/andro-simnet , demo video:
https://youtu.be/JmfS-ZtCbg4 , In Proceedings of the 16th Annual Conference
on Privacy, Security and Trust (PST), 201
Subcutaneous Sacrococcygeal Myxopapillary Ependymoma in Asian Female:A Case Report
Subcutaneous sacrococcygeal myxopapillary ependymoma is extremely rare tumor that has a tendency to develop in children and adolescents. There have been several case reports and sporadic reports in the literature. However, no case has been reported in an Asian patient, to the best of our knowledge. We describe a 25-year-old Asian female patient with a subcutaneous sacrococcygeal myxopapillary ependymoma that had been clinically diagnosed as a pilonidal cyst. The tumor was treated successfully by surgical excision and the patient is doing well without evidence of local recurrence or distant metastasis at 2 years after surgery.
Effective Vortex Mass from Microscopic Theory
We calculate the effective mass of a single quantized vortex in the BCS
superconductor at finite temperature. Based on effective action approach, we
arrive at the effective mass of a vortex as integral of the spectral function
divided by over frequency. The spectral function is
given in terms of the quantum-mechanical transition elements of the gradient of
the Hamiltonian between two Bogoliubov-deGennes (BdG) eigenstates. Based on
self-consistent numerical diagonalization of the BdG equation we find that the
effective mass per unit length of vortex at zero temperature is of order (=Fermi momentum, =coherence length), essentially
equaling the electron mass displaced within the coherence length from the
vortex core. Transitions between the core states are responsible for most of
the mass. The mass reaches a maximum value at and decreases
continuously to zero at .Comment: Supercedes prior version, cond-mat/990312
Establishment strategy of a rare wetland species Sparganium erectum in Korea
Abstract
Background
To reveal establishment strategy of Sparganium erectum, we tried to find realized niche of adults through field survey and effects of water level on the establishment process through mesocosm experiments.
Results
In the field survey, the height and coverage of community living in deeper water were greater than those of community living in shallow water. There was no statistically significant difference (p > 0.05) in the means of water and soil properties between the two communities. In mesocosm experiments, we found no correlation between water levels and germination rates, but S. erectum seedlings have characteristics of post germination seedling buoyancy when S. erectum seeds germinated in inundation conditions. Shoot height, total leaf length, and survival rates of sinking seedlings in shallow water levels at −5, 0, and 5 cm were higher than those in deeper water levels at 10 and 20 cm. Floating seedlings established in water levels of 3 and 6 cm only. The seedlings could live up to 6 weeks in floating state but died if they were unable to establish.
Conclusions
The water level around adult S. erectum communities in the field were different from the water level at which S. erectum seedlings can survive in the mesocosm experiments. The findings provided not only understanding of S. erectum habitat characteristics but also evidence to connect historical links between the early seedlings stage and adult habitat conditions. We suggested the logical establishment strategy of S. erectum based on the data.This study was funded by the Korea Ministry of Environment (MOE) as public technology program based on Environmental Policy (2016000210003) and by the Basic Science Research Program through the National Research Foundation of Korea (NRF-2015R1D1A1A01057373)
(E)-2,2′-[3-(2-Nitrophenyl)prop-2-ene-1,1-diyl]bis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one)
In the title compound, C25H29NO6, each of the cyclohexenone rings adopts a half-chair conformation. Each of the pairs of hydroxy and carbonyl O atoms are oriented to allow for the formation of intramolecular O—H⋯O hydrogen bonds, which are typical of xanthene derivatives. The nitro group is rotationally disordered over two orientations in a 0.544 (6):0.456 (6) ratio. In the crystal, weak intermolecualr C—H⋯O hydrogen bonds link molecules into layers parallel to the ab plane
Basic Fibroblast Growth Factor Activates MEK/ERK Cell Signaling Pathway and Stimulates the Proliferation of Chicken Primordial Germ Cells
BACKGROUND: Long-term maintenance of avian primordial germ cells (PGCs) in vitro has tremendous potential because it can be used to deepen our understanding of the biology of PGCs. A transgenic bioreactor based on the unique migration of PGCs toward the recipients' sex cord via the bloodstream and thereby creating a germline chimeric bird has many potential applications. However, the growth factors and the signaling pathway essential for inducing proliferation of chicken PGCs are unknown. METHODOLOGY/PRINCIPAL FINDINGS: Therefore, we conducted this study to investigate the effects of various combinations of growth factors on the survival and proliferation of PGCs under feeder-free conditions. We observed proliferation of PGCs in media containing bFGF. Subsequent characterization confirmed that the cultured PGCs maintained expression of PGC-specific markers, telomerase activity, normal migrational activity, and germline transmission. We also found that bFGF activates the mitogen-activated protein kinase kinase/extracellular-signal regulated kinase (MEK/ERK) signaling. Also, the expression of 133 transcripts was reversibly altered by bFGF withdrawal. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that chicken PGCs can be maintained in vitro without any differentiation or dedifferentiation in feeder free culture conditions, and subsequent analysis revealed that bFGF is one of the key factors that enable proliferation of chicken PGCs via MEK/ERK signaling regulating downstream genes that may be important for PGC proliferation and survival
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