469 research outputs found
Virtual network function placement and routing for multicast service chaining using merged paths
This paper proposes a virtual network function placement and routing model for multicast service chaining based on merging multiple service paths (MSC-M). The multicast service chaining (MSC) is used for providing a network-virtualization based multicast service. The MSC sets up a multicast path, which connects a source node and multiple destination nodes. Virtual network functions (VNFs) are placed on the path so that users on the destination nodes receive their desired services. The conventional MSC model configures multicast paths for services, each of which has the same source data and the same set of VNFs in a predefined order. In the MSC-M model, if paths of different services carry the same data on the same link, these paths are allowed to be merged into one path at that link, which improves the utilization of network resources. The MSC-M model determines the placement of VNFs and the route of paths so that the total cost associated with VNF placement and link usage is minimized. The MSC-M model is formulated as an integer linear programming (ILP) Problem. We prove that the decision version of VNF placement and routing problem based on the MSC-M model is NP-complete. A heuristic algorithm is introduced for the case that the ILP problem is intractable. Numerical results show that the MSC-M model reduces the total cost required to accommodate service chaining requests compared to the conventional MSC model. We discuss directions for extending the MSC-M model to an optical domain
Magnetic plateaus in the 1D antiferromagnetic spin-3/2 and spin-2 Ising chains with single-ion anisotropy
In this study, we have employed the classical transfer matrix technique to
investigate the magnetization plateaus, phase diagrams and other
thermodynamical properties of the one-dimensional antiferromagnetic spin-3/2
and spin-2 Ising chains with single-ion anisotropy in the presence of an
external magnetic field at very low temperature. We have showed that single
ion-anisotropy is one of the indispensable ingredients for an energy gap which
leads to magnetic plateau mechanism in one-dimensional antiferromagnetic Ising
spin chains. Other thermodynamical predictions seem to be provide this
argument.Comment: 14 pages, 15 Figure
Properties and evolution of emission in molecular aggregates of a perylene ammonium derivative in polymer matrices
Accepted 27 Jul 2015Size-dependent fluorescent properties of aggregates of a perylene ammonium derivative (PeryAm) were studied by steady-state and time-resolved spectroscopic methods. Quantitative analyses of aggregated states in aqueous solution indicated that the aggregation proceeded through dimer units of PeryAm. The fluorescence of the aggregate in the PVA film prepared from the aqueous solution continuously redshifted with an increase in the concentration of PeryAm in the mother liquor while keeping the absorption spectra in almost the same band shapes. Fluorescence anisotropy values of aggregates in the PVA film were dependent on the monitoring wavelength, and time profiles of the fluorescence at longer wavelengths showed a rapid increase just after the pulsed excitation. These results indicated efficient energy transfer to the stable sites in aggregates. Fluorescence microscopy images showed that aggregates were segregated in the PVA film and the color of the emission was dependent on the size of the aggregate. Under the steady-state irradiation, the emission color of the aggregates changed from green to yellow, which was attributable to the association of a small cluster of PeryAm with the green emission resulting in the formation of yellow-colored aggregates. On the basis of these results, we have discussed the mechanisms and dynamics of the aggregation and size-dependent emission in aggregates.ArticlePHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES. 14(10):1896-1902 (2015)journal articl
Seismic Velocity Structure in and around the Japanese Island Arc Derived from Seismic Tomography Including NIED MOWLAS Hi-net and S-net Data
Japanese Islands are composed of four plates, with two oceanic plates subducting beneath the two continental plates. In 2016 the National Research Institute for Earth Science and Disaster Resilience (NIED) Seafloor Observation Network for Earthquakes and Tsunamis along the Japan Trench (S-net) started seismic observation of the offshore Hokkaido to Boso region in the Pacific Ocean, and Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) was transferred to NIED. We add the NIED S-net and DONET datasets to NIED high-sensitivity seismograph network (Hi-net) and full range seismograph network (F-net) datasets used in the previous study and obtain the three-dimensional seismic velocity structure beneath the Pacific Ocean as well as Japanese Islands. NIED S-net data dramatically improve the resolution beneath the Pacific Ocean at depths of 10–20 km because the seismic stations are located above the earthquakes and on the east side of the Japan Trench. We find a NS high-Vp zone at depths of 20–30 km. The 2018 Eastern Iburi earthquake occurred below the northern part of this high-V zone. The coseismic slip plane of the 2011 Tohoku-oki earthquake has low Vp/Vs, but its large slip region has high Vp. The broad low-Vp/Vs region may play a role in large earthquake occurrence
Frustration-induced exotic properties of magnetic molecules
Geometric frustration of interacting spin systems is the driving force of a
variety of fascinating phenomena in low-dimensional magnetism. In this
contribution I will review recent results on frustration-induced effects in
magnetic molecules, i.e. zero-dimensional magnetic systems, as well as in a
recently synthesized frustrated molecule-based spin tube, i.e. a
one-dimensional spin system.Comment: 5 pages, 9 eps figures; proceedings of the symposium on "Spin- and
charge-correlations in molecule-based materials", October 2005, Koenigstein
(Taunus), German
Questionnaire survey on the continuity of home oxygen therapy after a disaster with power outages
AbstractBackgroundAfter the Great East Japan Earthquake, oxygen-dependent patients in areas experiencing power outages could not continue home oxygen therapy (HOT) without oxygen cylinders. The purpose of this study was to examine use of oxygen cylinders in areas experiencing power outages and the effects of HOT interruption on patients' health.MethodsQuestionnaires were mailed to 1106 oxygen-dependent patients and HOT-prescribing physicians in Akita, near the disaster-stricken area. We investigated patients' actions when unable to use an oxygen concentrator and classified the patients based on oxygen cylinder use. Patients who experienced an interruption of or reduction in oxygen flow rate by their own judgment were assigned to the “interruption” and “reduction” groups, respectively; those who maintained their usual flow rate were assigned to the “continuation” group. Differences were tested using analysis of variance and the χ2 tests.ResultsIn total, 599 patients responded to the questionnaire. Oxygen cylinders were supplied to 574 patients (95.8%) before their oxygen cylinders were depleted. Comparison of the continuation (n=356), reduction (n=64), and interruption (n=154) groups showed significant differences in family structure (p=0.004), underlying disease (p=0.014), oxygen flow rate (p<0.001), situation regarding use (p<0.001), knowledge of HOT (p<0.001), and anxiety about oxygen supply (p<0.001). There were no differences in changes in physical condition.ConclusionsMost patients could receive oxygen cylinders after the disaster. Some patients discontinued their usual oxygen therapy, but their overall health status was not affected
Crustal structure and growth of the Forearc region of Izu-Ogasawara arc
(独)海洋研究開発機構(JAMSTEC)では、2002年から伊豆・小笠原・マリアナ島弧において、大陸地殻の生成過程を明らかにすることを目的に構造調査を進め、現在の島弧地殻のボリュームより多くの玄武岩マグマが必要で島弧地殻を生成する過程でマフィックな島弧地殻の一部をマントル内に戻していること(Takahashi et al., 2007, 2008; Tatsumi et al., 2008)、火山フロントと背弧側の地殻の厚さ分布には相関があり過去のリフティングが検出されたこと(Kodaira et al., 2009)などがわかってきた。前弧域の地殻に関しては、厚い地殻と薄い地殻が存在すること(Takahashi et al., 2011)、地磁気異常から島弧的な構造があること(Yamazaki and Yuasa, 1998)がわかっているが、地殻構造から実証されていなかった。前弧域の地殻構造を求め、地殻進化の影響をどの程度受けているのか、前弧域の島弧成長を明らかにするために、(独)海洋研究開発機構の深海調査船「かいれい」を用いて人工地震探査を行った。 地震探査の測線は、新黒瀬からスミス海脚、第二東鳥島海丘、大町海山を通って、小笠原トラフに至る。得られた速度構造から前弧域は25km程度の地殻の厚い部分と10~15km程度の薄い部分があることが明らかになった。厚い地殻は、北緯32.5度付近、スミス海脚、第二東鳥島海丘、大町海山の下に分布する。新黒瀬側は厚い地殻を持たない。大町海山の内部には異常に厚い下部地殻が分布する。薄い地殻が分布するところでは、堆積層が厚く地殻の厚さの半分近くを占める。大町海山以外の地殻が厚く分布するところでは、P波速度6km/sの速度コンターが上に凸、7km/sの速度コンターが下に凸の形状を示す。火山フロントに沿った地殻構造では、むしろ6km/s以下の速度を持つ層が厚いことが示されている(Kodaira et al., 2007)。これは、前弧域下の島弧地殻は、火山フロント下と比較して未分化な物質を多く含むことを示唆おり、過去の掘削結果とも整合する(e.g., Taylor, 1992)。前弧海盆下の島弧地殻の分布は、地磁気異常の空間分布(Yamazaki and Yuasa, 1998)とよく合致する。新黒瀬周辺で見られる地磁気異常は、本研究から明らかになった地殻が薄く地殻全体が盛り上がっている形状と合致する。伊豆小笠原島弧の本州弧への衝突が新黒瀬の浅海部を作っているものと示唆される。SCG66-03発表要旨 / 日本地球惑星科学連合2012年大会(2012年5月20日~5月25日, 幕張メッセ国際会議場) / 日本惑星科学連合の許諾に基づき本文ファイルを掲
Experimental Verification of the Gapless Point in the =1 Antiferromagnetic Bond Alternating Chain
Susceptibility and high field magnetization measurements have been performed
on powder samples of an =1 bond alternating chain compound
[\{Ni(333-tet)(-N)\}](ClO) (333-tet=tetraamine
N,N'-bis(3-aminopropyl)-1,3-propanediamine). As the temperature is decreased,
the susceptibility exhibits a round maximum at around 120 K and decreases
gradually down to 10 K, and then falls down rapidly with a logarithmic
curvature which is behavior of the susceptibility of a gapless or a nearly
gapless antiferromagnetic chain. Magnetization up to 50 T at 1.4 K shows no or
a very small gap in this compound. We have carried out numerical calculations
for the =1 antiferromagnetic bond alternating chain with various alternating
ratios and obtained a very good agreement between experiments and
calculations for =0.6. We verify experimentally that the gapless point
exists around =0.6.Comment: 12 pages, 4 Postscript figures, uses REVTE
Comprehensive Investigation on the Interplay between Feline APOBEC3Z3 Proteins and Feline Immunodeficiency Virus Vif Proteins
As the hosts of lentiviruses, almost 40 species of felids (family Felidae) are distributed around the world, and more than 20 feline species test positive for feline immunodeficiency virus (FIV), a lineage of lentiviruses. These observations suggest that FIVs globally infected a variety of feline species through multiple cross-species transmission events during a million-year history. Cellular restriction factors potentially inhibit lentiviral replication and limit cross-species lentiviral transmission, and cellular APOBEC3 deaminases are known as a potent restriction factor. In contrast, lentiviruses have evolutionary-acquired viral infectivity factor (Vif) to neutralize the APOBEC3-mediated antiviral effect. Because the APOBEC3-Vif interaction is strictly specific for viruses and their hosts, a comprehensive investigation focusing on Vif-APOBEC3 interplay can provide clues that will elucidate the roles of this virus-host interplay on cross-species transmission of lentiviruses. Here, we performed a comprehensive investigation with 144 patterns of a round robin test using 18 feline APOBEC3Z3 genes, an antiviral APOBEC3 gene in felid, and 8 FIV Vifs and derived a matrix showing the interplay between feline APOBEC3Z3 and FIV Vif. We particularly focused on the interplay between the APOBEC3Z3 of three felids (domestic cat, ocelot, and Asian golden cat) and an FIV Vif (strain Petaluma), and revealed that residues 65 and 66 of the APOBEC3Z3 protein of multiple felids are responsible for the counteraction triggered by FIV Petaluma Vif. Altogether, our findings can be a clue to elucidate not only the scenarios of the cross-species transmissions of FIVs in felids but also the evolutionary interaction between mammals and lentiviruses
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