1,721,682 research outputs found
Application of 3D T1Black-Blood Imaging in the Diagnosis of Leptomeningeal Carcinomatosis: Potential Pitfall of Slow-Flowing Blood Reply
No full textA traffic control algorithm for Clos network type ATM switches
No full textThis paper presents a new traffic control algorithm for asynchronous transfer mode (ATM) switches composed of Clos network type switch fabric. In most traffic control algorithms previously proposed, an ATM switch has been considered as a single node, although the switch fabric of an ATM switch is usually of a network type. In this paper, we suggest a new control algorithm that is designed not only for the ATM network but also for the switch fabric and that can maintain high speed even in cases where buffer capacity of the switch fabric is limited. Main modules of the suggested algorithm are a traffic status detection mechanism based on non-parametric statistical tests, a cell-loss detection mechanism, and a cluster-based fair share computation procedure. Results of simulation experiments show that the suggested algorithm satisfactorily adjusts traffic rate of available bit rate services according to changes in traffic rate used by quality of service (QoS) guaranteed services. The results also show that the algorithm prevents cell losses relatively well and keeps the delay time of QoS guaranteed services short enough
Surface-enhanced Raman scattering (SERS) spectra of sodium benzoate and 4-picoline in Ag colloids prepared by gamma-irradiation
No full textPVP-protected silver colloids were prepared by gamma-irradiation and chemical reduction method. Surface-enhanced Raman scattering (SERS) spectra of sodium benzoate and 4-picoline in Ag colloids prepared by gamma-irradiation were recorded. The SERS spectra of sodium benzoate were successfully recorded in Ag colloids, whereas the Raman spectra did not appear without Ag colloids. The Raman spectra of 4-picoline were not detected without Ag colloids, while the SERS spectra of 4-picoline were increased by adding Ag colloids. The carboxylate group of sodium benzoate and N donor of 4-picoline were adsorbed on the surface of Ag nanoparticles. (c) 2004 Elsevier B.V. All fights reserved.The work was supported by the Science Foundation
of Hannam University, 2004
Reallocation of paths of ABR services in a multistage interconnection network (MIN)-typeATM switch network
No full textIn this paper, we develop algorithms for reallocating paths of available bit rate (ABR) services in an asynchronous transfer mode (ATM) switch network. ATM traffic control for fair share bandwidth allocation is usually performed under the assumption that paths of all services in a switch network are fixed. However, each connection may have multiple paths from an ingress queue to an egress queue since most ATM switch networks have the structure of the multistage interconnection network of switch elements. Therefore, paths already established for ABR connections may have to be changed to enhance throughput of the switch, if the ATM switch has the capability of adjusting paths of ABR connections while they are being served. We present three algorithms, in which throughput for ABR connections is estimated to decide whether or not paths of the connections should be changed. These algorithms are compared with an existing traffic management algorithm through simulation experiments. Results of the experiments show that the suggested algorithms give higher throughput in terms of the number of transmitted ABR cells without increasing the delay time of ABR services as well as quality of service (QoS) guaranteed services or decreasing the number of transmitted cells of QoS guaranteed services. (C) 2003 Elsevier B.V. All rights reserved
G-CSF loaded biodegradable PLGA nanoparticles prepared by a single oil-in-water emulsion method
No full textA new formulation method was developed for preparing poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles loaded with recombinant human granulocyte colony-stimulating factor (rhG-CSF). Lyophilized rhG-CSF powder and PLGA polymer were directly co-dissolved in a single organic phase, and the resulting solution was dispersed into an aqueous Solution. PLGA nanoparticles encapsulating rhG-CSF were produced by a spontaneous emulsion/solvent diffusion method. In this manner, rhG-CSF was molecularly dissolved in the polymer phase. Release profile of rhG-CSF from PLGA nanoparticles was compared with those from two kinds of PLGA microparticles which were separately prepared by either single oil-in-water (O/W) or double water-in-oil-in-water (W/O/W) emulsion technique. The sizes of rhG-CSF loaded nanoparticles, O/W microparticles, and W/O/W microparticles were about 257 nm, 4.7 mu m, and 4.3 mu m, respectively. For rhG-CSF nanoparticles,about 90% of encapsulated rhG-CSF was released out in a sustained manner from PLGA nanoparticles over a 1 week period, but for rhG-CSF microparticles, only about 20% of rhG-CSF Could be released out during the same period. Reversed phase and size exclusion chromatograms revealed that the structural integrity of released rhG-CSF from nanoparticles was nearly intact, compared to that of native rhG-CSF. (c) 2005 Elsevier B.V. All rights reserved.the Ministry of Health and Welfare, Korea
An efficient force planning system using multi-objective linear goal programming
No full textThis article examines the application of multi-objective linear goal programming in military budget planning. A lot of uncertainty exists in coefficients because of the difficulties in gathering accurate data in the defense domain. A solution is not generally made in a single step but is part of a process using multiple criteria decision support system (MCDSS). We recommend an approach using a rule-based post-optimal analysis for further interaction, to overcome these difficulties and yield a satisfactory solution. We achieved a saving in the annual budget in our case study. This system can also help to guarantee unforeseen military budget planning and provide a pragmatic approach to rigorously analyzing programming and budgeting issues. (C) 1997 Elsevier Science Ltd
Temperature-sensitive pluronic/poly(ethylenimine) nanocapsules for thermally triggered disruption of intracellular endosomal compartment
No full textPluronic hydrogel nanoparticles cross-linked with poly(ethylenimine) (PEI) were synthesized by a modified emulsification/solvent evaporation method. Pluronic F-127 preactivated at the terminal group with p-nitrophenyl chloroformate was dissolved in dichloromethane, and the organic solution was emulsified in deionized water containing PEI by sonication. Primary amine groups of PEI in the aqueous phase were conjugated and/or crosslinked with activated Pluronic F-127 in the vicinity of the water/dichloromethane interface, resulting in the formation of shell-cross-linked Pluronic/PEI nanocapsules. Pluronic/PEI nanocapsules exhibited a volume transition behavior over a temperature range of 24-33 degrees C. The thermally reversible swelling/deswelling of Pluronic/PEI nanocapsules was caused by temperature-dependent hydrophobic interaction of cross-linked and/or grafted Pluronic polymer chains in the nanocapsules. Pluronic/PEI nanocapsules were utilized to break up intracellular endosomal compartments by swelling-induced destabilization of the endosomal membrane triggered by a cold-shock treatment.the Ministry of Health and
Welfare, Korea
Oxidation, grain growth and reflow characteristics of copper thin films prepared by chemical vapor deposition
No full textOxidation and grain growth characteristics of copper thin films in an oxygen ambient were investigated. In general, reflow characteristics of thin films mainly depend on the surface self-diffusion of the film's material, but we found that the oxidation and grain growth could result in the reflow of copper thin films in an oxidizing atmosphere. Upon post-annealing at higher than 400 degrees C in an oxygen ambient, the normal grain growth and the agglomeration of copper occurred simultaneously and filled the patterns. This behavior was not observed in inert ambient annealings. Copper oxide was formed during the annealing in an oxygen ambient to a thickness of at most 20 nm. The grain growth is attributed to stresses produced during the surface oxidation of the copper. (C) 2000 Elsevier Science S.A. All rights reserved.The authors acknowledge the support of university research program supported by Ministry of Information and Communication in Korea for this work
Direct visualization of hyaluronic acid polymer chain by self-assembled one-dimensional array of gold nanoparticles
No full textCubic Ia3d large mesoporous silica: synthesis and replication to platinum nanowires, carbon nanorods and carbon nanotubes
No full textA new synthesis route to high-quality large mesoporous cubic Ia3d silica is reported, utilizing a triblock copolymer ( EO20PO70EO20) - butanol mixture for the structure direction in aqueous solution.The work was supported by the Korea Ministry of Science and Technology and the School of Molecular Science through the BK21 project
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