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991.
With the recent tremendous increase in the volume of Web 3.0 content, content recommendation systems (CRS) have emerged as an important aspect of social network services and computing. Thus, several studies have been conducted to investigate content recommendation methods (CRM) for CRSs. However, traditional CRMs are limited in that they cannot be used in the Web 3.0 environment. In this paper, we propose a novel way to recommend high-quality web content using degree of centrality and term frequency–inverse document frequency (TF–IDF). In the proposed method, we analyze the TF–IDF and degree of centrality of collected RDF site summary and friend-of-a-friend data and then generate content recommendations based on these two analyzed values. Results from the implementation of the proposed system indicate that it provides more appropriate and reliable contents than traditional CRSs. The proposed system also reflects the importance of the role of content creators. 相似文献
992.
Hyeun Hwan An Won Bae Han Yongdeok Kim Hee‐Soo Kim Yoong Oh Chong Seung Yoon 《Journal of Raman spectroscopy : JRS》2014,45(4):292-298
A cost‐effective way of fabricating lipid‐coated surface‐enhanced Raman spectroscopy (SERS) substrate having reproducible high SERS activity was proposed. Ag nanoparticle embedded in 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) and 1,2‐dioleoyl‐3‐trimethylammonium‐propane (DOTAP) membranes was produced by direct deposition of a 5‐nm‐thick layer of Ag onto the solid‐supported phospholipid membrane, and subsequent dissolution of the Ag nanoparticle‐embedded membrane in iso‐octane allowed easy one‐pot fabrication of DOPC‐ or DOTAP‐coated Ag nanoparticles. In particular, DOTAP produced nearly monodisperse lipid‐encapsulated Ag nanoparticles (9 nm in diameter) exhibiting reproducible high SERS activity (detecting up to 10 nM of rhodamine 6G and 0.5 μM of glutathione). In addition, the process was modified to incorporate variety of Raman active molecules (rhodamine 6G, malachite green, 4‐aminothiopheonol, 4‐mercaptopyridine) into the particle‐encapsulating lipid bilayer. The DOTAP/Raman dye‐coated Ag nanoparticles also generated high SERS activity to enable potential application of the DOTAP/Raman dye‐coated Ag nanoparticles feasible in different areas. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
993.
Ji Ho Jeong Sang Bae Lee Young Min Jhon Kwang Yong Song Je-Myung Jeong Kwanil Lee 《Applied physics. B, Lasers and optics》2014,116(1):91-96
We propose and experimentally demonstrate a novel method for the extension of the measurement range in Brillouin optical correlation domain analysis by switching the pump and probe waves for selectively inducing the stimulated Brillouin scattering (SBS) in the sensing fiber. In this scheme, two correlation peaks are located in the sensing fiber and SBS is alternatively induced at each position by pump/probe selective switching and optical attenuation. In the experiment, twice enlargement of measurement range is successfully achieved with 146-m fiber with a 10-cm spatial resolution. 相似文献
994.
Seung-Wook BaekJihoon Jeong Yu-Mi KimJung Hyun Kim Sungmin ShinJoongmyeon Bae 《Solid State Ionics》2011,192(1):387-393
Materials containing barium (Ba), such as SmBa0.5Sr0.5Co2O5-d/Ce0.9Gd0.1O1.9 (SBSC50) and Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF), are considered for use as an in-situ cathode in metal-supported solid oxide fuel cells (SOFCs). The electrochemical properties and sintering behavior of these materials are investigated in terms of area specific resistances (ASRs), I-V-P characteristics and microstructure. The properties of in-situ cathodes comprised of SBSC50 and BSCF are compared with those of conventional cathodes, such as La0.8Sr0.2MnO3-d (LSM), La0.8Sr0.2FeO3-d (LSF), La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) and Sm0.5Sr0.5CoO3-d/Ce0.8Sm0.2O1.9 (SSC40). Impedance spectroscopy analysis using Nyquist and Bode plots and microstructure analysis is conducted to understand the reason behind electrochemical performance differences between in-situ cathodes and sintered cathodes. From this analysis, we are also able to verify the electrochemical behavior of well-defined in-situ cathodes. SBSC50 and BSCF are the incorporated in our metal-supported cells without the use of any additional sintering process. The metal-supported cells are successfully fabricated using a high temperature sinter-joining process and we fail to detect any defects or deformation after fabrication. At an operating temperature of 800 °C, metal-supported cells with SBSC50 and BSCF cathodes exhibit maximum power densities of 0.50 Wcm-2 and 0.65 Wcm-2, respectively. 相似文献
995.
Choi Sang-Jun Kim Guk-Bae Lee Kyoobin Kim Ki-Hong Yang Woo-Young Cho Soohaeng Bae Hyung-Jin Seo Dong-Seok Kim Sang-Il Lee Kyung-Jin 《Applied Physics A: Materials Science & Processing》2011,102(4):1019-1025
The mammalian brain is far superior to today’s electronic circuits in intelligence and efficiency. Its functions are realized
by the network of neurons connected via synapses. Much effort has been extended in finding satisfactory electronic neural
networks that act like brains, i.e., especially the electronic version of synapse that is capable of the weight control and
is independent of the external data storage. We demonstrate experimentally that a single metal–oxide–metal structure successfully
stores the biological synaptic weight variations (synaptic plasticity) without any external storage node or circuit. Our device
also demonstrates the reliability of plasticity experimentally with the model considering the time dependence of spikes. All
these properties are embodied by the change of resistance level corresponding to the history of injected voltage-pulse signals.
Moreover, we prove the capability of second-order learning of the multi-resistive device by applying it to the circuit composed
of transistors. We anticipate our demonstration will invigorate the study of electronic neural networks using non-volatile
multi-resistive device, which is simpler and superior compared to other storage devices. 相似文献
996.
Bae Yoon Cheol Lee Ah Rahm Kwak June Sik Im Hyunsik Do Young Ho Hong Jin Pyo 《Applied Physics A: Materials Science & Processing》2011,102(4):1009-1013
Bilayer TiO
x
(oxygen rich, region 1)/TiO
y
(oxygen poor, region 2) homojunctions were evaluated as resistive switching elements where the TiO
x
layers were designed with various oxygen contents. Depending on the oxygen ion content, controllable memory windows were
observed by changing the off-state (high-resistance state), while the on-state (low resistance) was left with very little
change. The cause of the variable memory windows in resistive switching phenomena appears to be the increasing amounts of
movable oxygen ions between the TiO
x
and TiO
y
layers. In addition, the X-ray photoelectron spectroscopy measurements of the initial, low resistance, and high-resistance
states in the homojunctions demonstrated the possible change of metallic and insulating Ti sub-oxide phases at the interfaces
and oxygen ion rich region due to the migration of oxygen ions. 相似文献
997.
Choi J Cho SB Lee BS Joung YK Park K Han DK 《Langmuir : the ACS journal of surfaces and colloids》2011,27(23):14232-14239
A method of securing the adhesion of biodegradable polymer coating was investigated for drug-eluting metal stents, using surface-initiated ring-opening polymerization (SI-ROP) of L-lactide. Introduction of oligolactide on the stainless steel (SS) surface was successful and the thickness of the oligolactide grafts remained on the nanometer scale, as determined by ellipsometry. The presence of an oligolactide graft was also identified using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and electron spectroscopy for chemical analysis (ESCA). On top of the grafts, poly(D,L-lactide-co-glycolide) (PLGA) coating was carried out on different substrates such as SS control, plasma-treated SS, and lactide-grafted (referred to as a nanocoupled) SS using electrospraying. When the adhesion forces were measured with a scratch tester, the nanocoupled SS showed the strongest interfacial adhesion between polymer coating layer and metal substrate. The outcome of the peel-off test was also consistent with the result of the scratch test. When degradation behavior of the polymer coating in vitro was examined for up to 4 weeks in a continuous fluid flow, the SEM images demonstrated that polymer degradation was obvious due to hydration and swelling of the polymer matrix. Although the matrix completely disappeared after 4 weeks for SS control and plasma-treated substrates, the nanocoupled SS was persistent with some polymer matrix. In addition, the release profiles of SRL-loaded PLGA coating appeared slightly different between control and nanocoupled groups. This work suggested that the concept of nanocoupling remarkably improved the interfacial adhesion stability between metal surface and polymer layer and controlled drug release, and showed the feasibility of drug-eluting stents. 相似文献
998.
Jun-Young Bae SeungCheol Yang Jung Ho Jin KyungHo Jung Joon-Soo Kim Byeong-Soo Bae 《Journal of Sol-Gel Science and Technology》2011,58(1):114-120
Methacrylate zirconium siloxane (MZS) resin was synthesized by a sol–gel reaction of 3-(trimethoxysilyl)propyl methacrylate,
diphenylsilanediol, and zirconium n-propoxide chelated with methacrylic acid. Also, propylene glycol monomethyl ether acetate
was added as a solvent to synthesize a homogeneous and long-term stable resin by controlling the reactivity among the precursors.
A High condensation degree of the resin and the formation of Si–O–Zr hetero-metal bonds were verified by 29Si NMR and FT-IR spectroscopy. The MZS resin was spin-coated and photo-polymerized to fabricate a highly transparent MZS hybrimer
coating film. The refractive index and dielectric constant of the film increased according to the zirconium content, up to
1.59 and 3.65, respectively. 相似文献
999.
Junqiang?Liu Tae-Hyun?Bae Omoyemen?Esekhile Sankar?Nair Christopher?W.?Jones William?J.?KorosEmail author 《Journal of Sol-Gel Science and Technology》2011,60(2):189-197
A facile three step sol–gel-precipitation process is used to synthesize Mg(OH)2 nanowhiskers on micron-sized zeolite 5A particle surfaces at room temperature. The putative amorphous gelation product, Mg(OH)n(OR)2−n, forms first by a controlled hydrolysis and condensation reaction involving magnesium isopropoxide and water, ultimately
leading to precipitation to form Mg(OH)2 structures on the zeolite surface. The optimum conditions for one dimensional Mg(OH)2 whisker formation are found to be six times the stoichiometric amount of water using 1 M HCl as the catalyst for the sol–gel
reaction. The one-dimensional Mg(OH)2 whiskers have an average diameter of 5–10 nm and length of 50–100 nm. The zeolite micropores are not affected by the Mg(OH)2 whiskers formed on the surface. The surface roughened zeolite 5A, with a Mg(OH)2 content of about 9 wt%, showed improved adhesion between the zeolite and the polymer in a mixed-matrix composite membrane. 相似文献
1000.
Dong F Guo W Bae JH Kim SH Ha CS 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(45):12802-12808
Magnetic particles have become very promising materials for drug delivery. However, preparation of magnetite particles with high surface area, biocompatibility, strong magnetic response, and suitable particle size still remains a major challenge. In this report, magnetite nanocrystal clusters with high surface areas were fabricated through a solvothermal process by introducing ammonium acetate as a porogen and trisodium citrate as a surface modification agent. The porosity, which was controlled by the reactant concentration, has been investigated in detail. The surface area of the nanocrystal clusters was as high as 141 m(2) g(-1). Ibuprofen, as a model drug, was entrapped into the magnetite carriers. The interfacial interaction between the carboxylic groups on the drug molecules and the carboxylate groups on the carriers enhanced the loading efficiency. Low cytotoxicity in MCF-7 cell and in vitro constant drug release behavior combined with the high drug loading efficiency and high saturation magnetization values demonstrated the potential of the as-synthesized magnetite materials in targeted drug release systems. 相似文献