• Journal of the Korean Chemical Society
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• v.25 no.3
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• pp.166-171
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• 1981

The reactions of trimethylbenzenes were investigated over dealuminated, cation-exchanged mordenite catalysts. Higher reaction temperature favored the formation of disproportionation products. In the reaction of 1,2,4-trimethylbenzene, the formation of 1,3,5-trimethylbenzene and the disproportionation products decreased sharply with reaction time. The product distribution, especially the distribution of trimethylbenzenes, suggests that the effective pore diameter of Ba-exchanged dealuminated mordenite catalysts lies somewhere between 8.1 and 8.6${\AA}$.

• Journal of the Korean Chemical Society
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• v.25 no.3
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• pp.172-176
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• 1981

The formation of $C_2-C_{10}$ hydrocarbons from methanol over shape-selective ZSM-5 zeolite catalysts is studied. It seems that $C_2-C_5$ olefins formed from methanol via dimethylether are transformed further to higher hydrocarbons containing higher concentration of aromatics by the acid sites of ZSM-5. Unique cross linked channel structure and its hydrophobicity seems to be mainly responsible for its high activity of ZSM-5 catalyst for the conversion of methanol.

• KSTLE International Journal
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• v.3 no.1
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• pp.49-53
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• 2002

Inconel 690 for nuclear steam generator tube has more chromium than the conventionally used Inconel 600 in order to increase the corrosion resistance. TD evaluate the tribological characteristics under fretting condition the fretting tests as well as sliding tests were carried out in elevated temperature water environment. Fretting tests of the cross-cylinder type were done under various vibrating amplitudes and applied normal loads in order to measure the friction forces and wear volumes. Also, the conventional sliding tests of pin-en-disk type were carried out to compare the test results. In fretting, the friction was very sensitive to the load and the amplitude. The friction coefficient decreased with increasing load and decreasing amplitude. Also, the wear of Inconel 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and of ten drastically different wear rates can occur. It was fecund that the fretting wear coefficients in water were increased as increasing the temperature of water.

• Journal of the Korean Ceramic Society
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• v.49 no.2
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• pp.155-160
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• 2012

This paper reported a simple deposition-precipitation method, introducing the metal (Ni, Ag and Sn) and $Na_2S{\cdot}5H_2O$ to preparedispersion metal sulfide nanoparticles on the surface of the Multi-walled carbon nanotube for synthesis of CNT-$M_xS_y$ ($NiS_2$, $Ag_2S$, SnS) composite photocatalysts. The characterization of the prepared CNT-$M_xS_y$ ($NiS_2$, $Ag_2S$, SnS) composites was performed by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis and BET analysis. Furthermore, the MB degradation rate constant for CNT-SnS composite was $5.68{\times}10^{-3}$ under visible light irradiation, which was much higher than the corresponding values for other samples. The detailed formation and photocatalytic mechanism are also provided here.

• Journal of the Korean Mathematical Society
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• v.48 no.5
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• pp.969-984
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• 2011

This paper discusses the hypercyclicity of weighted composition operators acting on the space of holomorphic functions on the open unit ball $B_N$ of $\mathbb{C}^N$. Several analytic properties of linear fractional self-maps of $B_N$ are given. According to these properties, a few necessary conditions for a weighted composition operator to be hypercyclic in the space of holomorphic functions are proved. Besides, the hypercyclicity of adjoint of weighted composition operators are studied in this paper.

• Journal of Information Technology Services
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• v.11 no.sup
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• pp.139-152
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• 2012

In the medical web forum, people share medical experience and information as patients and patents' families. Some people search medical information written in non-expert language and some people offer words of comport to who are suffering from diseases. Medical web forums play a role of the informative support and the emotional support. We propose the automatic classification model of articles in the medical web forum into the information support and emotional support. We extract text features of articles in web forum using text mining techniques from the perspective of linguistics and then perform supervised learning to classify texts into the information support and the emotional support types. We adopt the Support Vector Machine (SVM), Naive-Bayesian, decision tree for automatic classification. We apply the proposed model to the HealthBoards forum, which is also one of the largest and most dynamic medical web forum.

• Korean Journal of Pharmacognosy
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• v.36 no.2 s.141
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• pp.65-69
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• 2005

The extract contents of various Phellinus species (Hymenochaetaceae) including P. linteus, P. baumii, P. pini and P. igniarius of domestic and foreign products, were examined to standardize the quality of these products. The differences of various extract contents were identified and compared between different species of Phellinus products. The thin layer chromatographic patterns were also analyzed and six unidentified samples were thought to originate from P. baumii and P. igniarius. The chemical standardization for the quality control of various origins could be suggested by this study.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.224-228
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• 1991

The effect of linoleate hydroperoxides(LAHPO) on pepsin activity was investigated. The activity of pepsin was largely decreased by LAHPO at various temperatures and pH. The inactivation of pepsin seems to be the radicals in the system because ascorbate and metal ions enhanced the inactivation of enzyme by LAHPO. It was shown by SDS-PAGE that LAHPO caused scission of the enzyme in the model system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1223-1236
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• 2014

With the extension of wireless technology, vehicular ad hoc networks provide important services for the dissemination of general data and emergency warnings. However, since, the vehicle topology frequently changes from a dense to a sparse network depending on the speed of the moving vehicles and the time of day, vehicular ad hoc networks require a protocol that can facilitate the efficient and reliable dissemination of emergency messages in a highly mobile environment under dense or intermittent vehicular connectivity. Therefore, this paper proposes a new vehicular broadcast protocol, called BL-CAST, that can operate effectively in both dense and sparse network scenarios. As a low overhead multi-hop broadcast protocol, BL-CAST does not rely on the periodic exchange of beacons for updating location information. Instead, the location information of a vehicle is included in a broadcast message to identify the last rebroadcasting vehicle in an intermittently connected network. Simulation results show that BL-CAST outperforms the DV-CAST protocol in terms of the end-to-end delay, message delivery ratio and network overhead.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.8-13
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• 1991

In order to investigate interactions of autoxidizing lipids with protein, enzyme and peroxidizing linoleate were reacted in freeze-dried and emulsion systems at various level of water activities. Peroxide value, TBA value of oxidized linoleate increased during incubation Solubilities and the activities of enzymes decreased as water activity increased.