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        • Topic category analysis on twitter via cross-media strategy

          Springer Science + Business Media 2016 MULTIMEDIA TOOLS AND APPLICATIONS Vol.75 No.20

          <P>The growing popularity of social media provides a huge volume of social data including Tweets. These collections of social data can be potentially useful, but the extent of meaningful data in these collections has not been sufficiently researched, especially in South Korea Twitter data. In general, the South Korea Twitter data has been researched as a source of political media. Nonetheless, previous research on South Korea Twitter data has not adequately covered what kind of trend Twitter represents in terms of major topic categories such as politics, economics, or sports. In this paper, we present a cross-media approach to define the nature of South Korea Tweets by inferring the topic category distribution through short-text categorization. We select newspapers as cross-media, examine the categorization of news articles from major newspapers, and then train our classifier based on the features from each topic category. In addition, for grafting news topics onto South Korea Tweets, we propose a word clustering and filtering approach to exclude those words that do not provide semantic content for the topic categories. Based on the proposed procedures, we analyze the South Korea Tweets to determine the primary topic category focus of Twitter users. We observe the special behaviors of the South Korea Twitter users based on various parameters such as date, time slot, and day of the week. Because our research includes a macroscopic analysis of Twitter data using a cross-media strategy, our research can provide useful resources for other social media analysis as well.</P>

        • Amelioration of Horticultural Growing Media Properties Through Rice Hull Biochar Incorporation

          Kim, H. S.,Kim, K. R.,Yang, J. E.,Ok, Y. S.,Kim, W. I.,Kunhikrishnan, A.,Kim, K. H. Springer Science + Business Media 2017 Waste and biomass valorization Vol.8 No.2

          <P>The current study was conducted in order to examine the applicability of rice hull derived biochar (BC) to improve the properties of growing media (GM). Biochar was incorporated into a growing media composed of coir dust, perlite and vermiculite at 0, 1, 2 and 5 % (w/w). Subsequently, the physicochemical properties of the GM-BC mixtures were determined in the cultivation of kale (Brassica oleracea L. var. acephala) for 25 days through the observation of the plant growth response. During kale cultivation in the GM-BC mixtures, the leachates were collected and analyzed to determine the changes in nutrient levels due to BC amendment. Application of rice hull-derived BC increased the retention of nutrients in the growing media due to a biochar-induced increase in cation exchange capacity, in addition to the biochar nutrient supply such as potassium and phosphorus. Furthermore, a higher water content of the growing media was observed when BC was used as an amendment, mainly due to the increased proportion of pore space available for water storage. The growth rate of kale was also increased as the biochar incorporation rate was increased. For example, the dry weight of the kale shoots was 150 % higher when grown in media containing 5 % GM-BC mixture than with the control growing media (with no biochar). From these results, it can be concluded that the rice hull-derived biochar would be a practically applicable amendment to improve the properties of the growing media.</P>

        • Effect of a microwave warming of cell culture media on cell viability and confluence rate

          Yoon, J. K.,Sim, W. Y.,Xu, F.,Lee, W. G. Springer Science + Business Media 2016 Microsystem Technologies Vol.22 No.9

          <P>Here we present a method for rapidly and stably warming up a small volume of cell culture media that can maintain cell viability and confluence rate. This method uses microwave radiation for warming without any direct contact with water, preventing the potential issue of contamination induced by the use of a water bath. To demonstrate the proof of concept validation, we used a conventional microwave oven for warming cell culture media. In our experiments, it took only 10 s to warm a 50 mL-media tube (mostly proper volume for the use of microfluidic cell culture experiments) up to 37 degrees C. Multiple tubes can also be used to increase the volume of cell culture media by placing them in a plastic support within the oven at the same time in a scalable manner. The results show that there was no jump discontinuity to a higher temperature than 37 degrees C within 10 s. Both apoptosis and necrosis were monitored and examined to confirm whether the new method can affect cell viability and metabolism. The proposed method is fast, easy and user-friendly in conventional cell culture process, even scalable for the use of large media volume, and free of biological contamination due to water contact occurred by use of conventional water baths. We urthermore believe that this approach can be potentially helpful for advancing on-chip cell culture process that may require a small volume of cell culture media often used in microfluidic devices.</P>

        • Uncovering stakeholders in public–private relations on social media: a case study of the 2015 Volkswagen scandal

          Jung, K.,Chilton, K.,Valero, J. N. Springer Science + Business Media 2017 Quality & quantity Vol.51 No.3

          <P>While researchers have focused on the nature of interpersonal communication on social media, few have investigated the patterns and structures of interactions among stakeholders engaged in an unexpected event. On September 18, 2015, the United States Environmental Protection Agency issued a notice of violation of the U.S. Clean Air Act to Volkswagen Group of America, Inc., citing Volkswagen's inappropriate software that circumvented the United States' emission standards. This research is systemically designed to examine the evolutionary structures of interpersonal issue networks on social media by focusing on the 2015 Volkswagen scandal on social media. The interpersonal network emerged and evolved to build a discourse on issues by stakeholders after the event. By using longitudinal data collected from the Volkswagen USA's Facebook page between September 17 and 20, 2015, this research tests four hypothesized network structures, which are reciprocity, transitivity, popularity, and activity, which assess the evolution of interpersonal issue networks. The results of exponential random graph models, analyzing 4131 stakeholders, show that interpersonal issue networks on social media have evolved overtime into a set of reciprocal relations and stakeholders transmitting critical information to bystanders. The findings imply that stakeholders who have Volkswagen's cars and stocks play a critical role in placating the scandal by mutually interacting with diverse bystanders on social media.</P>

        • SCIESCOPUS

          Beacon-based active media control interface in indoor ubiquitous computing environment

          Springer Science + Business Media 2016 CLUSTER COMPUTING Vol.19 No.1

          <P>In ubiquitous computing, diverse media technologies have recently been extensively researched and applied to various fields. The goal of media technologies is to improve our daily lives by enabling us to control activemedia devices such as smart phones, tablets, and TVs. The locations of users are important to providing a variety of services to users. In addition, given that all devices cannot be simultaneously utilized, and only one device is sometimes being used, the location information can be utilized to help determine one of the core active media devices at a specific instant in time. This paper proposes an active media-control interface that is based on location recognition methods using beacons in indoor ubiquitous computing. In the proposed environment, users have a beacon that denotes the location of each user. The one that is the nearest from the beacon is selected from among multiple active media devices for servicing. In the experiments, four access points and one beacon was used to validate the proposed method. The advantage of the proposed method is that it enables us to apply active media technology to indoor environments. By recognizing user locations in indoor environments, several kinds of active media services become available.</P>

        • Photoelectrochemical performance of surfactant (polyvinyl alcohol) assisted PbS thin films grown by chemical route

          Nikam, S. S.,Suryawanshi, M. P.,Gaikwad, M. A.,Kim, J. H.,Moholkar, A. V. Springer Science + Business Media 2017 Journal of materials science. Materials in electro Vol.28 No.7

          <P>Polyvinyl alcohol is used as a surfactant in the chemical bath deposition of PbS thin films, which causes compact, pinhole free and uniform PbS thin films. Influence of deposition time on the structural, optical, morphological, compositional, electro-chemical and photo-electrochemical (PEC) properties of the PbS thin films are studied. The charge transfer resistance is analysed using electrochemical impedance spectroscopy. The best PEC device fabricated using optimized deposition time (3 h) showed short circuit current density (J(sc)) of 1.68 mA. After annealing the optimised P-63 sample at 75 A degrees C for 1.5 h the composition changed from Pb rich to near stoichiometric. For typical PA sample J(sc) improves to 2.13 mA and photo conversion efficiency advances from 0.045 to 0.072%.</P>

        • Studies of hypro-mellose (HPMC) functionalized ZnS:Mn fluorescent quantum dots

          Jain, A.,Jain, A.,Panwar, S.,Singh, R.,Singhal, M.,Sharma, J. K.,Ahuja, R.,Jeon, H. C.,Kang, T. W.,Kumar, S. Springer Science + Business Media 2017 Journal of materials science. Materials in electro Vol.28 No.2

          <P>Fluorescent ZnS:Mn quantum dots coated with hypro-mellose (HPMC) were synthesized by using simple and facile chemical precipitation technique in which HPMC acts as a novel organic surfactant to passivate the surface, to tune the optical properties and also to functionalize the surface of quantum dot for a futuristic controlled drug release applications. Morphological and optical characterizations were done to see the effect of HPMC coating on ZnS: Mn quantum dots. Structural and morphological studies was done by using XRD and TEM respectively. XRD studies confirms the pure zinc blende phase for all the samples. TEM studies shows that HPMC is efficiently doing the surface passivation in doped quantum dots. Optical studies were done by using UV-visible, FTIR and time resolved photoluminescence. UV-visible studies shows that quantum confinement effect is more prominent and also tunable in case of HPMC coated manganese doped ZnS quantum dots. FTIR studies confirms the functionalization of HPMC on the surface of doped ZnS quantum dots. Laser induced time resolved photoluminescence studies were also done to see the effect of HPMC on the photoluminescence intensity of doped quantum dots. Time resolved studies clearly shows the much desired luminescence stability of the HPMC coated quantum dots. It is observed that both the structural and optical characteristics have strong dependence on capping concentration. As HPMC is a very important viscoelastic polymer and organic surfactant used in various types of drug formulations, these studies opens a new way in the area of efficient drug delivery, controlled drug release and targeting.</P>

        • Effect of the intermediate sulfide layer on the Cu2ZnSnS4-based solar cells

          Yu, S. M.,Lim, K. S.,Shin, D. W.,Oh, T. S.,Yoo, J. B. Springer Science + Business Media 2017 Journal of materials science. Materials in electro Vol.28 No.7

          <P>Cu2ZnSnS4 (CZTS) thin-film solar cells were fabricated using Cu/Sn/Zn and Cu/SnS/Zn precursors. The precursors were prepared using a magnetron-sputtering system with subsequent annealing (sulfurization) in a sulfur atmosphere. Sulfurization was carried out at 580 A degrees C for 1 h in an H2S/N-2 environment at atmospheric pressure. The growth behavior of CZTS thin films with different precursors during sulfurization was investigated and their properties were analyzed using X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, and Raman spectroscopy. The CZTS thin film sulfurized using the Cu/Sn/Zn metallic precursor exhibited inhomogeneous growth with detrimental secondary phases, including Cu2S and ZnS, resulting in significant degradation in V-oc, J(sc) and FF. In contrast, the CZTS thin film formed using a Cu/SnS/Zn precursor showed uniform growth without secondary phases on the surface and 4.1% power conversion efficiency, which was greater than that of the solar cell formed with the metallic precursor.</P>

        • Novel synthesis of efficient counter electrode by facile arrested precipitation technique (APT)

          Jadhav, S. S.,Mali, S. S.,Hong, C. K.,Patil, P. S.,Bhosale, P. N.,Mulik, G. N. Springer Science + Business Media 2016 Journal of materials science. Materials in electro Vol.27 No.4

          <P>In the present investigation, we have successfully synthesized nanogranular thin film of copper sulfoselenide Cu-2(S, Se) as efficient counter electrode to CdS0.7Se0.3 photoanode by facile arrested precipitation technique (APT). The deposited photoanode was annealed at 150 A degrees C in vacuum oven and used for further characterization. Optical absorption study suggested the band gap energy of photoanode is 1.75 eV. X-ray diffraction results indicate that APT is a favorable technique to synthesize pure nanocrystalline CdS0.7Se0.3 thin films having hexagonal crystal structure. An electrochemical impedance spectroscopy analysis confirms the charge transfer resistance. X-ray photoelectron spectroscopy reveals stoichiometry at valance state of Cu-2(S, Se) counter and CdS0.7Se0.3 photoanode. The enhanced photoconversion efficiency achieved was 0.42 % for this counter electrode due to systematic study.</P>

        • Mesoporous architecture of TiO2 microspheres via controlled template assisted route and their photoelectrochemical properties

          Bhat, T. S.,Mali, S. S.,Korade, S. D.,Shaikh, J. S.,Karanjkar, M. M.,Hong, C. K.,Kim, J. H.,Patil, P. S. Springer Science + Business Media 2017 Journal of materials science. Materials in electro Vol.28 No.1

          <P>Anatase titanium dioxide (TiO2) microspheres were successfully synthesized via a controlled chemical route using carbon spheres as sacrificial templates. The morphology has been controlled by varying the deposition time of carbonaceous (c) spheres from 4 to 16 h with the interval of 4 h, which affect the size of TiO2 spheres. The structural, morphological, optical, compositional and photoelectrochemical properties of the TiO2 thin films were studied. X-ray diffraction (XRD) pattern confirms the formation of anatase TiO2 with the tetragonal crystal structure. Field emission scanning electron microscopy analysis revealed that the synthesized anatase TiO2 microspheres has average diameter of similar to 330-510 nm. The blueshift in optical absorption is observed due to Mie scattering. The indirect optical band gap energy of TiO2 was varied over 3.05-3.16 eV, with the increase in deposition time. The HRTEM and SAED results show the polycrystalline nature of the sample which is in good agreement with the XRD. The anatase TiO2 hollow spheres with mesoporous walls and high specific surface area i.e. 41 m(2) g(-1) was obtained using this simple method. The films were photoelectrochemically active with maximum current density 531 mu A/cm(2) under 100 mW/cm(2) illuminations.</P>

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