960 research outputs found

    Ocean renewable energy in Malaysia: The potential of the Straits of Malacca

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    The need for renewable energy is a global demand due to both the economic factors and the environmental concerns. Malaysian government has been supportive on the research and development in the renewable energies. Renewable Energy Act (2011) and Sustainable Energy Development Authority Act (2011) have been enacted to boost the industry of renewable energy. This paper presents the current status and future prospects of renewable energy in Malaysia with particular focus on the ocean renewable energy. Five types of ocean renewable energy were reviewed including tidal barrage, tidal current energy, wave energy, Ocean Thermal Energy Conversion (OTEC) and salinity gradient power. The comparison of various types of ocean renewable energy has been made to present their recent technologies in electricity generation. Tidal current energy is identified as a preferable option particularly in the Straits of Malacca

    Clustering Memes in Social Media

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    The increasing pervasiveness of social media creates new opportunities to study human social behavior, while challenging our capability to analyze their massive data streams. One of the emerging tasks is to distinguish between different kinds of activities, for example engineered misinformation campaigns versus spontaneous communication. Such detection problems require a formal definition of meme, or unit of information that can spread from person to person through the social network. Once a meme is identified, supervised learning methods can be applied to classify different types of communication. The appropriate granularity of a meme, however, is hardly captured from existing entities such as tags and keywords. Here we present a framework for the novel task of detecting memes by clustering messages from large streams of social data. We evaluate various similarity measures that leverage content, metadata, network features, and their combinations. We also explore the idea of pre-clustering on the basis of existing entities. A systematic evaluation is carried out using a manually curated dataset as ground truth. Our analysis shows that pre-clustering and a combination of heterogeneous features yield the best trade-off between number of clusters and their quality, demonstrating that a simple combination based on pairwise maximization of similarity is as effective as a non-trivial optimization of parameters. Our approach is fully automatic, unsupervised, and scalable for real-time detection of memes in streaming data.Comment: Proceedings of the 2013 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM'13), 201

    The Core- and Pan-Genomes of Photosynthetic Prokaryotes

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    Radiation Modeling for the Reentry of the Hayabusa Sample Return Capsule

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    Predicted shock-layer emission signatures during the reentry of the Japanese Hayabusa capsule are presented and compared with flight measurements conducted during an airborne observation mission in NASA's DC-8 Airborne Laboratory. For selected altitudes at 11 points along the flight trajectory of the capsule, lines of sight were extracted from flow field solutions computed using the in-house high-fidelity CFD code, DPLR. These lines of sight were used as inputs for the line-by-line radiation code NEQAIR, and emission spectra of the air plasma were computed in the wavelength range from 300 nm to 1600 nm, a range which covers all of the different experiments onboard the DC-8. In addition, the computed flow field solutions were post-processed with the material thermal response code FIAT, and the resulting surface temperatures of the heat shield were used to generate thermal emission spectra based on Planck radiation. Both spectra were summed and integrated over the flow field. The resulting emission at each trajectory point was propagated to the DC-8 position and transformed into incident irradiance to be finally compared with experimental data

    Causes of delays in the construction phase of Chinese building projects

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    Purpose: Delays during construction are one of the common scenarios in the construction industry. The purpose of this paper is to identify the primary causes of delays in the construction phase of building construction projects in China. Design/methodology/approach: Questionnaire survey approach was adopted across the four typical cities in China, namely, Beijing, Shanghai, Chongqing and Shenzhen. In total, 115 sets of valid responded questionnaires were collected and analyzed. Findings: The results show that the causes of variations, delays in progress payments, exceptionally low bids and subcontractors’ poor performance and communication issues were the most important causes of delays in China. Originality/value: This research is the first questionnaire survey on the causes of delays in the construction phase of building construction projects in China. The comparative analysis shows two unique causes of delays in the Chinese construction industry, such as “difficulty in claiming indemnity” and “unreasonable upfront capital demanded by client.” It also reveals different ranked causes of delays as per distinguished political and economic situations in China. The research findings can be referred by construction projects in other countries that are funded or partnered with China

    Larkin-Ovchinnikov-Fulde-Ferrell phase in the superconductor (TMTSF)2ClO4: Theory versus experiment

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    We consider a formation of the Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase in a quasi-one-dimensional (Q1D) conductor in a magnetic field, parallel to its conducting chains, where we take into account both the paramagnetic spin-splitting and orbital destructive effects against superconductivity. We show that, due to a relative weakness of the orbital effects in a Q1D case, the LOFF phase appears in (TMTSF)2_2ClO4_4 superconductor for real values of its Q1D band parameters. We compare our theoretical calculations with the recent experimental data by Y. Maeno's group [S. Yonezawa et al., Phys. Rev. Lett. \textbf{100}, 117002 (2008)] and show that there is a good qualitative and quantitative agreement between the theory and experimental data.Comment: 4 pages, 1 figur

    A coordinated approach for supply-chain tracking in the liquefied natural gas industry

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    With the increased size and complexity of liquefied natural gas (LNG) projects, supplychain management has become a challenging process due to involvements of the remote location of the project site and the multiple stakeholders. The transparency and traceability of the supply-chain are critical as any surpluses or shortages of materials will put the project at risk. Currently, limited research has been conducted on LNG projects considering the total supply-chain perspective, which refers to all stages of materials tracking in off-site manufacturing, transportation, and site logistics. The purpose of this research is to propose a framework of a coordinated approach for supply-chain tracking in the LNG industry. Two focus group studies were organized to develop the proposed framework: One for LNG construction supply chain process development, and another for alternative tracking technologies selection. In addition, two experiments, namely off-site fabrication tracking and site logistics tracking, were conducted in a field to evaluate the feasibility of the proposed framework. Technology limitations were also discussed in terms of field implementation

    Thermal Decomposition Kinetics of Cumene Hydroperoxide

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    The thermal decomposition and runaway reaction of cumene hydroperoxide (CHP) in cumene were studied by thermal analysis and by using the VSP-II adiabatic calorimeter. Decomposition kinetics were determined in various CHP concentrations in cumene. The reaction order of 20wt%, 35wt%, 50wt%, 65wt%, and 80wt% was determined to be 0.5, and the Arrhenius parameters were measured as Ea (kJmol−1) = 122.0 ± 3.0 and ln A (min−1 M1/2) = 30.0 ± 1.2. This new determination of the reaction order as equal to one half implies the same mechanism of decomposition regardless of CHP concentration. Chromatography and IR spectroscopy was combined with calorimetry data to determine the thermal decomposition kinetics. The preliminary rate determining step was considered to be the decomposition of CHP by dimer association. A reaction mechanism for CHP thermal decomposition is proposed
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