37,751 research outputs found

    The relationship between national policy and industrial development in the UK and South Korea, 1940s–2000s

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    Copyright © 2010 Massachusetts Institute of Technology.No abstract available

    Learning Points and Routes to Recommend Trajectories

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    The problem of recommending tours to travellers is an important and broadly studied area. Suggested solutions include various approaches of points-of-interest (POI) recommendation and route planning. We consider the task of recommending a sequence of POIs, that simultaneously uses information about POIs and routes. Our approach unifies the treatment of various sources of information by representing them as features in machine learning algorithms, enabling us to learn from past behaviour. Information about POIs are used to learn a POI ranking model that accounts for the start and end points of tours. Data about previous trajectories are used for learning transition patterns between POIs that enable us to recommend probable routes. In addition, a probabilistic model is proposed to combine the results of POI ranking and the POI to POI transitions. We propose a new F1_1 score on pairs of POIs that capture the order of visits. Empirical results show that our approach improves on recent methods, and demonstrate that combining points and routes enables better trajectory recommendations

    Ultrafast Photoinduced Formation of Metallic State in a Perovskite-type Manganite with Short Range Charge and Orbital Order

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    Femtosecond reflection spectroscopy was performed on a perovskite-type manganite, Gd0.55Sr0.45MnO3, with the short-range charge and orbital order (CO/OO). Immediately after the photoirradiation, a large increase of the reflectivity was detected in the mid-infrared region. The optical conductivity spectrum under photoirradiation obtained from the Kramers-Kronig analyses of the reflectivity changes demonstrates a formation of a metallic state. This suggests that ferromagnetic spin arrangements occur within the time resolution (ca. 200 fs) through the double exchange interaction, resulting in an ultrafast CO/OO to FM switching.Comment: 4 figure

    SMA outflow/disk studies in the massive star-forming region IRAS18089-1732

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    SMA observations of the massive star-forming region IRAS 18089-1732 in the 1mm and 850mu band reveal outflow and disk signatures in different molecular lines. The SiO(5--4) data show a collimated outflow in the northern direction. In contrast, the HCOOCH3(20--19) line, which traces high-density gas, is confined to the very center of the region and shows a velocity gradient across the core. The HCOOCH3 velocity gradient is not exactly perpendicular to the outflow axis but between an assumed disk plane and the outflow axis. We interpret these HCOOCH3 features as originating from a rotating disk that is influenced by the outflow and infall. Based on the (sub-)mm continuum emission, the mass of the central core is estimated to be around 38M_sun. The dynamical mass derived from the HCOOCH3 data is 22Msun, of about the same order as the core mass. Thus, the mass of the protostar/disk/envelope system is dominated by its disk and envelope. The two frequency continuum data of the core indicate a low dust opacity index beta ~ 1.2 in the outer part, decreasing to beta ~ 0.5 on shorter spatial scales.Comment: 7 pages of text, 1 table, 3 figures, accepted for ApJ Letter

    Modelling and evaluation of aircraft contrails for 4-dimensional trajectory optimisation

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    Contrails and aircraft-induced cirrus clouds are reputed being the largest components of aviation-induced global warming, even greater than carbon dioxide (CO2) exhaust emissions by aircraft. This article presents a contrail model algorithm specifically developed to be integrated within a multi-objective flight trajectory optimization software framework. The purpose of the algorithm is to supply to the optimizer a measure of the estimated radiative forcing from the contrails generated by the aircraft while flying a specific trajectory. In order to determine the precise measure, a comprehensive model is employed exploiting the Schmidt-Appleman criterion and ice-supersaturation regions. Additional parameters such as the solar zenith angle, contrail lifetime and spread are also considered. The optimization of flight trajectories encompassing such contrail model allows for selective avoidance of the positive radiative forcing conditions, such as only avoiding persistent contrails, or contrails which lead to negative radiative forcing. The model assesses the radiative forcing associated with 4-Dimensional (4D) trajectories in a 4D weather field, encompassing both the local time-of-day and the contrail lifetime. Some preliminary algorithm validation activities are presented, including a simulation case study involving a medium-range domestic flight of a turbofan aircraft from Melbourne to Brisbane

    Submillimeter Array multiline observations of the massive star-forming region IRAS 18089-1732

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    Submillimeter Array (SMA) observations of the high-mass star-forming region IRAS 18089-1732 in the 1 mm and 850 μ\mum band with 1 GHz bandwidth reveal a wealth of information. We present the observations of 34 lines from 16 different molecular species. Most molecular line maps show significant contributions from the outflow, and only few molecules are confined to the inner core. We present and discuss the molecular line observations and outline the unique capabilities of the SMA for future imaging line surveys at high spatial resolution.Comment: Accepted for ApJ Letters, SMA special volum

    Oral cancer secretome: Identification of cancer-associated proteins

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    This study aims to identify cancer-associated proteins in the secretome of oral cancer cell lines. We have successfully established four primary cell cultures of normal cells with a limited lifespan without human telomerase reverse transcriptase (hTERT) immortalization. The secretome of these primary cell cultures were compared with that of oral cancer cell lines using 2DE. Thirty five protein spots were found to have changed in abundance. Unambiguous identification of these proteins was achieved by MALDI TOF/TOF. In silico analysis predicted that 24 of these proteins were secreted via classical or nonclassical mechanisms. The mRNA expression of six genes was found to correlate with the corresponding protein abundance. Ingenuity Pathway Analysis (IPA) core analysis revealed that the identified proteins were relevant in, and related to, cancer development with likely involvements in tumor growth, metastasis, hyperproliferation, tumorigenesis, neoplasia, hyperplasia, and cell transformation. In conclusion, we have demonstrated that a comparative study of the secretome of cancer versus normal cell lines can be used to identify cancer-associated proteins.Article Link: http://onlinelibrary.wiley.com/doi/10.1002/elps.201300126/abstrac

    Multi-domain active sound control and noise shielding

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    This paper describes an active sound control methodology based on difference potentials. The main feature of this methodology is its ability to automatically preserve “wanted” sound within a domain while canceling “unwanted” noise from outside the domain. This method of preservation of the wanted sounds by active shielding control is demonstrated with various broadband and realistic sound sources such as human voice and music in multiple domains in a one-dimensional enclosure. Unlike many other conventional active control methods, the proposed approach does not require the explicit characterization of the wanted sound to be preserved. The controls are designed based on the measurements of the total field on the boundaries of the shielded domain only, which is allowed to be multiply connected. The method is tested in a variety of experimental cases. The typical attenuation of the unwanted noise is found to be about 20 dB over a large area of the shielded domain and the original wanted sound field is preserved with errors of around 1 dB and below through a broad frequency range up to 1 kHz. © 2011 Acoustical Society of Americ
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