Nuclear Physics B - Proceedings Supplements | Year: 2014
Results obtained by the ATLAS and CMS experiments, using data collected in 2011, on the tt production cross section in channels containing a tau lepton in the final state, are presented. The cross sections in the lepton-plus-tau and in the hadronic tau-plus-jets final states have been measured by both collaborations. The technique for the tau lepton reconstruction as well as for the b-jet identification, used by ATLAS and CMS, are described. The trigger and the offline strategies for these measurements are detailed. The results obtained by ATLAS and CMS are compatible with each other and in agreement with the Standard Model (SM) expectation. No hints of new physics are observed. © 2014 Elsevier B.V. Source
Lee J.-E.,Kyungpook National University |
Jung S.-H.,Kyungpook National University |
Park H.-M.,Kyungpook National University |
Kwon S.,Kyungpook National University |
And 2 more authors.
Advances in Atmospheric Sciences | Year: 2015
Fall velocity-diameter relationships for four different snowflake types (dendrite, plate, needle, and graupel) were investigated in northeastern South Korea, and a new algorithm for classifying hydrometeors is proposed for distrometric measurements based on the new relationships. Falling ice crystals (approximately 40 000 particles) were measured with a two-dimensional video disdrometer (2DVD) during a winter experiment from 15 January to 9 April 2010. The fall velocity-diameter relationships were derived for the four types of snowflakes based on manual classification by experts using snow photos and 2DVD measurements: the coefficients (exponents) for different snowflake types were 0.82 (0.24) for dendrite, 0.74 (0.35) for plate, 1.03 (0.71) for needle, and 1.30 (0.94) for graupel, respectively. These new relationships established in the present study (PS) were compared with those from two previous studies. Hydrometeor types were classified with the derived fall velocity-diameter relationships, and the classification algorithm was evaluated using 3× 3 contingency tables for one rain-snow transition event and three snowfall events. The algorithm showed good performance for the transition event: the critical success indices (CSIs) were 0.89, 0.61 and 0.71 for snow, wet-snow and rain, respectively. For snow events, the algorithm performance for dendrite and plate (CSIs = 1.0 and 1.0, respectively) was better than for needle and graupel (CSIs = 0.67 and 0.50, respectively). © 2015, Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg. Source
Albert M.,FNAL |
Bakken J.,FNAL |
Bonacorsi D.,University of Bologna |
Brew C.,Stfc Ral |
And 32 more authors.
Journal of Physics: Conference Series | Year: 2010
The CMS Collaboration relies on 7 globally distributed Tier-1 computing centres located at large Universitàies and national laboratories for a second custodial copy of the CMS RAW data and primary copy of the simulated data, data serving capacity to Tier-2 centres for analysis, and the bulk of the reprocessing and event selection capacity in the experiment. The Tier-1 sites have a challenging role in CMS because they are expected to ingest and archive data from both CERN and regional Tier-2 centres, while they export data to a global mesh of Tier-2s at rates comparable to the raw export data rate from CERN. The combined capacity of the Tier-1 centres is more than twice the resources located at CERN and efficiently utilizing this large distributed resources represents a challenge. In this article we will discuss the experience building, operating, and utilizing the CMS Tier-1 computing centres. We will summarize the facility challenges at the Tier-1s including the stable operations of CMS services, the ability to scale to large numbers of processing requests and large volumes of data, and the ability to provide custodial storage and high performance data serving. We will also present the operations experience utilizing the distributed Tier-1 centres from a distance: transferring data, submitting data serving requests, and submitting batch processing requests. © 2010 IOP Publishing Ltd. Source
Yeh W.-H.,NCU |
Chiu T.-C.,NCU |
Li E.S.,NTUT |
Liou Y.-A.,Center for Space and Remote Sensing Research |
And 2 more authors.
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2012
In this research, a ray tracing model is built up to simulate the propagation of signal in global positioning system (GPS) radio occultation (RO) mission. When GPS signal propagate through the Earth's atmosphere, it will be bent and delayed due to the gradient atmosphere refractive index and received by low Earth orbit (LEO) satellite. Then the parameter profiles of atmosphere can be retrieved by using the received signal. In the previous research, in order to simplify the simulation, the Earth's atmosphere is assumed as spherical symmetry and the positions of GPS and LEO satellites are not considered in simulations. In the model, the shape of the Earth is assumed as an ellipse. The information of European Centre for Medium-Range Weather Forecasts (ECMWF) is used to construct the refractive index of Earth's atmosphere. And two aiming algorithm are developed to control the initial propagating direction of GPS signal to begin from the prescribed GPS satellite position and end at the LEO satellite position. The model is tested and verified by comparing with analytical and observational data. © 2012 IEEE. Source
Shadiev R.,NCKU |
Hwang W.-Y.,Graduate Institute of Network Learning Technology |
Yeh S.-C.,NCU |
Yang S.J.H.,NCU |
And 4 more authors.
Proceedings - 2013 IEEE 13th International Conference on Advanced Learning Technologies, ICALT 2013 | Year: 2013
This study aimed to investigate effects of unidirectional versus reciprocal teaching strategies on computer programming learning. Thus, this study conducted an experiment with participating novice programmers, who applied no strategies, unidirectional, and reciprocal teaching strategies for computer programming learning by using a web-based learning system (VPen). Yet, this study explored participants' perceptions toward the VPen system and the strategies. The paper reports results of this study as well as it provides useful suggestions on application of the strategies by using the VPen for teaching and research community of this field and for future studies. © 2013 IEEE. Source