460 research outputs found

    The status of intranetwork magnetic field observations with THEMIS

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    Weak magnetic fields inside network cells are an important component of the solar magnetic field and they have been observed by a number a groups in the past few years, which yielded important clues to their behavior. However it is important to confirm these different results and to state with greater precision the properties of intranetwork magnetic features (vector magnetic field, lifetime...). In this paper we describe some of the multi-line spectro-polarimetric observations made with the THEMIS telescope in June 2000 in order to study the intranetwork magnetic fields. We highlight the data processing and some limitations we met when performing this study

    Report of the Scientific Council Meeting 01 -15 June 2017

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    Council met at the Sobey Building, Saint Mary’s University, Halifax, NS, Canada, during 01 – 15 June 2017, to consider the various matters in its Agenda. Representatives attended from Canada, Denmark (in respect of Faroe Islands and Greenland), the European Union (France, Germany (via WebEx), Portugal, Spain, the United Kingdom and the European Commission), Japan, the Russian Federation and the United States of America. Observers from the Ecology Action Centre and Dalhousie University were also present. The Executive Secretary, Scientific Council Coordinator and other members of the Secretariat were in attendance. The Executive Committee met prior to the opening session of the Council to discuss the provisional agenda and plan of work. The Council was called to order at 1000 hours on 01 June 2017. The provisional agenda was adopted with modification. The Scientific Council Coordinator was appointed the rapporteur. The Council was informed that the meeting was quorate and authorization had been received by the Executive Secretary for proxy votes from the European Union, Denmark (in respect of Faroe Islands and Greenland), Iceland, Japan, Republic of Korea, and Norway. The opening session was adjourned at 1200 hours on 01 June 2017. Several sessions were held throughout the course of the meeting to deal with specific items on the agenda. The Council considered adopted the STACFEN report on 8 June 2017, and the STACPUB, STACFIS and STACREC reports on 15 June 2017. The concluding session was called to order at 0830 hours on 15 June 2017. The Council considered and adopted the report the Scientific Council Report of this meeting of 01 -15 June 2017. The Chair received approval to leave the report in draft form for about two weeks to allow for minor editing and proof-reading on the usual strict understanding there would be no substantive changes. The meeting was adjourned at 1430 hours on 15 June 2017. The Reports of the Standing Committees as adopted by the Council are appended as follows: Appendix I - Report of the Standing Committee on Fisheries Environment (STACFEN), Appendix II - Report of Standing Committee on Publications (STACPUB), Appendix III - Report of Standing Committee on Research Coordination (STACREC), and Appendix IV - Report of Standing Committee on Fisheries Science (STACFIS). The Agenda, List of Research (SCR) and Summary (SCS) Documents, and List of Representatives, Advisers and Experts, are given in Appendix V-VII. The Council’s considerations on the Standing Committee Reports, and other matters addressed by the Council follow in Sections II-XV

    Report of the Working Group on Commercial Catches (WGCATCH)

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    The Working Group on Commercial Catches (WGCATCH), chaired by Hans Gerritsen (Ireland) and Nuno Prista (Sweden), met in Lisbon, Portugal, 9–13 November 2015. WGCATCH is responsible for documenting national fishery sampling schemes, establishing best practice and guidelines on sampling and estimation procedures, and providing advice on other uses of fishery data. The meeting was attended by 30 participants from 15 countries. The group addressed a large number of terms of reference and the meeting was con-ducted through presentations, discussions and analysis of questionnaires. The main terms of reference were addressed in subgroups. The report is structured directly along the terms of reference and the main outcomes are listed below. Data collection schemes for small-scale fisheries WGCATCH provided descriptions of national small-scale fisheries through question-naires. An overview was obtained on the current data collection methods. Two major approaches were identified - census (e.g., sales, logbooks) and sampling methods (e.g., catch surveys) - and their main pros and cons were discussed. In most cases, specific sampling approaches are needed for these fisheries. The group developed a work plan to establish good-practice guidelines. Analysis of case studies of commercial fishery sampling designs and estimation Case studies of sampling designs and estimation involving megrim in divisions 7-8 were presented. A common theme is that issues with practical implementation of prob-ability-based sampling remain. WGCATCH summarized the main issues and provided a set of possible solutions. The group also provided guidance on dealing with previous data collected under métier-based sampling designs. Simulation models to investigate survey designs Several simulation studies were presented, most of them outlining the work of fishPi project (funded under MARE/2014/19) in evaluating regional sampling designs. A crit-ical review was carried out and WGCATCH produced general considerations and guidelines. WGCATCH recommends that these are taken into account when analysing the results of simulations of regional sampling design at RCM level. The affect of the landing obligation on catch sampling opportunities The affects on sampling and data quality of the current implementation of the landing obligation in the Baltic were reviewed. The group found that refusal rates for observer trips have increased to nearly 100% in at least one country, while in many other coun-tries on-board observer programmes did not suffer noticeable changes. WGCATCH established that the catches below the minimum size cannot be accurately estimated by sampling the landings below the minimum size because an unknown proportion of the catches may be discarded. The group also reiterated that it is important that the logbooks distinguish landings below and above the minimum size. Publication on statistically sound sampling schemes WGCATCH drafted detailed plans to produce a peer-reviewed paper in 2016. The pa-per will provide a synthesis of the evolution of sampling design towards best practice, illustrated with a number of concise case studies. Estimation procedures in the Regional Database (RDB) The work of WKRDB 2015 presented alongside existing and planned estimation pro-cedures in the RDB. Current work by Norway on a software package that will allow design-based estimation and optimization for stock assessment purposes was also pre-sented. The advantages of ensuring compatibility of this new software with the devel-opments currently planned for RDB-FishFrame are underscored. Repository of resources relevant to catch sampling WGCATCH initiated a repository with key resources; putting them into context with brief descriptions or review of each report, paper, book, website, software package etc. The intention is for this repository to be made available online by ICES. Sampling of incidental bycatches WGCATCH agreed to start routine documentation of sampling practices for bycatches of protected, endangered and threatened species (PETS) and rare fish species as well as routine evaluation of the limitations of current methods for collection and analysis. Training course on Design and Analysis of Statistical Sound catch sampling pro-grammes WGCATCH considered continuous training and expertise on sampling design, estima-tion and simulation to be the basis for successful implementation of statistical sound catch sampling programs. A new ICES Training Course in Design and Analysis of Sta-tistical Sound will take place at ICES HQ in Copenhagen, 12–16 September 2016. WGCATCH recommends that RCMs promote the attendance of these meetings among all MS involved

    Machine learning enables completely automatic tuning of a quantum device faster than human experts

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    Variability is a problem for the scalability of semiconductor quantum devices. The parameter space is large, and the operating range is small. Our statistical tuning algorithm searches for specific electron transport features in gate-defined quantum dot devices with a gate voltage space of up to eight dimensions. Starting from the full range of each gate voltage, our machine learning algorithm can tune each device to optimal performance in a median time of under 70 minutes. This performance surpassed our best human benchmark (although both human and machine performance can be improved). The algorithm is approximately 180 times faster than an automated random search of the parameter space, and is suitable for different material systems and device architectures. Our results yield a quantitative measurement of device variability, from one device to another and after thermal cycling. Our machine learning algorithm can be extended to higher dimensions and other technologies

    Modeling Sustainability Reporting with Ternary Attractor Neural Networks

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    International Conference on Mining Intelligence and Knowledge Exploration. Cluj-Napoca, Romania, December 20–22, 2018This work models the Corporate Sustainability General Reporting Initiative (GRI) using a ternary attractor network. A dataset of years evolution of the GRI reports for a world-wide set of companies was compiled from a recent work and adapted to match the pattern coding for a ternary attractor network. We compare the performance of the network with a classical binary attractor network. Two types of criteria were used for encoding the ternary network, i.e., a simple and weighted threshold, and the performance retrieval was better for the latter, highlighting the importance of the real patterns’ transformation to the three-state coding. The network exceeds the retrieval performance of the binary network for the chosen correlated patterns (GRI). Finally, the ternary network was proved to be robust to retrieve the GRI patterns with initial noise.This work has been supported by Spanish grants MINECO (http://www.mineco.gob.es/) TIN2014-54580-R, TIN2017-84452-R, and by UAMSantander CEAL-AL/2017-08, and UDLA-SIS.MG.17.02

    Sensitive radio-frequency read-out of quantum dots using an ultra-low-noise SQUID amplifier

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    Fault-tolerant spin-based quantum computers will require fast and accurate qubit readout. This can be achieved using radio-frequency reflectometry given sufficient sensitivity to the change in quantum capacitance associated with the qubit states. Here, we demonstrate a 23-fold improvement in capacitance sensitivity by supplementing a cryogenic semiconductor amplifier with a SQUID preamplifier. The SQUID amplifier operates at a frequency near 200 MHz and achieves a noise temperature below 600 mK when integrated into a reflectometry circuit, which is within a factor 120 of the quantum limit. It enables a record sensitivity to capacitance of 0.07 aF/ \sqrt{Hz}. The setup is used to acquire charge stability diagrams of a gate-defined double quantum dot in a short time with a signal-to-noise ration of about 38 in 1 μs of integration time

    STRENGTHENING REGIONAL COOPERATION IN FISHERIES DATA COLLECTION

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    fishPi was a research project with the aim of “Strengthening regional cooperation in the area of fisheries data collection”. The project brought together over 40 experts from 13 scientific institutes in 12 countries (10 member states (MS)) and two internationally recognised survey design experts. It was funded by EU MARE grant MARE/2014/19, with a 14 month timeline commencing in April 2015. This project has trialled the way sampling designs would be developed in a regional setting and showed that collaboration and consultation is required at face to face meetings through regional groups that focus on a particular group of fisheries. The project was the first step in this process and one of the main outcomes is the framework to take the process forward; developing data formats, data sharing agreements and easily accessible software for data sharing, checking and analysis, and for the simulation testing of sampling designs.European Unio

    Red Clump Morphology as Evidence Against a New Intervening Stellar Population as the Primary Source of Microlensing Toward the LMC

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    We examine the morphology of the color-magnitude diagram (CMD) for core helium-burning (red clump) stars to test the recent suggestion by Zaritsky & Lin (1997) that an extension of the red clump in the Large Magellanic Cloud (LMC) toward brighter magnitudes is due to an intervening population of stars that is responsible for a significant fraction of the observed microlensing toward the LMC. Using our own CCD photometry of several fields across the LMC, we confirm the presence of this additional red clump feature, but conclude that it is caused by stellar evolution rather than a foreground population. We do this by demonstrating that the feature (1) is present in all our LMC fields, (2) is in precise agreement with the location of the blue loops in the isochrones of intermediate age red clump stars with the metallicity and age of the LMC, (3) has a relative density consistent with stellar evolution and LMC star formation history, and (4) is present in the Hipparcos CMD for the solar neighborhood where an intervening population cannot be invoked. Assuming there is no systematic shift in the model isochrones, which fit the Hipparcos data in detail, a distance modulus of μLMC=18.3\mu_{LMC} = 18.3 provides the best fit to our dereddened CMD.Comment: 21 pages LaTex (aaspp4.sty), including three tables and 9 figures (1 is .ps, 8 are .gif). Accepted for publication by Astronomical Journal on March 16, 1998. One error corrected and major revisions now lead to an even stronger argument for the stellar evolutionary origin of features in the LMC color magnitude diagram, claimed by others to be an intervening stellar population and major source of microlensing optical depth toward the LM

    Report of the Working Group on Commercial Catches (WGCATCH)

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    The Working Group on Commercial Catches (WGCATCH), chaired by Mike Arm- strong (UK) and Hans Gerritsen (Ireland), met in ICES HQ, Copenhagen, Denmark, 10–14 November 2014. The meeting was attended by 34 experts from 21 laboratories or organizations, covering 16 countries. Currently, an important task for WGCATCH is to improve and review sampling sur- vey designs for commercial fisheries, particularly those for estimating quantities and size or age compositions of landings and discards and providing data quality indica- tors. However, the scope of WGCATCH is broader than this, covering many other aspects of collection and analysis of data on fishing activities and catches. This will be end-user driven, and coordinated with the work of other ICES data EGs such as the Working Group on Biological Parameters (WGBIOP), the Planning Group on Data Needs for Assessments and Advice (PGDATA) and the Working Group on Recrea- tional Fisheries Surveys (WGRFS) to ensure synergy and efficiency. The report of the meeting commences with background information on the formation of WGCATCH and its overall role. The remainder of the report provides the out- comes for each of the Terms of Reference (ToRs) and responses to external requests, the proposed future work plan and the ToRs for the 2015 meeting. The group formed two large subgroups to deal with the two major terms of reference which are the development of guidelines for carrying out sampling of catches on shore and the provision of advice on adapting sampling programmes to deal with the landing obligation. In order to evaluate methods and develop guidelines for best practice in carrying out sampling of commercial sampling of commercial fish catches onshore, a question- naire was circulated before the meeting. This questionnaire was structured around guidelines developed by the ICES Workshop on Practical Implementation of Statisti- cally Sound Catch Sampling Programmes (WKPICS) for best practice at each stage of the sampling process, and asked for a description of current practices at each of these stages. Based on these questionnaires, common and specific problems were cata- logued and potential solutions were identified. At the same time, the discussion of the questionnaires provided a form of peer-review of the sampling designs and iden- tified where improvements could be made. WGCATCH provided guidelines for de- signing a sampling survey and summarized earlier guidelines provided by the 2010 Workshop on methods for merging métiers for fishery based sampling (WKMERGE) The other main subject addressed by WGCATCH concerns the provision of advice on adapting sampling protocols to deal with the impact of the introduction of the land- ing obligation, which will alter discarding practices and result in additional catego- ries of catch being landed. A second questionnaire was circulated before the meeting to allow the group to identify the fleets that will be affected and possible issues that are anticipated, as well as to propose solutions to adapt existing monitoring and sampling schemes and to quantify bias resulting from the introduction of this regula- tion. WGCATCH outlined a range of likely scenarios and the expected effects of these on fishery sampling programmes, and developed guidelines for adapting sam- pling schemes. The group also explored a range of analyses that could be conducted in order to quantify bias resulting from the introduction of the landing obligation. Finally a number of pilot studies/case studies were summarized, highlighting the practical issues involve
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