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Variceal bleeding: consensus meeting report from the Brazilian Society of Hepatology; Hemorragia digestiva alta varicosa: relatório do 1º Consenso da Sociedade Brasileira de Hepatologia

BITTENCOURT, Paulo Lisboa; FARIAS, Alberto Queiroz; STRAUSS, Edna; MATTOS, Angelo Alves de; Brazilian Society of Hepatology - Pannel of the 1st Brazilian Consensus of Variceal Bleeding
Fonte: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE Colégio Brasileiro de Cirurgia Digestiva - CBCD Sociedade Brasileira de Motilidade Digestiva - SBMD Federação Brasileira de Gastroenterologia - FBGSociedade Brasileira de Hepatologia - SBHSociedade Brasileira de Endoscopia Digestiva - SOBED Publicador: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE Colégio Brasileiro de Cirurgia Digestiva - CBCD Sociedade Brasileira de Motilidade Digestiva - SBMD Federação Brasileira de Gastroenterologia - FBGSociedade Brasileira de Hepatologia - SBHSociedade Brasileira de Endoscopia Digestiva - SOBED
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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In the last decades, several improvements in the management of variceal bleeding have resulted in a significant decrease in morbidity and mortality of patients with cirrhosis and bleeding varices. Progress in the multidisciplinary approach to these patients has led to a better management of this disease by critical care physicians, hepatologists, gastroenterologists, endoscopists, radiologists and surgeons. In this respect, the Brazilian Society of Hepatology has, recently, sponsored a consensus meeting in order to draw evidence-based recommendations on the management of these difficult-to-treat subjects. An organizing committee comprised of four people was elected by the Governing Board and was responsible to invite 27 researchers from distinct regions of the country to make a systematic review of the subject and to present topics related to variceal bleeding, including prevention, diagnosis, management and treatment, according to evidence-based medicine. After the meeting, all participants met together for discussion of the topics and the elaboration of the aforementioned recommendations. The organizing committee was responsible for writing the final document. The meeting was held at Salvador, May 6th, 2009 and the present manuscript is the summary of the systematic review that was presented during the meeting...

A flexible consensus scheme for multicriteria group decision making under linguistic assessments

PARREIRAS, R. O.; EKEL, P. Ya.; MARTINI, J. S. C.; PALHARES, R. M.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.5%
The present paper proposes a flexible consensus scheme for group decision making, which allows one to obtain a consistent collective opinion, from information provided by each expert in terms of multigranular fuzzy estimates. It is based on a linguistic hierarchical model with multigranular sets of linguistic terms, and the choice of the most suitable set is a prerogative of each expert. From the human viewpoint, using such model is advantageous, since it permits each expert to utilize linguistic terms that reflect more adequately the level of uncertainty intrinsic to his evaluation. From the operational viewpoint, the advantage of using such model lies in the fact that it allows one to express the linguistic information in a unique domain, without losses of information, during the discussion process. The proposed consensus scheme supposes that the moderator can interfere in the discussion process in different ways. The intervention can be a request to any expert to update his opinion or can be the adjustment of the weight of each expert`s opinion. An optimal adjustment can be achieved through the execution of an optimization procedure that searches for the weights that maximize a corresponding soft consensus index. In order to demonstrate the usefulness of the presented consensus scheme...

Efficient and robust adaptive consensus services based on oracles

Sampaio, Lívia; Brasileiro, Francisco Vilar; Nunes, Raul Ceretta; Jansch, Ingrid Eleonora Schreiber
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
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Due to their fundamental role in the design of faulttolerant distributed systems, consensus protocols have been widely studied. Most of the research in this area has focused on providing ways for circumventing the impossibility of reaching consensus on a purely asynchronous system subject to failures. Of particular interest are the indulgent consensus protocols based upon weak failure detection oracles. Following the first works that were more concerned with the correctness of such protocols, performance issues related to them are now a topic that has gained considerable attention. In particular, a few studies have been conducted to analyze the impact that the quality of service of the underlying failure detection oracle has on the performance of consensus protocols. To achieve better performance, adaptive failure detectors have been proposed. Also, slowness oracles have been proposed to allow consensus protocols to adapt themselves to the changing conditions of the environment, enhancing their performance when there are substantial changes on the load to which the system is exposed. In this paper we further investigate the use of these oracles to design efficient consensus services. In particular, we provide efficient and robust implementations of slowness oracles based on techniques that have been previously used to implement adaptive failure detection oracles. Our experiments on a widearea distributed system show that by using a slowness oracle that is well matched with a failure detection oracle...

Ocular allergy latin american consensus

Santos,Myrna Serapião dos; Alves,Milton Ruiz; Freitas,Denise de; Sousa,Luciene Barbosa de; Wainsztein,Ricardo; Kandelman,Sérgio; Lozano,Mauricio; Beltrán,Francisco; Lozada,Oscar Baça; Santacruz,Concepción; Guzzo,Giovanni; Zaccarelli Filho,Carlos Albe
Fonte: Conselho Brasileiro de Oftalmologia Publicador: Conselho Brasileiro de Oftalmologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
36.54%
PURPOSE: To establish current definition, classification and staging, and to develop diagnosis and treatment recommendations for ocular allergy, by using Delphi approach. METHODS: Ten Latin American experts on ocular allergy participated in a 4-round Delphi panel approach. Four surveys were constructed and answered by panelists. A two-thirds majority was defined as consensus. Definition, classification, staging and diagnosis and treatment recommendations were the main outcomes. RESULTS: "Ocular allergy" was proposed as the general term to describe ocular allergic diseases. Consensus regarding classification was not reached. Signs and symptoms were considered extremely important for the diagnosis. It was consensus that a staging system should be proposed based on the disease severity. Environmental control, avoidance of allergens and the use of artificial tears were recommended as first line treatment. The secondary treatment should include topical anti-histamines, mast cell stabilizers and multi actions drugs. Topical non-steroidal anti-inflammatory and vasoconstrictors were not recommended. Topical corticosteroids were recommended as third line of treatment for the most severe keratoconjunctivitis. Consensus was not reached regarding the use of systemic corticosteroids or immunosuppressant. Surgical approach and unconventional treatments were not recommended as routine. CONCLUSION: The task of creating guidelines for ocular allergies showed to be very complex. Many controversial topics remain unsolved. A larger consensus including experts from different groups around the world may be needed to further improve the current recommendations for several aspects of ocular allergy.

3rd BRAZILIAN CONSENSUS ON Helicobacter pylori

Coelho,Luiz Gonzaga; Maguinilk,Ismael; Zaterka,Schlioma; Parente,José Miguel; Passos,Maria do Carmo Friche; Moraes-Filho,Joaquim Prado P.
Fonte: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED Publicador: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
Relevância na Pesquisa
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Significant progress has been obtained since the Second Brazilian Consensus Conference on Helicobacter pylori Infection held in 2004, in São Paulo, SP, Brazil, and justify a third meeting to establish updated guidelines on the current management of H. pylori infection. The Third Brazilian Consensus Conference on H pylori Infection was organized by the Brazilian Nucleus for the Study of Helicobacter, a Department of the Brazilian Federation of Gastroenterology and took place on April 12-15, 2011, in Bento Gonçalves, RS, Brazil. Thirty-one delegates coming from the five Brazilian regions and one international guest, including gastroenterologists, pathologists, epidemiologists, and pediatricians undertook the meeting. The participants were allocated in one of the five main topics of the meeting: H pylori, functional dyspepsia and diagnosis; H pylori and gastric cancer; H pylori and other associated disorders; H pylori treatment and retreatment; and, epidemiology of H pylori infection in Brazil. The results of each subgroup were submitted to a final consensus voting to all participants. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. Seventy per cent and more votes were considered as acceptance for the final statement. This article presents the main recommendations and conclusions to guide Brazilian doctors involved in the management of H pylori infection.

Efficient and robust adaptive consensus services based on oracles

Sampaio,Lívia; Brasileiro,Francisco; Nunes,Raul Ceretta; Jansch-Pôrto,Ingrid
Fonte: Sociedade Brasileira de Computação Publicador: Sociedade Brasileira de Computação
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2005 EN
Relevância na Pesquisa
36.57%
Due to their fundamental role in the design of faulttolerant distributed systems, consensus protocols have been widely studied. Most of the research in this area has focused on providing ways for circumventing the impossibility of reaching consensus on a purely asynchronous system subject to failures. Of particular interest are the indulgent consensus protocols based upon weak failure detection oracles. Following the first works that were more concerned with the correctness of such protocols, performance issues related to them are now a topic that has gained considerable attention. In particular, a few studies have been conducted to analyze the impact that the quality of service of the underlying failure detection oracle has on the performance of consensus protocols. To achieve better performance, adaptive failure detectors have been proposed. Also, slowness oracles have been proposed to allow consensus protocols to adapt themselves to the changing conditions of the environment, enhancing their performance when there are substantial changes on the load to which the system is exposed. In this paper we further investigate the use of these oracles to design efficient consensus services. In particular, we provide efficient and robust implementations of slowness oracles based on techniques that have been previously used to implement adaptive failure detection oracles. Our experiments on a widearea distributed system show that by using a slowness oracle that is well matched with a failure detection oracle...

ABC1 Consensus Conference – a German Perspective: First International Consensus Conference on Advanced Breast Cancer (ABC1), Lisbon, November 5, 2011

Thomssen, Christoph; Marschner, Norbert; Untch, Michael; Decker, Thomas; Hegewisch-Becker, Susanna; Jackisch, Christian; Janni, Wolfgang; Hans-Joachim, Lück; von Minckwitz, Gunter; Scharl, Anton; Schneeweiss, Andreas; Tesch, Hans; Welt, Anja; Harbeck, Na
Fonte: S. Karger GmbH Publicador: S. Karger GmbH
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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A group of German breast cancer experts (medical oncologists and gynaecologists) reviewed and commented on the results of the first international ‘Advanced Breast Cancer First Consensus Conference’ (ABC1) for the diagnosis and treatment of advanced breast cancer. The ABC1 Conference is an initiative of the European School of Oncology (ESO) Metastatic Breast Cancer Task Force in cooperation with the EBCC (European Breast Cancer Conference), ESMO (European Society of Medical Oncology) and the American JNCI (Journal of the National Cancer Institute). The main focus of the ABC1 Conference was metastatic breast cancer (stage IV). The ABC1 consensus is based on the vote of 33 breast cancer experts from different countries and has been specified as a guideline for therapeutic practice by the German expert group. It is the objective of the ABC1 consensus as well as of the German comments to provide an internationally standardized and evidence-based foundation for qualified decision-making in the treatment of metastatic breast cancer.

The Indian National Association for Study of the Liver (INASL) Consensus on Prevention, Diagnosis and Management of Hepatocellular Carcinoma in India: The Puri Recommendations

Kumar, Ashish; Acharya, Subrat K.; Singh, Shivaram P.; Saraswat, Vivek A.; Arora, Anil; Duseja, Ajay; Goenka, Mahesh K.; Jain, Deepali; Kar, Premashish; Kumar, Manoj; Kumaran, Vinay; Mohandas, Kunisshery M.; Panda, Dipanjan; Paul, Shashi B.; Ramachandran,
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality and healthcare expenditure in patients with chronic liver disease. There are no consensus guidelines on diagnosis and management of HCC in India. The Indian National Association for Study of the Liver (INASL) set up a Task-Force on HCC in 2011, with a mandate to develop consensus guidelines for diagnosis and management of HCC, relevant to disease patterns and clinical practices in India. The Task-Force first identified various contentious issues on various aspects of HCC and these issues were allotted to individual members of the Task-Force who reviewed them in detail. The Task-Force used the Oxford Center for Evidence Based Medicine—Levels of Evidence of 2009 for developing an evidence-based approach. A 2-day round table discussion was held on 9th and 10th February, 2013 at Puri, Odisha, to discuss, debate, and finalize the consensus statements. The members of the Task-Force reviewed and discussed the existing literature at this meeting and formulated the INASL consensus statements for each of the issues. We present here the INASL consensus guidelines (The Puri Recommendations) on prevention, diagnosis and management of HCC in India.

Lower Bounds for Achieving Synchronous Early Stopping Consensus with Orderly Crash Failures

Wang, Xianbing; Teo, Yong Meng; Cao, Jiannong
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 434519 bytes; application/pdf
EN
Relevância na Pesquisa
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In this paper, we discuss the consensus problem for synchronous distributed systems with orderly crash failures. For a synchronous distributed system of n processes with up to t crash failures and f failures actually occur, first, we present a bivalency argument proof to solve the open problem of proving the lower bound, min (t + 1, f + 2) rounds, for early-stopping synchronous consensus with orderly crash failures, where t < n - 1. Then, we extend the system model with orderly crash failures to a new model in which a process is allowed to send multiple messages to the same destination process in a round and the failing processes still respect the order specified by the protocol in sending messages. For this new model, we present a uniform consensus protocol, in which all non-faulty processes always decide and stop immediately by the end of f + 1 rounds. We prove that the lower bound of early stopping protocols for both consensus and uniform consensus are f + 1 rounds under the new model, and our proposed protocol is optimal.; Singapore-MIT Alliance (SMA)

Local average consensus in distributed measurement of spatial–temporal varying parameters: 1D case

Cai, Kai; Anderson, Brian D. O.; Yu, Changbin; Mao, Guoqiang
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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We study a new variant of consensus problems, termed ‘local average consensus’, in networks of agents. We consider the task of using sensor networks to perform distributed measurement of a parameter which has both spatial (in this paper 1D) and temporal variations. Our idea is to maintain potentially useful local information regarding spatial variation, as contrasted with reaching a single, global consensus, as well as to mitigate the effect of measurement errors. We employ two schemes for computation of local average consensus: exponential weighting and uniform finite window. In both schemes, we design local average consensus algorithms to address first the case where the measured parameter has spatial variation but is constant in time, and then the case where the measured parameter has both spatial and temporal variations. Our designed algorithms are distributed, in that information is exchanged only among neighbors. Moreover, we analyze both spatial and temporal frequency responses and noise propagation associated with the algorithms. The tradeoffs of using local consensus, as compared to standard global consensus, include higher memory requirement and degraded noise performance. Arbitrary updating weights and random spacing between sensors are also analyzed in the proposed algorithms.; K. Cai’s work was supported by Program to Disseminate Tenure Tracking System and Grants-in-Aid for Scientific Research No. 26870169...

European integration and consensus politics in the Low Countries : observations on an under-researched relationship

BEYERS, Jan; VOLLAARD, Hans; DUMONT, Patrick
Fonte: Instituto Universitário Europeu Publicador: Instituto Universitário Europeu
Tipo: Trabalho em Andamento Formato: application/pdf; digital
EN
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The Netherlands, Belgium and Luxembourg are well-known cases of consensus politics. Traditionally, decision-making in the Low Countries has been characterized by broad involvement, power sharing and making compromises. These countries were also founding member states of the European Union (EU) and its predecessors. However, the relationship between European integration and the tradition of domestic consensus politics remains unclear. In order to explore this relationship this paper presents the conceptual framework and a short summary of the recently published book European Integration and Consensus Politics in the Low Countries (edited by Hans Vollaard, Jan Beyers and Patrick Dumont; Routledge). The authors discuss how consensus politics would shape the impact of European integration. They also analyse whether European integration may undermine the fundamental characteristics of consensus politics in the Low Countries. Drawing on consociationalism and Europeanization research, they provide a comprehensive overview of Europeanization in the three Low Countries as well as a better understanding of the varieties of consensus politics across and within these countries. In doing this they refer to a wide range of in-depth studies on a variety of political actors such as governments...

Analyzing consensus approaches in fuzzy group decision making: advantages and drawbacks

Cabrerizo, F.J.; Moreno, J. M.; P??rez, I. J.; Herrera-Viedma, E.
Fonte: Universidade de Granada Publicador: Universidade de Granada
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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Two processes are necessary to solve group decision making problems: a consensus process and a selection process. The consensus process is necessary to obtain a nal solution with a certain level of agreement between the experts while the selection process is necessary to obtain such a nal solution. Clearly, it is preferable that the set of experts reach a high degree of consensus before applying the selection process. In order to measure the degree of consensus, different approaches have been proposed. For example, we can use hard consensus measures, which vary between 0 (no consensus or partial consensus) and 1 (full consensus), or soft consensus measures, which assess the consensus degree in a more exible way. The aim of this paper is to analyze the different consensus approaches in fuzzy group decision making problems and discuss their advantages and drawbacks. Additionally, we study the future trends.

A consensus model for group decision making problems with unbalanced fuzzy linguistic information

Cabrerizo, F.J.; Alonso, S.; Herrera-Viedma, E.
Fonte: Universidade de Granada Publicador: Universidade de Granada
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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Most group decision making problems based on linguistic approaches use symmetrically and uniformly distributed linguistic term sets to express experts opinions. However, there exist problems whose assessments need to be represented by means of unbalanced linguistic term sets, i.e., using term sets which are not uniformly and symmetrically distributed. The aim of this paper is to present a consensus model for group decision making problems with unbalanced fuzzy linguistic information. This consensus model is based on both a fuzzy linguistic methodology to deal with unbalanced linguistic term sets and two consensus criteria, consensus degrees and proximity measures. To do so, we use a new fuzzy linguistic methodology improving another approach to manage unbalanced fuzzy linguistic information,1 which uses the linguistic 2-tuple model as representation base of unbalanced fuzzy linguistic information. In addition, the consensus model presents a feedback mechanism to help experts for reaching the highest degree of consensus possible. There are two main advantages provided by this consensus model. Firstly, its ability to cope with group decision making problems with unbalanced fuzzy linguistic information overcoming the problem of finding different discrimination levels in linguistic term sets. And...

Managing the consensus in group decision making in an unbalanced fuzzy linguistic context with incomplete information

Cabrerizo, F.J.; P??rez, I. J.; Herrera-Viedma, E.
Fonte: Universidade de Granada Publicador: Universidade de Granada
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.57%
To solve group decision making problems we have to take in account different aspects. On the one hand, depending on the problem, we can deal with different types of information. In this way, most group decision making problems based on linguistic approaches use symmetrically and uniformly distributed linguistic term sets to express experts opinions. However, there exist problems whose assessments need to be represented by means of unbalanced linguistic term sets, i.e., using term sets which are not uniformly and symmetrically distributed. On the other hand, there may be cases in which experts do not have an in-depth knowledge of the problem to be solved. In such cases, experts may not put their opinion forward about certain aspects of the problem and, as a result, they may present incomplete information. The aim of this paper is to present a consensus model to help experts in all phases of the consensus reaching process in group decision making problems in an unbalanced fuzzy linguistic context with incomplete information. As part of this consensus model, we propose an iterative procedure using consistency measures to estimate the incomplete information. In addition, the consistency measures are used together with consensus measures to guided the consensus model. The main novelty of this consensus model is that it supports the management of incomplete unbalanced fuzzy linguistic information and it allows to achieve consistent solutions with a great level of agreement.

Consensus-based recommendations of Australian podiatrists for the prescription of foot orthoses for symptomatic flexible pes planus in adults

Banwell, H.A.; Mackintosh, S.; Thewlis, D.; Landorf, K.B.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
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Background: Foot orthoses are commonly used for symptomatic flexible pes planus in adults. However, there are no clinical guidelines for the prescription of customised foot orthoses that are specific to this population. The aim of this study was to investigate prescription habits of Australian podiatrists for customised foot orthoses for symptomatic flexible pes planus in adults and to develop consensus-based practice recommendations for the prescription of these foot orthoses. Methods: A four round Delphi survey was undertaken with 24 podiatric experts to establish current use and rationale for individual prescription variables of customised foot orthoses for symptomatic flexible pes planus in adults. Round one determined prescription use (consensus) and rounds two, three and four determined the rationale for use (agreement) of prescription variables across the rearfoot, midfoot, forefoot, as well as accommodation and materials used. For consensus and agreement to be accepted, 70% of the respondents were required to use or agree on the rationale for use of individual prescription variables. Results: Consensus was reached in round one for two variables, choice of shell material (polyolefin) and when to prescribe a forefoot post balanced to perpendicular. In rounds two...

La question du consensus en situation de collaboration interorganisationnelle : le cas de la Table québécoise de la sécurité routière

Brodin, Stevan
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Ce mémoire propose de décrire et comprendre les pratiques communicationnelles menant à la prise de décision consensuelle d’une collaboration interorganisationnelle (CI) spécifique, la Table québécoise de la sécurité routière (TQSR). Nous adoptons la perspective de la communication constitutive des organisations (CCO) développée par « l’École de Montréal » pour appréhender les dimensions constitutives de ces pratiques de communication et de ce mode privilégié de décision en CI. Après un aperçu de la littérature disponible en matière de CI et concernant la notion de consensus, nous proposons de nous concentrer sur les pratiques communicationnelles du consensus en adoptant la perspective du consensus par absence d’opposition d’Urfalino (2014). L’analyse de conversation et les principes d’une approche rhétorique sont ensuite mobilisés pour rendre compte des pratiques de communication qui permettent l’accomplissement du consensus lors d’une séance plénière du troisième cycle de travail de la TQSR, spécifiquement consacrée à la rédaction de son rapport final. Nous verrons que 1) les pratiques communicationnelles mobilisées facilitent l’arrêt de la décision et que 2) celles-ci sont constitutives du consensus qui favorise l’unité du collectif de collaboration.; This thesis aims at describing and understanding the communication practices that sustain the consensual decision-making of an interorganizational collaboration (CI) collective...

Reach almost sure consensus with only group information

Lin, Zhiyun; Hou, Jian; Yan, Gangfeng; (Brad) Yu, Changbin
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 7 pages
Relevância na Pesquisa
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This brief presents a new distributed scheme to solve the consensus problem for a group of agents if neither their absolute states nor inter-agent relative states are available. The new scheme considers a random partition of agents into two subgroups at each step and then uses the relative group representative state as feedback information for the consensus purpose. It is then shown that almost sure consensus can be achieved under the proposed scheme in both discrete time and continuous time. For the discrete time case, almost sure consensus is achieved if and only if the weighting parameter for state update is greater than one. For the continuous time case, almost sure consensus is realized when the weighting parameter is positive. Moreover, it is shown that if a uniform probability is considered for group selection, then the group of agents can reach average consensus in mean.; The work of Lin was supported by Zhejiang Provincial Natural Science Foundation of ChinaLR13F030002. The work of Yu was supported in part by the Australian Research Council through Discovery Project DP-130103610, a Queen Elizabeth II Fellowship under Grant DP-110100538, the National Natural Science Foundation of China (61375072), and the Open Research Project (No. ICT1427) of the State Key Laboratory of Industrial Control Technology...

Contribution to the knowledge of hierarchical clustering algorithms and consensus clustering. Studies applied to personal recognition by hands biometrics

Sousa, Lúcia
Fonte: Instituto Politécnico de Viseu Publicador: Instituto Politécnico de Viseu
Tipo: Tese de Doutorado
Publicado em 29/06/2015 ENG
Relevância na Pesquisa
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In exploratory data analysis, hierarchical clustering algorithms with its features can provide different clusterings when applied to the same data set. In the presence of several clusterings, each one identifying a specific data structure, consensus clustering provide a contribution to deal with this issue. The work reported here is composed by two parts: In the first part, we intend to explore the profile of base hierarchical clusterings, according to their variabilities, to obtain the consensus clustering. As a first result of our researches, we identified the consensus clustering technique as having better performance than the others, depending on the characteristics of hierarchical clusterings used as base. This result allows us to identify a sufficient condition for the existence of consensus clustering, as well as define a new strategy to evaluate the consensus clustering. It also leads to study a new property of hierarchical clustering algorithms. In the second part, we explore a real-world application. In a first analysis, we use data sets derived by biometrics extracted from hands for personal recognition. We show that the hierarchical clusterings obtained by SEP/COP algorithms, can provide results with great accuracy when applied to these data sets. Furthermore...

Finite-time Consensus for Multi-agent Networks with Unknown Inherent Nonlinear Dynamics

Cao, Yongcan; Ren, Wei
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/02/2013
Relevância na Pesquisa
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This paper focuses on analyzing the finite-time convergence of a nonlinear consensus algorithm for multi-agent networks with unknown inherent nonlinear dynamics. Due to the existence of the unknown inherent nonlinear dynamics, the stability analysis and the finite-time convergence analysis of the closed-loop system under the proposed consensus algorithm are more challenging than those under the well-studied consensus algorithms for known linear systems. For this purpose, we propose a novel stability tool based on a generalized comparison lemma. With the aid of the novel stability tool, it is shown that the proposed nonlinear consensus algorithm can guarantee finite-time convergence if the directed switching interaction graph has a directed spanning tree at each time interval. Specifically, the finite-time convergence is shown by comparing the closed-loop system under the proposed consensus algorithm with some well-designed closed-loop system whose stability properties are easier to obtain. Moreover, the stability and the finite-time convergence of the closed-loop system using the proposed consensus algorithm under a (general) directed switching interaction graph can even be guaranteed by the stability and the finite-time convergence of some special well-designed nonlinear closed-loop system under some special directed switching interaction graph...

Consensus on the management of intracranial germ-cell tumours; A multi-disciplinary Delphi method to identify consensus in the management of intracranial germ cell tumours

Murray, Matthew J.; Bartels, Ute; Nishikawa, Ryo; Fangusaro, Jason; Matsutani, Masao; Nicholson, James C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Article; accepted version
EN
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This is the accepted manuscript. It is currently embargoed pending publication.; The management of intracranial germ cell tumours (ICGCT) is complex. It was agreed at the 2013 Third International ICGCT Symposium (Cambridge, UK) to undertake a multi-disciplinary Delphi process to identify consensus in their management. Seventy-seven delegates from the Symposium were selected as suitable experts and were invited to participate in the Delphi survey; 64 (83%) responded. Those invited represented multiple disciplines from the Far East, Australasia, Europe and America. Thirty-eight consensus statements, encompassing aspects of work-up, staging, treatment and follow-up, were prepared. To achieve consensus, statements required ?70% agreement from ?60% of respondents. Overall, 34/38 statements (89%) met consensus criteria. This international Delphi approach has defined key areas of consensus which will guide and streamline future management of ICGCT. In addition, it has identified areas of different understanding and practice internationally which should be the focus of future collaborative studies. Such efforts will likely translate into improved patient outcomes.