A cardinal dissensus measure based on the Mahalanobis distance

Producción CientíficaIn this paper we address the problem of measuring the degree of consensus/dissensus in a context where experts or agents express their opinions on alternatives or issues by means of cardinal evaluations. To this end we propose a new class of distance-based consensus model, the family of the Mahalanobis dissensus measures for profiles of cardinal values. We set forth some meaningful properties of the Mahalanobis dissensus measures. Finally, an application over a real empirical example is presented and discussed.Ministerio de Economía, Industria y Competitividad (Project CGL2008-06003-C03-03/CLI)Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178)Ministerio de Economía, Industria y Competitividad (Project ECO2012-31933

A new consensus ranking approach for correlated ordinal information based on Mahalanobis distance

Producción CientíficaWe investigate from a global point of view the existence of cohesiveness among experts’ opinions. We address this general issue from three basic essentials: the management of experts’ opinions when they are expressed by ordinal information; the measurement of the degree of dissensus among such opinions; and the achievement of a group solution that conveys the minimum dissensus to the experts’ group. Accordingly, we propose and characterize a new procedure to codify ordinal information. We also define a new measurement of the degree of dissensus among individual preferences based on the Mahalanobis distance. It is especially designed for the case of possibly correlated alternatives. Finally, we investigate a procedure to obtain a social consensus solution that also includes the possibility of alternatives that are correlated. In addition, we examine the main traits of the dissensus measurement as well as the social solution proposed. The operational character and intuitive interpretation of our approaches are illustrated by an explanatory example.Ministerio de Economía, Industria y Competitividad (ECO2012–32178

A new consensus measure based on Pearson correlation coefficient

Obtaining consensual solutions is an important issue in decision making processes. It depends on several factors such as experts’ opinions, principles, knowledge, experience, etc. In the literature we can find a considerable amount of consensus measurement from different research areas (from a Social Choice perspective: Alcalde-Unzu and Vorsatz [1], Alcantud, de Andres Calle and Cascon [2] and Bosch [3], among others and from Decision Making Theory: Gonzalez-Arteaga, Alcantud and de Andres Calle [4] and Gonzalez-Pachon [5], Herrera, Herrera-Viedma and Chiclana [7], Herrera-Viedma et al. [6] and Wu et al. [8], among others ). Most of them have a common point, they are based on distances or similarity functions. In the present contribution we propose a new approach based on the use of the Pearson correlation coefficient to measure consensus. Moreover, we suppose a general framework considering experts’ opinions modelled by fuzzy preference relation. The new correlation consensus measurement takes into account concordance between preferences intensities for pairs of alternatives and it verifies important properties. In addition, we prove that our proposal is a different approach to traditional consensus measures based on distances or similarities. References [1] J. Alcalde-Unzu and M. Vorsatz. Measuring the cohesiveness of preferences: An axiomatic analysis. Social Choicer and Welfare, 41:965–988, 2013. [2] J. C. R. Alcantud, R. de Andes Calle, and J. M. Cascon. Consensus and the act of voting. Studies in Microeconomics, 1(1):1–22, 2013. [3] R. Bosch. Characterizations of Voting Rules and Consensus Measures. PhD thesis, Tilburg University, 2005. [4] T. Gonzalez-Arteaga, J.C.R. Alcantud, and R. de Andres Calle. A cardinal dissensus measure based on the Mahalanobis distance. European Journal of Operational Research, In press. [5] J. Gonzalez-Pachon and C. Romero. Distance-based consensus methods: a goal programming approach. Omega, 27(3):341–347, 1999. [6] E. Herrera-Viedma, F. J. Cabrerizo, J. Kacprzyk, and W. Pedrycz. A review of soft consensus models in a fuzzy environment. Information Fusion, 17:4–13, 2014. [7] E. Herrera-Viedma, F. Herrera, and F. Chiclana. A consensus model for multiperson decision making with different preference structures. IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans, 32(3):394–402, 2002. [8] J. Wu, F. Chiclana, and E. Herrera-Viedma. Trust based consensus model for social network in an incomplete linguistic information context. Applied Soft Computing, 35:827– 839, 2015

ÇOK DEĞİŞKENLİ AYKIRI DEĞER TESPİTİ İÇİN KLASİK VE DAYANIKLI MAHALANOBİS UZAKLIK ÖLÇÜTLERİ: FİNANSAL VERİ İLE BİR UYGULAMA

Çok değişkenli veri setlerinde aykırı değerlerin varlığı anakütle parametre tahminini zorlaştırmakta ve hata varyansını arttırarak kullanılan istatistiki testin gücünü azaltmaktadır. Bu durum, değişkenlerin eşit varyansa ve çok değişkenli normal dağılıma sahip olduğu varsayımlarından sapmalara sebep olmaktadır. Çok değişkenli aykırı değer tespitinde kullanılan tekniklerden biri olan Mahalanobis uzaklığı, aykırı değişkenlere karşı hassas ölçütler olan çok değişkenli ortalamalar ve kovaryans matrisine dayalı olarak hesaplanmakta; çok değişkenli veri setlerinde aykırı gözlemlerin tespitinin engellenmesi veya normal gözlemlerin aykırı gözlem olarak tespit edilmesi problemlerine karşı dayanıklı ölçütlerle de kullanılmaktadır. Bu çalışmada, çok değişkenli aykırı değer tespitinde kullanılan klasik ve dayanıklı Mahalanobis ölçütlerinin aykırı gözlem tespitlerinin karşılaştırılması amaçlanmıştır. Uygulama verisi olarak, Ocak 2013 – Aralık 2017 döneminde New York ve NASDAQ borsasında yatırımcılar tarafından gerçekleştirilen 1.239.507 adet hisse senedi alım ve satım işlemi kullanılmıştır. Aykırı işlemlerin tespitinde miktar ve hacim değişkenleri ele alınarak, her bir işlem için klasik ve dayanıklı ölçütlere dayalı uzaklık skorları hesaplanarak, söz konusu teknikler karşılaştırılmıştır. Çalışma sonucunda, klasik Mahalanobis ölçütü ve En Küçük Hacimli Elipsoid ile tespit edilemeyen maskelenmiş aykırı gözlemlerin, Hızlı Minimum Kovaryans Determinant yöntemiyle tespit edilmiş olduğu; söz konusu yöntemin finans uygulama alanında çok değişkenli veri setlerinde aykırı gözlemlerin tespiti için kullanılabilecek etkin bir veri madenciliği yöntemi olduğu sonucuna ulaşılmıştır

A new measure of consensus with reciprocal preference relations: The correlation consensus degree

Producción CientíficaThe achievement of a ‘consensual’ solution in a group decision making problem depends on experts’ ideas, principles, knowledge, experience, etc. The measurement of consensus has been widely studied from the point of view of different research areas, and consequently different consensus measures have been formulated, although a common characteristic of most of them is that they are driven by the implementation of either distance or similarity functions. In the present work though, and within the framework of experts’ opinions modelled via reciprocal preference relations, a different approach to the measurement of consensus based on the Pearson correlation coefficient is studied. The new correlation consensus degree measures the concordance between the intensities of preference for pairs of alternatives as expressed by the experts. Although a detailed study of the formal properties of the new correlation consensus degree shows that it verifies important properties that are common either to distance or to similarity functions between intensities of preferences, it is also proved that it is different to traditional consensus measures. In order to emphasise novelty, two applications of the proposed methodology are also included. The first one is used to illustrate the computation process and discussion of the results, while the second one covers a real life application that makes use of data from Clinical Decision-Making.Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178

Evaluation of the business environment of participating countries of the Belt and Road Initiative

As an important indicator for measuring the quality of business environment of different countries, ease of doing business (EDB) issued by the World Bank (WB) provides an important reference for investors in making decisions on transnational investment. The calculation method for EDB issued by the WB is improved using a technique for order preference by similarity to an ideal solution (TOPSIS) method based on Mahalanobis distance. Based on various indicator data in 2019, business environments in 121 countries participating in “the Belt and Road Initiative (BRI)” were empirically analysed and compared through such models. The result showed that TOPSIS method based on Mahalanobis distance can more fully utilise information and take the effect of negative ideal points into account. Therefore, compared with ranking method by the WB, TOPSIS method based on Mahalanobis distance is more applicable for ranking BRI countries. The ranking results indicated significant geographical characteristics. The EDB rankings obtained through the WB overestimate the business environments of countries in Central and Eastern Europe while underestimate those in Southeast Asia, Africa, etc. First published online 22 September 202

Social-Media-Daten: Chancen und Herausforderungen der Nutzung von Social-Media-Daten im Kontext wissenschaftlicher Forschung

Im Rahmen der vorliegende Arbeit konnten Chancen und Herausforderungen von Social Media Datenanalysen aufgezeigt werden. Um das Potenzial dieser nutzen zu können, ist eine interdisziplinäre Herangehensweise erforderlich. Während die vorliegenden Publikationen noch durch eine Einzelperson realisiert werden konnten, wird klar das die Einbeziehung der unterschiedlichen Disziplinen eine verstärkte Zusammenarbeit erfordert. Die Erweiterung der Agenten basierten Simulation um die „Mean Field Game Theory“ erfordert z.B. fortgeschrittene Kenntnisse der Physik, Sentiment Analysen erfordert die Zusammenarbeit von Linguisten und Informatikern, Clusteranalysen bedürfen der Zusammenarbeit von Datenanalytikern und Soziologen. Um das Potential der Analyseergebnisse zu heben sollten Wirtschaftswissenschaftler einbezogen bzw. sind diese Treiber und Wertschöpfer. Somit ist zukünftig eine verstärkte Zusammenarbeit zu erwarten, welches zu komplexen Formen der Zusammenarbeit führen wird. Dies wiederum bedingt Konzepte und Frameworks, um die Zusammenarbeit transparent und verständlich gestalten zu können

Análise remota do eletrocardiograma para detecção de eventos isquêmicos

The evolution of technologies for remote services delivery over the Internet unveils a new frontier in the development of the knowledge needed to implement health prevention measures. In this study, a computational tool was conceived for the remote analysis of multiple lead electrocardiograms. As a proof of concept, a method for detecting ST-T segment changes related to ischemic episodes in remote computing is proposed. The architecture combines only open source software that allows incremental object-oriented programming and support multiuser services via the Web, focusing on system evolution within the academic world. The technique used to detect ischemic events favored low computational cost and storage of both data and metadata in a database. It was anchored in a method of interpolation by weighted least squares and histograms, capable of detecting the positions of the QRS complexes, and the respective positions of J points and T waves. These points were used as borderline positions in obtaining representative under curve areas for the subsequent detection of ischemic events in the leads present in the research file. After assessment with engineering students, we conclude that the platform, architecture, and programming techniques provide a satisfactory tool for ischemic event management that can be used to develop new biomedical signal processing techniques that support the risk assessment of myocardial dysfunction.A evolução das tecnologias para entrega de serviços remotos pela Internet revela uma nova fronteira no desenvolvimento do conhecimento necessário para implementar medidas de prevenção da saúde. Neste estudo, uma ferramenta computacional foi concebida para a análise remota de eletrocardiogramas de múltiplas derivações. Como prova de conceito, um método é proposto para detectar alterações no segmento ST-T relacionadas a episódios isquêmicos através da computação remota. A arquitetura combina apenas software de código aberto que permite programação incremental orientada a objetos e oferece suporte a serviços multiusuário via Web, com foco na evolução do sistema no mundo acadêmico. A técnica utilizada para detectar eventos isquêmicos favoreceu o baixo custo computacional e armazenamento de dados e metadados em um Banco de Dados. Foi ancorado em um método de interpolação por mínimos quadrados ponderados e histogramas, capazes de detectar as posições dos complexos QRS e as respectivas posições dos pontos J e ondas T. Esses pontos foram usadas como posições limítrofes na obtenção de áreas representativas sob curvas para a subsequente detecção de eventos isquêmicos nas derivações presentes no arquivo de pesquisa. Após avaliação junto a discentes de engenharia, concluímos que a plataforma, arquitetura e técnicas de programação fornecem uma ferramenta satisfatória para o gerenciamento de eventos isquêmicos, a qual pode ser usada para o desenvolvimento de novas técnicas de processamento de sinais biomédicos que objetivem apoiar a avaliação de risco de disfunção miocárdic

The versatility of counselling psychology in the field of substance misuse

The present study was part of a nationwide multisite trial of contingency management (CM) implemented by the National Treatment Agency for Substance Misuse (NTA). The research programme aimed to target drug using, health and attendance related behaviours to gain an understanding of the acceptability and feasibility of contingency management to the UK substance misuse population. The use of CM to incentivise abstinence from an illicit substance was recommended in the guidelines of the National Institute for Health and Clinical Excellence (NICE, 2007). This study examined whether CM reduced concurrent crack cocaine misuse among opiate maintenance clients at a community drug and alcohol service (NHS). The study employed a quasi experimental design in which twenty-one (n = 21) opiate maintenance clients voluntarily chose to participate in the CM group. The incentive consisted of monetary based vouchers in the CM group, contingent upon the submission of cocaine free urine samples. A natural unplanned comparison group (n = 21) developed from participants that initially agreed to participate in the CM intervention but did not attend any of the scheduled reinforcement sessions. These clients continued to receive standard treatment (ST), including opiate maintenance treatment and key working. The data analysis consisted of two parts of data analysis; the first part employed a between-group analysis to compare the frequency of self-reported crack cocaine misuse for the CM and ST groups at baseline, 1 week after the 12-week CM intervention concluded and at 6 months follow-up. The analysis showed that there was a significant difference in crack use at followup and that there was a decrease in crack use over time in the CM group but not in the ST group. The second part utilised a within-group analysis, investigating study results for evidence of clinically meaningful changes on an individual participant level in the CM group. Accordingly, 5 participants (24%) demonstrated statistical and clinical improvement. Additionally, a survival analysis revealed that the estimated median time to study dropout was 14 days. These results seemed to indicate onset of crack abstinence is likely to occur early in treatment or not at all. The results of the study provide a tentative overview of the feasibility and generalisability of a voucher based contingency management programme reducing crack use among clients in opiate maintenance treatment in the UK. The 29 implications of the study will be discussed in relation to clinical practice and future research. Finally, a brief discussion of the moral and ethical concerns about using incentives in health care will be provided. This information will be useful in expanding this evidence-based approach into community settings