Temporal Pattern of Online Communication Spike Trains in Spreading a Scientific Rumor: How Often, Who Interacts with Whom?

We study complex time series (spike trains) of online user communication while spreading messages about the discovery of the Higgs boson in Twitter. We focus on online social interactions among users such as retweet, mention, and reply, and construct different types of active (performing an action) and passive (receiving an action) spike trains for each user. The spike trains are analyzed by means of local variation, to quantify the temporal behavior of active and passive users, as a function of their activity and popularity. We show that the active spike trains are bursty, independently of their activation frequency. For passive spike trains, in contrast, the local variation of popular users presents uncorrelated (Poisson random) dynamics. We further characterize the correlations of the local variation in different interactions. We obtain high values of correlation, and thus consistent temporal behavior, between retweets and mentions, but only for popular users, indicating that creating online attention suggests an alignment in the dynamics of the two interactions.Comment: A statistical data analysis & data mining on Social Dynamic Behavior, 9 pages and 7 figure

Tracing Linguistic Relations in Winning and Losing Sides of Explicit Opposing Groups

Linguistic relations in oral conversations present how opinions are constructed and developed in a restricted time. The relations bond ideas, arguments, thoughts, and feelings, re-shape them during a speech, and finally build knowledge out of all information provided in the conversation. Speakers share a common interest to discuss. It is expected that each speaker's reply includes duplicated forms of words from previous speakers. However, linguistic adaptation is observed and evolves in a more complex path than just transferring slightly modified versions of common concepts. A conversation aiming a benefit at the end shows an emergent cooperation inducing the adaptation. Not only cooperation, but also competition drives the adaptation or an opposite scenario and one can capture the dynamic process by tracking how the concepts are linguistically linked. To uncover salient complex dynamic events in verbal communications, we attempt to discover self-organized linguistic relations hidden in a conversation with explicitly stated winners and losers. We examine open access data of the United States Supreme Court. Our understanding is crucial in big data research to guide how transition states in opinion mining and decision-making should be modeled and how this required knowledge to guide the model should be pinpointed, by filtering large amount of data.Comment: Full paper, Proceedings of FLAIRS-2017 (30th Florida Artificial Intelligence Research Society), Special Track, Artificial Intelligence for Big Social Data Analysi

Polaritonic states in a dielectric nanoguide: localization and strong coupling

Propagation of light through dielectrics lies at the heart of optics. However, this ubiquitous process is commonly described using phenomenological dielectric function $\varepsilon$ and magnetic permeability $\mu$, i.e. without addressing the quantum graininess of the dielectric matter. Here, we present a theoretical study where we consider a one-dimensional ensemble of atoms in a subwavelength waveguide (nanoguide) as fundamental building blocks of a model dielectric. By exploring the roles of the atom-waveguide coupling efficiency, density, disorder, and dephasing, we establish connections among various features of polaritonic light-matter states such as localization, super and subradiance, and strong coupling. In particular, we show that coherent multiple scattering of light among atoms that are coupled via a single propagating mode can gives rise to Rabi splitting. These results provide important insight into the underlying physics of strong coupling reported by recent room-temperature experiments with microcavities and surface plasmons.Comment: 10 pages, 6 figure

Market Disciplining Role of Crisis on the Restructuring of the Turkish Banking Sector

This paper aims to find the productivity change in the banking sector between 1990 and 2006, with an emphasis to the period after 2001 crisis during which the Turkish banking system experienced a structural change. Using DEA, we find the Malmquist TFP Change Index and its mutually exclusive and exhaustive components of efficiency and technological changes over time. Additionally, we further decompose the technical efficiency change into pure technical and scale efficiency changes. The productivity of the banking sector is found out to have increased, the main reason being technological improvement rather than efficiency increase. For the cases of productivity decline, however, the changes come from the efficiency side rather than technology. An analysis with respect to the ownership status revealed that foreign banks were the most efficient group until 2001 after which state banks captured the first place. We attribute this change to the inflation accounting practice as well as better management of state banks with less political intrusion. The analysis with respect to bank size reveals that before 2000, the most efficient bank group was the medium-scale banks (the banks mainly purchased by foreign banks) followed by small banks while the efficiency scores converged after 2001.Turkish Banking Sector; Data Envelopment Analysis; Efficiency; Productivity; Post-Crises Period

Why Do Foreign Banks Invest In Turkey?

Sound macroeconomic policies, increasing global liquidity and higher real returns in developing countries played an important role in canalizing capital towards developing markets. Recent improvement in the developing Turkish economy brought the issue of foreign entry to the foreground. High growth potential backed by an increasing population, falling inflation rates and the birth of the mortgage sector made Turkey an ideal place to expand into. This article is not concerned about whether foreign entry is good nor does it discuss the subsequent effects. Rather, it attempts exclusively to shed light on the motivations behind entry to Turkey utilizing recent entry cases.Globalization of Banking; Turkish Banking Industry; Foreign Bank Entry

Structural Change and the Efficiency of Banking In Turkey: Does Ownership Matter?

In a period of increasing foreign bank entry, the popular question of “what does foreign bank entry bring to the Turkish banking sector?” can partly be answered with respect to the productivity effects. This paper aims to find the productivity change in the banking sector between 1990 and 2007 just before the global crisis. We are especially interested in the period beginning with 2001 after which the Turkish banking system has almost been flooded with foreign banks. Using a sample of 20 commercial banks, we attempt to find the Data Envelopment Analysis (DEA) type Malmquist Total Factor Productivity Change Index over the specified period. We also look at the source of this change decomposing this index into its mutually exclusive and exhaustive components of efficiency change and technological change. Additionally, we further decompose the technical efficiency change into pure technical efficiency change and scale efficiency change. The DEA results guide us in comparing the performances of banks of different ownership status (state, private and foreign banks) and of different sizeTurkish Banking Industry, Foreign Bank Entry, Globalization of Banking, Data Envelopment Analysis, Efficiency