Constructive journalism has become a popular term in recent years, and has been the basis of a number of seminars, conferences, courses at journalism schools, fellowship programs, and research ...projects. This article traces the origins of constructive journalism by describing and discussing the proponents, precedents, and principles of the movement. The article shows that constructive journalism is no new term and that its inherent principles share similarities with other well-known movements in the history of journalism. These include action journalism that was popular on both sides of the Atlantic at the turn of last century and public journalism that flourished at the turn of this century. Common for most of these movement are, however, their lack of conceptual clarity. The differences and similarities between constructive journalism, past movements, and more classical conceptions of journalism are analyzed through the framework of the Journalistic Compass that delineates four classical roles within journalism. The article concludes by describing the opportunities–and difficulties – that this recent movement faces as still more persons and organizations lay claim to practicing constructive journalism and it discusses how the proponents might learn from former movements that have gained popularity for a period but whose importance has since diminished.
Ye 2011 showed recently that the simplex method with Dantzig’s pivoting rule, as well as Howard’s
policy iteration
algorithm, solve discounted Markov decision processes (MDPs), with a constant ...discount factor, in strongly polynomial time. More precisely, Ye showed that both algorithms terminate after at most
O
(
mn
1−
γ
log
n
1−
γ
) iterations, where
n
is the number of states,
m
is the total number of actions in the MDP, and 0 <
γ
< 1 is the discount factor. We improve Ye’s analysis in two respects. First, we improve the bound given by Ye and show that Howard’s policy iteration algorithm actually terminates after at most
O
(
m
1−
γ
log
n
1−
γ
) iterations. Second, and more importantly, we show that the same bound applies to the number of iterations performed by the
strategy iteration
(or
strategy improvement
) algorithm, a generalization of Howard’s policy iteration algorithm used for solving 2-player turn-based
stochastic games
with discounted zero-sum rewards. This provides the first strongly polynomial algorithm for solving these games, solving a long standing open problem. Combined with other recent results, this provides a complete characterization of the complexity the standard strategy iteration algorithm for 2-player turn-based stochastic games; it is strongly polynomial for a fixed discount factor, and exponential otherwise.
We consider some well-known families of two-player zero-sum perfect-information stochastic games played on finite directed graphs. The families include stochastic parity games, stochastic mean payoff ...games, and simple stochastic games. We show that the tasks of solving games in each of these classes (quantitiatively or strategically) are all polynomial time equivalent. In addition, we exhibit a linear time algorithm that given a simple stochastic game and the values of all positions of that game, computes a pair of optimal strategies.
ON THE COMPLEXITY OF NUMERICAL ANALYSIS ALLENDER, Eric; BÜRGISSER, Peter; KJELDGAARD-PEDERSEN, Johan ...
SIAM journal on computing,
01/2009, Letnik:
38, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We study two quite different approaches to understanding the complexity of fundamental problems in numerical analysis: (a) the Blum-Shub-Smale model of computation over the reals; and (b) a problem ...we call the "generic task of numerical computation," which captures an aspect of doing numerical computation in floating point, similar to the "long exponent model" that has been studied in the numerical computing community. We show that both of these approaches hinge on the question of understanding the complexity of the following problem, which we call PosSLP: Given a division-free straight-line program producing an integer $N$, decide whether $N>0$. In the Blum-Shub-Smale model, polynomial-time computation over the reals (on discrete inputs) is polynomial-time equivalent to PosSLP when there are only algebraic constants. We conjecture that using transcendental constants provides no additional power, beyond nonuniform reductions to PosSLP, and we present some preliminary results supporting this conjecture. The generic task of numerical computation is also polynomial-time equivalent to PosSLP. We prove that PosSLP lies in the counting hierarchy. Combining this with work of Tiwari, we obtain that the Euclidean traveling salesman problem lies in the counting hierarchy--the previous best upper bound for this important problem (in terms of classical complexity classes) being PSPACE. In the course of developing the context for our results on arithmetic circuits, we present some new observations on the complexity of the arithmetic circuit identity testing (ACIT) problem. In particular, we show that if $n!$ is not ultimately easy, then ACIT has subexponential complexity.
HemiCAP for complex osteochondral defects (OCDs) in talus has been on the market since 2008. Few follow-up studies exist. Patients with complex OCDs were followed for up to 81 months.
31 consecutive ...patients were assessed preoperatively and at final follow-up, mean 50 months. All patients were treated with the HemiCAP®, Arthrosurface Inc., USA inlay. Inclusion criteria were complex OCDs of the medial or lateral talus dome.
All outcome measures i.e. AOFAS, FAOS and NRS improved significantly.
71.8 % of the cohort were employed preoperatively.
At final follow up 87.5% were employed. No revisions of the HemiCAP was performed, but 41,9% had supplementary surgery. 1 patient had a superficial infection otherwise no complications were found. Preoperative and final follow-up x-rays were analysed.
Mid-term results after HemiCAP talus are good. Patient information and selection is mandatory due to the high numbers of additional surgeries following the HemiCap implantation.
News values and newsworthiness have been central concepts of Journalism Studies since they were first introduced to the public over a hundred years ago. Seminal studies of 20th-century media ...examining news values and the intricately connected concept of gatekeeping have been cited, added to, and rigorously criticized. In the digital age, news travels effortlessly across the Internet, permeating the once exclusive and closed-off platforms of legacy news organizations. Audiences increasingly rely on alternative platforms for news consumption. This complicates our previous understandings of the flow of news, and it invites new gatekeepers to the table, simultaneously shaping and deciding what is considered newsworthy. This article recontextualizes the classical concept of news values by reviewing news value research of 21st-century digital legacy media resulting in three archetypical platform types through which legacy media news travels: intra-media, inter-media, and extra-media platforms. Inspired by social psychologist Kurt Lewin’s gatekeeping theory and the concept of platformization, this article presents a new conceptual framework that delineates the forces and factors that affect news flow in a digital era.
The present article suggests that the brief history of Western television news dramaturgy can be expounded as three major waves: from the early days of the talking heads in the studio, over the ...narrativization of the field report to a (re-)current studio- and field-based talking heads format. In order to analyze the latest development entering the third wave, we propose a theoretically based dramaturgical model for the television news item. The analysis concludes that, with the current ‘return’ of the talking heads format, the pre-produced and pre-packaged bulletin program about past events is dissolving and transforming into an evaluative present- and future-oriented update format that resembles the 24-hour newsonly channels. Production time merges with broadcast time so that the uncertainty of live spreads to the dramaturgy.
Digital Gatekeeping Bro, Peter; Wallberg, Filip
Digital journalism,
07/2014, Letnik:
2, Številka:
3
Journal Article
Recenzirano
This paper describes what has happened to the principles and practices of gatekeeping as digital technologies have spread inside and outside newsrooms; and it has a particular focus on news values ...among a new generation of gatekeepers who use social media to produce, publish and distribute news stories. The article builds theoretically on the concepts of gatekeeping and news values, and it is based empirically on a year-long study of the news processes related to the use of Facebook. Data material includes an analysis of how more than 200,000 news stories-that were published on the websites of major news organizations in Denmark from June 2011 to June 2012-were shared, recommended and commented upon in different social contexts. The article concludes by discussing some of the prevailing news values in the news media and the social media.
Gatekeeping in a Digital Era Bro, Peter; Wallberg, Filip
Journalism practice,
01/2015, Letnik:
9, Številka:
1
Journal Article
Recenzirano
The original concept of gatekeeping within journalism was based on a particular research method, a particular sub-profession within the news media, and a particular-now extinct-technological ...platform. This article describes and discusses what has happened to the function of gatekeeping as new technologies have developed, and it suggests that three models of gatekeeping are present in the digital era. The first model is based on a process of information, the second model is based on a process of communication, and the third and last model is based on a process of elimination, where the function of gatekeeping is taken over by people outside the newsrooms. All three models have been part of the history of journalism from the very beginning, but their importance for news reporters and the news media have changed with the invention of new technological means, methods and tools. This reassessment of the principles, practices and new technological platforms for gatekeeping concludes by discussing the ways in which our models of journalism can affect not only researchers but also news reporters and audiences.
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