Hasil untuk "Competition"

S. Makridakis, Evangelos Spiliotis, V. Assimakopoulos

Abstract The M4 Competition follows on from the three previous M competitions, the purpose of which was to learn from empirical evidence both how to improve the forecasting accuracy and how such learning could be used to advance the theory and practice of forecasting. The aim of M4 was to replicate and extend the three previous competitions by: (a) significantly increasing the number of series, (b) expanding the number of forecasting methods, and (c) including prediction intervals in the evaluation process as well as point forecasts. This paper covers all aspects of M4 in detail, including its organization and running, the presentation of its results, the top-performing methods overall and by categories, its major findings and their implications, and the computational requirements of the various methods. Finally, it summarizes its main conclusions and states the expectation that its series will become a testing ground for the evaluation of new methods and the improvement of the practice of forecasting, while also suggesting some ways forward for the field.

Dimosthenis Karatzas, L. G. I. Bigorda, Anguelos Nicolaou et al.

Results of the ICDAR 2015 Robust Reading Competition are presented. A new Challenge 4 on Incidental Scene Text has been added to the Challenges on Born-Digital Images, Focused Scene Images and Video Text. Challenge 4 is run on a newly acquired dataset of 1,670 images evaluating Text Localisation, Word Recognition and End-to-End pipelines. In addition, the dataset for Challenge 3 on Video Text has been substantially updated with more video sequences and more accurate ground truth data. Finally, tasks assessing End-to-End system performance have been introduced to all Challenges. The competition took place in the first quarter of 2015, and received a total of 44 submissions. Only the tasks newly introduced in 2015 are reported on. The datasets, the ground truth specification and the evaluation protocols are presented together with the results and a brief summary of the participating methods.

Chih-Hao Chang, J. Qiu, David O’Sullivan et al.

Failure of T cells to protect against cancer is thought to result from lack of antigen recognition, chronic activation, and/or suppression by other cells. Using a mouse sarcoma model, we show that glucose consumption by tumors metabolically restricts T cells, leading to their dampened mTOR activity, glycolytic capacity, and IFN-γ production, thereby allowing tumor progression. We show that enhancing glycolysis in an antigenic "regressor" tumor is sufficient to override the protective ability of T cells to control tumor growth. We also show that checkpoint blockade antibodies against CTLA-4, PD-1, and PD-L1, which are used clinically, restore glucose in tumor microenvironment, permitting T cell glycolysis and IFN-γ production. Furthermore, we found that blocking PD-L1 directly on tumors dampens glycolysis by inhibiting mTOR activity and decreasing expression of glycolysis enzymes, reflecting a role for PD-L1 in tumor glucose utilization. Our results establish that tumor-imposed metabolic restrictions can mediate T cell hyporesponsiveness during cancer.

K. Coyte, Jonas Schluter, K. Foster

M. Porter, J. Heppelmann

Yvonne Tay, Johannes Rinn, P. Pandolfi

E. Atashpaz-Gargari, C. Lucas

P. Krugman

S. Salop

Steven B. Andrews, R. Burt

The study analyzes the social structure of competition. It addresses the consequences of voids in relational and resource networks. Competitive behavior can be understood in terms of player access to "holes" in the social structure of the competitive arena. Those "structural holes" are network gaps between players which create entrepreneurial opportunities for information access, timing, referrals, and for control. A player brings capital to the competitive arena and walks away with profit determined by the rate of return where the capital was invested. The rate of return is keyed to the social structure of the competitive arena. Each player brings three kinds of capital to the competitive arena: financial capital, such as money and investments; human capital, such as his or her natural qualities and skills; and social capital, i.e. networks of other players. Social capital is the final determinant of competitive success. Something about the structure of a player's network (his or her relations with other players, such as colleagues, friends, and clients), and the location of the player's network in the structure of the arena defines the player's chances of getting higher rates of return. These chances are enhanced by two kinds of network benefits for those who can exploit structural holes: information and control. Opportunities for success are many, but it is information that plays a central role in seizing them; structural holes determine who knows about opportunities, what they know, and who gets to participate. Structural holes also generate control benefits, giving certain players an advantage in negotiating their relationships. Following sociological theory, a player who derives benefit from structural holes by brokering relationships between other conflicted players is called tertius gaudens. The essential tension in tertius strategies is not hostility of participants, but rather uncertainty; no one has absolute authority in the relationship under negotiation. The findings of empirical research indicate that structural holes are advantageous to suppliers and customers, but not to producers in their negotiated transactions, because suppliers and customers benefit from competition among producers. The information and control benefits of structural holes are advantageous to managers, and the managers who develop those benefits are an asset to the firm employing them. Managers with networks rich in structural holes often reach promotion faster. Hole effects are most evident for managers operating on a social frontier, i.e. in places where two social worlds meet. Social frontiers involve continual negotiations of the expectations of the manager and those of the people across the frontier, and thus more entrepreneurial skill is required. The most serious frontier is the political boundary between top leadership and the rest of the firm. To move up the corporate ladder, a manager has to transform his or her frame of reference from that of an employee protected by the firm, to that of a leader responsible for the firm. The findings also indicate that women and entry-rank men tend to be promoted earlier because they build hierarchical networks around a strategic partner who helps them break into higher ranks. Although the reported differences between the manager networks have clear implications for promotions, there are no differences among managers in their tendencies to have one network rather than another, which is especially striking with respect to the sex and rank differences that are observed to be important in distinguishing network effects. Structural holes provide a theoretical connection between micro and macro levels of sociological analysis. The structural hole argument extends other theories, such as personality theory, interface theory of markets and population ecology, and resource dependence and transaction cost theory

H. Hotelling

M. Darby, E. Karni

James F. Moore

D. Tilman

Nirvikar Singh, X. Vives

S. Kotha

David W. Johnson, Roger T. Johnson

N. Daw, Y. Niv, P. Dayan

S. Hunt, R. Morgan

J. Rietveld, Melissa A. Schilling

Over the past three decades, platform competition—the competition between firms that facilitate transactions and govern interactions between two or more distinct user groups who are connected via an indirect network—has attracted significant interest from the fields of management and organizations, information systems, economics, and marketing. Despite common interests in research questions, methodologies, and empirical contexts by scholars from across these fields, the literature has developed mostly in isolated fashion. This article offers a systematic and interdisciplinary review of the literature on platform competition by analyzing a sample of 333 articles published between 1985 and 2019. The review contributes by (a) documenting how the literature on platform competition has evolved; (b) outlining four themes of shared scholarly interest, including how network effects generate “winner-takes-all” dynamics that influence strategies, such as pricing and quality; how network externalities and platform strategy interact with corporate-level decisions, such as vertical integration or diversification into complementary goods; how heterogeneity in the platform and its users influences platform dynamics; and how the platform “hub” orchestrates value creation and capture in the overall ecosystem; and (c) highlighting several areas for future research. The review aims to facilitate a broader understanding of the platform competition research that helps to advance our knowledge of how platforms compete to create and capture value.