121 research outputs found

    DFSeer: A visual analytics approach to facilitate model selection for demand forecasting

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    Selecting an appropriate model to forecast product demand is critical to the manufacturing industry. However, due to the data complexity, market uncertainty and users' demanding requirements for the model, it is challenging for demand analysts to select a proper model. Although existing model selection methods can reduce the manual burden to some extent, they often fail to present model performance details on individual products and reveal the potential risk of the selected model. This paper presents DFSeer, an interactive visualization system to conduct reliable model selection for demand forecasting based on the products with similar historical demand. It supports model comparison and selection with different levels of details. Besides, it shows the difference in model performance on similar products to reveal the risk of model selection and increase users' confidence in choosing a forecasting model. Two case studies and interviews with domain experts demonstrate the effectiveness and usability of DFSeer.Comment: 10 pages, 5 figures, ACM CHI 202

    Interplay between phosphorylation and palmitoylation mediates plasma membrane targeting and sorting of GAP43.

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    Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43

    The Prohibition of the Proposed Springer-Prosiebensat.1-Merger: How Much Economics in German Merger Control?

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    We review the Bundeskartellamt (Federal Cartel Office Germany) decision on the proposed merger between Springer and ProSiebenSat.1 from an economic point of view. In doing so, it is not our goal to analyse whether the controversial decision by the Bundeskar-tellamt has been correct or flawed from a legal point of view. Instead, we analyse whether the economic reasoning in the decision document reflects state-of-the-art economic theory on conglomerate mergers. Regarding such types of mergers, anticompetitive effects either do not occur regularly or are more often than not overcompensated by efficiency gains, so that a standard welfare perspective demands reluctance concerning antitrust interventions. This is particularly true if two-sided markets, like media markets, are involved. However, anticompe-titive conglomerate mergers are not impossible, in particular in neighbouring markets where there is some relationship between the products of the merging companies. In line with the more-economic approach in European merger control, a particular thorough line of argumen-tation, backed with particularly convincing economic evidence, is necessary to justify a pro-hibition of a conglomerate merger from an economic point of view. Against this background, we do not find the reasoning of the Bundeskartellamt entirely convincing and sufficiently strong to justify a prohibition of the proposed combination from an economic perspective. The reasons are that (i) the Bundeskartellamt fails to continuously consider consumer and customer welfare as the relevant standards, (ii) positive efficiency and welfare effects of cross-media strategies are neglected, (iii) in contrast, the competition agency sometimes ap-pears to view profitability of post-merger strategy options to be per se anticompetitive (effi-ciency offence), (iv) the incontestability of the relevant markets is not sufficiently substanti-ated, (v) inconsistencies occur regarding the symmetry of the TV advertising market duopoly versus the unique role of the BILD-Zeitung and (vi) the employment of modern economic instruments appears to be underdeveloped. Thus, we conclude that the Bundeskartellamt has not embraced the European more-economic approach in the analysed decision. However, one can discuss whether economic effects are overcompensated in this case by concerns about a reduction in diversity of opinion and threats to free speech. Similar to the Bundeskartellamt, we do not consider these concerns in our analysis

    Modern Industrial Economics and Competition Policy: Open Problems and Possible Limits

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    Naturally, competition policy is based on competition economics made applicable in terms of law and its enforcement. Within the different branches of competition economics, modern industrial economics, or more precisely gametheoretic oligopoly theory, has become the dominating paradigm both in the U.S. (since the 1990s Post-Chicago movement) and in the EU (so-called more economic approach in the 2000s). This contribution reviews the state of the art in antitrust-oriented modern industrial economics and, in particular, critically discusses open questions and possible limits of basing antitrust on modern industrial economics. In doing so, it provides some hints how to escape current enforcement problems in industrial economics-based competition policy on both sides of the Atlantic. In particular, the paper advocates a change of the way modern industrial economics is used in competition policy: instead of more and more case-by-cases analyses, the insights from modern industrial economics should be used to design better competition rules

    What Drives the Productive Efficiency of a Firm? The Importance of Industry, Location, R&D, and Size

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    This paper investigates the factors that explain the level and dynamics of manufacturing firm productive efficiency. In our empirical analysis, we use a unique sample of about 39,000 firms in 256 industries from the German Cost Structure Census over the years 1992-2005. We estimate the efficiencies of the firms and relate them to firm-specific and environmental factors. We find that (1) about half the model's explanatory power is due to industry effects, (2) firm size accounts for another 20 percent, and (3) location of headquarters explains approximately 15 percent. Interestingly, most other firm characteristics, such as R&D intensity, outsourcing activities, or the number of owners, have extremely little explanatory power. Surprisingly, our findings suggest that higher R&D intensity is associated with being less efficient, though higher R&D spending increases a firm's efficiency over time
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