Multilevel comparison of deep learning models for function quantification in cardiovascular magnetic resonance: On the redundancy of architectural variations

Background: Cardiac function quantification in cardiovascular magnetic resonance requires precise contouring of the heart chambers. This time-consuming task is increasingly being addressed by a plethora of ever more complex deep learning methods. However, only a small fraction of these have made their way from academia into clinical practice. In the quality assessment and control of medical artificial intelligence, the opaque reasoning and associated distinctive errors of neural networks meet an extraordinarily low tolerance for failure. Aim: The aim of this study is a multilevel analysis and comparison of the performance of three popular convolutional neural network (CNN) models for cardiac function quantification. Methods: U-Net, FCN, and MultiResUNet were trained for the segmentation of the left and right ventricles on short-axis cine images of 119 patients from clinical routine. The training pipeline and hyperparameters were kept constant to isolate the influence of network architecture. CNN performance was evaluated against expert segmentations for 29 test cases on contour level and in terms of quantitative clinical parameters. Multilevel analysis included breakdown of results by slice position, as well as visualization of segmentation deviations and linkage of volume differences to segmentation metrics via correlation plots for qualitative analysis. Results: All models showed strong correlation to the expert with respect to quantitative clinical parameters (r(z)(') = 0.978, 0.977, 0.978 for U-Net, FCN, MultiResUNet respectively). The MultiResUNet significantly underestimated ventricular volumes and left ventricular myocardial mass. Segmentation difficulties and failures clustered in basal and apical slices for all CNNs, with the largest volume differences in the basal slices (mean absolute error per slice: 4.2 +/- 4.5 ml for basal, 0.9 +/- 1.3 ml for midventricular, 0.9 +/- 0.9 ml for apical slices). Results for the right ventricle had higher variance and more outliers compared to the left ventricle. Intraclass correlation for clinical parameters was excellent (>= 0.91) among the CNNs. Conclusion: Modifications to CNN architecture were not critical to the quality of error for our dataset. Despite good overall agreement with the expert, errors accumulated in basal and apical slices for all models

Consumer Brand Defense-Management

In today's digitized and connected world, brands are operating in an environment characterized by the ever-looming danger of online brand criticism. Such brand criticism is particularly delicate because of adverse effects such as a worse brand evaluation that can lead to a lower turnover in the long run (e.g., Luo 2009; Pfeffer, Zorbach, and Carley 2014; Relling et al. 2016). Thus, from a managerial perspective, it becomes increasingly vital to be prepared to handle such criticism (Herhausen et al. 2019). In that matter, a large portion of research focused on crisis and webcare communication (e.g., excusing or denying responsibility; e.g., Coombs and Holladay 2002; Lee and Song 2010; Li, Cui, and Peng 2018; Zhao, Jiang, and Su 2020) to counter the brand criticism. One insightful example of brand criticism with a subsequent managerial response goes back to April 2017. After passengers had already boarded a plane of United Airlines, airport security violently removed a passenger who refused to give up his seat needed by crew members. Some passengers filmed the scene and uploaded it to YouTube. This video went viral on Social Media and was critically discussed in many media outlets (Zdanowicz and Grinberg 2017). Consequently, the stock price of United Airlines plunged (Reklaitis 2017), and the CEO felt compelled to apologize officially (Munoz 2017a, 2017b). However, the CEO's statements and an interview with ABC television made things even more precarious because people did not believe him to be honest and thought it was an act (ABC News 2017). Thus, an official management response may sometimes not be enough to condemn the brand criticism. Yet, managers are often not alone in their quest to fight brand criticism. In fact, it can be observed that positive-minded consumers support brands against criticism. Accordingly, despite the international outrage about United Airlines, some consumers exposed themselves on Social Media and in comment sections of newspapers by holding against the criticism and defending United Airlines. For example, in the Washington Post, a consumer wrote: "Think about it. Do you think United really wanted things to play out this way on this airplane? They had to call in airport security to deal with the situation. It was the security people who roughed the guy up. United is paying the price for their actions (…)" (Aratani 2017). This consumer comment exemplifies the phenomenon of "consumer brand defense (CBD)," which refers to consumers who are responding to brand criticism with supportive replies (Ammann et al. 2021). CBD hereby represents a valuable resource for brands in fighting brand criticism, especially because consumers' communication is often perceived as unbiased and more credible than official brand statements (Allsop, Bassett, and Hoskins 2007; Bickart and Schindler 2001; Godes and Mayzlin 2004; Senecal and Nantel 2004). However, even though stimulating CBD might constitute an effective strategy in mitigating the harmful effects of brand criticism, research about this phenomenon remains scarce. In more detail, first research endeavors examined the concrete manifestation of such consumer brand defense behavior and its prevalence (e.g., Colliander and Hauge Wien 2013; Hassan and Casaló Ariño 2016), contingency factors that encourage brand defenders (Hassan and Casaló Ariño 2016; Ilhan, Kübler, and Pauwels 2018), the driving role of a strong emotional relationship with the defended brand (e.g., Dalman, Buche, and Min 2019), CBD's consequences on observers (Esmark Jones et al. 2018; Hong and Cameron 2018; Weitzl and Hutzinger 2017), and first suggested strategies to activate consumer brand defenders (Dineva, Breitsohl, and Garrod 2017; Scholz and Smith 2019). Taken together, the prevailing research about CBD still falls short of answering some of the most pertinent questions, such as consumer brand defenders’ motivational drivers, and thus, leaves us with substantial research gaps. This dissertation examines research questions from three distinct perspectives to provide actionable insights into CBD’s management. Paper 1 focuses on the consumer brand defender’s motivational drivers and their relationship with the defended brand. Based on these two factors, the consumers are segmented into different types of consumer brand defenders. The unit of investigation in paper 2 is the neutral observer of online brand discussions. This research project is dedicated to studying CBD’s effect under different conditions (e.g., in conjunction with an official brand response) and scrutinizes the impact of an employee’s defense comment (e.g., written in his leisure time with his private social media account). Lastly, paper 3 takes the brand’s perspective as a potential facilitator of CBD. More specifically, this research proposes a novel way of handling brand criticism by directly appealing to consumers to defend the brand. In that matter, the paper investigates the effectiveness of such CBD appeals. Taken together, these three papers’ findings address essential research gaps in CBD’s examination and allow for more effective exploitation of CBD’s potential. Specifically, by inspecting brand defenders’ motives and the nature of their brand relationship, paper 1 identifies possible levers to stimulate CBD. Further, paper 2 tests CBD’s positive effects on observers under different conditions and thereby provides information under which circumstances an official brand response might be advantageous or, on the opposite, not even necessary. Finally, paper 3 extends a brand’s repertoire of reactions in the face of criticism by contriving a practical approach to activate the brand’s defenders

Brand Defense durch die Community – Wenn Konsumenten und Konsumentinnen Marken verteidigen

Täglich sind Unternehmen im Internet Kritik ausgesetzt. Solche Kritik und der Umgang mit dieser stellt für die Unternehmen eine grosse Herausforderung dar. In den letzten Jahren konnte zunehmend beobachtet werden, dass Konsumentinnen und Konsumenten Marken verteidigen, die unter Kritik stehen, und so zum Schutz des Markenimages beitragen. Forschung im Bereich von Mundpropaganda hat gezeigt, dass Kommunikation durch Konsumenten als glaubwürdiger beurteilt wird als die Unternehmenskommunikation selbst. Könnte also die Verteidigung der Marke durch Konsumenten sogar wirkungsvoller sein als unternehmenseigene Reaktionen auf Onlinekritik? Können Markenverteidiger und Markenverteidigerinnen gezielt zum Schutz des Markenimages eingesetzt werden? Was treibt sie an, sich öffentlich für eine kritisierte Marke einzusetzen? Dieses Referat liefert erste Erkenntnisse zu diesen Fragen und öffnet im Anschluss die Diskussion im Plenum zum neuen Phänomen der Markenverteidigung durch Konsumenten und Konsumentinnen

Investigating the True Effect of Corporate Reputation on Firm Performance Disentangling the Measurement Jungle

Various scholars provide evidence for a positive relationship between corporate reputation (CR) and firm performance. Building on this effectiveness hypothesis this study compares empirically the most prominent measurements and rankings of CR. The applied methodologies of the identified rankings vary in three main areas: Surveyed stakeholder groups, number of dimensions, and method of data collection. This poses the question if these variations affect the performance implications of CR. Results indicate that comprehensively including the proposed dimensions of CR matters – in other words, the conceptualization of CR is key for understanding its performance implications. On the other hand, the operationalization (groups of respondents, method of data collection) seems to play a lesser role in demonstrating the CR-firm performance relationship. This implies that managers and academics should rather focus on the appropriate conceptualization and less so on the operationalization of CR

A Typology of Consumer Brand Defenders: When Egoists, Justice Fighters and Brand Fans Defend your Brand

Recently, it became evident that more and more consumers defend brands online against criticism. Although this phenomenon is of high practical relevance to recover from negative critique such as NWOM, so far, research about the motives that drive consumers to defend a brand is very limited. Drawing on prosocial behavior literature, we identify key motives as drivers of consumer brand defense (CBD), namely, egoism, reciprocal altruism, and equity restoration as well as the consumer-brand relationship and its hot and rather cold components. A large-scale study with 570 actual brand defenders and a subsequent cluster analysis lead to three distinct brand defender types: the egoists, the justice fighters, and the brand fans. Thereby, we extend the literature on prosocial behavior to the phenomenon of CBD and conclude with recommendations for managers based on the three defender types

A Typology of Consumer Brand Defenders

In today’s digital world, consumers are becoming increasingly empowered in their interactions with brands.Sometimes they help brands but, unfortunately, they are increasingly hurting brands as well.Traditional marketing strategies have focused on brandbuilding but in today’s context, companies need to develop brand defense strategies. In this session, the authors will discuss various aspects of brand defense including customer toxicity, managerial responses to brand sabotage, building brand immunity, various types of brand defenders, and consumer creepiness