A Shapley Value-Based Approach to Discover Influential Nodes in Social Networks

Our study concerns an important current problem, that of diffusion of information in social networks. This problem has received significant attention from the Internet research community in the recent times, driven by many potential applications such as viral marketing and sales promotions. In this paper, we focus on the target set selection problem, which involves discovering a small subset of influential players in a given social network, to perform a certain task of information diffusion. The target set selection problem manifests in two forms: 1) top-k nodes problem and 2) lambda-coverage problem. In the top-k nodes problem, we are required to find a set of k key nodes that would maximize the number of nodes being influenced in the network. The lambda-coverage problem is concerned with finding a set of k key nodes having minimal size that can influence a given percentage lambda of the nodes in the entire network. We propose a new way of solving these problems using the concept of Shapley value which is a well known solution concept in cooperative game theory. Our approach leads to algorithms which we call the ShaPley value-based Influential Nodes (SPINs) algorithms for solving the top-k nodes problem and the lambda-coverage problem. We compare the performance of the proposed SPIN algorithms with well known algorithms in the literature. Through extensive experimentation on four synthetically generated random graphs and six real-world data sets (Celegans, Jazz, NIPS coauthorship data set, Netscience data set, High-Energy Physics data set, and Political Books data set), we show that the proposed SPIN approach is more powerful and computationally efficient. Note to Practitioners-In recent times, social networks have received a high level of attention due to their proven ability in improving the performance of web search, recommendations in collaborative filtering systems, spreading a technology in the market using viral marketing techniques, etc. It is well known that the interpersonal relationships (or ties or links) between individuals cause change or improvement in the social system because the decisions made by individuals are influenced heavily by the behavior of their neighbors. An interesting and key problem in social networks is to discover the most influential nodes in the social network which can influence other nodes in the social network in a strong and deep way. This problem is called the target set selection problem and has two variants: 1) the top-k nodes problem, where we are required to identify a set of k influential nodes that maximize the number of nodes being influenced in the network and 2) the lambda-coverage problem which involves finding a set of influential nodes having minimum size that can influence a given percentage lambda of the nodes in the entire network. There are many existing algorithms in the literature for solving these problems. In this paper, we propose a new algorithm which is based on a novel interpretation of information diffusion in a social network as a cooperative game. Using this analogy, we develop an algorithm based on the Shapley value of the underlying cooperative game. The proposed algorithm outperforms the existing algorithms in terms of generality or computational complexity or both. Our results are validated through extensive experimentation on both synthetically generated and real-world data sets.

Influence limitation in multi-campaign social networks: A Shapley value based approach

We investigate the problem of influence limitation in the presence of competing campaigns in a social network. Given a negative campaign which starts propagating from a specified source and a positive/counter campaign that is initiated, after a certain time delay, to limit the the influence or spread of misinformation by the negative campaign, we are interested in finding the top k influential nodes at which the positive campaign may be triggered. This problem has numerous applications in situations such as limiting the propagation of rumor, arresting the spread of virus through inoculation, initiating a counter-campaign against malicious propaganda, etc. The influence function for the generic influence limitation problem is non-submodular. Restricted versions of the influence limitation problem, reported in the literature, assume submodularity of the influence function and do not capture the problem in a realistic setting. In this paper, we propose a novel computational approach for the influence limitation problem based on Shapley value, a solution concept in cooperative game theory. Our approach works equally effectively for both submodular and non-submodular influence functions. Experiments on standard real world social network datasets reveal that the proposed approach outperforms existing heuristics in the literature. As a non-trivial extension, we also address the problem of influence limitation in the presence of multiple competing campaigns.

Customer value based entry decision in International markets the concept of International Added Customer Equity

Market entry decisions are some of a firm's most important long-term strategic choices. Still, the international marketing literature has not yet fully incorporated the idea of relationship marketing in general, and the customer value concept in particular, as a basis for market entry decisions. This article presents some conceptual ideas about a customer value based market selection model. The metric International Added Customer Equity (IACE), a straightforward decision criterion derived from the customer equity concept is presented as an additional decision criterion for export market selection and ultimately market entry.

Using value-based partnerships to support community engaged learning : benefits, challenges, stakeholder perspectives

Increasingly, the not-for-profit sector, as an emerging contributor to the creative economy, is creating a context for engaging creative practitioners in developing solutions to complex problems, triggering a demand for skills and knowledge needed to address this complexity. Across the university and community contexts alternative models of engagement are emerging to support this dynamic. This paper presents a case study of a creative project in which a value-based approach is used to foster a collaborative partnership between community partners and a multidisciplinary team of final year Creative Industries students who in the course of the project developed a range of communication resources, including a social media campaign, an interactive game and a series of short films to support volunteer engagement and leadership initiatives. The paper considers the implications this values approach has for the design of service learning curriculum for multidisciplinary creative teams and the potential it has to support meaningful collaboration between creatives and the not-for-profit sector. It further explores how it impact on student and partner engagement, learning outcomes and the benefits for the partner organisation. The paper concludes that a value-based approach to university-community engagement has the potential to support and enable a greater degree of reciprocity, deeper engagement between stakeholders and greater relevance of the final outcome.

Indoor location-based analytics systems: Portuguese market compettive assessment and entry procing strategy of BIPs' technology in Sonae Sierra Shopping malls stores

This project attempts to provide an in-depth competitive assessment of the Portuguese indoor location-based analytics market, and to elaborate an entry-pricing strategy for Business Intelligence Positioning System (BIPS) implementation in Portuguese shopping centre stores. The role of industry forces and company’s organizational resources platform to sustain company’s competitive advantage was explored. A customer value-based pricing approach was adopted to assess BIPS value to retailers and maximize Sonae Sierra profitability. The exploratory quantitative research found that there is a market opportunity to explore every store area types with tailored proposals, and to set higher-than-tested membership fees to allow a rapid ROI, concluding there are propitious conditions for Sierra to succeed in BIPS store’s business model in Portugal.

Modeling and illustrating requirement prioritization in public e-service development from a value-based perspective

A major problem in e-service development is the prioritization of the requirements of different stakeholders. The main stakeholders are governments and their citizens, all of whom have different and sometimes conflicting requirements. In this paper, the prioritization problem is addressed by combining a value-based approach with an illustration technique. This paper examines the following research question: How can multiple stakeholder requirements be illustrated from a value-based perspective in order to be prioritizable? We used an e-service development case taken from a Swedish municipality to elaborate on our approach. Our contributions are: 1) a model of the relevant domains for requirement prioritization for government, citizens, technology, finances and laws and regulations; and 2) a requirement fulfillment analysis tool (RFA) that consists of a requirement-goal-value matrix (RGV), and a calculation and illustration module (CIM). The model reduces cognitive load, helps developers to focus on value fulfillment in e-service development and supports them in the formulation of requirements. It also offers an input to public policy makers, should they aim to target values in the design of e-services.

Vállalati versenyképesség – a vevői érték és a képességalapú megközelítés összekapcsolása (Competitiveness of firms – combining the customer value and the capability based approach)

A cikk központi kérdése a vállalati versenyképesség. Két meghatározó menedzsmentmegközelítés – a vevői érték és az erőforrás-, képességalapú stratégiai menedzsment – fogalmi rendszerére, illetve koncepcióira alapozva a szerzők kialakítottak és a "Versenyben a világgal 2004–2006 – gazdasági versenyképességünk vállalati nézőpontból" című kutatás adatbázisát használva teszteltek egy a vállalati versenyképesség belső struktúrájára rávilágító elméleti modellt. A modell empirikus tesztelésének eredménye szerint a kialakított koncepció a vállalati versenyképesség elemzésének hasznos eszköze, mely alkalmas arra, hogy a vizsgált vállalatok esetében igazolja, vagy éppen megcáfolja a meghatározott, ún. összehangolt kompetenciák meglétét. ________The main issue of this article is the competitiveness of firms. Based on conceptual system and concepts of two determinant management approaches – the customer value and the resource and capability based strategic management – the authors have developed and tested a theoretical model of the inside structure of the competitiveness of firms using the database of Competing with the World 2004-2006 – the competitiveness of the Hungarian economy from enterprise point of view. According to the result of the empiric test of the model the developed concept has been a profitable tool of the analysis of the enterprise competitiveness and it has been suited for confirming or confuting determinated so called aligned competencies being in the case of examined firms.

On IT and business value in developing countries : A complementarities-based approach

Developing economies accommodate more than three quarters of the world's population. This means understanding their growth and well-being is of critical importance. Information technology (IT) is one resource that has had a profound effect in shaping the global economy. IT is also an important resource for driving growth and development in developing economies. Investments in developing economies, however, have focused on the exploitation of labor and natural resources. Unlike in developed economies, focus on IT investment to improve efficiency and effectiveness of business process in developing economies has been sparse, and mechanisms for deriving better IT-related business value is not well understood. This study develops a complementarities-based business value model for developing economies, and tests the relationship between IT investments, IT-related complementarities, and business process performance. It also considers the relationship between business processes performance and firm-level performance. The results suggest that a coordinated investment in IT and IT-related complementarities related favorably to business process performance. Improvements in process-level performance lead to improvements in firm-level performance. The results also suggest that the IT-related complementarities are not only a source of business value on their own, but also enhance the IT resources' ability to contribute to business process performance. This study demonstrates that a coordinated investment approach is required in developing economies. With this approach, their IT resources and IT-related complementaries would help them significantly in improving their business processes, and eventually their firm-level performances.

Customer Value Formation in Practice: A Practice-Theoretical Approach

This thesis introduces a practice-theoretical approach to understanding customer value formation to be used in the field of service marketing and management. In contrast to current studies trying to understand value formation by analysing customers as independent actors and thinkers, it is in this work suggested that customer value formation can be better understood by analysing how value is formed in the practices and contexts of the customers. The theoretical approach developed in this thesis is applied in an empirical study of family cruises. The theoretical analysis in this thesis results in a new approach for understanding customer value formation. Customer value is, according to this new approach, something that is formed in practice, meaning that value is formed in constellations of the customer and contextual elements like tools, physical spaces and contextually embedded images and know-how. This view is different from the current views that tend to see value as subjectively created, co-created, perceived or experienced by the customer. The new approach has implications on how we view customer value, but also on the methods and techniques we can use to understand customer value in empirical studies. It is also suggested that services could in fact be reconceptualised as practices. According to the stance presented in this thesis the empirical analysis of customer value should not focus on individual customers, but should instead take the contextual entity of practices as its unit of analysis. Therefore, ethnography is chosen as a method for exploring how customer value is formed in practice in the case of family cruises on a specific cruise vessel. The researcher has studied six families, as well as the context of the cruise vessel with various techniques including non-participant observation, participant observation and interviews in order to create an ethnographic understanding of the practices carried out on board. Twenty-one different practices are reported and discussed in order to provide necessary insight to customer value formation that can be used as input for service development.

Mobile E-commerce business model – A value web based approach to business models in mobile gaming industry

Tämän tutkimuksen tavoitteena oli tutkia langattomien internet palveluiden arvoverkkoa ja liiketoimintamalleja. Tutkimus oli luonteeltaan kvalitatiivinen ja siinä käytettiin strategiana konstruktiivista case-tutkimusta. Esimerkkipalveluna oli Treasure Hunters matkapuhelinpeli. Tutkimus muodostui teoreettisesta ja empiirisestä osasta. Teoriaosassa liitettiin innovaatio, liiketoimintamallit ja arvoverkko käsitteellisesti toisiinsa, sekä luotiin perusta liiketoimintamallien kehittämiselle. Empiirisessä osassa keskityttiin ensin liiketoimintamallien luomiseen kehitettyjen innovaatioiden pohjalta. Lopuksi pyrittiin määrittämään arvoverkko palvelun toteuttamiseksi. Tutkimusmenetelminä käytettiin innovaatiosessiota, haastatteluja ja lomakekyselyä. Tulosten pohjalta muodostettiin useita liiketoimintakonsepteja sekä kuvaus arvoverkon perusmallista langattomille peleille. Loppupäätelmänä todettiin että langattomat palvelut vaativat toteutuakseen useista toimijoista koostuvan arvoverkon.

The value of peer support and a strengths-based approach in a groupwork programme for fathers in a family support setting

This paper seeks to share and critically explore the learning gained through the genesis, realisation, and facilitation process of Just for Dads, a groupwork programme for fathers, run in a family support setting. It highlights the importance of and challenges involved in engaging men in practice, and in groupwork aimed at fathers in particular. It recounts the significance of using a strengths perspective as a framework for engaging fathers in groupwork and highlights its value as experienced by participants and facilitators. The dynamic of peer learning which developed as a key part of the groupwork process is discussed, both in relation to how it was experienced by participants and also the degree to which the facilitators were part of that dynamic. Overall the paper aims to document and air key issues arising in this relatively unexplored arena of groupwork and family support practice.