Probing Limits of Information Spread with Sequential Seeding

We consider here information spread which propagates with certain probability from nodes just activated to their not yet activated neighbors. Diffusion cascades can be triggered by activation of even a small set of nodes. Such activation is commonly performed in a single stage. A novel approach based on sequential seeding is analyzed here resulting in three fundamental contributions. First, we propose a coordinated execution of randomized choices to enable precise comparison of different algorithms in general. We apply it here when the newly activated nodes at each stage of spreading attempt to activate their neighbors. Then, we present a formal proof that sequential seeding delivers at least as large coverage as the single stage seeding does. Moreover, we also show that, under modest assumptions, sequential seeding achieves coverage provably better than the single stage based approach using the same number of seeds and node ranking. Finally, we present experimental results showing how single stage and sequential approaches on directed and undirected graphs compare to the well-known greedy approach to provide the objective measure of the sequential seeding benefits. Surprisingly, applying sequential seeding to a simple degree-based selection leads to higher coverage than achieved by the computationally expensive greedy approach currently considered to be the best heuristic

Seeds Buffering for Information Spreading Processes

Seeding strategies for influence maximization in social networks have been studied for more than a decade. They have mainly relied on the activation of all resources (seeds) simultaneously in the beginning; yet, it has been shown that sequential seeding strategies are commonly better. This research focuses on studying sequential seeding with buffering, which is an extension to basic sequential seeding concept. The proposed method avoids choosing nodes that will be activated through the natural diffusion process, which is leading to better use of the budget for activating seed nodes in the social influence process. This approach was compared with sequential seeding without buffering and single stage seeding. The results on both real and artificial social networks confirm that the buffer-based consecutive seeding is a good trade-off between the final coverage and the time to reach it. It performs significantly better than its rivals for a fixed budget. The gain is obtained by dynamic rankings and the ability to detect network areas with nodes that are not yet activated and have high potential of activating their neighbours.Comment: Jankowski, J., Br\'odka, P., Michalski, R., & Kazienko, P. (2017, September). Seeds Buffering for Information Spreading Processes. In International Conference on Social Informatics (pp. 628-641). Springe

Online Influence Maximization in Non-Stationary Social Networks

Social networks have been popular platforms for information propagation. An important use case is viral marketing: given a promotion budget, an advertiser can choose some influential users as the seed set and provide them free or discounted sample products; in this way, the advertiser hopes to increase the popularity of the product in the users' friend circles by the world-of-mouth effect, and thus maximizes the number of users that information of the production can reach. There has been a body of literature studying the influence maximization problem. Nevertheless, the existing studies mostly investigate the problem on a one-off basis, assuming fixed known influence probabilities among users, or the knowledge of the exact social network topology. In practice, the social network topology and the influence probabilities are typically unknown to the advertiser, which can be varying over time, i.e., in cases of newly established, strengthened or weakened social ties. In this paper, we focus on a dynamic non-stationary social network and design a randomized algorithm, RSB, based on multi-armed bandit optimization, to maximize influence propagation over time. The algorithm produces a sequence of online decisions and calibrates its explore-exploit strategy utilizing outcomes of previous decisions. It is rigorously proven to achieve an upper-bounded regret in reward and applicable to large-scale social networks. Practical effectiveness of the algorithm is evaluated using both synthetic and real-world datasets, which demonstrates that our algorithm outperforms previous stationary methods under non-stationary conditions.Comment: 10 pages. To appear in IEEE/ACM IWQoS 2016. Full versio

Aquaculture Asia, vol. 8, no. 3, pp.1-58, July - September 2003

CONTENTS: Ornamental Fish Farming – Successful Small Scale Aqua business in India, by Abalika Ghosh, B. K. Mahapatra and N.C. Datta. Tilapia: A species for Indian Aquaculture? by Graham Mair. Peri-urban food production in Southeast Asia, by Peter Edwards. Shrimp Farming Practices and its Socio- Economic Consequences in East Godavari District, Andhra Pradesh, India - A Case Study, by M.Kumaran, P.Ravichandran, B.P.Gupta and A.Nagavel. Breeding technique of Malaysian golden arowana, Scleropages formosus in concrete tanks, by Mohamad Zaini Suleiman. Captive Breeding of Peacock Eel, Macrognathus aculeatus, by S.K.Das and N. Kalita. Substrate based aquaculture systems: Farmer innovation withstands scientific scrutiny and proves robust, by M.C. Nandeesha. [Farmers as Scientists series] Extension in shrimp health management: experiences from an MPEDA/NACA program in Andhra Pradesh, India, by PA Padiyar, MJ Phillips, M Primphon, CV Mohan, BV Bhat, VS Rao, G Ravi Babu, ABCh Mohan, GN Murthy and P Chanratchakool. The status and treatment of serious diseases of freshwater prawns and crabs in China, by Yang Xianle and Huang Yanping. Guidelines for improvement of water quality and volume in shrimp farm (แนวทางในการปรับปรุงคุณภาพ และปริมาณน้ำในฟาร์มกุ้ง), by Pornlerd Chanratchakool. Improvement of larval rearing technique for Humpback grouper, Cromileptes altivelis, by Ketut Sugama, Suko Ismi, Shogo. Kawahara and Mike Rimme

Aquaculture Asia, Vol.14, No.1, pp.1-51, January-March 2009

Peter Edwards writes on rural aquaculture: Myanmar revisited. Harvesting, traditional preservation and marketing of fishes of Chalan Beel, Bangladesh, by Galib, S.M. and Samad, M.A. Role of community in production and supply of larger, quality fingerlings, by Radheyshyam, De, H.K. and Saha, G.S. Can rice-fish farming provide food security in Bangladesh? by Ahmed, N. and Luong-Van, J. Nutritional and food security for rural poor through multi-commodity production from a lake of eastern Uttar Pradesh, by Singh, S.K. Emerging boost in Sri Lankan reservoir fish production: a case of adoption of past research findings, by Amarasinghe, U.S., Weerakoon, D.E.M., Athukorala, D.A. Farming the freshwater prawn Macrobrachium malcolmsonii, by Radheyshyam Breeding and seed production of butter catfish, Ompok pabda (Siluridae) at Kalyani Centre of CIFA, India, by Chakrabarti, P.P., Chakrabarty, N.M. and Mondal, S.C. Asia-Pacific Marine Finfish Aquaculture Magazine Use of fish in animal feeds: a fresh perspective National strategies for aquatic animal health management, by Mohan, C.V. NACA Newsletter

How to Influence People with Partial Incentives

We study the power of fractional allocations of resources to maximize influence in a network. This work extends in a natural way the well-studied model by Kempe, Kleinberg, and Tardos (2003), where a designer selects a (small) seed set of nodes in a social network to influence directly, this influence cascades when other nodes reach certain thresholds of neighbor influence, and the goal is to maximize the final number of influenced nodes. Despite extensive study from both practical and theoretical viewpoints, this model limits the designer to a binary choice for each node, with no way to apply intermediate levels of influence. This model captures some settings precisely, e.g. exposure to an idea or pathogen, but it fails to capture very relevant concerns in others, for example, a manufacturer promoting a new product by distributing five "20% off" coupons instead of giving away one free product. While fractional versions of problems tend to be easier to solve than integral versions, for influence maximization, we show that the two versions have essentially the same computational complexity. On the other hand, the two versions can have vastly different solutions: the added flexibility of fractional allocation can lead to significantly improved influence. Our main theoretical contribution is to show how to adapt the major positive results from the integral case to the fractional case. Specifically, Mossel and Roch (2006) used the submodularity of influence to obtain their integral results; we introduce a new notion of continuous submodularity, and use this to obtain matching fractional results. We conclude that we can achieve the same greedy $(1-1/e-\epsilon)$-approximation for the fractional case as the integral case. In practice, we find that the fractional model performs substantially better than the integral model, according to simulations on real-world social network data

An analysis of UK Policing Engagement via Social Media

Police forces in the UK make use of social media to communicate and engage with the public. However, while guidance reports claim that social media can enhance the accessibility of policing organisations, research studies have shown that exchanges between the citizens and the police tend to be infrequent. Social media usually act as an extra channel for delivering messages, but not as a mean for enabling a deeper engagement with the public. This has led to a phenomena where police officers and staff started to use social media in a personal capacity in the aim of getting closer to the public. In this paper, we aim to understand what attracts citizens to engage with social media policing content, from corporate as well as from non-corporate accounts. Our approach combines learnings from existing theories and studies on user engagement as well as from the analysis of 1.5 Million posts from 48 corporate and 2,450 non-corporate Twitter police accounts. Our results provide police-specific guidelines on how to improve communication to increase public engagement and participation

A snapshot on crowdfunding

This article addresses crowdfunding, a relatively new form of informal financing of pro-jects and ventures. It describes its principle characteristics and the range of players in this market. The different business models of crowdfunding intermediaries are explored and illustrated. A first attempt is made to classify the different forms of funding and business models of crowdfunding intermediaries. Based on the available empirical data the paper discusses the economic relevance of crowdfunding and its applicability to start-up financing and funding creative ventures and research projects. --