Hierarchical Coding for Distributed Computing

Coding for distributed computing supports low-latency computation by relieving the burden of straggling workers. While most existing works assume a simple master-worker model, we consider a hierarchical computational structure consisting of groups of workers, motivated by the need to reflect the architectures of real-world distributed computing systems. In this work, we propose a hierarchical coding scheme for this model, as well as analyze its decoding cost and expected computation time. Specifically, we first provide upper and lower bounds on the expected computing time of the proposed scheme. We also show that our scheme enables efficient parallel decoding, thus reducing decoding costs by orders of magnitude over non-hierarchical schemes. When considering both decoding cost and computing time, the proposed hierarchical coding is shown to outperform existing schemes in many practical scenarios.Comment: 7 pages, part of the paper is submitted to ISIT201

Toward Optimal Financial Reward Allocation for Promoting Knowledge Sharing Activity in CoPs

The purpose of this study is to introduce CoP reward allocation (COREA) system that efficiently solves a mathematical optimization problem to optimally allocate limited financial reward and to promote knowledge sharing activities in CoPs. To test the validity and usefulness of COREA, we simulate three knowledge sharing climates in which the majority of CoPs performs below-, on-, or above-average. In addition, we also allow knowledge sharing activity of CoPs to improve or deteriorate over years in each climate. Our experimental results confirm that the proposed COREA system performs significantly better than the currently available reward system over various scenarios. In particular, the COREA system finds approximately optimal financial reward allocations for many cases in which the current reward system fails to find solutions that meet constraints

Health Diagnosis of Communities of Practices (CoPs)

The purpose of this study is to provide a multi-level framework to diagnose the structural healthiness of CoPs and present a new metric, Bottleneck Impact Score (BIS), to measure the seriousness of bottlenecks in knowledge sharing activities among CoPs members. After analyzing knowledge sharing activities of 4,414 members from 59 CoPs, we confirm that while only a small number of CoP members actively engage in both transferring and receiving knowledge, most experts are not core players and they are reluctant to share their knowledge with others. We also find that only few CoPs can be classified as knowledge “sharing” community while most of CoPs suffer from inactive participation of employees with high expertise and are diagnosed as having at least one of master-apprenticeship and knowledge drain bottlenecks. Interestingly, we also find that CoPs members in field division such as Iron&Steel, Rolling, and Maintenance department more actively participate in knowledge sharing than CoPs members in Staff department. Finally, BISs are used to measure and compare the seriousness of six different types of bottlenecks in CoPs and departments

Vip-Focused Crm Strategies In An Open-Market

Nowadays, an open-market which provides sellers and consumers a cyber place for making a transaction over the Internet has emerged as a prevalent sales channel because of convenience and relatively low price it provides. However, there are few studies about CRM strategies based on VIP consumers for an open-market even though understanding VIP consumers’ behaviours in an open-market is absolutely important to increase its revenue. Therefore, we propose CRM strategies focused on VIP customers, obtained by analyzing the transaction data of VIP customers from an open-market using data mining techniques. To that end, we first defined the VIP customers in terms of recency, frequency and monetary (RFM) values. Then, we used data mining techniques to develop a model which best classifies customers into VIPs or non-VIPs. We also validate each of promotion types in the aspect of effectiveness to VIP customers and identify association rules among the types from the transactions of VIP customers. Then, based on the findings from these experiments, we propose strategies from the perspectives of CRM dimensions such as customer identification, attraction, retention and development for the open-market to thrive

Clinical characteristics of 2009 pandemic influenza A (H1N1) infection in children and the performance of rapid antigen test

PurposeIn autumn 2009, the swine-origin influenza A (H1N1) virus spread throughout South Korea. The aims of this study were to determine the clinical characteristics of children infected by the 2009 H1N1 influenza A virus, and to compare the rapid antigen and real-time polymerase chain reaction (PCR) tests.MethodsWe conducted a retrospective review of patients ≥18 years of age who presented to Soonchunhyang University Hospital in Seoul with respiratory symptoms, including fever, between September 2009 and January 2010. A real-time PCR test was used to definitively diagnose 2009 H1N1 influenza A infection. Medical records of confirmed cases were reviewed for sex, age, and the time of infection. The decision to perform rapid antigen testing was not influenced by clinical conditions, but by individual factors such as economic conditions. Its sensitivity and specificity were evaluated compared to real-time PCR test results.ResultsIn total, 934 patients tested positive for H1N1 by real-time PCR. The highest number of patients (48.9%) was diagnosed in November. Most patients (48.2%) were aged between 6 and 10 years. Compared with the H1N1 real-time PCR test results, the rapid antigen test showed 22% sensitivity and 83% specificity. Seventy-eight patients were hospitalized for H1N1 influenza A virus infection, and fever was the most common symptom (97.4%).ConclusionFor diagnosis of 2009 H1N1 influenza A virus infection, the rapid antigen test was inferior to the real-time PCR test in both sensitivity and specificity. This outcome suggests that the rapid antigen test is inappropriate for screening