A Message Service for Opportunistic Computing in Disconnected MANETs

International audienceDisconnected mobile ad hoc networks (or D-MANETs) are partially or intermittently connected wireless networks in which instant end-to-end connectivity between any pair of mobile hosts is never guaranteed. Recent advances in delay/disruption-tolerant networking make it possible to support communication in such conditions, but designing and implementing distributed applications for D-MANETs is still a challenging task. Middleware systems such as the Java Message Service (JMS) have made application development easy and cost-effective in traditional wired networks. In this paper, we introduce JOMS (Java Opportunistic Message Service), a JMS provider specifically designed for D-MANETs, and with which pre-existing or new JMS-based applications can be easily deployed in such networks

JOMS: a Java Message Service Provider for Disconnected MANETs

International audienceA disconnected mobile ad hoc network (or D-MANET) is a wireless network, which because of the sparse distribution of mobile hosts appears at best as a partially or intermittently connected network. Designing and implementing distributed applications capable of running in such a challenged environment is not a trivial task. Middleware systems such as Java Message Service (JMS) have made application development easy and cost-effective in traditional wired networks. It can be expected that middleware systems designed specifically for D-MANETs bring similar benefits. In this paper, we introduce JOMS (Java Opportunistic Message Service), a JMS provider for D-MANETs with which pre-existing and new JMS-based applications can be deployed simply in D-MANETs

Scaling up antiretroviral therapy in Uganda: using supply chain management to appraise health systems strengthening

BACKGROUND: Strengthened national health systems are necessary for effective and sustained expansion of antiretroviral therapy (ART). ART and its supply chain management in Uganda are largely based on parallel and externally supported efforts. The question arises whether systems are being strengthened to sustain access to ART. This study applies systems thinking to assess supply chain management, the role of external support and whether investments create the needed synergies to strengthen health systems. METHODS: This study uses the WHO health systems framework and examines the issues of governance, financing, information, human resources and service delivery in relation to supply chain management of medicines and the technologies. It looks at links and causal chains between supply chain management for ART and the national supply system for essential drugs. It combines data from the literature and key informant interviews with observations at health service delivery level in a study district. RESULTS: Current drug supply chain management in Uganda is characterized by parallel processes and information systems that result in poor quality and inefficiencies. Less than expected health system performance, stock outs and other shortages affect ART and primary care in general. Poor performance of supply chain management is amplified by weak conditions at all levels of the health system, including the areas of financing, governance, human resources and information. Governance issues include the lack to follow up initial policy intentions and a focus on narrow, short-term approaches. CONCLUSION: The opportunity and need to use ART investments for an essential supply chain management and strengthened health system has not been exploited. By applying a systems perspective this work indicates the seriousness of missing system prerequisites. The findings suggest that root causes and capacities across the system have to be addressed synergistically to enable systems that can match and accommodate investments in disease-specific interventions. The multiplicity and complexity of existing challenges require a long-term and systems perspective essentially in contrast to the current short term and program-specific nature of external assistanc

Clarifying Resource Dependence: A Multi-Dimensional Approach to Dependence and Autonomy in Entrepreneurial Firms

Entrepreneurial firms face dependence on other firms in the external environment to access resources critical for the development and survival of the firm. While substantial research has examined resource dependence and how firms may remedy such dependencies, the literature often fails to acknowledge key factors that can predict and explain firm behavior and outcomes in such situations. Firms are shown to enter into inter-organizational relationships in order to remedy resource dependencies, but studies typically evaluate such relationships according to their structure, rather than the resource being sought. Research also frequently ignores the role of autonomy in resource dependence. As gaining autonomy is the primary goal of resource dependence remedies, studies thus often assume autonomy is gained or may fail to consider the social complexity of the environment. Resource dependence remedies are also shown to vary in terms of their relationship to performance, creating additional questions within the literature. This dissertation seeks to shed light on these issues by considering the type of resource sought during a dependence remedy, the role of autonomy in dependence remedies, and how remedies relate to firm performance

Theoretical foundations of equity based foreign market entry decisions: a review of the literature and recommendations for future research

This paper reviews the theoretical foundations of the equity based foreign market entry (FME) decisions literature. We analyse 1055 academic FME papers published over four decades (1970–2013). We identify and analyse the theories that informed and guided FME research over time. Our review indicates that scholars have recently started to challenge some of the core assumptions of established theories, draw on and integrate insights from multiple theoretical perspectives which, in turn, generated a multiplicity of approaches for studying FME decisions and their performance outcomes. The paper discusses the explanatory power of the different theories, assesses the relevance of the different theoretical perspectives to our understanding of current FME phenomena and recommends directions for further research

The Role of Socio-Demographic Factors in the Coverage of Breast Cancer Screening:Insights From a Quantile Regression Analysis

Background: In Flanders, breast cancer (BC) screening is performed in a population-based breast cancer screening program (BCSP), as well as in an opportunistic setting. Women with different socio-demographic characteristics are not equally covered by BC screening. Objective: To evaluate the role of socio-demographic characteristics on the lowest 10th and highest 90th quantile levels of BC screening coverage. Methods: The 2017 neighborhood-level coverage rates of 8,690 neighborhoods with women aged 50-69 and eligible for BCSP and opportunistic screening were linked to socio-demographic data. The association between socio-demographic characteristics and the coverage rates of BCSP and opportunistic screening was evaluated per quantile of coverage using multivariable quantile regression models, with specific attention to the lowest 10th and highest 90th quantiles. Results: The median coverage in the BCSP was 50%, 33.5% in the 10th quantile, and 64.5% in the 90th quantile. The median coverage of the opportunistic screening was 12, 4.2, and 24.8% in the 10th and 90th quantile, respectively. A lower coverage of BCSP was found in neighborhoods with more foreign residents and larger average household size, which were considered indicators for a lower socioeconomic status (SES). However, a higher average personal annual income, which was considered an indicator for a higher SES, was also found in neighborhoods with lower coverage of BCSP. For these neighborhoods, that have a relatively low and high SES, the negative association between the percentage of foreign residents, average household size, and average personal annual income and the coverage in the BCSP had the smallest regression coefficient and 95% confidence interval (CI) values were -0.75 (95% CI: -0.85, -0.65), -13.59 (95% CI: -15.81, -11.37), and -1.05 (95% CI: -1.18, -0.92), respectively, for the 10th quantile. The neighborhoods with higher coverage of opportunistic screening had a relatively higher average personal annual income, with the largest regression coefficient of 1.72 (95% CI: 1.59, 1.85) for the 90th quantile. Conclusions: Women from relatively low and high SES neighborhoods tend to participate less in the BCSP, whereas women with a relatively high SES tend to participate more in opportunistic screening. For women from low SES neighborhoods, tailored interventions are needed to improve the coverage of BCSP

Universal Mobile Service Execution Framework for Device-To-Device Collaborations

There are high demands of effective and high-performance of collaborations between mobile devices in the places where traditional Internet connections are unavailable, unreliable, or significantly overburdened, such as on a battlefield, disaster zones, isolated rural areas, or crowded public venues. To enable collaboration among the devices in opportunistic networks, code offloading and Remote Method Invocation are the two major mechanisms to ensure code portions of applications are successfully transmitted to and executed on the remote platforms. Although these domains are highly enjoyed in research for a decade, the limitations of multi-device connectivity, system error handling or cross platform compatibility prohibit these technologies from being broadly applied in the mobile industry. To address the above problems, we designed and developed UMSEF - an Universal Mobile Service Execution Framework, which is an innovative and radical approach for mobile computing in opportunistic networks. Our solution is built as a component-based mobile middleware architecture that is flexible and adaptive with multiple network topologies, tolerant for network errors and compatible for multiple platforms. We provided an effective algorithm to estimate the resource availability of a device for higher performance and energy consumption and a novel platform for mobile remote method invocation based on declarative annotations over multi-group device networks. The experiments in reality exposes our approach not only achieve the better performance and energy consumption, but can be extended to large-scaled ubiquitous or IoT systems

Moving Targets: Geographically Routed Human Movement Networks

We introduce a new communication paradigm, Human-to-human Mobile Ad hoc Networking (HuManet), that exploits smartphone capabilities and human behavior to create decentralized networks for smartphone-to-smartphone message delivery. HuManets support stealth command-and-control messaging for mobile BotNets, covert channels in the presence of an observer who monitors all cellular communication, and distributed protocols for querying the state or content of targeted mobile devices. In this paper, we introduce techniques for constructing HumaNets and describe protocols for efficiently routing and addressing messages. In contrast to flooding or broadcast schemes that saturate the network and aggressively consume phone resources (e.g., batteries), our protocols exploit human mobility patterns to significantly increase communication efficiency while limiting the exposure of HuManets to mobile service providers. Our techniques leverage properties of smartphones – in particular, their highly synchronized clocks and ability to discern location information – to construct location profiles for each device. HuManets’ fully-distributed and heuristic-based routing protocols route messages towards phones with location profiles that are similar to those of the intended receiver, enabling efficient message delivery with limited effects to end-to-end latency

Board Committees in Corporate Governance: A Cross‐Disciplinary Review and Agenda for the Future

The importance of board committees – specialized subgroups that exist to perform many of the board\u27s most critical functions, such as setting executive compensation, identifying potential board members, and overseeing financial reporting – has grown over time due to increased legal requirements and greater complexity of the environment in which firms operate. This has resulted in a large body of work examining board committees across the accounting, finance, and management disciplines. However, this research has developed rather independently within each discipline, preventing scholars and practitioners from developing a comprehensive understanding of board committees. To address this issue, we conduct a comprehensive review of the literature that: 1) summarizes and synthesizes antecedents and outcomes associated with board committees in publicly‐traded firms in English common law countries; and 2) offers a critical analysis of existing research, providing recommendations for advancements and new directions in board committee research