A new mechanism for distributed managers persistence

SNMP is currently a worldwide used network management framework. However, it only describes the structure of management information and how to access it, i.e., low-level operations, presenting no considerations about information interpretation or other highlevel tasks. Recent work in this area has managed to define several modules suitable for management distribution (DISMAN), which implies building agents that can cope with rather complex information structures. In the case of information loss, for example due to an agent reset, it is not practicable to force the management station to define and configure the information once again. In this paper we present an XML based data model that can provide a structure for distributed managers persistency. Moreover, it can be used to define macros to group together elementary SNMP operations and to describe what should a mobile agent do when meeting some SNMP agent

Mutual Fund Flows and Performance in Rational Markets

We develop a simple rational model of active portfolio management that provides a natural benchmark against which to evaluate observed relationship between returns and fund flows. We show that many effects widely regarded as anomalous are consistent with this simple explanation. In the model, investments with active managers do not outperform passive benchmarks because of the competitive market for capital provision, combined with decreasing returns to scale in active portfolio management. Consequently, past performance cannot be used to predict future returns, or to infer the average skill level of active managers. The lack of persistence in active manager returns does not imply that differential ability across managers is nonexistent or unrewarded, that gathering information about performance is socially wasteful, or that chasing performance is pointless. A strong relationship between past performance and the ow of funds exists in our model, indeed this is the market mechanism that ensures that no predictability in performance exists. Calibrating the model to the fund flows and survivorship rates, we nd these features of the data are consistent with the vast majority (80%) of active managers having at least enough skill to make back their fees.

On consistency maintenance in service discovery

Communication and node failures degrade the ability of a service discovery protocol to ensure Users receive the correct service information when the service changes. We propose that service discovery protocols employ a set of recovery techniques to recover from failures and regain consistency. We use simulations to show that the type of recovery technique a protocol uses significantly impacts the performance. We benchmark the performance of our own service discovery protocol, FRODO against the performance of first generation service discovery protocols, Jini and UPnP during increasing communication and node failures. The results show that FRODO has the best overall consistency maintenance performance

H2O: An Autonomic, Resource-Aware Distributed Database System

This paper presents the design of an autonomic, resource-aware distributed database which enables data to be backed up and shared without complex manual administration. The database, H2O, is designed to make use of unused resources on workstation machines. Creating and maintaining highly-available, replicated database systems can be difficult for untrained users, and costly for IT departments. H2O reduces the need for manual administration by autonomically replicating data and load-balancing across machines in an enterprise. Provisioning hardware to run a database system can be unnecessarily costly as most organizations already possess large quantities of idle resources in workstation machines. H2O is designed to utilize this unused capacity by using resource availability information to place data and plan queries over workstation machines that are already being used for other tasks. This paper discusses the requirements for such a system and presents the design and implementation of H2O.Comment: Presented at SICSA PhD Conference 2010 (http://www.sicsaconf.org/

ElasTraS: An Elastic Transactional Data Store in the Cloud

Over the last couple of years, "Cloud Computing" or "Elastic Computing" has emerged as a compelling and successful paradigm for internet scale computing. One of the major contributing factors to this success is the elasticity of resources. In spite of the elasticity provided by the infrastructure and the scalable design of the applications, the elephant (or the underlying database), which drives most of these web-based applications, is not very elastic and scalable, and hence limits scalability. In this paper, we propose ElasTraS which addresses this issue of scalability and elasticity of the data store in a cloud computing environment to leverage from the elastic nature of the underlying infrastructure, while providing scalable transactional data access. This paper aims at providing the design of a system in progress, highlighting the major design choices, analyzing the different guarantees provided by the system, and identifying several important challenges for the research community striving for computing in the cloud.Comment: 5 Pages, In Proc. of USENIX HotCloud 200

Why does mutual fund performance not persist? The impact and interaction of fund flows and manager changes

This paper investigates the reasons for the lack of long-term persistence in the investment performance of actively managed equity mutual funds. We document that the responses of investors, fund managers, and investment management companies to past performance have an important impact on future performance. Conditioning on fund flows and manager changes allows us to predict future performance of both past outperforming (winner) and past underperforming (loser) funds. Recent winner funds, experiencing neither high inflows nor the departure of a skilled fund manager, outperform by 3.60 percentage points based on risk-adjusted returns in the following year, relative to winner funds suffering from both effects. We also find that the performance of the worst performing funds experiencing both the replacement of the fund manager (internal governance) and high outflows (external governance) enjoy a subsequent increase in performance of 2.40 percentage points in the following year, relative to loser funds not experiencing these effects. Among loser funds, in particular, both mechanisms appear to interact strongly.Mutual Funds; Performance Persistence; Fund Flows; Manager Turnover

Management Compensation and the Performance of Mutual Funds

This paper examines the mutual fund market as a market for the sale of management services using an unbalanced panel of 860 US equity funds over the 1976-1993 period. From among the performance measures for which investors have the necessary information to compute, we find that the Jensen measure best explains the change in market shares over time. It is found, however, that investors actually value the systematic component of risk more than indicated by the use of Jensen's performance measure. Our results also suggest that investors in load funds are less responsive to both components of performance (risk and return) than are investors in no-load funds. Investors, moreover, value recent past performance differently for funds with different attributes. An important result of the paper relating to the incentives provided with the widely used fixed-fee compensation schemes is that past fund performance influences individual investment decisions and hence future net asset values of funds, implying strong incentives for managers to increase their performance and by doing so, their compensation.

Investor Behavior in the Mutual Fund Industry: Evidence from Gross Flows

Using a large sample of monthly gross flows from 1997 to 2003, we uncover several previously undocumented regularities in investor behavior. First, investor purchases and sales produce fund-level gross flows that are highly persistent. Persistence in fund flows dominates performance as a predictor of future fund flows. More importantly, failing to account for flow persistence leads to incorrect inferences with respect to the relation between performance and flows. Second, we document that investors react differently to performance depending on the type of fund, and that investor trading activity produces meaningful differences in the persistence of fund flows across mutual fund types. Third, at least some investors appear to evaluate and respond to mutual fund performance over much shorter time spans than previously assessed. Additionally, we document differences in the speed and magnitude of investors’ purchase and sales responses to performance

OpenPING: A Reflective Middleware for the Construction of Adaptive Networked Game Applications

The emergence of distributed Virtual Reality (VR) applications that run over the Internet has presented networked game application designers with new challenges. In an environment where the public internet streams multimedia data and is constantly under pressure to deliver over widely heterogeneous user-platforms, there has been a growing need that distributed VR applications be aware of and adapt to frequent variations in their context of execution. In this paper, we argue that in contrast to research efforts targeted at improvement of scalability, persistence and responsiveness capabilities, much less attempts have been aimed at addressing the flexibility, maintainability and extensibility requirements in contemporary distributed VR platforms. We propose the use of structural reflection as an approach that not only addresses these requirements but also offers added value in the form of providing a framework for scalability, persistence and responsiveness that is itself flexible, maintainable and extensible. We also present an adaptive middleware platform implementation called OpenPING1 that supports our proposal in addressing these requirements