Asynchronous Announcements

We propose a multi-agent epistemic logic of asynchronous announcements, where truthful announcements are publicly sent but individually received by agents, and in the order in which they were sent. Additional to epistemic modalities the logic contains dynamic modalities for making announcements and for receiving them. What an agent believes is a function of her initial uncertainty and of the announcements she has received. Beliefs need not be truthful, because announcements already made may not yet have been received. As announcements are true when sent, certain message sequences can be ruled out, just like inconsistent cuts in distributed computing. We provide a complete axiomatization for this \emph{asynchronous announcement logic} (AA). It is a reduction system that also demonstrates that any formula in $AA$ is equivalent to one without dynamic modalities, just as for public announcement logic. The model checking complexity is in PSPACE. A detailed example modelling message exchanging processes in distributed computing in $AA$ closes our investigation

Asynchronously Replicated Shared Workspaces for a Multi-Media Annotation Service over Internet

This paper describes a world wide collaboration system through multimedia Post-its (user generated annotations). DIANE is a service to create multimedia annotations to every application output on the computer, as well as to existing multimedia annotations. Users collaborate by registering multimedia documents and user generated annotation in shared workspaces. However, DIANE only allows effective participation in a shared workspace over a high performance network (ATM, fast Ethernet) since it deals with large multimedia object. When only slow or unreliable connections are available between a DIANE terminal and server, useful work becomes impossible. To overcome these restrictions we need to replicate DIANE servers so that users do not suffer degradation in the quality of service. We use the asynchronous replication service ODIN to replicate the shared workspaces to every interested site in a transparent way to users. ODIN provides a cost-effective object replication by building a dynamic virtual network over Internet. The topology of this virtual network optimizes the use of network resources while it satisfies the changing requirements of the users

Direct deliberative local governance using online media – consensual problem solving or a recalcitrant pluralism?

This paper describes and analyses distinct patterns of 'governance conversation' observed in interactions on a discussion list that aims to support local, direct, governance in a geographically colocated community in South Africa. Although each pattern relates to governance, making 'binding decisions', which has been seen as a key attribute of deliberative democratic processes, is almost entirely absent from the observed interactions. Nonetheless, the exchanges appear to be relevant and useful to the broader process of local direct deliberative governance. We investigate the extent to which the patterns feature instrumental or expressive dialogue, and subsequently support consensual or pluralist outcomes. The results propose that online interaction is particularly suited to facilitating the pluralist deliberation required to manage complex local governance problems. The outcomes observed in the case study further suggest the potential value of an infrequently investigated context of online deliberation – that of citizen-to-citizen deliberation of geographically local issues; and presents a broader conception of the role of online deliberation in local governance, where formal decision making is frequently over privileged in research

Cognitive and Social Help Giving in Online Teaching: An Exploratory Study

While literature suggests that college students may be less reluctant to seek help in online rather than traditional courses, little is known about how online instructors give help in ways that lead to increased student help seeking and academic success. In this study, we used theories and research on learning assistance and scaffolding, teacher immediacy, social presence, and academic help seeking to explore through a cross-case study design how three online instructors differed in their use of cognitive and social supports and how those differences related to student perceptions of support, help seeking, and performance. Primary data sources included all course postings by the instructors, interviews with the instructors, observational field notes on course discussions, student interviews, and final student grades. Archived course documents and student discussion postings were secondary data sources. Data analysis revealed that while all instructors provided cognitive and social support, they varied in their level of questioning, use of direct instruction, support for task structuring, and attention to group dynamics. This variation in teaching presence related to differences across the courses in student perceptions of support, student help seeking in course discussions, and final course grades. Implications for online teaching and suggestions for further research are offered

K-Trek: A Peer-to-Peer Approach To Distribute Knowledge In Large Environments

In this paper, we explore an architecture, called K-Trek, that enables mobile users to travel across knowledge distributed over a large geographical area (ranging from large public buildings to a national park). Our aim is providing, dis-tributing, and enriching the environment with location-sensitive information for use by agents on board of mobile and static devices. Local interactions among K-Trek devices and the distribution of information in the larger environment adopt some typical peer-to-peer patterns and techniques. We introduce the architecture, discuss some of its potential knowledge management applications, and present a few experimental results obtained with simulation

Applications of computer communications in education.

Applications of computer communications can be used in many ways in education. An overview is given of a number of categories of computer communications applications in learning-related activities. Particular attention is given to a new type of system called a course-support environment. In this type of system a database is integrated with Web-based tools and applications, and used to generate a course-support environment accessed via a standard Web browser. Some examples are given. The article moves on to an overview of various issues confronting the acceptance of computer communication systems in educational settings, and indicates some of the ways in which computer communications engineers will have to deal with those issue

The Indian exchange rate and central bank action: A GARCH analysis

We study, with daily and monthly data sets, the impact of conventional monetary policy measures such as interest rates, intervention and other quantitative measures, and of Central Bank communication on exchange rate volatility. Since India has a managed float, we also test if the measures affect the level of the exchange rate. Using dummy variables in the best of an estimated family of GARCH models, we find forex market intervention to be the most effective of all the CB instruments evaluated for the period of analysis. We also find that CB communication has a large potential but was not effectively used.exchange rate volatility, monetary policy, intervention, communication, GARCH

On Conditional Cryptocurrency With Privacy

In this paper, we present the design and imple-mentation of a conditional cryptocurrency system with privacy protection. Unlike the existing approaches that often depend on smart contracts where cryptocurrencies are first locked in a vault, and then released according to event triggers, the conditional cryptocurrency system encodes event outcome as part of a cryptocurrency note in a UTXO based system. Without relying on any triggering mechanism, the proposed system separates event processing from conditional coin transaction processing where conditional cryptocurrency notes can be transferred freely in an asynchronous manner, only with their asset values conditional to the linked event outcomes. The main advantage of such design is that it enables free trade of conditional assets and prevents assets from being locked. In this work, we demonstrate a method of confidential conditional coin by extending the Zerocoin data model and protocol. The system is implemented and evaluated using xJsnark

The Indian Exchange Rate and Central Bank Action : A GARCH Analysis

We study, with daily and monthly data sets, the impact of conventional monetary policy measures such as interest rates, intervention and other quantitative measures, and of Central Bank communication on exchange rate volatility. Since India has a managed float, we also test if the measures affect the level of the exchange rate. Using dummy variables in the best of an estimated family of GARCH models, we find forex market intervention to be the most effective of all the CB instruments evaluated for the period of analysis. We also find that CB communication has a large potential but was not effectively used.exchange rate volatility, monetary policy, intervention, communication, GARCH