Computer Science Journal (AGH University of Science and Technology, Krakow)
Not a member yet
476 research outputs found
Sort by
USING TAGS IN AN AIML-BASED CHATTERBOT TO IMPROVE ITS KNOWLEDGE
Get PDFNowadays, it is common to find on the Internet different conversational robots which interact with users simulating a natural language conversation. Among them, we can emphasize the chatterbots based on AIML language. In this paper we present an AIML based chatterbot that shows as its main contribution the use of tags and folksonomies. Thanks to its use, we can generate a context for each conversation, being able to maintain a state for each user in the system, and improving the adaptation capabilities of the bot
A TOOLKIT FOR STORAGE QOS PROVISIONING FOR DATA-INTENSIVE APPLICATIONS
Get PDFThis paper describes a programming toolkit developed in the PL-Grid project, named QStorMan, which supports storage QoS provisioning for data-intensive applications in distributed environments. QStorMan exploits knowledge-oriented methods for matching storage resources to non-functional requirements, which are defined for a data-intensive application. In order to support various usage scenarios, QStorMan provides two interfaces, such as programming libraries or a web portal. The interfaces allow to define the requirements either directly in an application source code or by using an intuitive graphical interface. The first way provides finer granularity, e.g., each portion of data processed by an application can define a different set of requirements. The second method is aimed at legacy applications support, which source code can not be modified. The toolkit has been evaluated using synthetic benchmarks and the production infrastructure of PL-Grid, in particular its storage infrastructure, which utilizes the Lustre file system
SLA-BASED JOB SUBMISSION AND SCHEDULING WITH THE GLOBUS TOOLKIT 4
Get PDFHigh performance computing is nowadays mostly performed in a best effortfashion. This is surprising as the closely related topic of grid computing, whichdeals with the federation of resources from multiple domains in order to supportlarge jobs, and cloud computing, which promises seemingly infinite amounts ofcompute and storage, both offer quality of service (QoS), albeit in different ways.Long-term service level agreements (SLAs), which require the establishment ofSLAs long in advance of their actual usage, seem a promising way for the offeringof QoS guarantees in an HPC environment in a way that is not disruptive to thebusiness models employed today. This work uses the long-term SLA approachas a basis for the provisioning of service levels for HPC resources and presentsan SLA management framework to support this. Flexibility is provided byproviding SLAs with different service levels, support for which is integratedinto job submission and scheduling. The SLA management framework can, ona high level, be used in a generic fashion and an implementation is presentedthat is evaluated against a motivating scenario
ENRICHING WSN ENVIRONMENT WITH CONTEXT INFORMATION
Get PDFCurrently the Internet of Things environment suffer from a variety of uniqueproblems such as low throughput, inadequate support for mobility and notcompatible(and often close) application environments. However, characteristicof physical environment often provides opportunities to address these problems.This paper explores concepts of enriching the WNS environment withcontext-based information. By context we consider all data available in sensorsenvironment, not only data processed by them. Currently this data are not utilizedby sensors, but we think that they can improve overall functionality of thesensor network. We also discuss the practical challenges facing the integrationof such an approach into the sensor application stack
ERLANG-BASED SENSOR NETWORK MANAGEMENT FOR HETEROGENEOUS DEVICES
Get PDFThe paper describes a system designed to manage and collect data from the network of heterogeneous sensors. It was implemented using Erlang OTP and CouchDB for maximum fault tolerance, scalability and ease of deployment. It is resistant to poor network quality, shows high tolerance for software errors and power failures, operates on flexible data model. Additionally, it is available to users through an Web application, which shows just how easy it is to use the server HTTP API to communicate with it. The whole platform was implemented and tested on variety of devices like PC, Mac, ARM-based embedded devices and Android tablets
A STUDY ON THE ROLE OF NON-HYPERLINK TEXT ON WEB NAVIGATION
Get PDFCognitive models of web navigation have been used for evaluating websitesand predicting user navigation behavior. Currently they predict the correcthyperlink by using information from the hyperlink text alone and ignore allother textual information on a webpage. The validity of this assumption isexamined by investigating the role of non-hyperlink text on user navigationbehavior. In the first experiment, we created two versions of a website byremoving the non-hyperlink text from it. We found that there was no significanteffect of non-hyperlink text on the user navigation behavior. Participants wereequally accurate, selected the same set of pages to visit and spent the sameamount of time on that common set with or without non-hyperlink text. Thisresult validates the assumptions of those models of user-navigation behaviorthat consider information from the hyperlink text only. However, in a followupexperiment, we included high-relevance and low-relevance pictures on thewebsite, and repeated the experiment with and without non-hyperlink text.We found that participants were more accurate in the presence of non-hyperlinktext than without it. This result suggests that the presence of pictures mightprime the users to pay attention to non-hyperlink text, which increases the taskaccuracy
AUTOMATIC PROXY GENERATION AND LOAD-BALANCING-BASED DYNAMIC CHOICE OF SERVICES
Get PDFThe paper addresses the issues of invoking services from within workflows which are becoming an increasingly popular paradigm of distributed programming. The main idea of our research is to develop a facility which enables load balancing between the available services and their instances. The system consists of three main modules: a proxy generator for a specific service according to its interface type, a proxy that redirects requests to a concrete instance of the service and load-balancer (LB) to choose the least loaded virtual machine (VM) which hosts a single service instance. The proxy generator was implemented as a bean (in compliance to EJB standard) which generates proxy according to the WSDL service interface description using XSLT engine and then deploys it on a GlassFish application server using GlassFish API, the proxy is a BPEL module and load-balancer is a stateful Web Service
Dataspace Support Platform for e-Science
Get PDFThis work intends to provide a data management solution based on the concepts of dataspaces for the large-scale and long-term management of scientific data. Our approach is to semantically enrich the existing relationship among primary and derived data items, and to preserve both relationships and data together within a dataspace to be reused by owners and others. To enable reuse, data must be well preserved. Preservation of scientific data can best be established if the full life cycle of data is addressed. This is challenged by the e-Science life cycle ontology, whose major goal is to trace the semantics about procedures in scientific experiments. We present a theoretical dataspace model for e-Science applications, its implementation within a dataspace support platform and an experimental evaluation on top of two real world application domains
ASSESSMENT OF RISKS INTRODUCED TO SAFETY CRITICAL SOFTWARE BY AGILE PRACTICES — A SOFTWARE ENGINEER’S PERSPECTIVE
Get PDFIn this article we investigate the problem of applying agile practices into safetycriticalprojects. The goal of our research is to investigate potential benefitsfrom introducing agile practices into safety-critical environment and to present asolution providing for balancing agile approach with more disciplined assurancetechniques, bringing the best of the two worlds together. In this article wepresent the supporting ideas such as assurance argument patterns along witha case study. The case study investigates how software engineers perceive risksassociated with the introduction of agile practices and collect their ideas on howthese risks could be mitigated
LAZY SHORTEST PATH COMPUTATION IN DYNAMIC GRAPHS
Get PDFoai:ojs.journals.agh.edu.pl:article/4We address the problem of single-source shortest path computation in digraphs with non-negative edge weights subjected to frequent edge weight decreases such that only some shortest paths are requested in-between updates. We optimise a recent semidynamic algorithm for weight decreases previously reported to be the fastest one in various conditions, resulting in important time savings that we demonstrate for the problem of incremental path map construction in usersteered image segmentation. Moreover, we extend the idea of lazy shortest path computation to digraphs subjected to both edge weight increases and decreases, comparing favourably to the fastest recent state-of-the-art algorithm