Constructing secure service compositions with patterns

In service based applications, it is often necessary to construct compositions of services in order to provide required functionality in cases where this is not possible through the use of a single service. Whilst creating service compositions, it is necessary to ensure not only that the functionality required of the composition is achieved but also that certain security properties are preserved. In this paper, we describe an approach to constructing secure service compositions. Our approach is based on the use of composition patterns and rules that determine the security properties that should be preserved by the individual services that constitute a composition in order to ensure that security properties of the overall composition are also satisfied. Our approach extends a framework developed to support the runtime service discovery

Ontology-based patterns for the integration of business processes and enterprise application architectures

Increasingly, enterprises are using Service-Oriented Architecture (SOA) as an approach to Enterprise Application Integration (EAI). SOA has the potential to bridge the gap between business and technology and to improve the reuse of existing applications and the interoperability with new ones. In addition to service architecture descriptions, architecture abstractions like patterns and styles capture design knowledge and allow the reuse of successfully applied designs, thus improving the quality of software. Knowledge gained from integration projects can be captured to build a repository of semantically enriched, experience-based solutions. Business patterns identify the interaction and structure between users, business processes, and data. Specific integration and composition patterns at a more technical level address enterprise application integration and capture reliable architecture solutions. We use an ontology-based approach to capture architecture and process patterns. Ontology techniques for pattern definition, extension and composition are developed and their applicability in business process-driven application integration is demonstrated

Finding secure compositions of software services: Towards a pattern based approach

In service based systems, there is often a need to replace services at runtime as they become either unavailable or they no longer meet required quality or security properties. In such cases, it is often necessary to build compositions of services that can replace a problematic service because no single service with a sufficient match to it can be located. In this paper, we present an approach for building compositions of services that can preserve required security properties. Our approach is based on the use of secure composition patterns which are applied in connection with basic discovery mechanisms to build secure service compositions

Designing Secure Service Workflows in BPEL

This paper presents an approach that we have developed to support the design of secure service based applications in BPEL. The approach is based on the use of secure service composition patterns, which are proven to preserve composition level security properties if the services that are composed according to the pattern satisfy other properties individually. The secure service composition patterns are used for two purposes: (a) to analyse whether a given workflow fragment satisfies a given security property, and (b) to generate com-positions of services that could substitute for individual services within the workflow that cause the violation of the security properties. Our approach has been implemented in a tool that is based on Eclipse BPEL Designer

End-User Service Computing: Spreadsheets as a Service Composition Tool

In this paper, we show how spreadsheets, an end-user development paradigm proven to be highly productive and simple to learn and use, can be used for complex service compositions. We identify the requirements for spreadsheet-based service composition, and present our framework that implements these requirements. Our framework enables spreadsheets to send requests and retrieve results from various local and remote services. We show how our tools support different composition patterns, and how the style of declarative dependencies of spreadsheets can facilitate service composition. We also discuss novel issues identified by using the framework in several projects and education

TRUSTED SERVICE COMPOSITION FOR DISTRIBUTED REAL-TIME AND EMBEDDED SYSTEMS

poster abstractDistributed real-time and embedded (DRE) software systems are expected to provide high quality-of-service (QoS) attributes, e.g., scalability, reliability, and security, in conjunction with correct functionality built atop of infrastructure with limited capabilities. Given the many complex and conflicting QoS and functional attributes of DRE systems, a major challenge in developing such software systems is to guaranteeing it trustworthiness, i.e., the degree of confidence that the system adheres to its specification. Current state-of-the-art methods use service orientation to compose systems from reusable and trusted services, and validate the trustworthiness of the end system using runtime evidences. The major shortcoming of this approach is that trust is considered an afterthought (i.e., not an integral part of the software development lifecycle). Trustworthiness of a system should be evaluated based on the trustworthiness of different properties of the system, including its functionality and QoS attributes. Our research extends current state-of-the-art methods for developing trusted DRE systems by considering development time factors of the composition (e.g., properties of individual services, interaction patterns, and compatibility with other services). It is a major research challenge to evaluate the composition of trustworthiness for different system properties with different composition patterns. Our current and future research work to address this challenge includes identifying trust composition operators for different types of compositions, deriving a formal model of trust composition, and validating our approach with a case study using a distributed tracking system

Pattern Based Design and Verification of Secure Service Compositions

Ensuring the preservation of security is a key requirement and challenge for Service-Based Systems (SBS) due to the use of third party software services not operating under different security perimeters. In this paper, we present an approach for verifying the security properties of SBS workflows and adapting them if such properties are not preserved. Our approach uses secure service composition patterns. These patterns encode proven dependencies between service level and workflow level security properties. These dependencies are used in reasoning processes supporting the verification of SBS workflows with respect to workflow security properties and their adaptation in ways that guarantee the properties if necessary. Our approach has been implemented by extending the Eclipse BPEL Designer and validated experimentally. The experimental evaluation has produced positive results, indicating that even for complex workflows and large sets of secure service composition patterns verification can be performed efficiently

Eros and Pilgrimage in Chaucer’s and Shakespeare’s Poetry

The paper discusses erotic desire and the motif of going on pilgrimage in the opening of Geoffrey Chaucer’s General Prologue to The Canterbury Tales and in William Shakespeare’s sonnets. What connects most of the texts chosen for consideration in the paper is their diptych-like composition, corresponding to the dual theme of eros and pilgrimage. At the outset, I read the first eighteen lines of Chaucer’s Prologue and demonstrate how the passage attempts to balance and reconcile the eroticism underlying the description of nature at springtime with Christian devotion and the spirit of compunction. I support the view that the passage is the first wing of a diptych-like construction opening the General Prologue. The second part of the paper focuses on the motif of pilgrimage, particularly erotic pilgrimage, in Shakespeare’s sonnets. I observe that most of the sonnets that exploit the conceit of travel to the beloved form lyrical diptychs. Shakespeare reverses the medieval hierarchy of pilgrimage and desire espoused by Chaucer. Both poets explore and use to their own ends the tensions inherent in the juxtaposition of sacred and profane love. Their compositions encode deeper emotional patterns of desire: Chaucer’s narrator channels sexual drives into the route of communal national penance, whereas the Shakespearean persona employs religious sentiments in the service of private erotic infatuations

What explains changes in full-time and part-time employment in Western Germany? : a new method on an old question

"From 1992 to 2005, part-time employment in Western Germany has grown by 82 percent, whereas full-time employment has shrunk by 14 percent. Behind these general figures there is substantial variation of employment schemes across industries. Beside this, the share of the service industries in gross value added has grown, whereas the importance of manufacturing and construction has decreased considerably. We analyse the extent to which the changes in part-time and full-time employment can be explained by changes in the sectoral composition of the economy or by other factors. Using West German yearly data from 1992-2005, we estimate a regression analogue shiftshare model. It allows us to divide the overall development of employment into the business cycle effect, the sector effect and the employment status effect. Moreover, we control for sectoral gross value added, unit labour costs and working time. As a methodological contribution we extend the shift-share approach into a dynamic panel model. We use a bias-corrected least squares dummy variable (LSDVc) estimator which is appropriate for our data structure. As a second step, we decompose the fixed effects of the LSDVc estimation into parameters for part-time, full-time, and self-employment as well as six sectors. Our results confirm previous deterministic shift-share analyses: Characteristics inherent in full-time or part-time employment dominantly explain changes in employment patterns in Western Germany. The sectoral composition of the economy plays a significant but minor role. The model extensions reveal that much of the status and sector effects in the simple shiftshare analysis can be captured by determinants of labour demand." (Author's abstract, IAB-Doku) ((en))Vollzeitarbeit - Determinanten, Teilzeitarbeit - Determinanten, Wirtschaftsstrukturwandel, Shift-Analyse, Arbeitskräftenachfrage, Westdeutschland, Bundesrepublik Deutschland

Species richness, densities, habitat relationships, and conservation of the avian community of the high-altitude forests of Totonicapán, Guatemala

Department Head: Kenneth Ray Wilson.2010 Summer.Includes bibliographical references (pages 80-81).The Northern Central American Highlands, which include the mountains of Chiapas, Guatemala, El Salvador, and Honduras, are a recognized endemic bird area (Stattersfield et al. 1998) as well as a biodiversity "hotspot" (Myers et al. 2000). The coniferous forests of the regional park "Los Altos de San Miguel Totonicapán" lie within this region. Despite the importance of this area for global avian biodiversity, little research has been conducted in Los Altos, in part because the local Mayan authorities who manage the forest prohibit entry of all outsiders. As part of my Peace Corps Masters International work, I lived for 2½ years in the town of Totonicapán and gained entry to the forests of Los Altos. I worked with local community agencies to design a research project that provides both valuable baseline information on avian community composition, distribution, and abundance, and also a set of environmental education materials and income generation opportunities to help local communities achieve bird conservation. During the rainy and dry seasons in 2008-2009, we used standard distance sampling methods to conduct point counts at 34 locations in the forest. To explore patterns of bird habitat use, we measured 13 vegetation covariates at each point. Community-level analyses with program COMDYN indicated a high level of species richness which did not fluctuate between seasons, and canonical correlation analysis at the community level revealed that average diameter at breast height of trees and understory density were relatively strong predictors of bird community composition. Species-level analysis of selected species revealed interesting patterns of detection probabilities and densities varying between seasons. Finally, species-habitat relationships were explored using an AIC framework and a model-averaging approach to determine the relative importance of vegetation covariates in predicting point level density of selected species. Results from this study reveal the previously unknown composition, distribution, and habitat use patterns of the avian community, and provide the Totonicapán Forestry Office, CONAP (Guatemalan National Park Service), and the local Maya K'iche' authorities with the first baseline information on avian ecology in the forests of Los Altos