Browsing by Author "Hsu, Hwai-Jung"

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A Delegation Framework for Task-Role Based Access Control in WFMS
(2011-05-01)
Hsu, Hwai-Jung
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Wang, Feng-Jian
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資訊工程學系
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Department of Computer Science
Access control is important for protecting information integrity in workflow management system (WfMS). Compared to conventional access control technology such as discretionary, mandatory, and role-based access control models, task-role-based access control (TRBAC) model, an access control model based on both tasks and roles, meets more requirements for modern enterprise environments. However, few discussions on delegation mechanisms for TRBAC are made. In this paper, a framework considering temporal constraints to improve delegation and help automatic delegation in TRBAC is presented. In the framework, the methodology for delegations requested from both users and WfMS is discussed. The constraints for delegatee selection such as delegation loop and separation of duty (SOD) are addressed. With the framework, a sequence of algorithms for delegation and revocation of tasks are constructed gradually. Finally, a comparison is made between our approach and the representative related works.
Separation of Concerns in Analysis of Artifact Anomalies within Workflow Models
(2016)
Wang, Feng-Jian
;
Lu, Tenny
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Hsu, Hwai-Jung
;
資訊工程學系
;
Department of Computer Science
Workflows which realize parts of business goals in a particular order automate the business processes within enterprises. To guarantee the correctness of workflow execution, analyses on structural integrity of workflows are essential. However, comparing to the sequential activities, the activities executed in orders, the anomalies caused by parallel activities are far more complicated for analysis. Therefore, separation of concerns among sequential and parallel issues while doing analysis can reduce the complexity among analysis time and human recognition. In this paper, we propose an innovative methodology considering sequential and parallel issues separately within workflow models to detect anomalies in a given workflow. As a result, the cost for anomaly detection is lowered and the complexity for human recognition of the anomaly issues is reduced.
Using Artifact Flow Diagrams to model Artifact Usage Anomalies
(2009)
Hsu, Hwai-Jung
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Wang, Feng-Jian
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資訊工程學系
;
Department of Computer Science
Workflow is a set of tasks which are systematized to achieve certain business goal(s), where the tasks run in a particular order under automatic control. Artifacts, collections of data items, are necessary for task (process) executions in a workflow. However, an execution may yield unexpected results due to improper artifact manipulation: e.g., activities miss artifact or artifact conflict occur at an activity dynamically. Therefore, the analyses on artifact usage in design phase are very important for quality insurance. This paper presents a model of artifact flow diagrams to state the artifact usage anomalies in processes transmitting artifacts based on DCDC, Distinct Control and Data Channel, model. There are four types of artifact usage anomalies identified in DCDC and the formal statement of each anomaly is described correspondingly for future study of anomaly search.