International Journal of Software Engineering and Knowledge Engineering

Emergent behavior is an important issue in distributed systems' design. Detecting and removing emergent behavior during the design phase will lead to huge savings in deployment costs of such systems. An effective approach for the design of distributed systems is to describe system requirements using scenarios. A scenario, commonly known as a message sequence chart or a sequence diagram, is a temporal sequence of messages sent between system components. However, scenario-based specifications are prone to subtle deficiencies with respect to analysis and validation known as incompleteness and partial description. In this research, a method for detecting emergent behavior of scenario-based specification is proposed. The method is demonstrated and verified using a mine-sweeping robot as an example. Furthermore it has been demonstrated in this paper that scenario-based specifications can be used in agile software development and that the proposed methodologies in this research can be utilized effectively in agile approaches.

Software defect prediction is an acknowledged approach used to achieve better product quality and to better utilize resources needed for that purpose. One known method for predicting the number of defects is to apply case-based reasoning (CBR). In this paper, different attribute weighting techniques for CBR-based defect prediction are analyzed. One of the weighting techniques used in this work, Sensitivity Analysis based on Neural Networks (SANN), is based on sensitivity analysis of the impact of attributes as part of neural network analysis. Neural networks are applicable when there are non-linear and complicated relationships among the attributes. Since weighting plays a key role in the CBR model, using an efficient weight calculation method can change the results. The results of SANN are compared with applying uniform weights and weights gained from Multiple Linear Regression (MLR).

Evaluation of the accuracy of the overall method for applying the three different weighting techniques is done over five data sets, comprising about 5000 modules from NASA. Two quality measures are applied: Average Absolute Error (AAE) and Average Relative Error (ARE). In addition to the variation of weighting techniques, the impact of varying the number of nearest neighbors is studied.

The three main results of the empirical analysis are: (i) In the majority of cases, SANN achieves the most accurate results; (ii) uniform weighting performs better than the MLR-based weighting heuristic; and (iii) there is no significant preference pattern for defining the number of similar objects used for prediction in CBR.

Ubiquitous Computing promises seamless access to a wide range of applications and Internet-based services from anywhere, at anytime, and using any device. In this scenario, new challenges for the practice of software development arise: Applications and services must keep a coherent behavior, a proper appearance, and must adapt to a plenty of contextual usage requirements and hardware aspects. Especially, due to its interactive nature, the interface content of Web applications must adapt to a large diversity of devices and contexts. In order to overcome such obstacles, this work introduces an innovative methodology for content adaptation of Web 2.0 interfaces. The basis of our work is to combine static adaption — the implementation of static Web interfaces; and dynamic adaptation — the alteration, during execution time, of static interfaces so as for adapting to different contexts of use. In hybrid fashion, our methodology benefits from the advantages of both adaptation strategies — static and dynamic. In this line, we designed and implemented UbiCon, a framework over which we tested our concepts through a case study and through a development experiment. Our results show that the hybrid methodology over UbiCon leads to broader and more accessible interfaces, and to faster and less costly software development. We believe that the UbiCon hybrid methodology can foster more efficient and accurate interface engineering in the industry and in the academy.

With the rapid development of economic globalization and informationization, the Chinese e-government is still in its adolescence with a long way ahead. Based on some recent research in Guangdong province, we find that e-government affair systems play important roles therein and represent a certain kind of application called Form-centered Application Systems (FAS). After much investigation and analysis on e-government's background, daily routine and regulations, we summarize some rules and disciplines of its business process modeling, based on which we characterize requirements of FAS. Though currently many process modeling approaches or techniques have been proposed and widely used, they can not fully and easily meet the special needs. In this paper, we introduce a new business process model called Double-State Based Business Process Description Model (DSBPDM), which is composed of Business Process Model (BPM) and Dispatching Model (DM), where BPM enriches Finite State Machine (FSM) Model by three constraint checks, business logic and message passing, whereas DM delineates the dispatching and executing status of the business object in its lifetime. After presenting DSBPDM's formal definition, we discuss the essence of process forwarding by deducing its operational semantics formally. In this way, key issues such as explicit state and operation representation, rigorous constraint expression, complex authorization check, and full picture of the dispatching and executing of business objects are nicely tackled. Our practice shows that building FAS system with DSBPDM and its supporting platform fits the requirements well, provides an open and transparent view of business process, satisfies the needs of the public and officials, and helps to get a comprehensive insight into the meaning of business process forwarding.

In our previous work, we presented a Z-based formalism, called NZ, by which one can explicitly specify bounded, unbounded, erratic, angelic, demonic, loose, strict, singular, and plural nondeterminism. The NZ notation is mainly based on a new notion of operation schemas, called multi-schema. Since the operations of the Z schema calculus do not work on multi-schemas anymore, in this paper we augment NZ with a new set of schema calculus operations that can be applied on multi-schemas as well as ordinary operation schemas. To demonstrate the usability of the resulting formalism, we show how this formalism can assist to model game-like situations and concurrent systems as two well-known classes of nondeterministic systems.