Test case generation is the most important part of the testing efforts, the automation of specification based test case generation needs formal or semi-formal specifications. As a semi-formal modelling language, UML is widely used to describe analysis and design specifications by both academia and industry, thus UML models become the sources of test generation naturally. Test cases are usually generated from the requirement or the code while the design is seldom concerned, this paper proposes an approach to generate test cases directly from UML activity diagram using gray-box method, where the design is reused to avoid the cost of test model creation. In this approach, test scenarios are directly derived from the activity diagram modelling an operation. Then all the information for test case generation, i.e. input/output sequence and parameters, the constraint conditions and expected object method sequence, is extracted from each test scenario. At last, the possible values of all the input/output parameters could be generated by applying category-partition method, and test suite could be systematically generated to find the inconsistency between the implementation and the design. A prototype tool named UMLTGF has been developed to support the above process.
In recent years, social application with shopping has become an indispensable activity in people's daily lives. A number of previous studies have investigated various risks in online shopping and consumer's belief. However, few scholars paid more attention to buying behavior, especially on consumer's cross-platform buying behavior. Although consumers can purchase goods directly in platforms that have given them information, they also buy target products on other platforms. This study conceptualizes and implements concepts such as perceived risk, trust, negative reports, and consumer cross-platform buying behavior. A questionnaire survey of users (n = 366) was conducted, and a basic description and comparison of consumers' cross-platform buying behavior were made in terms of consumers' perception of the risk of product effects, consumers' perception of service risks, and consumers' perceptions of other risks. The degree of trust in the platform and negative reports about the platform also affect cross-platform buying behavior. As a result, these findings are discussed and explained, and some reference is provided for related platforms. Besides, the study's finding concerning consumer's buying behavior depends on the security of platform in people's conceptions.
BackgroundBone substation grafts, such as hydroxyapatite (HA) and tricalciumphosphate (TCP), have been extensively used in clinical applications, but evidence suggests that they offer poor osteoinductive properties compared to allografts and autografts. In order to increase bone growth with such grafts, Bone Morphogenetic Protein 2 (BMP-2) was incorporated into a three dimensional reservoir. The purpose of the present study was to develop a novel drug delivery system which is capable of controlled release of BMP-2.MethodsDBB were prepared from bovine cancellous bone harvested from fetal bovine femur or tibia and then sinting at 1000°C. BMP-2-loaded chitosan (CS) microspheres were fabricated by cross-linking. Then the treated DBB powders were blended with chitosan microspheres solution. Finally, the composites were lyophilized with a freeze dryer to obtain the DBB/CMs scaffolds. X-ray diffractor (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) were used to characterize the sample. The quantification of the delivery profile of BMP-2 was determined using an enzyme-linked immunosorbent assay (ELISA) kit. The in vitro assays were to characterize the biocompatibility of this composite.ResultsIn this study, BMP-2/Chitosan (CS) microspheres were successively loaded onto a deproteinized bovine bone (DBB) scaffold. The release profile of BMP-2 indicated an initial burst release followed by a more even sustained release. An in vitro bioactivity assay revealed that the encapsulated growth factor was biologically active.ConclusionsThe cell culture assay suggest that the excellent biocompatibility of the DBB- BMP-2/CS. Therefore, this novel microsphere scaffold system can be effectively used in current tissue engineering applications.
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