A new method for detecting various variants of GoF design patterns using conceptual signatures

Software design patterns are well-known solutions for solving commonly occurring problems in software design. Detecting design patterns used in the code can help to understand the structure and behavior of the software, evaluate the quality of the software, and trace important design decisions. To develop and maintain a software system, we need sufficient knowledge of design decisions and software implementation processes. However, the acquisition of knowledge related to design patterns used in complex software systems is a challenging, time-consuming, and costly task. Therefore, using a suitable method to detect the design patterns used in the code reduces software development and maintenance costs. In this paper, we proposed a new method based on conceptual signatures to improve the accuracy of design pattern detection. So we used the conceptual signatures based on the purpose of patterns to detect the patterns’ instances that conform to the standard structure of patterns, and cover more instances of patterns’ variants and implementation versions of the patterns and improve the accuracy of pattern detection. The proposed method is a specific process in two main phases. In the first phase, the conceptual signature and detection formula for each pattern is determined manually. Then in the second phase, each pattern in the code is detected in a semi-automatic process using the conceptual signature and pattern detection formula. To implement the proposed method, we focused on GoF design patterns and their variants. We evaluated the accuracy of our proposed method on five open-source projects, namely, Junit v3.7, JHotDraw v5.1, QuickUML 2001, JRefactory v2.6.24, and MapperXML v1.9.7. Also, we performed our experiments on a set of source codes containing the instances of GoF design patterns’ variants for a comprehensive and fair evaluation. The evaluation results indicate that the proposed method has improved the accuracy of design pattern detection in the code.

     

Geographic Information System-based tools in environmental management

The authors reviewed existing modelling platforms as part of a large study of water and pollution pathways through catchments in Ireland (Irish EPA Pathways project). Worldwide, work on producing catchment management tools (CMTs) has been underway for some time and some of the tools identified here date from as early as 1989. Some of the management problems and model conceptualisations have not changed very much but now there is a stronger emphasis on water quality and more concern about a wider range of contaminants. What has changed substantially is the use of Geographical Information System and Graphical Windows interfaces as technologies supporting a wider practical use of these tools. This review of existing CMTs identified three systems which would be candidates if a CMT had to be deployed immediately in Ireland. All have a rigid catchment model structure and lack the flexibility to include any new scientific information or flow-path conceptualisation that may emerge. The same modelling structure is used for all parts of the catchment, with spatial variation represented by parameter variation only and not variation in model structure. They also have rigid graphical user interfaces which cannot be tailored to match any specific requirements that may emerge from the pathways end-user workshops. Thus a CMT with a more flexible and accessible modelling structure is required if the results of current research are to be incorporated.     

Effect of different application techniques on microshear bond strength of self-etch adhesives to dentin

Objectives: To investigate the effect of different self-etch adhesive systems application techniques: active or passive in a single or double layer on adhesive–dentin microshear bond strength.

Methods: Occlusal surfaces of 48 extracted human molars were ground to expose flat superficial dentin surfaces. Specimens were randomly divided into two main groups according to the tested self-etch adhesive system either: One-step self-etch (Adper^TM easy-one) or two-step self-etch (Adper^TM SE Plus). Each adhesive system was applied on the prepared dentin surfaces followed one of these techniques: (1) Passive application of a single layer, (2) Active application of single layer, (3) Passive application of double adhesive layer (with light curing in between), and (4) Active application of double adhesive layers. Resin composite was packed inside micro-tubes fixed on the bonded dentin surfaces and light cured for 40 s. All specimens were stored in artificial saliva either for 24 h or 3 months before testing. Microshear bond strength test was employed using a universal testing machine at a crosshead speed of 0.5 mm/min.

Results: Adper^TM SE Plus showed higher significant microshear bond strength in compared with Adper^TM easy-one. For both adhesive systems active application showed higher significant microshear bond strength to dentin than passive application. Double application of adhesive systems showed lower microshear bond strength than single application.

Conclusion: Active application of self-etch adhesives could improve the dentin microshear bond strength. Double application with curing in between the layers did not improve the bond strength to the tested adhesive.     

CuI Immobilized on Tricationic Ionic Liquid Anchored on Functionalized Magnetic Hydrotalcite (Fe3O4/HT-TIL-CuI) as a Novel,Magnetic and Efficient Nanocatalyst for Ullmann-Type C–N Coupling Reaction

One of the most important reactions in organic synthesis is Ullmann-type C–N coupling reaction which has been used for preparation of numerous biologically active compounds. In this work, CuI immobilized on tricationic ionic liquid anchored on functionalized magnetic hydrotalcite (Fe₃O₄/HT-TIL-CuI) has been successfully prepared and fully characterized by different techniques, including fourier-transform infrared spectroscopy, vibrating sample magnetometer, thermo gravimetric analysis, transmission electron microscopy, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping, zeta potential, X-ray diffraction, temperature programmed desorption of ammonia (NH₃-TPD), temperature-programmed reduction and inductively coupled plasma. The results showed that the as-prepared nanocatalyst possesses plate-like morphology with approximate size of 50 nm and superparamagnetic behavior. Also, total acidity and total hydrogen consumption of the nanocatalyst were measured to be 8.5 and 1.41 mmol g^?1, respectively. This nanocatalyst exhibited favorable performance for C–N coupling reaction among a variety of aryl halides and N(H)-heterocycles (benzimidazoles, pyrazoles and triazoles) in the presence of 2.5 mol% of nanocatalyst without any additives under air atmosphere revealing high yields in all cases. Besides, it is noted that in the present system the desired product can be easily and quickly isolated and nanocatalyst also recovered magnetically from the reaction mixture employing a permanent magnet for at least six consecutive trials without a discernible decrease in catalytic activity which makes the proposed methodology appropriate for industrial. The findings demonstrated the advantages of the present method as no need for neutral atmosphere, appropriate times, recyclability of the catalyst, broad substrate scope, minimization of chemical waste, simple purification of products, easy workup process, and high yields.