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1.
ContextSince the emergence of the aspect oriented paradigm, several studies have been conducted to test the contribution of this new paradigm compared to the object paradigm. However, in addition to this type of studies, we need also comparative studies that assess the aspect approaches mutually. The motivations of the latter include the enhancement of each aspect approach, devising hybrid approaches or merely helping developers choosing the suitable approach according to their needs. Comparing advanced separation of concerns approaches is the context of our work.ObjectiveWe aim at making an assessment of how the aspect approaches deal with crosscutting concerns. This assessment is based on quantitative attributes such as coupling and cohesion that evaluate the modularity as well as on qualitative observations.MethodWe selected three of well-known aspect approaches: AspectJ, JBoss AOP and CaesarJ, all the three based on Java. We conducted then, a comparative study using the GoF design patterns. In order to be fair we asked a group of Master students to achieve the implementation of all patterns with the three approaches. The use of these implementations as hypothetical benchmarks allowed us to achieve two kinds of comparison: a quantitative one based on structural and performance metrics, and qualitative one based on observations collected during the implementation phase.ResultsThe quantitative comparison shows some advantages like the using of fewer components with AspectJ and the strong cohesion with CaesarJ and weaknesses, as the high internal coupling caused by the inner classes of CaesarJ. The qualitative comparison gives comments about the approach understandability and others qualitative concepts.ConclusionThis comparison highlighted strengths and weaknesses of each approach, and provided a referential work that can help choosing the right approach during software development, enhancing aspect approaches or devising hybrid approaches that combine best features.  相似文献   

2.
The paper describes how the medial-axis construction of a geometric domain can be used in the design of cable-membrane structures. The developed method can be used in a conceptual design tool suggesting different shapes to an architect. At the same time this method can also help in the discretisation of a cable-membrane structure by automatically generating finite element meshes of the structures. The paper includes examples to demonstrate the capabilities of the method.  相似文献   

3.
Contradictions caused by the various design constraints present increasing challenges to efficiency and innovation in product development. TRIZ provides Inventive Principles (IPs) and Contradiction Matrix that are the most frequently applied in conflict resolution. However, the high-level abstraction and subjective selection of IPs inhibit achieving the transformation process from paradoxical states to physical structures. To fill this gap, a contradiction solving method by integrating deep learning and technological evolution patterns for product conceptual design is proposed, which illustrates the mechanism of contradiction transition from the perspective of system evolution and supplies a systematic and model-based design approach. Firstly, generic engineering parameters are extracted to define the underlying contradictions transformed from critical defects which are found out through function modeling and root-conflict analysis. Then, a fully-connected deep neural network with excellent performance is developed to uncover the non-linear relationships between engineering parameters and evolution patterns. Finally, an evolution tree based on the predicted patterns is constructed to visualize transformation potentials of a technical system and help designers generate innovative specific solutions. In addition, a case study concerning design conflict resolution for beat-up system of three-dimensional tubular weaving machine is used to validate the adaptability and reliability of the proposed approach.  相似文献   

4.
利用混沌系统的相轨迹对初值敏感而列噪声免疫的特性,提出采用三角波和正弦波分别作策动力对微弱三角波信号的幅值进行检测。最后,在Matlab/Simulink环境下进行仿真实验。结论表明:混沌理论可以实现对信噪比很低的三角波信号幅值进行检测,并且取得较高的精度。  相似文献   

5.
Reducing the impact of conflicts on requirement-function-structure mapping in the early stage of product design is an important measure to achieve conceptual innovation, which relies on accurate reasoning of multi-domain knowledge. As product requirements become more personalized and diverse, traditional discrete knowledge organization and reasoning methods are difficult to adapt to the challenges of continuity and precision in conceptual solution. Knowledge graphs with complex networks have obvious advantages in association detection, knowledge visualization, and explainable reasoning of implicit knowledge, which offer innovative opportunities for conflict resolution in conceptual design. Therefore, a smart conflict resolution model using a multi-layer Knowledge Graph for Conceptual Design(mKGCD) is proposed in this study. A knowledge expression form of FBS-oriented design patent vocabulary is proposed, which is used for knowledge entity recognition and relation extraction based on natural language processing. A label mapping method based on inventive principles is used for patent classification and a four-layer semantic network for conflict resolution is constructed. Through semantic distance calculation, the designer's requirements for function/behavior/structure are smart deployed to obtain appropriate knowledge. A case study of the conceptual design of a collapsible installation and handling equipment demonstrates the feasibility of the proposed approach. The proposed method can not only meet the functional solution and innovation in the context of different design requirements, but also effectively improve the design efficiency in the iterative design process by means of multiple meanings of one graph.  相似文献   

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The paper describes a Computer Aided Software Engineering (CASE) tool to support conceptual database modelling. One popular approach for conceptual database modelling is use of the Entity-Relationship (ER) model. The paper proposes the use of an Enhanced Entity-Relationship (EER) model for conceptual database modelling. This Enhanced Entity-Relationship model extends the Entity-Relationship model by incorporating the generalization/specialization, aggregation and categorization abstractions. The CASE tool, which is based on the Enhanced Entity-Relationship model, is known as the Enhanced Entity-Relationship Diagrammer (EERD). In addition, the CASE tool supports direct visual query and update based on the EERM.  相似文献   

8.
Design is situational, which means the explicit consideration of the state of the environment, the knowledge and experience of the designer, and the interaction between the designer and the environment during designing interact. When computer-aided innovation systems (CAIs) are applied to the design, the environment and the situation are different from the traditional design process and environment. The basic principles of some CAIs available in the world market are directly related to theory of inventive problem solving (TRIZ). Special TRIZ solutions, which have a few inventive principles and the related cases for contradiction problem solving, are medium-solutions to domain problems. The second stage analogy process is used to generate domain solutions and in this process, the TRIZ solutions are used as source designs of analogy-based process. Unexpected discoveries (UXDs) are the key factors to trigger designers to generate new ideas for domain solutions. The type of UXDs for the specific TRIZ solutions is studied and a UXDs-driven contradiction solving for conceptual design is formed. A case study shows the application of the process step by step.  相似文献   

9.
Functional Size Measurement (FSM) methods are intended to measure the size of software by quantifying the functional user requirements of the software. The capability to accurately quantify the size of software in an early stage of the development lifecycle is critical to software project managers for evaluating risks, developing project estimates and having early project indicators. In this paper, we present OO-Method Function Points (OOmFP), which is a new FSM method for object-oriented systems that is based on measuring conceptual schemas. OOmFP is presented following the steps of a process model for software measurement. Using this process model, we present the design of the measurement method, its application in a case study, and the analysis of different evaluation types that can be carried out to validate the method and to verify its application and results.  相似文献   

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11.
In the traditional design process for a 3D environment, people usually depict a rough prototype to verify their ideas, and iteratively modify its configuration until they are satisfied with the general layout. In this activity, one of the main operations is the rearrangement of single and composite parts of a scene. With current desktop virtual reality (VR) systems, the selection and manipulation of arbitrary objects in 3D is still difficult. In this work, we present new and efficient techniques that allow even novice users to perform meaningful rearrangement tasks with traditional input devices. The results of our work show that the presented techniques can be mastered quickly and enable users to perform complex tasks on composite objects. Moreover, the system is easy to learn, supports creativity, and is fun to use.  相似文献   

12.
This paper describes how to improve dynamic transport timetables. Mostly, such information as departure time, gate number, platform number, intermediate stops, and delays is arranged per flight or train. Each train or flight has one line or one column. A field observation of passengers using such a system showed that presenting information in this fashion is not optimal. Of passengers, 38% were unable to find the correct departure time. We analysed the performance of passengers. This analysis suggested that the information should not be arranged per train or flight but per destination. Each train or flight has one line or one column. An empirical comparison supported this conclusion. When a destination-based structure was used, the number of correct answers was 16% higher, the delay of each passenger was 75% less, and the time needed to search for a train decreased by 42%.  相似文献   

13.
With the actual penetration of expert systems into the business world, the question is, how the expert system idea can be used to enhance the existing information systems with more intelligence in usage and operation. This interest is not surprising due to the advancement of the fifth generation of computer technology, and avid interest in the field of Artificial Intelligence. Therefore design of an information system for an application becomes more complex, and the inability of the human designer to deal with it increases. For designing intelligent systems, we have to be able to forecast the behavior of the information system more precisely before implementing it, i.e. we'have to support the specification process.Clearly the technology, such as Data base systems, is leading on efficiency issues as those needed for the construction, retrieval and manipulation of large shared data base. On the other hand, the AI techniques have improved significantly with function such as deductive reasoning and natural language processing. It is important to find way to merge these technologies into one mainstream of computing. A meeting point for the two areas is the issue of conceptual knowledge modelling, so that models can be created that will define the role and the ways to use data in AI systems. In the framework of this study, one possible expert system design aid environment has been suggested to assist the designer in his work.In a conceptual modelling environment a model is given for analysing complex real world problems known as the Conceptual Knowledge Model (CKM), represented by a Graphical and a Formal Representation. The Graphical Representation consists of three graphs: Conceptual Requirement Graph, Conceptual Behavior Graph, and Conceptual Structure Graph. These graphs are developed by involving the expert during the design process. The graphs are then transformed into first-order predicate logic to represent the logical axioms of a theory, which constitutes the knowledge base of the Expert System. The model suggested here is a step towards closing the gap between the theory of the conventional data base theory and AI databases.  相似文献   

14.
A conceptual approach for the die structure design   总被引:3,自引:0,他引:3  
A large number of decisions are made during the conceptual design stage which is characterized by a lack of complete geometric information. While existing CAD systems supporting the geometric aspects of design have had little impact at the conceptual design stage. To support the conceptual die design and the top–down design process, a new concept called conceptual assembly modeling framework (CAMF) is presented in this paper. Firstly, the framework employs the zigzag function-symbol mapping to implement the function design of the die. From the easily understood analytical results of the function-symbol mapping matrix, the designer can evaluate the quality of a proposed die concept. Secondly, a new method—logic assembly modeling is proposed using logic components in this framework to satisfy the characteristic of the conceptual die design. Representing shapes and spatial relations in logic can provide a natural, intuitive method of developing complete computer systems for reasoning about die construction design at the conceptual stage. The logic assembly which consists of logic components is an innovative representation that provides a natural link between the function design of the die and the detailed geometric design.  相似文献   

15.
As a data mining method, clustering, which is one of the most important tools in information retrieval, organizes data based on unsupervised learning which means that it does not require any training data. But, some text clustering algorithms cannot update existing clusters incrementally and, instead, have to recompute a new clustering from scratch. In view of above, this paper presents a novel down-top incremental conceptual hierarchical text clustering approach using CFu-tree (ICHTC-CF) representation, which starts with each item as a separate cluster. Term-based feature extraction is used for summarizing a cluster in the process. The Comparison Variation measure criterion is also adopted for judging whether the closest pair of clusters can be merged or a previous cluster can be split. And, our incremental clustering method is not sensitive to the input data order. Experimental results show that the performance of our method outperforms k-means, CLIQUE, single linkage clustering and complete linkage clustering, which indicate our new technique is efficient and feasible.  相似文献   

16.
为解决设计模式演化后难以挖掘的问题,提出引入特征规则的设计模式变体挖掘方法.通过逆向工程中的大类图拆分方法获取设计模式参与者角色及关系,根据设计模式指导的软件分簇方法识别职能相似的有效参与者及关系,制定设计模式变体挖掘规则,通过在基于文法产生优化的设计模式识别方法中引入变体规则特征信息来挖掘设计模式变体,设计单例变体与...  相似文献   

17.
A method for acquiring conceptual design knowledge in physical systems is proposed and implemented based on EBL (explanation-based learning), ‘value engineering methodologies’ and ‘axiomatic design approaches’. In this method, the structural features of designed objects are analysed to yield a systematic explanation of how they function and attain their design goals and why they are used for attaining the goals.The ‘how’ explanation results in a generalized version of the functional diagram used in value engineering from which various levels of general design knowledge can be extracted. The quality of the extracted knowledge is then discussed with reference to its mode of acquisition.The ‘why’ explanation yields a deeper understanding of the designed objects from which we can extract meta-planning or strategic knowledge for selecting rational plans from among other possible alternatives. This explanation is obtained by regarding the object in question as being the result of strategically rational decisions and actions which are subject to the ‘design axioms’.  相似文献   

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19.
This paper is concerned with the development of a new method for the design of energy transfer filters (ETFs). ETFs are a new class of non-linear filters recently proposed by the authors, which employ non-linear effects to transfer signal energy from one frequency band to a different frequency location. The new method uses the powerful orthogonal least squares (OLS) algorithm to solve the least squares problem associated with the design and compared with previous methods achieves much better filtering performance.  相似文献   

20.
Data matrices are widely used in the automotive, aerospace and computer manufacturing industries. In industry, they are used to identify objects used in process control. In this paper, we focus on detecting data matrices where a camera is configured to see it in a perpendicular direction that is typical in machine vision applications. In this case, the image projection can be modeled as a similarity transform. Data matrices are attached or marked by laser on the surface of objects, and have L-shaped solid lines which act as references for decoding. Under a similarity transform, distances from the center of a data matrix to each side of the L-shape are equal. This symmetric property is used to detect a data matrix, and experimental results show the feasibility of the proposed algorithm.  相似文献   

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