Virtual machine framework for constructing domain-specific languages

An object-oriented framework is proposed for constructing a virtualmachine (VM) to be used in the context of incrementally and iteratively developing a domain-specific language (DSL).The framework iswritten in C#. It includes abstract instruction and environment classes. By extending these, a concrete layer of classes is obtained whose instances define the semantics of a set of instructions, as well as one or more execution environment instances that can be manipulated by the instructions. The framework provides a generic mechanism for reading a set of instructions, executing them sequentially by default but branching if necessary, storing or retrieving internal variables, and accessing and manipulating the environment as per the instructions. In general, each instruction can execute an arbitrary C# method as specified by the developer. The syntactic form of instructions is limited to five possibilities. Using the framework, a range of VMs can be generated, each tailored to support a developerdesigned target-level DSL. Since each such language is built in terms of these five instruction formats, these targetlevel languages share a common syntactic structure. The result is a platform to support an incremental iterative language design and implementation approach that involves the following three phases: determine a set of targetlevel instructions with semantics appropriate to the specific domain; determine source-level language instructions whose syntax appeals to the domain specialist and provide a simple compiler to map the source to target instructions. The first two phases are relatively disjoint and importantly separate syntax concerns from semantics concerns. The final phase is quite straightforward. Comparative performance results support the use of the framework as an alternative to using an interpreter or hardcoded VM for DSL development.     

Aspect-oriented prolog in a language processing context

Language processors can be derived from logic grammars. That several concerns in the processor such as parsing, several kinds of analysis or transformations, can be specified as aspects of the logic grammar is demonstred. For that purpose, the authors bring the concepts of aspect-oriented programming to Prolog in a systematic way, based on established Prolog technology. The authors illustrate that typical Prolog programming techniques can be described as generic aspects and provided in a library to support reusable concerns. A domain-specific language (DSL) is developed to improve readability of aspect-oriented specifications.     

Hybrid molecular-continuum fluid models: implementation within a general coupling framework

Over the past three years we have been developing a new approach for the modelling and simulation of complex fluids. This approach is based on a multiscale hybrid scheme, in which two or more contiguous subdomains are dynamically coupled together. One subdomain is described by molecular dynamics while the other is described by continuum fluid dynamics; such coupled models are of considerable importance for the study of fluid dynamics problems in which only a restricted aspect requires a fully molecular representation. Our model is representative of the generic set of coupled models whose algorithmic structure presents interesting opportunities for deployment on a range of architectures including computational grids. Here we describe the implementation of our HybridMD code within a coupling framework that facilitates flexible deployment on such architectures.     

Extending grammars and metamodels for reuse: the Reuseware approach

The trend towards domain-specific languages leads to an ever-growing plethora of highly specialised languages. Developers of such languages focus on their specific domains rather than on the technical challenges of language design. The generic features of languages are rarely included in special-purpose languages. One very important feature is the ability to formulate partial programs in separate encapsulated entities, which can be composed into complete programs in a well-defined manner. A language-independent approach is presented that adds useful constructs for defining components. The authors discuss the underlying concepts and describe a composition environment and tool supporting these ideas-the reuseware composition framework. To evaluate this approach, the authors enrich the (Semantic) Web query language Xcerpt with an additional useful reuse concept - modules.     

A cutting plane approach for the single-product assembly system design problem

This paper evaluates a new branch-and-cut approach, establishing a computational benchmark for the single-product, assembly system design (SPASD) problem. Our approach, which includes a heuristic, preprocessing, and two cutgenerating methods, outperformed OSL in solving a set of 102 instances of the SPASD problem. The approach is robust; test problems show that it can be applied to variations of the generic SPASD problem that we encountered in industry.     

Unsupervised Domain Adaptation Based on Discriminative Subspace Learning for Cross-Project Defect Prediction

Cross-project defect prediction (CPDP) aims to predict the defects on target project by using a prediction model built on source projects. The main problem in CPDP is the huge distribution gap between the source project and the target project, which prevents the prediction model from performing well. Most existing methods overlook the class discrimination of the learned features. Seeking an effective transferable model from the source project to the target project for CPDP is challenging. In this paper, we propose an unsupervised domain adaptation based on the discriminative subspace learning (DSL) approach for CPDP. DSL treats the data from two projects as being from two domains and maps the data into a common feature space. It employs cross-domain alignment with discriminative information from different projects to reduce the distribution difference of the data between different projects and incorporates the class discriminative information. Specifically, DSL first utilizes subspace learning based domain adaptation to reduce the distribution gap of data between different projects. Then, it makes full use of the class label information of the source project and transfers the discrimination ability of the source project to the target project in the common space. Comprehensive experiments on five projects verify that DSL can build an effective prediction model and improve the performance over the related competing methods by at least 7.10% and 11.08% in terms of G-measure and AUC.     

Autonomous Eyewitness Identification by Employing Linguistic Rules for Disaster Events

Social networking platforms provide a vital source for disseminating information across the globe, particularly in case of disaster. These platforms are great mean to find out the real account of the disaster. Twitter is an example of such platform, which has been extensively utilized by scientific community due to its unidirectional model. It is considered a challenging task to identify eyewitness tweets about the incident from the millions of tweets shared by twitter users. Research community has proposed diverse sets of techniques to identify eyewitness account. A recent state-of-the-art approach has proposed a comprehensive set of features to identify eyewitness account. However, this approach suffers some limitation. Firstly, automatically extracting the feature-words remains a perplexing task against each feature identified by the approach. Secondly, all identified features were not incorporated in the implementation. This paper has utilized the language structure, linguistics, and word relation to achieve automatic extraction of feature-words by creating grammar rules. Additionally, all identified features were implemented which were left out by the state-of-the-art model. A generic approach is taken to cover different types of disaster such as earthquakes, floods, hurricanes, and wildfires. The proposed approach was then evaluated for all disaster-types, including earthquakes, floods, hurricanes, and fire. Based on the static dictionary, the Zahra et al. approach was able to produce an F-Score value of 0.92 for Eyewitness identification in the earthquake category. The proposed approach secured F-Score values of 0.81 in the same category. This score can be considered as a significant score without using a static dictionary.     

Prediction of debonding strength of tensile hybrid bonded joints using fracture mechanics

In order to improve the debonding strength of double shear lap (DSL) joints between aluminum plates and carbon fiber reinforced plastic (CFRP) plates, a hybrid bonded fiber reinforced plastics (HB-FRP) technique was proposed in this paper. Debonding strength of the HB-FRP was tested and investigated analytically and numerically. Fracture failure of the aluminum-adhesive interface was identified as the dominant failure mode of the joint. Compared with normal bond joints, the debonding strength of HB-FRP joints can be increased by 71% in experiments. The strain energy release rate (SERR) criterion based on linear elastic fracture mechanics (LEFM) was adopted to estimate the debonding strength of bond joints. Good agreement among theoretical predictions, numerical simulations and experimental data were achieved.     

大规模定制模式下定制程度的优选分析

大规模定制运用于生产时,定制程度可作为功能的个性化程度.从制造设计的角度来看,定制化产品的类设计参数与类功能需求间存在映射关系,而类功能需求可由定制程度予以表达后进行加权评分;从顾客认可和销售利润来看,顾客对定制化产品的认可可借以顾客满意度来反应,如果针对具体的产品,顾客满意度和产品销售利润均可找到以定制程度为变量的拟合函数.因此,在追求类功能需求评分、顾客满意度和利润函数值尽可能高的目的下,可以求出定制程度的最优解.     

A method for the evaluation of the response probability density function of some linear dynamic systems subjected to non-Gaussian random load

This paper deals with the characterization of the random response of linear systems subjected to stochastic load. It proposes a new method based on the new version of the Probabilistic Transformation Method (PTM) that allows obtaining, with a very low computational effort, the probability density function of the response. An important aspect of the proposed approach is the ability to join directly the pdfs of the input load with those of the response. Based on the step-by-step integration method, explicit solutions will be proposed for the random response of systems loaded by seismic and windy sampled inputs.     

Producibility Analysis Using Metrics Based on Physical Process Models

This paper presents an approach to evaluating producibility which is intended to enhance the ability of engineers to quickly design low-cost and high-quality parts. We divide all production processes into two categories: trajectory-dominated processes in which a generic tool is moved in a trajectory to form the part shape, and process-physics-dominated processes in which shaped tools are used to form similarly shaped parts. We focus on process-physics-dominated processes and on producibility problems that arise because of part shape. We argue that for these processes the currently popular approach of representing parts as collections of geometric features may be inappropriate for evaluating producibility. We propose an alternative approach and representation. Our approach consists of first identifying the different failure modes of the process and then defining producibility metrics corresponding to the likelihood of encountering each failure mode. This set of metrics is used to represent the degree to which a part is easily manufactured. Finally, we demonstrate this approach by developing a set of metrics for evaluating the producibility of aluminum extrusions. We use extrusions from the Boeing 777 to validate the metrics.     

Integrated DSL Test, Analysis, and Operations

This paper describes methods of integrating the digital subscriber line (DSL) automated test, data from network elements, analyses, and DSL operations, including work-force administration. Fiber-to-the-node systems using very-high-rate DSL 2 will particularly need the integrated DSL test to increase customer satisfaction and streamline operations to reduce costs. The integrated DSL test extends beyond copper tests to encompass all elements of DSL service, all through the network and at higher layers. An integrated test system queries multiple test points, including network elements, allowing physical and higher layer problems to be identified. Diagnosis, fault isolation, and even suggested reconfigurations are all automated in software. A number of techniques, which are implementable in software, are described, which can show the root cause of many intricate troubles to relatively unskilled technicians. Automated maintenance routines can isolate faults in flowthrough testing, automatically issuing trouble tickets toward the correct work center: Internet service providers, central offices, outside plants, user PCs, etc. New triple-play services have high customer expectations for easy-to-use TV and voice services, with demanding bit rates and reliability requirements that can be ensured with an integrated test.     

Parallel optical image processing with image-logic algebra and a polynomial approach

An interesting relationship between an optical parallel-processing single-instruction-multiple-data generic language, called image-logic algebra, and a polynomial approach for processing binary images by electronic computers is shown. Using only two basic operations of the ILA, one can reformulate a number of algorithms developed earlier in the polynomial approach into algorithms in the ILA environment. Thus a large number of new algorithms for parallel optical processing of binary images can be developed in the ILA environment that are fast and efficient.     

Automating deployment planning with an aspect weaver

Deployment has emerged as a major challenge in distributed real-time and embedded (DRE) systems. Application deployment planners must integrate numerous functional and non-functional constraints, such as security and performance, to produce correct deployment plans. The numerous deployment constraints and their complex interactions make manually deducing correct/efficient deployments hard. Four contributions to the study of automated deployment processes are presented. First, it shows that a deployment planner and an aspect weaver accomplish the same abstract problem - that is, mapping items from a source set (advice or components) to items in a target set (joinpoints or nodes) according to a set of rules - and uses this abstract definition of deployment planning to automate it with an aspect weaver. Second, this paper describes how the ScatterML domain-specific aspect language incorporates complex global constraints for specifying deployment pointcuts. Third, we show how static aspect weaving problems can be reduced to a constraint satisfaction problem and a constraint solver used to deduce a correct weaving. Fourth, we show that phrasing weaving as a constraint satisfaction problem and automating deployment through a constraint solver-based weaver yields several key benefits, ranging from guaranteed deployment plan correctness to bounds on worst-case solution quality.     

Learning context-free grammar rules from a set of program

The grammar of a programming language is important because it is used in developing program analysis and modification tools. Sometimes programs are written in dialects-minor variations of standard languages. Normally, grammars of standard languages are available but grammars of dialects may not be available. A technique for reverse engineering context-free grammar rules is presented. The proposed technique infers rules from a given set of programs and an approximate grammar is generated using an iterative approach with backtracking. The correctness of the approach, is explained and a set of optimisations proposed to make the approach more efficient. The approach and the optimisations are experimentally verified on a set of programming languages.     

利用声相关流速剖面仪观测深水散射层

讨论了利用声相关流速剖面仪进行深水散射层观测的可行性。结合声相关流速剖面仪垂直发射编码调制信号、多阵元接收的特点以及测量流剖面三维速度的优势,提出利用回波强度和垂向速度两种方法对深水散射层进行观测。在23kHz声相关流速剖面仪工程样机海试数据的基础上,利用这两种观测方法对DSL进行了观测。观测结果表明：利用声相关流速剖面仪可以直观地观测深水散射层的分布及运动规律,这两种观测方法是实际可行的。     

Critical attributes of transdermal drug delivery system (TDDS) – a generic product development review

Bioequivalence testing of transdermal drug delivery systems (TDDS) has always been a subject of high concern for generic companies due to the formulation complexity and the fact that they are subtle to even minor manufacturing differences and hence should be clearly qualified in terms of quality, safety and efficacy. In recent times bioequivalence testing of transdermal patches has gained a global attention and many regulatory authorities worldwide have issued recommendations to set specific framework for demonstrating equivalence between two products. These current regulatory procedures demand a complete characterization of the generic formulation in terms of its physicochemical sameness, pharmacokinetics disposition, residual content and/or skin irritation/sensitization testing with respect to the reference formulation. This paper intends to highlight critical in vitro tests in assessing the therapeutic equivalence of products and also outlines their valuable applications in generic product success. Understanding these critical in vitro parameters can probably help to decode the complex bioequivalence outcomes, directing the generic companies to optimize the formulation design in reduced time intervals. It is difficult to summarize a common platform which covers all possible transdermal products; hence few case studies based on this approach has been presented in this review.     

A conforming unified finite element formulation for the vibration of thick beams and frames

Beams and frames are common features in many engineering structures and in this paper an approach is given to model their dynamic behaviour adequately. Whilst the eigen‐frequencies of continuous systems comprising of slender beams can be identified, in most cases of practical interest, by means of Euler or Timoshenko beam theory, for structures comprising of thick beam models this is not necessarily true since such idealizations constrain the cross‐sections to remain planar. This paper suggests an alternative approach by means of a unified fully conforming plane stress rectangular finite element which is believed to allow for more realistic representation of the shear effects and hence the strain field around the joints of such structures. The usefulness and functionality of this improved numerical approach is explored via comparison against a non‐conforming two‐dimensional plate as well as one‐dimensional Euler–Bernoulli and Timoshenko finite element formulations corresponding to a variety of beam aspect ratios representing the structures of a rotor and a portal frame. The idealization is shown to be particularly advantageous for simulating the effects of shear distortion where beams join at right angles and the transverse forces in one member interact with the extensional forces of the adjoining structure. Copyright © 2004 John Wiley & Sons, Ltd.