Programmable applications: exploring the potential for language/interface symbiosis

Programmable applications are software systems that seek to combine the learnability and accessibility of direct manipulation interfaces with the expressive power and range of programming languages. In this paper we explore techniques for creatively integrating language and interface constructs within programmable applications. Using SchemePaint—a programmable graphics application—as a source of examples, we demonstrate how an interface and language can combine symbolically and thereby provide powerful modes of expression within applications.     

Textual Data Mining to Support Science and Technology Management

This paper surveys applications of data mining techniques to large text collections, and illustrates how those techniques can be used to support the management of science and technology research. Specific issues that arise repeatedly in the conduct of research management are described, and a textual data mining architecture that extends a classic paradigm for knowledge discovery in databases is introduced. That architecture integrates information retrieval from text collections, information extraction to obtain data from individual texts, data warehousing for the extracted data, data mining to discover useful patterns in the data, and visualization of the resulting patterns. At the core of this architecture is a broad view of data mining—the process of discovering patterns in large collections of data—and that step is described in some detail. The final section of the paper illustrates how these ideas can be applied in practice, drawing upon examples from the recently completed first phase of the textual data mining program at the Office of Naval Research. The paper concludes by identifying some research directions that offer significant potential for improving the utility of textual data mining for research management applications.     

How do architecture patterns and tactics interact? A model and annotation

Software architecture designers inevitably work with both architecture patterns and tactics. Architecture patterns describe the high-level structure and behavior of software systems as the solution to multiple system requirements, whereas tactics are design decisions that improve individual quality attribute concerns. Tactics that are implemented in existing architectures can have significant impact on the architecture patterns in the system. Similarly, tactics that are selected during initial architecture design significantly impact the architecture of the system to be designed: which patterns to use, and how they must be changed to accommodate the tactics. However, little is understood about how patterns and tactics interact. In this paper, we develop a model for the interaction of patterns and tactics that enables software architects to annotate architecture diagrams with information about the tactics used and their impact on the overall structure. This model is based on our in-depth analysis of the types of interactions involved, and we show several examples of how the model can be used to annotate different kinds of architecture diagrams. We illustrate the model and annotation by showing examples taken from real systems, and describe how the annotation was used in architecture reviews. Tactics and patterns are known architectural concepts; this work provides more specific and in-depth understanding of how they interact. Its other key contribution is that it explores the larger problem of understanding the relation between strategic decisions and how they need to be tailored in light of more tactical decisions.     

A symbolic interpretation for back-propagation networks

Two main problems for the neural network (NN) paradigm are discussed: the output value interpretation and the symbolic content of the connection matrix. In this article, we construct a solution for a very common architecture of pattern associators: the backpropagation networks. First, we show how Zadeh's possibility theory brings a formal structure to the output interpretation. Properties and practical applications of this theory are developed. Second, a symbolic interpretation for the connection matrix is proposed by designing of an algorithm. By accepting the NN training examples as input this algorithm produces a set of implication rules. These rules accurately model the NN behavior. Moreover, they allow to understand it, especially in the cases of generalization or interference.     

Configuring policies in public health applications

Public health is a complex practice due to the requirements of different jurisdictions. These requirements present a challenging environment in which to develop public health applications; software must be flexible in order to adapt to the complexities of different jurisdictions. One approach is to integrate policy management. Policies that define the rules governing an application can be created, modified, or deleted based on the deployment of that application. This paper describes a software architecture and expert system implementation of a policy manager designed to address jurisdictional requirements in public health applications. We define our policy requirements and policy model, the components of the architecture, and how the architecture has been used to implement our policy manager. Finally, we present examples of how the policy manager has configured policies used in three public health applications.     

Storied spaces: Cultural accounts of mobility, technology, and environmental knowing

When we think of mobility in technical terms, we think of topics such as bandwidth, resource management, location, and wireless networks. When we think of mobility in social or cultural terms, a different set of topics come into view: pilgrimage and religious practice, globalization and economic disparities, migration and cultural identity, daily commutes and the suburbanization of cities.In this paper, we examine the links between these two aspects of mobility. Drawing on non-technological examples of cultural encounters with space, we argue that mobile information technologies do not just operate in space, but they are tools that serve to structure the spaces through which they move. We use recent projects to illustrate how three concerns with mobility and space—legibility, literacy, and legitimacy—open up new avenues for design exploration and analysis.     

A rapid prototyping software infrastructure for user interfaces in ubiquitous augmented reality

Recent user interface concepts, such as multimedia, multimodal, wearable, ubiquitous, tangible, or augmented-reality-based (AR) interfaces, each cover different approaches that are all needed to support complex human–computer interaction. Increasingly, an overarching approach towards building what we call ubiquitous augmented reality (UAR) user interfaces that include all of the just mentioned concepts will be required. To this end, we present a user interface architecture that can form a sound basis for combining several of these concepts into complex systems. We explain in this paper the fundamentals of DWARFs user interface framework (DWARF standing for distributed wearable augmented reality framework) and an implementation of this architecture. Finally, we present several examples that show how the framework can form the basis of prototypical applications.     

API-centric Linked Data integration: The Open PHACTS Discovery Platform case study

Data integration is a key challenge faced in pharmacology where there are numerous heterogeneous databases spanning multiple domains (e.g. chemistry and biology). To address this challenge, the Open PHACTS consortium has developed the Open PHACTS Discovery Platform that leverages Linked Data to provide integrated access to pharmacology databases. Between its launch in April 2013 and March 2014, the platform has been accessed over 13.5 million times and has multiple applications that integrate with it. In this work, we discuss how Application Programming Interfaces can extend the classical Linked Data Application Architecture to facilitate data integration. Additionally, we show how the Open PHACTS Discovery Platform implements this extended architecture.     

Using the cloud to develop applications supporting geo-collaborative Situated Learning

Situated Learning stresses the importance of the context in which learning takes place. It has been therefore frequently associated with informal learning or learning outside the classroom. Cloud technologies can play an important role supporting this type of learning, since it requires ubiquitous computing support, connectivity and access to data across various scenarios: on the field, in the classroom, at home, etc. In this paper we first present the situated learning theory and how we can take advantage of services offered by Cloud Computing to implement computer applications implementing learning activities based on this theory, providing pertinent geographical information and discussion boards. Next we propose a software architecture schema which can be used as a basis for integrating existing cloud services into new applications supporting learning activities. Then we present two examples developed with this approach with its viability and advantages. These are discussed in the concluding chapter.     

Explaining answers from the Semantic Web: the Inference Web approach

The Semantic Web lacks support for explaining answers from web applications. When applications return answers, many users do not know what information sources were used, when they were updated, how reliable the source was, or what information was looked up versus derived. Many users also do not know how implicit answers were derived. The Inference Web (IW) aims to take opaque query answers and make the answers more transparent by providing infrastructure for presenting and managing explanations. The explanations include information concerning where answers came from (knowledge provenance) and how they were derived (or retrieved). In this article we describe an infrastructure for IW explanations. The infrastructure includes: IWBase — an extensible web-based registry containing details about information sources, reasoners, languages, and rewrite rules; PML — the Proof Markup Language specification and API used for encoding portable proofs; IW browser — a tool supporting navigation and presentations of proofs and their explanations; and a new explanation dialogue component. Source information in the IWBase is used to convey knowledge provenance. Representation and reasoning language axioms and rewrite rules in the IWBase are used to support proofs, proof combination, and Semantic Web agent interoperability. The Inference Web is in use by four Semantic Web agents, three of them using embedded reasoning engines fully registered in the IW. Inference Web also provides explanation infrastructure for a number of DARPA and ARDA projects.     

Behavioral profiles—a way to model and validate program behavior

Software architecture contains, in addition to its structural part, interaction patterns that can be regarded as part of the architectural solution of the system. The interaction patterns define architecturally significant behavior of the software system. In this paper we propose a visual modeling language, behavioral profiles, for specifying architecturally significant behavioral rules for an application. The language is built on the Unified Modeling Language (UML), which is a visual language widely used in software development. We show how behavioral profiles can be used to support software designers in creating behavioral models that conform to some predefined rules and for ensuring that an application behaves correctly with respect to the rules given in the profiles. A tool called Bebop was built to support software engineers in behavioral profile‐based design and analysis of program behavior. To evaluate the approach and the tools in different application domains, they are utilized in three cases. The size of the applications used in the cases varies from small to quite large software systems, and from academic to industrial ones. The examples demonstrate how the approach presented can be used in practice for different steps in a software engineering process. The examples cover specializing an application framework and monitoring the program execution in run‐time. In addition, they show how behavioral profiles can be used to support guided program comprehension and to validate program execution by analyzing execution traces. Copyright © 2010 John Wiley & Sons, Ltd.     

Learning Syntax by Automata Induction

In this paper we propose an explicit computer model for learning natural language syntax based on Angluin's (1982) efficient induction algorithms, using a complete corpus of grammatical example sentences. We use these results to show how inductive inference methods may be applied to learn substantial, coherent subparts of at least one natural language — English — that are not susceptible to the kinds of learning envisioned in linguistic theory. As two concrete case studies, we show how to learn English auxiliary verb sequences (such as could be taking, will have been taking) and the sequences of articles and adjectives that appear before noun phrases (such as the very old big deer). Both systems can be acquired in a computationally feasible amount of time using either positive examples, or, in an incremental mode, with implicit negative examples (examples outside a finite corpus are considered to be negative examples). As far as we know, this is the first computer procedure that learns a full-scale range of noun subclasses and noun phrase structure. The generalizations and the time required for acquisition match our knowledge of child language acquisition for these two cases. More importantly, these results show that just where linguistic theories admit to highly irregular subportions, we can apply efficient automata-theoretic learning algorithms. Since the algorithm works only for fragments of language syntax, we do not believe that it suffices for all of language acquisition. Rather, we would claim that language acquisition is nonuniform and susceptible to a variety of acquisition strategies; this algorithm may be one these.     

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3 ^rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application. This work was done when the author was with Siemens Communications Inc., Boca Raton, FL     

A General-Purpose Many-Accelerator Architecture Based on Dataflow Graph Clustering of Applications

The combination of growing transistor counts and limited power budget within a silicon die leads to the utilization wall problem （a.k.a. ＂Dark Silicon＂）, that is only a small fraction of chip can run at full speed during a period of time. Designing accelerators for specific applications or algorithms is considered to be one of the most promising approaches to improving energy-efficiency. However, most current design methods for accelerators are dedicated for certain applications or algorithms, which greatly constrains their applicability. In this paper, we propose a novel general-purpose many-accelerator architecture. Our contributions are two-fold. Firstly, we propose to cluster dataflow graphs （DFGs） of hotspot basic blocks （BBs） in applications. The DFG clusters are then used for accelerators design. This is because a DFC is the largest program unit which is not specific to a certain application. We analyze 17 benchmarks in SPEC CPU 2006, acquire over 300 DFGs hotspots by using LLVM compiler tool, and divide them into 15 clusters based on graph similarity. Secondly, we introduce a function instruction set architecture （FISC） and illustrate how DFG accelerators can be integrated with a processor core and how they can be used by applications. Our results show that the proposed DFG clustering and FISC design can speed up SPEC benchmarks 6.2X on average.     

Innovation and evolution in integrated web application testing with TTCN-3

Over the last 10 years there has been continuous innovation and evolution in the technology of web applications. While originally designed as a telecom testing platform, TTCN-3 has proven to be a flexible and powerful platform for web application testing throughout this period. Major challenges to testing have been integration with unit test frameworks, service-oriented architecture, rich client interfaces, and security vulnerabilities. Through careful analysis and practical experience in industrial projects we have developed mechanisms to address each of these aspects of web application testing in TCN-3. These mechanisms are summarized here with examples drawn from our industrial experience to show how TTCN-3 provides significant advantages for testing web applications in comparison to other tools typically used in industry. We also present a significant extension to the model architecture for TTCN-3 which greatly facilitates web application testing that has been implemented by a major vendor and is now under consideration by the ETSI standards committee.     

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3^rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application. This work was done when the author was with Siemens Communications Inc., Boca Raton, FL     

Fine-grained visualization pipelines and lazy functional languages

The pipeline model in visualization has evolved from a conceptual model of data processing into a widely used architecture for implementing visualization systems. In the process, a number of capabilities have been introduced, including streaming of data in chunks, distributed pipelines, and demand-driven processing. Visualization systems have invariably built on stateful programming technologies, and these capabilities have had to be implemented explicitly within the lower layers of a complex hierarchy of services. The good news for developers is that applications built on top of this hierarchy can access these capabilities without concern for how they are implemented. The bad news is that by freezing capabilities into low-level services expressive power and flexibility is lost. In this paper we express visualization systems in a programming language that more naturally supports this kind of processing model. Lazy functional languages support fine-grained demand-driven processing, a natural form of streaming, and pipeline-like function composition for assembling applications. The technology thus appears well suited to visualization applications. Using surface extraction algorithms as illustrative examples, and the lazy functional language Haskell, we argue the benefits of clear and concise expression combined with fine-grained, demand-driven computation. Just as visualization provides insight into data, functional abstraction provides new insight into visualization.     

Acceleration of software algorithms using hardware/software co-design techniques

Currently there is significant interest in the design and implementation of embedded systems where the hardware and software subsystems are developed concurrently in order to meet design constraints. We present a development environment for general-purpose systems, where the objective is to accelerate the performance of software-based applications, which are specified by C programs. Such programs may be partitioned into hardware and software subsystems — a speed-critical region of the software is implemented in an FPGA in order to provide the performance acceleration. We also discuss two versions of the underlying system hardware architecture. Practical examples are given to illustrate our approach.     

Towards an RCC-Based Accelerator for Computational Fluid Dynamics Applications

Computational Fluid Dynamics (CFD) applications are a critical tool in designing sophisticated mechanical systems such as jet engines and gas turbines. CFD applications use intensive floating-point calculations and are typically run on High-Performance Computing (HPC) systems. We analyze three of the most compute intensive functions (Euler, Viscous, and Smoothing algorithms) and develop a baseline system architecture for accelerating these functions in RCC hardware. We then present detailed design data for the most compute intensive (Euler) function. Based on this analysis, we show that an RCC-based CFD accelerator—compared to conventional processors—promises dramatic improvement in sustained compute speed at better price-performance ratios coupled with much lower overall power consumption.     

Healing Web applications through automatic workarounds

We develop the notion of automatic workaround in the context of Web applications. A workaround is a sequence of operations, applied to a failing component, that is equivalent to the failing sequence in terms of its intended effect, but that does not result in a failure. We argue that workarounds exist in modular systems because components often offer redundant interfaces and implementations, which in turn admit several equivalent sequences of operations. In this paper, we focus on Web applications because these are good and relevant examples of component-based (or service-oriented) applications. Web applications also have attractive technical properties that make them particularly amenable to the deployment of automatic workarounds. We propose an architecture where a self-healing proxy applies automatic workarounds to a Web application server. We also propose a method to generate equivalent sequences and to represent and select them at run-time as automatic workarounds. We validate the proposed architecture in four case studies in which we deploy automatic workarounds to handle four known failures in to the popular Flickr and Google Maps Web applications. This work has been supported by the project PerSeoS funded by the Swiss National Fund.