John Linn

Speech-Aware Multimedia

Computer users have long desired a personal software agent that could execute verbal commands. Todays World Wide Web (WWW or Web), with its point and click hypertext interface, makes a tremendous amount of information readily available online. A speech interface would make the Web even more powerful, allowing us to access information by surfing the Web by voice. TI have developed Speech Aware Multimedia (SAM) with this in mind, to make information on the Web more accessible and useful. They combined an innovative speech recognition engine with the Web to let anyone browse arbitrary Web pages using only speech as the input medium. Speech brings added flexibility and power to the classical Web interface and makes information access more natural. Todays speech recognition capability is well matched to Web browsing. The Web page provides a natural, well defined context for a speech recognition application. The recognition engine does not need to recognize any and all possible phrases, but only those phrases pertaining to the specific page in view at the moment. This context imposes limits that significantly aid recognition performance. Furthermore, the visual information on a page prompts the user on what to request and how to request it by voice.

A component-based approach for embedded software development

The rapid growth in the demand of embedded systems and the increased complexity of embedded software pose an urgent need for advanced embedded software development techniques. Software technology is shifting toward semi-automated code generation and integration of systems from components. Component-based development (CBD) techniques can significantly reduce the time and cost for developing software systems. However, there are some difficult problems with the CBD approach. Component identification and retrieval as well as component composition require extensive knowledge of the components. Designers need to go through a steep learning curve in order to effectively compose a system out of available components. We discuss an integrated mechanism for component-based development of embedded software. We develop an On-line Repository for Embedded Software (ORES) to facilitate component management and retrieval. ORES uses an ontology-based approach to facilitate repository browsing and effective search. Based on ORES, we develop the code template approach to facilitate semi-automated component composition. A code template can be instantiated by different sets of components and, thus, offers more flexibility and configurability and better reuse. Another important aspect in embedded software is the nonfunctional requirements and properties. In ORES, we capture nonfunctional properties of components and provide facilities for the analysis of overall system properties.

An on-line repository for embedded software

The use of off-the-shelf components (COTS) can significantly reduce the time and cost of developing large-scale software systems. However, there are some difficult problems with the component-based approach. First, the developers have to be able to effectively retrieve components. This requires the developers to have an extensive knowledge of available components and how to retrieve them. After identifying the components, the developers also face a steep learning curve to master the use of these components. We are developing an On-line Repository for Embedded Software (ORES) to facilitate component management and retrieval. In this paper, we address the issues of designing software repository systems to assist users in obtaining appropriate components and learning to understand and use the components efficiently. We use an ontology to construct an abstract view of the organization of the components in ORES. The ontology structure facilitates repository browsing and effective search. We also develop a set of tools to assist with component comprehension, including a tutorial manager and a component explorer.

Reliability of systems of independently developable end-user assessable logical (IDEAL) programs

Computers are being used to automate critical services, including manufacturing systems, transportation, etc. For these critical applications, it is necessary to be able not only to achieve high quality but also to rigorously demonstrate that high quality has in fact been achieved. One approach that is used to facilitate prevention as well as detection of software faults is to decompose the requirements specification into more manageable portions. However, this does not necessarily enable the demonstration of high quality. This paper discusses a method of decomposing software into aspects that allows the system reliability to be inferred from the aspect reliabilities. Each aspect is independently developable, i.e., it can be designed and implemented independently of the other aspects in the system. In addition, each aspect is end-user assessable, i.e., it can be tested or verified by the end-user independently of any other aspect. We identify five classes of IDEAL (Independently Developable End-user Assessable Logical) aspects and, for each class, we present the conditions that must be satisfied in order to compute the system reliability from the aspect reliabilities.

Application of AI planning techniques to automated code synthesis and testing

Rapid growth in the demand for embedded systems and the increased complexity of embedded software pose an urgent need for advanced embedded software development techniques. One attractive approach is to enable semi-automated code generation and integration of systems from components. However, the implementation and validation of these systems requires a steep learning curve due to the large number, variety, and complexity of software components. In this paper, we discuss the potential application of AI planning techniques in assisting with the synthesis of glue code for assembling a system from existing components as well as automated testing of the system. The approach works by transforming component specifications into rules that operate on a domain-specific state space. Each rule captures the semantics of a method in a class. The code assembly and testing requirements are described by identifying conditions (goals) that should be achieved. An automated planning system computes a sequence of rules and their instantiations that will achieve the goal state. This sequence is then used to synthesize the code or to generate test cases. The approach is illustrated using an example.

A variable-rate CELP coder for fast remote voicemail retrieval using a notebook computer

Remote retrieval of compressed voicemail data over a telephone line is one of several emerging applications of speech coding. Using a notebook computer equipped with a modem, a user can remotely access a networked desktop unit located at their office or home to retrieve various types of information such as email, FAX, electronic documents as well as voicemail. By compressing the speech data, we reduce the amount of time needed for the transfer of voice data over the telephone line. We have developed a high-quality variable-rate CELP (code-excited linear prediction) coder which can be used in such an application. The coder operates at an average rate of 3 kb/s assuming 80% speech activity and uses several new techniques including a mode decision mechanism based on the use of a peakiness measure and a novel excitation search method called gain-matched analysis-by-synthesis. The coder gives quality comparable to the Microsoft GSM 6.10 Audio Codec at 13 kb/s.

A software enhancement system for embedded software development

This paper proposes a rule-based expert system model to assist developers in enhancing the quality of embedded software. The expert system supports semi-automated source code enhancements from multiple perspectives including optimization, reconfiguration to achieve quality of service (QoS) trade-offs, conformance to coding standards, etc., by defining a rule base that is composed of modularized and extensible rule sets. The rule sets are composed of re-usable rules; the rules capture the in-depth knowledge of different software experts. The expert system also adopts a technique to support automated fact generation. This allows the expert system to support processing programs developed in different programming languages

Embedded software development challenges in the digital signal processing era

The rapid growth of products that incorporate programmable digital signal processors is a driving-force for improving the embedded software development process. DSP-based product development presents some difficult challenges for manufacturers. Several embedded software development trends can be anticipated as the industry seeks to overcome these difficulties. The paper discusses some of the challenges for embedded DSP software development and projects some opportunities to address these challenges.