22319012
A Scalable Testing Framework for Location-Based Services
A novel testing framework for location based services is introduced. In particular, the paper showcases a novel architecture for such a framework. The implementation of the framework illustrates both the functionality and the feasibility of the framework proposed and the utility of the architecture. The new framework is evaluated through comparison to several other methodologies currently available for the testing of location-based applications. A case study is presented in which the testing framework was applied to a typical mobile service tracking system. It is concluded that the proposed testing framework achieves the best coverage of the entire location based service testing problem of the currently available methodologies; being equipped to test the widest array of application attributes and allowing for the automation of testing activities.
16085618
A TDD approach to introducing students to embedded programming
Learning embedded programming is a highly demanding exercise. The beginner is bombarded with complexity from the start: embedded production based around a myriad of C++ constructs with low-level elements integrated onto ever more complicated processor architectures. The picture is further compounded by tool support having unfamiliar roles and appearances from previous student experiences. This demanding situation often has the student bewildered; seeking for "a crutch" or the simplest way forward regardless of the overall consequences. To control this potentially chaotic picture, the instructor needs to introduce devices to combat this complexity. We argue that test driven development (TDD) should become the instructor's principal weapon in this fight. Reasons for this belief combined with our, and the students', experiences with this novel approach are discussed.
11798209
A Hardware-Assisted Tool for Fast, Full Code Coverage Analysis
Software reliability can be improved by using code coverage analysis to ensure that all statements are executed at least once during the testing process. When full code coverage information is obtained through software code instrumentation, high runtime performance overheads are incurred. Techniques that perform deferred or selective code instrumentation have shown success in reducing run-time overheads; however, the execution profile remains distorted. Techniques have been proposed that use internal processor hardware during the data gathering process, e.g. program counter logging. These approaches have been shown to reduce overheads; but currently trade swift execution for sparse code coverage. By combining the branch-vector hardware designed for debugging modern embedded processors with on-demand code coverage analysis, we have developed a new tool which provides full code coverage, while minimizing performance distortions. Experimental results show a performance impact of only 8 - 12%, while still providing 100% code coverage information.
8240301
E-RACE, A Hardware-Assisted Approach to Lockset-Based Data Race Detection for Embedded Products
Limited research exists for identifying data races under the specific characteristics found in embedded systems. E-RACE is a new style of data-race identification tool which directly utilizes specialized hardware capabilities to monitor the flow of data and instructions. Compared to existing data race analysis approaches, the hardware-assisted E-RACE tool has advantages of recognizing data-race issues without requiring extensive software code instrumentation. The tool is integrated into an Embedded Unit Testing Driven Development Framework to encourage the construction of testable code and early identification of data-races.
8493649
Empirical analysis of the correlation between amount-of-reuse metrics in the C programming language
Disclosed are the magnesium salts of N-carboxyamino acids, a process for their preparation, and their use of lubricating oil additives.
167449
Rigorous specification and conformance testing techniques for network protocols, as applied to TCP, UDP, and sockets
Network protocols are hard to implement correctly. Despite the existence of RFCs and other standards, implementations often have subtle differences and bugs. One reason for this is that the specifications are typically informal, and hence inevitably contain ambiguities. Conformance testing against such specifications is challenging.In this paper we present a practical technique for rigorous protocol specification that supports specification-based testing. We have applied it to TCP, UDP, and the Sockets API, developing a detailed 'post-hoc' specification that accurately reflects the behaviour of several existing implementations (FreeBSD 4.6, Linux 2.4.20-8, and Windows XP SP1). The development process uncovered a number of differences between and infelicities in these implementations.Our experience shows for the first time that rigorous specification is feasible for protocols as complex as TCP@. We argue that the technique is also applicable 'pre-hoc', in the design phase of new protocols. We discuss how such a design-for-test approach should influence protocol development, leading to protocol specifications that are both unambiguous and clear, and to high-quality implementations that can be tested directly against those specifications.
18147449
A flexible hardware encoder for low-density parity-check codes
We describe a flexible hardware encoder for regular and irregular low-density parity-check (LDPC) codes. Although LDPC codes achieve better performance and lower decoding complexity than turbo codes, a major drawback of LDPC codes is their apparently high encoding complexity. Using an efficient encoding method proposed by Richardson and Urbanke, we present a hardware LDPC encoder with linear encoding complexity. The encoder is flexible, supporting arbitrary H matrices, rates and block lengths. An implementation for a rate 1/2 irregular length 2000 LDPC code encoder on a Xilinx Virtex-II XC2V4000-6 FPGA takes up 4% of the device. It runs at 143 MHz and has a throughput of 45 million codeword bits per second (or 22 million information bits per second) with a latency of 0.18 ms. The performance can be improved by exploiting parallelism: several instances of the encoder can be mapped onto the same chip to encode multiple message blocks concurrently. An implementation of 16 instances of the encoder on the same device at 82 MHz is capable of 410 million codeword bits per second, 80 times faster than an Intel Pentium-lV 2.4 GHz PC.
166928377
Promoting health and productivity in the computerized office
9634553
Managing Change: An Ontology Version Control System
In this paper we present the basic requirements and initial design of a system which manages and facilitates changes to an OWL ontology in a multi-editor environment. This system uses a centralized client-server architecture in which the server maintains the current state and full history of all managed ontologies. Clients can access the current ontology version, all historical revisions, and differences between arbitrary revisions, as well as metadata associated with revisions. This system will be used by many other ontology based services, such as incremental reasoning, collaborative ontology development, advanced ontology search, and ontology module extraction. Taken holistically, this network of services will provide a rich environment for the development and management of ontology based information systems. 1 Motivation and Requirements We need for a system that manages access to a changing ontology. This requirement is experienced by a variety applications with different stakeholders. An illustrative use case is presented below. A large distributed organization requires integration and alignment of many heterogeneous data sources and information artifacts. They facilitate such integration by employing one or more expressive OWL ontologies that exist in defined relations to data sources, information artifacts, and an enterprise conceptual model. These ontologies, as a critical infrastructure components, have stakeholders throughout the organization and outside its boundaries. Further, they are developed and maintained concurrently by many parties. Individual stakeholders participate in the ontology engineering process in different ways. Some are primarily consumers, but may make detailed edits to areas of the ontologies critical to them. Others are charged with maintaining high-level ontology coherence and use an integrated ontology development environment, such as Protege-OWL, to collaborate with similar editors in realtime, leveraging tools to maintain a dynamic view of the ontology. All stakeholders rely on the ontologies being available and consistent across the organization. This use case illustrates a set of requirements: Client Performance The network is a potential bottleneck of any distributed or client-server system, but the critical work of ontology development is
26213696
Formal methods fact vs. fiction