Digital System Testing

This paper focuses on the importance of test driven development, in an interdisciplinary academic case study, involving unauthorized access and fraud. In it, Problem Based Learning (PBL) enabled the organization of an environment for diverse knowledge and skills, favorable to experimentation and prototyping of new models, methods, techniques, and tools. The application of the principles of agile methods aimed at overcoming difficulties related to the computer systems development, such as requirement changes, uncertainties, and risks, in order to improve quality. Unlike traditional methodologies, tests were used since the beginning of the development lifecycle with Acceptance Test Driven Development (ATDD). The agile testing quadrants guided the categorized elaboration of tests during unit testing, integration testing, system testing, and acceptance testing phases. The main contribution of this article was the integrated application of PBL, ATDD, and agile development in the case study of a Real-Time Embedded System for Unauthorized Access Control and Fraud Detection (Sistema Embarcado de Tempo Real para Controle de Acessos Indevidos e Deteccao de Fraudes-SETRAIF).

The analysis of granulometry of substances is relevant in a great variety of the research and industrial applications. Unfortunately, image-based algorithms for granulometry analysis are difficult to tune and validate. In a typical setup, one or more cameras acquire images of a scene with a great number of objects or particles that must be measured. The distribution of the sizes/shape characteristics of the elements are the common output of such systems. The creation of supervised image database where the coordinates of all elements are known is very important and it allows for testing in a suitable manner the final size/shape distribution of particles produced by the image processing system with respect to the real distribution. Due to the great amount of objects or particles in the images, it is not often convenient, or even impossible, to individually measure each single objects in order to test the capability of the image processing system to locate and measure the elements (creation of a supervised dataset). One possible solution encompasses the creation of a synthetic image dataset where the position of each elements is known a priori. In this paper we propose a virtual environment to create and test an imagebased granulometric system based on the 3D engine Blender. Results are encouraging and show the effectiveness of the proposed method.

In order to reduce the labor-intensive nature of evaluating quality of fused tracks in a multi-sensor, multi-platform environment, the Metrics Assessment System (MAS) was developed to provide heavily automated, real-time metric calculation and display. The MAS presents metrics in tables and graphs within the tactical display and provides overlays on the tactical display for focused assessment. Originally, MAS included standard kinematic metrics, but more recent work has generated additional metrics based on track-to-track versions of Track Purity, Target Effectiveness, and Assignment Accuracy, metrics derived from a confusion matrix analysis of the fused and known truth tracks, and Receiver Operating Characteristic Curves. Data mining tools were used to assess the effectiveness of candidate metrics for inclusion in the MAS. This paper describes the metrics, the evaluations, and the framework for metric assessment which this work has provided.

An organizational level test strategy needs to incorporate metrics to make the testing activities visible and available to process improvements. The majority of testing measurements that are done are based on faults found in the test execution phase. In contrast, this paper investigates metrics to support software test planning and test design processes. We have assembled metrics in these two process types to support management in carrying out evidence-based test process improvements and to incorporate suitable metrics as part of an organization level test strategy. The study is composed of two steps. The first step creates a relevant context by analyzing key phases in the software testing lifecycle, while the second step identifies the attributes of software test planning and test design processes along with metric(s) support for each of the identified attributes.

System testing is concerned with testing an entire system based on its specifications. In the context of object-oriented, UML development, this means that system test requirements are derived from UML analysis artifacts such as use cases, their corresponding sequence and collaboration diagrams, class diagrams, and possibly the use of the Object Constraint Language across all these artifacts. Our goal is to support the derivation of test requirements, which will be transformed into test cases, test oracles, and test drivers once we have detailed design information. Another important issue we address is the one of testability. Testability requirements (or rules) need to be imposed on UML artifacts so as to be able to support system testing efficiently. Those testability requirements result from a trade-off between analysis and design overhead and improved testability. The potential for automation is also an overriding concern all across our work as the ultimate goal is to fully support testing activities with high-capability tools.

In this paper we present our original approach to the model-based statistical usage testing of a class of communication protocol implementations that are based on the State design pattern and Java programming environment augmented with the class FSMSystem. The approach is based on the working environment that has been proven on a number of real-world projects. The working environment is created with the following set of tools: generic modeling environment with the operational profile model paradigm registered to it, operational profile model interpreter, generic test case generator, test case compiler, and the unit testing framework JUnit extended with the class TestBed that acts as both test driver and stub thus providing the complete test harness. In the paper we present the methodology of the model-based statistical usage testing of a class of communication protocol implementations, the tools that support this methodology, and the case study -the model based statistical usage testing of SIP INVITE client transaction, a part of the SIP protocol stack.

Model-based selective regression testing promises reduction in cost and labour by selecting a subset of the test suite corresponding to the modifications after system evolution. However, identification of modifications in the systems and selection of corresponding test cases is challenging due to interdependencies among models. State-based testing is an important approach to test the system behaviour. Unfortunately the existing state-based regression testing approaches do not care for dependencies of the state machine with other system models. This paper presents the tool support and evaluation of our statebased selective regression testing methodology for evolving state-based systems. START is an Eclipsebased tool for state-based regression testing compliant with UML 2.1 semantics. START deals with dependencies of state machines with class diagrams to cater for the change propagation. We applied the START on a case study and our results show significant reduction in the test cases ...

We present a new approach for conformance testing of protocols specified as a collection of communicating finite state machines (FSM's). Our approach uses a guided random walk procedure. This procedure attempts to cover all transitions in the component FSM's. We also introduce the concept of observers that check some aspect of protocol behavior. We present the result of applying our method to two example protocols: full-duplex alternating bit protocol and the ATM-adaptationlayer-convergence protocol. Applying our procedure to the ATM adaptation layer, 99% of component FSM's edges can be covered in a test with 11692 input steps. Previous approaches cannot do conformance test generation for standard protocols (such as asynchronous transfer mode (ATM) adaptation layer) specified as a collection of communicating FSM's.

Sensor networks for environmental data acquisition will play an important role in the development of future large data acquisition systems, particularly in oceanographic observation and operational oceanography. Within these scenarios, many challenges will be overcome by using emergent networking technologies which have been successfully tested in other fields where distributed systems are used.

Burn-in and stress testing are becoming increasingly important, a sine qua non in the electronics industry as customers become increasingly sensitive to failures occurring in the useful life of a product or system. Burn-in subjects the product to expected field extremes by exposing the product to accelerated temperature and voltages stress to screen infant mortalities (latent failures). In the past, burn in duration studies use constant failure rate statistics to model the classical bathtub curve describing early-life failure behavior of the product throughout its operating lifetime. Thus, FIT (Failure in Time) rate calculations were greatly inflated by including failures occurring long after the time of interest. This manifests in a requirement for a very low failure rate after the conservative burn-in stresses causes the need to sample larger number of units in order to differentiate between the passing and failing criteria. Furthermore, it makes the Burn-In study more complicated and reduces the chance of success.

A state-feedback controller was designed to simulate the Starling response of the heart in a mock circulatory system (MCS). The controller drives a voice coil actuator (VCA) to follow a reference volume, and thus generate the desired chamber pressure, by using position and speed feedbacks. The reference volume was adjusted according to the maximum ventricular elastance (Emax), end-systolic ventricular pressure, and left atrial pressure to respond to load variation in the MCS. The controller was tested in computer simulation by changing the load conditions and Emax of the MCS. The MCS along with the controller was able to reproduce human heart function from healthy to sick conditions. A rotary ventricular assist device (VAD) was then introduced in the simulation to test the MCS. The MCS was able to produce a consistent cardiac function even with the presence of the VAD. These results suggest that the new MCS control system is able to simulate the cardiac function for VAD test.

In this paper, a novel evolutionary algorithm-based approach to optimal design of multimachine power-system stabilizers (PSSs) is proposed. The proposed approach employs a particle-swarm-optimization (PSO) technique to search for optimal settings of PSS parameters. Two eigenvalue-based objective functions to enhance system damping of electromechanical modes are considered. The robustness of the proposed approach to the initial guess is demonstrated. The performance of the proposed PSO-based PSS (PSOPSS) under different disturbances, loading conditions, and system configurations is tested and examined for different multimachine power systems. Eigenvalue analysis and nonlinear simulation results show the effectiveness of the proposed PSOPSSs to damp out the local and interarea modes of oscillations and work effectively over a wide range of loading conditions and system configurations. In addition, the potential and superiority of the proposed approach over the conventional approaches is demonstrated.

Two types of addressable failure site test structures are developed. In-house program is coded to extract the electrical information and simulate the failure mode. A complete set of test structure modules for 0.25 um logic backend of line process is implemented in a test chip of 22x6.6 mm 2 . By using the novel test structure, the yield analysis and defect tracking of BEOL process development as well as low-k Fluorinated SiO 2 (FSG) process optimization are demonstrated.

This paper deals with the problem of digital visual inspection of thin-film disk heads. We will present machine vision algorithms and a supporting architecture that are integrated in a fully automated prototype system for disk head inspection. We will also elaborate on some specific methods, such as computation of the Hough transform and multicode masks in pipeline architectures, object segmentation in textured backgrounds, and matching of extracted defects with inspection specifications. Extensive experimented results will also be given.

This paper presents MATERA, a framework that integrates modeling in the Unified Modeling Language (UML), with requirement traceability across a model-based testing (MBT) process. The Graphical User Interface (GUI) of MAT-ERA is implemented as a plug-in in the NoMagic's MagicDraw modeling tool, combining existing capabilities of MagicDraw with custom ones. MATERA supports graphical specification of the requirements using SysML and tracing of them to the UML models specifying the SUT. Model validation is performed in MagicDraw using both predefined and custom validation rules. The resulting models are automatically transformed into input for the Conformiq Qtronic tool, used for automated test generation. Upon executing the test scripts generated by Qtronic in the NetHawk's East execution environment, the results of statistic analysis of the test run are presented in the GUI. The back-traceability of the covered requirements from test to models is also provided in the GUI to facilitate the identification of the source of possible errors in the models. The approach we present shows that existing model-based languages and tools are an enabler for model-based testing and for providing integrated tool support across the MBT process.

Decoupling techniques are extensively used in Power System State Estimation (PSSE). The most popular decou¬ pled algorithm is based on decoupling the gain matrix G. After decoupling, two diagonal submatrices Gn and G22 form two matrix equations with only half dimension. Hence, computing time and storage locations are reduced.

Sterotactic percutaneous lumpectomy is becoming an effective means of diagnosing and excising a small breast cancer. Radiation to the biopsy cavity by a brachytherapy balloon is an effective and minimally invasive method used to prevent recurrence of the cancer. Following percutaneous lumpectomy an elliptical shaped cavity is left in the breast. There is a period of up to four days prior to initiation of Brachytherapy while the tissue sample is undergoing pathology testing. If a small cancer is present and excised with clear margins Brachytherapy can be initiated. Currently there are no devices used to keep the cavity and track open between the time of percutaneous lumpectomy and the start of radiation therapy. Typically three invasive procedures are required, first the breast biopsy, second excision of the cancer and third balloon placement for future radiation treatments. The purpose of this project is to design a temporary cavity spacer and insertion method following percutaneous lumpectomy, allowing all three aspects of the procedure to be completed at the time of initial biopsy.

Integration testing has always been a challenge especially if the system under test is large with many subsystems and interfaces. This paper proposes an approach to design End-to-End (E2E) integration testing, including test scenario specification, test case generation and tool support. Test scenarios are specified as thin threads, each of which represents a single function from an end user's point of view. Thin threads can be organized hierarchically into a tree with each branch consisting of a set of related thin threads representing a set of related functionality. A test engineer can use thin-thread trees to generate test cases systematically, as well as carry out other related tasks such as risk analysis and assignment, regression testing, ripple effect analysis. A prototype tool has been developed to support E2E testing in a distributed environment on the J2EE platform.

Field programmable gate arrays (FPGAs) play many important roles, ranging from small glue logic replacement to System-on-Chip designs. Nevertheless, FPGA vendors can not accurately specify the energy consumption information of their products on the device data sheets because the energy consumption of FPGAs is strongly dependent on target circuit including resource utilization, logic partitioning, mapping, placement and route. While major CAD tools have started to report average power consumption under given transition activities, energy optimal FPGA design demands more detailed energy estimation.

The recently introduced random walker segmentation algorithm of has been shown to have desirable theoretical properties and to perform well on a wide variety of images in practice. However, this algorithm requires user-specified labels and produces a segmentation where each segment is connected to a labeled pixel. We show that incorporation of a nonparametric probability density model allows for an extended random walkers algorithm that can locate disconnected objects and does not require user-specified labels. Finally, we show that this formulation leads to a deep connection with the popular graph cuts method of .

This paper presents important issues on the design and implementation of a Multimedia Digital Classroom (MDC) system with its applications. The MDC system is implemented in Java language. It aims at providing important tools to support a distributed interactive ...

One of the most difficult problems that humanity currently faces is the sustainable development of our society, i.e. how to meet the needs of the present without compromising the ability of future generations to meet their own needs. Solving this challenge requires a multidisciplinary approach where researchers with different backgrounds combine their efforts. As software engineers, we can contribute to these efforts by offering existing software requirements modeling and analysis techniques as a means to integrate sustainability requirements in decision-making processes. In this paper, we use a popular language for modeling early requirements as a way to visualize the impact of alternative options on sustainability goals and to analyze the conflicts between sustainability and other problem-specific objectives. We apply this idea to the decision-making activities pertaining to the organization of the ICSE'09 conference itself. We find that the modeling activity significantly facilitates exploration, understanding and comparison of large numbers of possible sustainability measures and allows for better informed and justified decisions.

This paper traces the development of the broadcasting-satellite service (BSS) in India. It describes the key system test and demonstration experiments conducted in India prior to the development of an operational first-generation domestic satellite system. The BSS component of this system, the Indian National Satellite System (INSAT-l), has a character quite different from BSS or DBS developments elsewhere. The paper provides a general description of the INSAT-1 system, with particular reference to the services and the broad operational and technical features and characteristics of its BSS component.

In Virtual-Environment (VE) Applications, where virtual objects are presented in a head-mounted display, virtual images must be continuously stabilized in space against the user's head motion. Latencies in head-motion compensation cause virtual objects to swim around instead of being stable in space. This results in an unnatural feel, disorientation, and simulation sickness in addition to errors in fitting/matching of virtual and real objects. Visual update delays are a critical technical obstacle for implementation of head-mounted displays in a wide variety of applications. To address this problem, we propose to use machine learning techniques to define a forward model of head movement based on angular velocity information. In particular, we utilize recurrent neural network to capture the temporal pattern of pitch and yaw motion.

This paper presents a technique of re-using DFT logic for system functional and silicon debugging. By re-configuring the existing DFT logic implemented on an ASIC, we are able to 1) test each part of an ASIC in a system environment separately and thus locate manufacturing defects, 2) control and observe any state elements of an ASIC to facilitate system function

Packet classification is an enabling technology for next generation network services and often the primary bottleneck in high-performance routers. The performance and capacity of many algorithms and classification devices, including TCAMs, depend upon properties of the filter set and query patterns. Despite the pressing need, no standard filter sets or performance evaluation tools are publicly available. In response to this problem, we present ClassBench, a suite of tools for benchmarking packet classification algorithms and devices. ClassBench includes a Filter Set Generator that produces synthetic filter sets that accurately model the characteristics of real filter sets. Along with varying the size of the filter sets, we provide high-level control over the composition of the filters in the resulting filter set. The tool suite also includes a Trace Generator that produces a sequence of packet headers to exercise packet classification algorithms with respect to a given filter set. Along with specifying the relative size of the trace, we provide a simple mechanism for controlling locality of reference. While we have already found ClassBench to be very useful in our own research, we seek to eliminate the significant access barriers to realistic test vectors for researchers and initiate a broader discussion to guide the refinement of the tools and codification of a formal benchmarking methodology. The ClassBench tools are publicly available at the following site:

The paper deals with the quick prototype design and hardware-in-the-loop real-time test of the embedded control system of an indoor miniature quadrotor helicopter (UAV) before first flight. The control law is of backstepping type, the sensory system consists of a marker-based vision system outside the helicopter in radio connection with the embedded controller and a 3D inertial measurement unit (IMU) on the helicopter. Extended Kalman filters solve the state estimation problem. Brushless DC motors serve as actuators. For quick prototype design of the embedded controller MATLAB, Simulink, Real-Time Workshop and the MPC555 Target Compiler were used. Because of the critical character of the control of flying systems the whole embedded control system was hardware-in-the-loop tested by using DS1103 of dSPACE for real-time emulation of the indoor helicopter. During test the helicopter and the sensors were mapped to DS1103 and the test was performed in real-time using the helicopter and sensor models. Communication during the test was running using CAN bus protocol between the Freescale MPC555 processor of the embedded controller and the emulation of the helicopter and the sensors on DS1103.

A switched reluctance motor torque ripple reduction scheme using a B-spline neural network (BSNN) is presented. Closed-loop torque control can be implemented using an on-line torque estimator. Due to the local weight updating algorithm used for the BSNN, an appropriate phase current profile for torque ripple reduction can be obtained on-line in real time. It has good dynamic performance with respect to changes in torque demand. The scheme does not require high-bandwidth current controllers. Simulation and experimental results demonstrate the validity of the scheme.

A weighted cepstral distance measure is proposed and is tested in a speaker-independent isolated word recognition system using standard DTW (dynamic time warping) techniques. The measure is a statistically weighted distance measure with weights equal to the inverse variance of the cepstral coefficients. The experimental results show that the weighted cepstral distance measure works substantially better than both the Euclidean cepstral distance and the log likelihood ratio distance measures across two different databases. The recognition error rate obtained using the weighted cepstral distance measure was about 1 percent for digit recognition. This result was less than onefourth of that obtained using the simple Euclidean cepstral distance measure and about one-third of the results using the log likelihood ratio distance measure. The most significant performance characteristic of the weighted cepstral distance was that it tended to equalize the performance of the recognizer across different talkers.

This paper introduces an intrusion-detection device named honeyfiles. Honeyfiles are bait files intended for hackers to access. The files reside on a file server, and the server sends an alarm when a honey file is accessed. For example, a honeyfile named "passwords.txt" would be enticing to most hackers. The file server's end-users create honeyfiles, and the end-users receive the honeyfile's alarms. Honeyfiles can increase a network's internal security without adversely affecting normal operations. The honeyfile system was tested by deploying it on a honeynet, where hackers' use of honeyfiles was observed. The use of honeynets to test a computer security device is also discussed. This form of testing is a useful way of finding the faulty and overlooked assumptions made by the device's developers.

The first part of this dissertation presents an innovative method for the assessment of generation system reliability. In this method, genetic algorithm (GA) is used as a search tool to truncate the probability state space and to track the most probable failure states. GA stores system states, in which there is generation deficiency to supply system maximum load, in a state array. The given load pattern is then convoluted with the state array to obtain adequacy indices.

This paper encompasses t w o main topics: a broad and general analysis of the issue of performance evaluation of NLP systems and a report on a specific approach developed by the authors and experimented on a sample test case. More precisely, it first presents a brief survey of the major works in the area of NIP systems evaluation. Then, after introducing the notion of the life cycle of an N I P system, it focuses on the concept of performance evaluation and analyzes the scope and the major problems of the investigation. The tools generally used within computer science to assess the quality of a software system are briefly reviewed, and their applicability to the task of evaluation of NLP systems is discussed. Particular attention is devoted to the concepts of efficiency, correctness, reliability, and adequacy, and how all of them basically fail in capturing the peculiar features of performance evaluation of an N I P system is discussed. Two main approaches to performance evaluation are later introduced; namely, black-box-and modelbased, and their most important characteristics are presented. Finally, a specific model for performance evaluation proposed by the authors is illustrated, and the results of an experiment with a sample application are reported. The paper concludes with a discussion o n research perspectwes, open problems, and importance ofperformance evaluation to industrial applications.

In this paper, a methodology to estimate parameters of synchronous generator and its excitation system, based on the trajectory sensitivity technique, is proposed. Some alternatives are proposed for this technique regarding a future 'on-line' application.

This paper attempts to integrate RF technology into smoke detector circuitry. In the proposed system, a smoke detector upon senses smoke activates its alarm, sends a low voltage signal to all other smoke detectors in the vicinity. This low voltage signal activates the individual relays in the other smoke detectors causing them to emit a tone that alerts residents that one of the smoke detectors senses smoke. In this system the transmitter and receiver are installed in a unit and the need for a base is eliminated. The individual smoke detectors are equipped with all the electronics required to both send and receive signals. They are battery operated and therefore they require no external connections. They can be installed by a homeowner just as they would a normal smoke detector. The proposed design is aiming to have Cost efficient system, Compact design, easily expandable, Simple to install, Replaceable components. The system was tested indoor and outdoor with different distance and with the presence of noise.

In this paper we survey, consolidate, and present the state of the art in distributed database concurrency control. The heart of our analysts is a decomposition of the concurrency control problem into two major subproblems: read-write and write-write synchronization. We describe a series of synchromzation techniques for solving each subproblem and show how to combine these techniques into algorithms for solving the entire concurrency control problem. Such algorithms are called "concurrency control methods." We describe 48 principal methods, including all practical algorithms that have appeared m the literature plus several new ones. We concentrate on the structure and correctness of concurrency control algorithms. Issues of performance are given only secondary treatment.

The complexity of walking robots poses a number of control problems due to the large number of degrees of freedom involved in the robot's motion. This work deals with the design of a hexapod robot, whose legs have 3 rotative joints and the same configuration. The kinematics ...

The article presents the principle of operation and results of laboratory and simulation tests of a multi-pulse power network converter systems with direct-current voltage output, mating with shunt active power filter (APF). The discussed systems allow for significant reduction of undesirable higher harmonics in the power network current, including the elimination of harmonics of an order of 23 and 25, especially in the local power network supply conditions. The multi-pulse nature of operation of the system is obtained using set of coupled three-phase power network reactors (CTR).