Passive Testing Techniques Research Articles

Evaluation of passive network testing techniques in enterprise information systems

At the moment, the use of server devices, web applications, routers, switches, etc. has become widespread in modern information systems. These technologies have quite important advantages in the form of ease of use, a simple and convenient interface, even if their work is carried out through the use of the command line, the possibility of remote work via the Internet, as well as technologies for fast deployment. Quite often, modern technologies also have a large number of problems related to information security, because the development, testing and establishment of data transmission protocols between devices, the formation of the enterprise network architecture is very often carried out in a short time, and the company's resources become available via the Internet for users of both the company and customers, and for intruders. Vulnerabilities of varying degrees allow third parties to steal corporate information, carry out unauthorized data changes, disrupt the availability of enterprise applications, and cause Denial-of-Service problems. Currently, the problem of ensuring the security of infocommunication technologies is very relevant, so, according to, more than 60 % of all detected vulnerabilities relate to applications that use access to an external network. And more than 70 % of companies have critical risks of exploiting vulnerabilities in case of intrusion from the external perimeter of the network. One of the widespread methods of ensuring the security of network devices is the detection of vulnerabilities in order to eliminate them later. In this paper, modern methods and techniques of passive vulnerability detection in network systems are considered and their capabilities are analyzed.

Application of Outlier Detection Model in Korean Language and Culture Communication System Based on Artificial Intelligence.

With the continuous expansion of the Internet in China, network communication models and network services have become more and more complex, and with the increase of data types and diversification of data sources, network operation and maintenance projects have become more and more difficult. Passive statistical testing techniques for outliers are widely used, and many shortcomings have been pointed out, so there is an urgent need for improvement. After the research on the abnormal test of the text, it is determined that each method uses the visualization tool to simulate the data through the classification algorithm of the existing abnormal test and to identify the possibility of the data of each method and the PR diagram. The accuracy is counterintuitive. At present, Hallyu has a greater influence on the Internet, mainly in the fields of fashion and culture in Asian countries. Therefore, Korean language teaching has received widespread attention from the society, and combining cultural education with language teaching is an important way to improve the efficiency of language teaching. In the actual Korean language teaching work, a variety of Korean language materials are essential educational and teaching resources. The simulation results show that a large amount of training can make the DNN generate a better auto-encoder. In addition to strengthening the template for simulation training in deep learning, multiple supervisions of the data can be performed to reduce errors and improve efficiency.

Identification of fatigue damage evaluation using entropy of acoustic emission waveform

Acoustic emission (AE) is a passive nondestructive testing (NDT) technique which is employed to identify critical damage in structures before failure can occur. Currently, AE monitoring is carried out by calculating the features of the signal received by the AE sensor. User-defined acquisition settings (i.e., timing and threshold) significantly affect many traditional AE features such as count, energy, centroid frequency, rise time and duration. In AE monitoring, AE features are strongly related to the damage sources. Therefore, AE features that are calculated due to inaccurate user-defined acquisition settings can result in inaccurately classified damage sources. This work presents a new feature of the signal based on the measure of randomness calculated using second-order Renyi’s entropy. The new feature is computed from its discrete amplitude distribution making it independent of acquisition settings. This can reduce the need for human judgement in measuring the feature of the signal. To investigate the effectiveness of the presented feature, fatigue testing is conducted on an un-notched steel sample with simultaneous AE monitoring. Digital image correlation (DIC) is measured alongside AE monitoring to correlate both monitoring methods with material damage. The results suggest that the new feature is sensitive in identifying critical damages in the material.

The experimental comparison of parameters signals of acoustic emission during destructive test on composites based on cement

The paper reports the analysis of acoustic emission signals captured during compressive strength tests of fine-grained cement-based composites of various composition. Acoustic emission monitoring belongs to a non-invasive and passive non-destructive testing technique. It is one of the most sensitive experimental techniques to monitor cracking of materials. While the acoustic emission phenomenon is directly associated with nucleation of cracks in materials based on cement, the measurement of these kinds of materials is readily applied to detect cracking activity. An understanding of microstructure–performance relationships is the key to true understanding of material behaviour.

Experimental and simulation methods to study the Magnetic Tomography Method (MTM) for pipe defect detection

The Magnetic Tomography Method (MTM), a passive Non-Destructive Testing (NDT) technique based on the magneto-mechanical effect, has been claimed to be able to detect defects at large (>1 m) stand-off distances. In this study, the MTM signal was studied experimentally on a 4140-L80 pipe sample, in which a flat bottom defect was electrochemically generated. The Residual Magnetic Leakage Field (RMLF) signal was recorded using an annular array of AMR sensors. The experimental results show perturbations due to the defect (about 12 dB above noise level) only when the AMR sensors were positioned at a very low stand-off. The presence of ferromagnetic objects near the sensors could cause perturbations many times larger than that from a defect (about 18 dB above the noise level). A Finite Element (FE) model validated the experimental results. The model showed that there is a significant risk of false indications due to foreign ferromagnetic objects when measuring at a large distance from the pipe.

Formally testing the protocol performances

The validation of systems and specifically the conformance testing of communicating protocols is a crucial step to their development. Many approaches have been developed for a while, among which, the formal ones have proved their efficiency to test these protocols. These approaches are divided in two main sets: active and passive testing techniques. While they both have their own advantages and drawbacks, passive testing techniques are the only ones that can be applied when the controllability of the system interfaces is unavailable or when the implementation under test cannot be stimulated in runtime. In this paper, we present a logic-based passive testing approach to test in a formal way the conformance and the protocol performance requirements provided by the protocol standard or experts. We aim at formally specifying time related protocol properties in order to check them on real execution traces. Based on a new algorithm, a prototype is here developed and experienced. In order to evaluate and assess our technique, we present experiments through a set of IMS/SIP properties (regarding the conformance and the protocol performance) and execution traces. We finally discuss the results by providing relevant verdicts.

A novel approach for classification of failure modes in single lap joints using acoustic emission data

New innovative basalt fiber/epoxy composite materials are used in engineering applications such as aerospace, automotive, and civil structures due to the potential low cost of this material together with its mechanical characteristics and its failure mechanisms. Acoustic emission is a passive nondestructive testing technique for real-time monitoring of damage developed in materials and structures, which have been used successfully for the identification of damage mechanisms in composite joints under tensile loading. The present study is focussed on acoustic emission characterization of failure modes in three prominent joining methods namely, bonded, riveted, and hybrid joints during tensile test. Parametric analysis is performed on the acoustic emission data obtained during the tensile testing of these types of joints to discriminate the failure modes. Fast Fourier transform analysis using acoustic emission waveform analysis is carried out to analyze the different failure events and associate them with their dominant frequency ranges. The predominance of failure modes in each signal is used as a key in the study to discriminate failure modes on single-lap joints in basalt/epoxy composite laminate, and the results are validated with fast Fourier Transform analysis.

Using passive testing based on symbolic execution and slicing techniques: Application to the validation of communication protocols

This paper presents a new approach to perform passive testing based on the analysis of the control and data part of the system under test. Passive testing techniques are based on the observation and verification of properties on the behaviour of a system without interfering with its normal operation. Many passive testing techniques consider only the control part of the system and neglect data, or are confronted with an overwhelming amount of data values to process. In our approach, we consider control and data parts by integrating the concepts of symbolic execution and we improve trace analysis by introducing trace slicing techniques. Properties are described using Input–Output Symbolic Transition Systems (IOSTSs) and we illustrate in the paper how they can be tested on real execution traces optimizing the trace analysis. These properties can be designed to test the functional conformance of a protocol as well as security properties.In addition to the theoretical approach, we have developed a software tool that implements the algorithms presented in this paper. Finally, as a proof of concept of our approach and tool we have applied the techniques to a real-life case study: the SIP protocol. In particular, the proposed techniques are applied to a set of real execution traces extracted from an IMS/SIP architecture.

A Formal Data-Centric Approach for Passive Testing of Communication Protocols

There is currently a high level of consciousness of the importance and impact of formally testing communicating networks. By applying formal description techniques and formal testing approaches, we are able to validate the conformance of implementations to the requirements of communication protocols. In this context, passive testing techniques are used whenever the system under test cannot be interrupted or access to its interfaces is unavailable. Under such conditions, communication traces are extracted from points of observation and compared to the expected behavior formally specified as properties. Since most works on the subject come from a formal model context, they are optimized for testing the control part of the communication with a secondary focus on the data parts. In the current work, we provide a data-centric approach for black-box testing of network protocols. A formalism is provided to express complex properties in a bottom-up fashion starting from expected data relations in messages. A novel algorithm is provided for evaluation of properties in protocol traces. Experimental results on Session Initiation Protocol (SIP) traces for IP Multimedia Subsystem (IMS) services are provided.

Towards improved damage location using acoustic emission

The acoustic emission technique is a passive non-destructive testing technique that has significant potential for use as a structural health monitoring technique for many large-scale structures, allowing continuous global monitoring. The location capability of the acoustic emission technique is its most beneficial attribute; however, the location accuracy can often be limited in complex materials and structures. This article discusses recent advances in the location of acoustic emission signals. The key sources of errors are identified as signal arrival time measurement and processing algorithm limitations. A series of strategies for reducing the effects of both causes of error are presented. Additionally, the results of a case study are used to demonstrate a novel mapping technique for acoustic emission source location of fatigue crack signals in an aircraft landing gear component. Improvements in location accuracy of up to 87.5% were observed when compared with standard location calculation algorithms.

An advanced approach for modeling and detecting software vulnerabilities

ContextPassive testing is a technique in which traces collected from the execution of a system under test are examined for evidence of flaws in the system. ObjectiveIn this paper we present a method for detecting the presence of security vulnerabilities by detecting evidence of their causes in execution traces. This is a new approach to security vulnerability detection. MethodOur method uses formal models of vulnerability causes, known as security goal models and vulnerability detection conditions (VDCs). The former are used to identify the causes of vulnerabilities and model their dependencies, and the latter to give a formal interpretation that is suitable for vulnerability detection using passive testing techniques. We have implemented modeling tools for security goal models and vulnerability detection conditions, as well as TestInv-Code, a tool that checks execution traces of compiled programs for evidence of VDCs. ResultsWe present the full definitions of security goal models and vulnerability detection conditions, as well as structured methods for creating both. We describe the design and implementation of TestInv-Code. Finally we show results obtained from running TestInv-Code to detect typical vulnerabilities in several open source projects. By testing versions with known vulnerabilities, we can quantify the effectiveness of the approach. ConclusionAlthough the current implementation has some limitations, passive testing for vulnerability detection works well, and using models as the basis for testing ensures that users of the testing tool can easily extend it to handle new vulnerabilities.

On Embeddable Passive Testing

Despite fruitful research on passive testing algorithms and techniques, the concept of passive testing remains elusive, and is even dismissed as inherently inconsistent or a mere facon de parler. Consequently, passive testing still does not belong to the repository of conceptual, technological, and linguistic devices of computer science and telecommunications research communities. This work aims at “homing in” on the concept of passive testing. To this end, we concentrate on one aspect of this concept, namely on how a passive tester can be represented within the overall architecture of a distributed, reactive Discrete Event System. It is shown that such models in current use are deficient: internally inconsistent, or even “unimplementable”. A new, very simple model is proposed, which allows a passive tester to be treated as any other system entity. This allows the modelling of systems in which a passive tester is embedded. The potential uses of such systems are also identified.

Validation of the GSM-map protocol

This paper presents the results of experimentation performed on the application of a specification language and three conformance testing techniques to the validation of the gsm-map protocol (Global System for Mobile communication - Mobile Application Part). The gsm-map protocol is a component of the GSM radiocommunication system that describes the signaling functions required in signaling system SS7 to offer the services needed in a mobile network. The etsi standard describes this protocol in a semiformal way that we have formalized (using the sdl formal language), to improve its testability. We have then applied three different testing techniques : embedded testing techniques to perform the test of functional components embedded in the global system, global testing techniques to test the complete protocol and passive testing techniques to verify whether the protocol execution traces are accepted or not by the specification (represented by a finite state machine or by an extended finite state machine).

Ultrasonics in nondestructive evaluation

The use of ultrasonic waves in nondestructive evaluation is reviewed. Perspective is provided by a summary of the role played by nondestructive evaluation in the manufacture and utilization of structural components. Included are discussions of the methodologies for predicting part serviceability and of the constraints placed on the nondestructive measurement process by the mechanical designs and functions of structural components. The principles of active (ultrasonic) and passive (acoustic-emission) testing techniques are then reviewed. Specific examples of applications from several industries illustrate the capabilities and limitations of state-of-the-art techniques based on these principles. Detailed discussion is then given of present research and development activities designed to overcome these limitations, with particular emphasis on those areas best addressed by the tools of electrical engineering. Included are discussions of instrumentation, inspection performance modeling, flaw sizing techniques (including imaging systems), material property measurement techniques, and acousticemission techniques. The paper concludes with a consideration of important directions of future work.