• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.2
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• pp.11-25
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• 2020

This study proposes a method to manipulate fragmentation of disks by arbitrarily allocating and releasing the status of a disk cluster in the NTFS file system. This method allows experiments to be performed in several studies related to fragmentation problems on disk cluster. Typical applicable research examples include testing the performance of disk defragmentation tools according to the state of fragmentation, establishing an experimental environment for fragmented file carving methods for digital forensics, setting up cluster fragmentation for testing the robustness of data hiding methods within directory indexes, and testing the file system's disk allocation methods according to the various version of Windows. This method suggests how a single file occupies a cluster and presents an algorithm with a flowchart. It raises three tricky problems to solve the method, and we propose solutions to the problems. Experiments for allocating the disk cluster to be fragmented to the maximum extent possible, it then performs a disk defragmentation experiment to prove the proposed method is effective.

• MALSORI
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• no.63
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• pp.153-170
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• 2007

It is well known that when there is an acoustic mismatch between the speech obtained during training and testing, the accuracy of speaker verification systems drastically deteriorates. This paper presents the use of MFCCs' histogram enhancement technique in order to improve the robustness of a speaker verification system. The technique transforms the features extracted from speech within an utterance such that their statistics conform to reference distributions. The reference distributions proposed in this paper are uniform distribution and beta distribution. The transformation modifies the contrast of MFCCs' histogram so that the performance of a speaker verification system is improved both in the clean training and testing environment and in the clean training and noisy testing environment.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3445-3461
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• 2000

Although many different intrusion detectionsystems have been developed there have not been enough researches on the methodology for evaluating these intrusion delection systems. With this understanding,in this paper we present a methodology for evaluating infrusion detection systems from the view point of performance and robustness, both of which are considered the most important criteria Current research on evaluating the performance f intrusion detection systems mostly foduson the in issuse detection but not on the anormaly detection. Regarding evalieting robustness it is not easy to apply off -line methodologies and methods for testing robustness hae not been proposed in on -line methodolomes, In this paper we provide an systematic way of classifyin and generating anomalies and using this reult, present an methodology for evaluating the pertormance of intrusion detection systems in detecting anomaalies ans well as misuses . Moreover, ww study the factors that can damage the robustness of intrusion detection systems and suggest an methodology for assessing the robustness of intrusion detection systems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.725-734
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• 2016

SCADA(Supervisory Control and Data Acquisition) system is widely used for remote monitoring and control throughout the domestic industry. Due to a recent breach of security on SCADA systems, such as Stuxnet, the need of correctly established secure certification of a control system is growing. Currently, EDSA-CRT (Embedded Device Security Assurance-Communication Robustness Test), which tests the ability to provide core services properly in a normal/abnormal network protocol, is only focused on the testing of IP-based protocols such as IP, ARP, TCP, etc. Thus, in this paper, we propose test requirements for DNP3 protocol based on EDSA-CRT. Our analysis show that the specific test cases provide plentiful evidences that DNP3 should follow based on its functional requirements. As a result, we propose 33 specific test case for DNP3 protocol.

• Journal of the Korean Statistical Society
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• v.30 no.3
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• pp.347-366
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• 2001

Robust analogues of the likelihood ratio test are considered for testing of hypotheses involving multiple discrete distributions. The test statistics are generalizations of the Hellinger deviance test of Simpson(1989) and disparity tests of Lindsay(1994), obtained by looking at a 'penalized' version of the distances; harris and Basu (1994) suggest that the penalty be based on reweighting the empty cells. The results show that often the tests based on the ordinary and penalized distances enjoy better robustness properties than the likelihood ratio test. Also, the tests based on the penalized distances are improvements over those based on the ordinary distances in that they are much closer to the likelihood ratio tests at the null and their convergence to the x$^2$ distribution appears to be dramatically faster; extensive simulation results show that the improvement in performance of the tests due to the penalty is often substantial in small samples.

• Smart Structures and Systems
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• v.6 no.1
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• pp.57-72
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• 2010

This paper presents the most significant results obtained within a broad-ranging experimental program aiming to evaluate both the effectiveness and the robustness of a Base Isolation (BIS) and a Tuned Mass Damper (TMD) combined control strategy (BI & TMD). Following a brief description of the experimental model set-up and the adopted kinematic scaling technique, this paper describes the identification procedures carried out to characterize the system''s model. The dynamic response of a small-scale model to recorded earthquake excitations, which has been scaled by using the Buckingham pi-theorem, are later presented and discussed. Finally, the effectiveness and robustness of the combined control strategy is evaluated by comparing the model's dynamic response. In particular, reduction in relative displacements and absolute accelerations due to the application of different mass damping systems is investigated.

• The Journal of the Acoustical Society of Korea
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• v.15 no.4E
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• pp.28-36
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• 1996

In this paper, we propose a new evaluation methodology which can more clearly show the performance of the allophone modeling algorithm generally used in large vocabulary speech recognition. The proposed evaluation method shows the running characteristics and limitations of the modeling algorithm by testing how the variation of phonetic environments of training data affects the recognition performance and the desirable number of free parameters to be estimated. Using the method, we experiment results, we conclude that, in vocabulary-independent recognition task, the phonetic diversity of training data greatly affects the robustness of model, and it is necessary to develop a proper measure which can determine the number of states compromizing the robustness and the precision of the HMnet better than the conventional modeling efficiency.

• Transactions on Electrical and Electronic Materials
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• v.7 no.4
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• pp.184-188
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• 2006

This work describes efforts in the fabrication and testing of robust microelectromechanical systems (MEMS). Robustness is typically achieved by investigating non-silicon substrates and materials for MEMS fabrication. Some of the traditional MEMS fabrication techniques are applicable to robust MEMS, while other techniques are drawn from other technology areas, such as electronic packaging. The fabrication technologies appropriate for robust MEMS are illustrated through laminated polymer membrane based pressure sensor arrays. Each array uses a stainless steel substrate, a laminated polymer film as a suspended movable plate, and a fixed, surface micromachined back electrode of electroplated nickel. Over an applied pressure range from 0 to 34 kPa, the net capacitance change was approximately 0.14 pF. An important attribute of this design is that only the steel substrate and the pressure sensor inlet is exposed to the flow; i.e., the sensor is self-packaged.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.175-183
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• 2011

Performance of digital video watermarking is an assessment that hides a lot of information in digital videos. Therefore, it is required to find a way that enables to store lots of bits of data into a high quality video of the frequency area of digital contents. Hence, this paper designs a watermarking system improving security with an enhancing watermarking based on invisible watermarking and embedding an watermarking on LH and HL subband and its subband by transforming wavelet after the extraction of luminance component from the frames of video by compromising robustness and invisible of watermarking elements. The performance analysis of security of watermarking is carried out with a statistic method, and makes an assessment of robustness against variety of attacks to invisible watermarking. We can verify the security of watermarking against variety of attacks by testing robustness and invisible through carrying out general signal processing like noise addition, lossy compression, and Low-Pass filtering.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.3
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• pp.135-142
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• 2012

The Quality of embedded system depends on the embedded software. As the complexity and the size of embedded software have been increasing, it is more likely that the software may include faults, and the reliability and stability issues are getting more important. In this paper, we propose a remote test tool for software based on VxWorks by using fault injection method. The test tool consists of test server and test client for testing on the cross development environment. The test server operates in the host system and user can not only test but also monitor the software by using it. The test client operates in the target system and it controls kernel objects and sends the input data into the software when receiving the control and data from the test server. We developed the prototype software and demonstrated the ability of testing software robustness by injecting faults.