• Structural Engineering and Mechanics
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• v.75 no.1
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• pp.71-86
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• 2020

This paper presents a study on the mechanical behavior of buried pipelines crossing faults using experimental and numerical methods. A self-made soil-box was used to simulate normal fault, strike-slip fault and oblique slip fault. The effects of some important parameters, including the displacement and type of fault, the buried depth and the diameter of pipe, on the deformation modes and axial strain distribution of the buried pipelines crossing faults was studied in the experiment. Furthermore, a finite element analysis (FEA) model of spring boundary was developed to investigate the performance of the buried pipelines crossing faults, and FEA results were compared with experimental results. It is found that the axial strain distribution of those buried pipelines crossing the normal fault and the oblique fault is asymmetrical along the fault plane and that of buried pipelines crossing the strike-slip fault is approximately symmetrical. Additionally, the axial peak strain appears near both sides of the fault and increases with increasing fault displacement. Moreover, the axial strain of the pipeline decreases with decreasing buried depth or increasing ratios of pipe diameter to pipe wall thickness. Compared with the normal fault and the strike-slip fault, the oblique fault is the most harmful to pipelines. Based on the accuracy of the model, the regression equations of the axial distance from the peak axial strain position of the pipeline to the fault under the effects of buried depth, pipe diameter, wall thickness and fault displacement were given.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1520-1531
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• 1999

In this paper, we present a first step for developing a method of verifying both safety and correctness of object-oriented design specification. As first, we analyze the discrepancies, which can occur between requirements specification and design specification, to make clear target faults. Then, we propose a new design verification method which aims at detecting faults in the design specification. The key idea of the proposed framework is that all elements to be verified can be extracted based on the requirements specification, safety standards, and design specification given for the target product These elements are expressed using three kinds of tables for verification, and thus, the verification steps can be greatly simplified. Here, we assume that component library, standards for safety and design specification obtained from the Booch's object-oriented design method are given. At the beginning, the designers construct a design table based on a design specification, and the verifiers construct a correctness table and a safety table from component library and standards for safety Then, by comparing the items on three tables, the verifiers verification a given design specification and detect faults in it. Finally, using an example of object-oriented design specification, we show that faults concerning safety or correctness can be detected by the new design verification method.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.6
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• pp.248-262
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• 2008

As the number of large size multimedia files increases and the importance of individual's digital data grows, storage devices have been advanced to store more data into smaller spaces. In such circumstances, a physical damage in a storage device can destroy large amount of important data. Therefore, it is needed to verify the robustness of various physical faults in storage device before certain systems are used. We developed SOAR(Storage Reliability Analyzer), Storage Reliability Analyzer, to detect physical faults in diverse kinds of HDD hardware components and to recover the systems from those faults. This is a useful tool to verify robustness and reliability of a disk. SOAR uses three unique methods of creating physical damages on a disk and two unique techniques to apply the same feature on file systems. In this paper, we have performed comprehensive tests to verify the robustness and reliability of storage device with SOAR, and from the verification result we could confirm SOAR is a very efficient tool.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.86-92
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• 2009

As increasing of using induction motors, the induction motors faults cause serious damage to the industry. Therefore to find out faults of induction motor is recognized as important problem awaiting solution. But to make matters worse, the faults of induction motors often progress through long time. It means that early diagnosis is very important. Many researches have been progressed and general method of diagnosis is using vibration sensor to diagnose fault of induction motor. However, although it is reliability technique, it demands high price and it is difficult to use. This paper presents an implementation of technique for fault diagnosis of induction motor using wavelet transform based stator current and it is composed with algorithm that decides whether fault existence or not using C++ based on windows software. The algorithm will be accomplished in real-time using current data acquisition board and PC automatically with Neural Network algorithm.

• Tunnel and Underground Space
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• v.19 no.2
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• pp.132-145
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• 2009

Faults in rock mass have strong influences on the behaviors of rock structure such as rock slope, tunnel and underground space. Thus, it is very important to analyse for the characteristics of fault rocks in design for tunnel. But, due to the limitation of geotechnical investigation in design stages, tunnel engineers have to carry out the face mapping and additional geological survey during tunnel excavation to find the distribution of faults and the engineering properties of faults for support and reinforcement design of tunnel. In this study, various geological survey and field tests were carried out to analyse the characteristics of the large thrust fault zone through the large sectional tunnel is constructed in mica-schist region. Also, the distribution of structural geology, the shape of thrust faults and the mechanical properties of fault rock were studied for the reasonable design of the reinforcement and support method for the highly fractured fault zone in the large-span tunnel.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.187-196
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• 2016

We conducted three-dimensional finite element analysis to predict the presence of upcoming fault zones during tunneling. The analysis considered longitudinal displacements measured at tunnel face, and used 28 numerical models with various fault attitudes. The x-MR (moving range) control chart was used to analyze quantitatively the effects of faults distributed ahead of the tunnel face, given the occurrence of a longitudinal displacement. The numerical models with fault were classified as fault gouge, fault breccia, and fault damage zones. The width of fault cores was set to 1 m (fault gouge 0.5 m and fault breccia 0.5 m) and the width of fault damage zones was set to 2 m. The results, suggest that fault centers could be predicted at 2~26 m ahead of the tunnel face and that faults could be predicted earliest in the 45° dip model. In addition, faults could be predicted earliest when the angle between the direction of tunnel advance and the strike of the fault was smallest.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.991-998
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• 2003

There are many methods to enhance the fault tolerance of the CORBA based real time systems by viewpoints. Among them, this paper provides a method to enable seamless services where the systems based on the CORBA have object's faults originated processing real time information. Namely, this paper observes a method to deal efficiently with object's faults happening in 3 tier architecture environments. It is possible to replicate objects as a way to enhance the fault tolerance considering object's faults. Along with it, this paper shows a method to enhance the fault tolerance ultimately and then keep the service continuity by prividing a way to allow to continue to run the systems until the FT-CORBA based one's faults are recovered.

• Journal of the Korean Geophysical Society
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• v.2 no.3
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• pp.201-208
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• 1999

A high-resolution seismic profile acquired across the middle part of the Pungam Basin, one of the Cretaceous sedimentary basins in Korea, has been interpreted to delineate subsurface geological structures. Boundary faults, intrusive bodies, and unconformity surfaces are identified on the seismic section. Basin fills are divided into five depositional units (Units I, II, III, IV, and V in descending order). The normal faults were formed by transtentional movement along a sinistral strike-slip fault zone. Unconsolidated sediments, a weathered layer, and sedimentary layers overly the Precambrian gneiss. The granite body intruded at the southeastern part contacts the adjacent sedimentary rocks by a near-vertical fault. Granitic intrusions caused tectonic fractures and normal faults of various sizes. An andesitic intrusive body indicates post-depositional magmatic intrusions. Continuous strike-slip movements have deformed basin-filling sediments (Units I and II).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.4
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• pp.266-276
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• 2001

Due to the rapid development of semiconductor technology, the complexity of VLSI circuits has heavily increased. With the increased densities of integrated circuits, several different types of faults can occur Thus, testing such circuits is becoming a sever problem. Delay testing can detect system timing failures caused by delay faults. However, the conventional delay fault coverage in terms of the number of detected faults may not be an effective measure of delay testing because, unlike a stuck-at-faults, the impact of a delay fault is dependent on its delay defect size rather than on its existence. Thus, the effectiveness of delay testing is dependent on the propagation delay of the path to be tested, the delay defect size, and the system clock interval. This paper proposes a new delay defect fault coverage that considers both propagation delay of the path to be tested and additional delay defect size. And the relationship between delay defect fault coverage and defect level is analyzed.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.57-64
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• 1999

To effectively identify near-surface faults with vertical slips from seismic refraction data, the GRM interpretation technique is tested and investigated in terms of various parameters through computer modeling. A characteristic change in shape of the velocity-analysis function near faults is noticed, and a new strategy of `Slope Variation Indicator (SVI)' is developed and tested in this study. The SVI is defined as a first horizontal derivative of the difference of velocity analysis functions for a large XY value and a small one, respectively. As the dip of refractor decreases and as the difference in XY value increases, the peak value of SVI increases and its duration decreases. Consequently, the SVI indicates accurately the location of buried fault in the test models. The SVI is believed to be an efficient tool in seismic refraction method to investigate location and distribution of shallowly buried faults.