• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.254-255
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• 2011

This paper presents a method to analysis the effect for integrating Sihwa tidal power into power systems. Especially, power flow, fault current, voltage and contingency of sihwa tidal power plant area are calculated and the generation characteristics of tidal machine are analyzed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.116.4-116
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• 2001

We consider a robust configuration problem of inertial sensors for inertial navigation system(INS). Fault detection and isolation(FDI) is necessary to improve reliability of the system. For FDI, there used to be more than three mutually orthogonal sensors and thus we have to consider configuration methods of sensors. Various studies in this area have been done, but the former results did not consider effect of uncertainty(misalignment, scale factor error) to determine the configuration of the sensors. In this paper robust configuration of sensors is proposed through sensitivity analysis. Also total least square(TLS) method ...

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.37-39
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• 2004

To restrain abnormal voltage and effective operation in protect system, some of customer in Korea earth their own transformer in 154kV power system. The above ground system has some problems if ground fault occurs in other related area such as ground relay errors, under count register in two element register system. There for most huge customers opens the ground neutral and it causes errors in insulate and protection coordination and register system. In this paper presents the solution for above system.

• IE interfaces
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• v.20 no.4
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• pp.458-468
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• 2007

Artificial immune systems (AIS) are one of natural computing inspired by the natural immune system. The fault detection, the pattern recognition, the system control and the optimization are major application area of artificial immune systems. This paper gives a concept of artificial immune systems and useful techniques as like the clonal selection, the immune network theory and the negative selection. A concise survey on the optimization problem based on artificial immune systems is generated. The overall performance of artificial immune systems for the optimization problem is discussed.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.640-642
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• 1995

This paper describes the present state and development prospect on the protective relaying under high resistance earth faults in transmission systems. Especially it is difficult to detect the fault accompanied with high resistance contary to low resistance. In the complicated power system if the detection is failed, power failure will be occured in large area. New technology with respect to such a problem must be developed. This paper introduces research and development trend in home and abroad.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.227-235
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• 2014

The deformation modulus is one of the essential factors in determining ground behavior and safety during tunnel excavation. In this study, we conducted a back-analysis using crown settlements measured during tunnel excavation, using a horizontal inclinometer on a fault zone of pegmatite, and calculated the deformation modulus of the fault zone. This deformation modulus calculation was then compared with deformation moduli found through established relationships that use the correlation between RMR and the deformation modulus, as well as the results of pressure-meter tests. The deformation moduli calculated by back-analysis differs significantly from the deformation moduli determined through established relationships, as well as the results from pressure-meter tests conducted across the study area. Furthermore, the maximum crown settlements derived from numerical analysis conducted by applying deformation moduli determined by these established relationships and the pressure-meter tests produced noticeable differences. This result indicates that in the case of a weak rock mass, such as a fault zone, it is inappropriate to estimate the deformation modulus using preexisting relationships, and caution must be taken when considering the geological and geotechnical characteristics of weak rock.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.107-127
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• 2003

After detailed geological mapping, structural and fracture-density data were collected and analyzed in the vicinity of Cheonseong and Jeongjok Mts., Gyeongsangnam-do. A extensive dextral strike-slip fault (Beopgi Fault) Parallel to Yangsan and Dongrae Faults, a dextral-transtensional-NW fault, and a few intermittent faults have been found in the study area. Based on strike and frequency, fracture system has been divided into three sets such as NNE-trending J1 ($NS-40^{\circ}E$), WNW-trending J2 ($N50^{\circ}-80^{\circ}W$), and ENE-trending J3 ($N60^{\circ}-90^{\circ}E$). According to analysis of fracture density, it is revealed as follows: (a) Jl is the combination of Y-, P-, and R-shear fractures due to the dextral strike-slip of the Beopgi Fault. (b) J2 is the preexisted fracture zone conducting the intrusion of granite. Two tensional fractures dipping to NNE and SSW respectively have been induced by intrusion of granite and followed crustal uplift. (c) J3 is the tensional fracture developed between Yangsan and Dongrae Faults having NNE trend and dextral strike-slip sense. This study aims to reduce environmental impact and insure stability of underground facilities and tunnels.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.149-166
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• 2018

Many large earthquakes have continuously been reported and resulted in significant human casualties and extensive damages to properties globally. The accident of Fukushima nuclear power plant in Japan was caused by a mega-tsunami, which is a secondary effect associated with the Tohoku large earthquake (M=9.0, 2011. 3. 11.). Most earthquakes occur by reactivation of pre-existing active faults. Therefore, the importance of paleoseismological study have greatly been increased. The Korean peninsula has generally been considered to be a tectonically stable region compared with neighboring countries such as Japan and Taiwan, because it is located on the margin of the Eurasian intra-continental region. However, the recent earthquakes in Gyeongju and Pohang have brought considerable insecurity on earthquake hazard. In particular, this region should be secure against earthquake, because many nuclear facilties and large industrial facilities are located in this area. However, some large earthquakes have been reported in historic documents and also several active faults have been reported in southeast Korea. This study explains the evaluation methods of geological structures on active fault, fault damage zone, the relationship between earthquake and active fault, and respect distance. This study can contribute to selection of safe locations for nuclear facilities and to earthquake hazards and disaster prevention.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.4
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• pp.26-33
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• 2012

As the flash memory has increased the market share of data storage in imbedded system and occupied the most of area in a system, It has a profound impact on system reliability. Flash memory is divided NOR/NAND-type according to the cell array structure, and is classified as SLC(Single Level Cell)/MLC(Multi Level Cell) according to reference voltage. Although NAND-type flash memory is slower than NOR-type, but it has large capacity and low cost. Also, By the effect of demanding mobile market, MLC NAND-type is widely adopted for the purpose of the multimedia data storage. Accordingly, Importance of fault detection algorithm is increasing to ensure MLC NAND-type flash memory reliability. There are many researches about the testing algorithm used from traditional RAM to SLC flash memory and it detected a lot of errors. But the case of MLC flash memory, testing for fault detection, there was not much attempt. So, In this paper, Extend SLC NAND-type flash memory fault detection algorithm for testing MLC NAND-type flash memory and try to reduce these differences.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.171-189
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• 2007

A study of anisotropy of magnetic susceptibility (AMS) was undertaken on Cretaceous granitic, volcanic and sedimentary rocks in the eastern region of the Yangsan fault, southeast Korea. A total of 542 independently oriented core samples collected form 77 sites were studied. The main magnetic mineral in granitic rocks is magnetite according to the magnitude of bulk susceptibility, high-temperature susceptibility variation and isothermal remanent magnetization. Both of magnetic lineation and foliation with NE-SW trends are revealed in the granitic rocks, while volcanic rocks show scattered directions and sedimentary rocks show only load foliation parallel to the bedding planes. The following evidences read to the conclusion that both magnetic fabrics in the granitic rocks have been obtained by a tectonic stress before full solidification of the magma: (i) A fully hardened granitic rocks would get hardly any fabric, (ii) Difference of the magnetic fabric trends with those of the geological structures in the granitic rocks themselves formed by brittle deformation after solidification (e.g. patterns of small-faults and joints), (iii) Kinking of biotite and undulose extinction in quartz observed under the polarizing microscope, (iv) Discordance of magnetic fabrics in the granitic rocks with those in the surrounding rocks. The NE-SW trend of the magnetic foliations suggests a NW-SE compressive stress of nearly contemporaneous with the emplacement of the granitic rocks. The compression should have caused a sinistral strike-slip movement of the Yangsan Fault considering the trend of the latter. As the age of the granitic rocks in the study area is reported to be around $60\sim70$ Ma, it is concluded that the Yangsan fault did the sinistral strike-slip movement during this time (L. Cretaceous Maastrichtian - Cenozoic Paleocene).