• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.176-179
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• 2006

We are using COS to purpose blocking the excess current and to protect the transformer. But the fuse of COS is melt due to the overload if the excess current flows and it destroy an air severing relations to clear as strong arc happens. Such phenomenon induces an impact ambient noise and it gives the circumstance area resident or pedestrian the fear. Thus, We are the actual circumstances which an ambient noise countermeasure establishment have desired urgently. In this study, we grasp the characteristic of an impact ambient noise which a COS fuse happens the melting and study the method to reduce an impact ambient noise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1062-1068
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• 2007

We are using COS to block the excess current and to protect the transformer. But the fuse of COS is melt due to the overload resulting from the excess current flows and it destroys an air severing relations to clear as strong arc happens. Such phenomenon induces an impact ambient noise and it gives the circumstance area resident or pedestrian the fear. Thus, it is necessary that we urgently need to control the ambient noise from the actual circumstances. In this study, we investigate the characteristic of an impact ambient noise associate with the melting state of the COS fuse and suggest the method to reduce the noise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.70-74
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• 2008

We are using COS to purpose blocking the excess current and to protect the transformer. But the fuse of COS is melt due to the overload if the excess current flows and it destroy an air severing relations to clear as strong arc happens. Such phenomenon induces an impact ambient noise and it gives the circumstance area resident or pedestrian the fear. Thus, We are the actual circumstances which an ambient noise countermeasure establishment have desired urgently. In this study, we grasp the characteristic of an impact ambient noise which a COS fuse happens the melting and study the method to reduce an impact ambient noise.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.474_475
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• 2009

Recently the grid-connected PV system is increased in the power system. According to this trend, protection coordination issues are becoming more important when the PV generation is connected to the power system. In this paper, we model the PV system using EMTP/ATPDRAW and analyze the impact of the PV generation for the fuse coordination.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.703-707
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• 2001

The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight increase the over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection. First, the problem of adding inductance of existing High-Speed and new Typower fuses in DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.5
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• pp.1141-1149
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• 2016

Deduplicated filesystem can reduce usage of storage. However, it be able to recover deleted block. We studied sanitization of deduplicated filesystem, LessFS which is based on FUSE(Filesystem in USErspace). First, we show a vulnerability recover deleted data in the deduplicated filesystem. We implement sanitization of deduplicated filesystem considering the part of fingerprint DB with data blocks. It takes 60~70 times compared to without sanitization. Which means access time to fingerprint DB and overhead derived from increase of number of chunk have a critical impact on sanitization time. But in case of more than 65,536 Byte of chunksize, it is faster than normal filesystem without deduplication.

• International Journal of Aerospace System Engineering
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• v.9 no.2
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• pp.1-9
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• 2022

The NEA release mechanism is used to provide restraint and release functions with low shock for critical deployment operations on solar arrays after launch. The GK3 solar array consists of 2 wings and 6 hold down points per panel. The NEA SSD9103S1 is a part of the GK3 solar array hold-down and release mechanism. Each NEA unit is equipped with two Z-diodes which provide power to a NEA unit connected in series after actuation of the fuse wire. This paper presents the hot firing test results of a quadrature NEA SSD9103S1 configuration. One output powers a maximum of 4 NEA SSD9103S1 units simultaneously. The necessary actuation pulse duration has been determined to meet margin requirement for thermal energy of minimum 4. Actuation thermal energy difference is about 6.6% between each half of two fired serial NEAs. Thermal energy margin at worst case is minimum 5.9 in case of an actuation pulse duration of 500 ms. Two series Zener impedance depend on current applied has been characterized by an additional actuation after all fuse wires are open circuit. Total number of actuation commands to the GK3 NEA unit reduce drastically from 24 in case of single NEA configuration down to 8 in case of parallel and quadrature NEA configurations. It can be accommodated by the existing HP2U Pyro design without any impact.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.993-1014
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• 2021

This paper proposes a new image retrieval method called the 3D integrated multi-index to fuse SIFT (Scale Invariant Feature Transform) visual words with other features at the indexing level. The advantage of the 3D integrated multi-index is that it can produce finer subdivisions in the search space. Compared with the inverted indices of medium-sized codebook, the proposed method increases time slightly in preprocessing and querying. Particularly, the SIFT, contour and colour features are fused into the integrated multi-index, and the joint cooperation of complementary features significantly reduces the impact of false positive matches, so that effective image retrieval can be achieved. Extensive experiments on five benchmark datasets show that the 3D integrated multi-index significantly improves the retrieval accuracy. While compared with other methods, it requires an acceptable memory usage and query time. Importantly, we show that the 3D integrated multi-index is well complementary to many prior techniques, which make our method compared favorably with the state-of-the-arts.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.1-10
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• 2008

The Bird strike to small aircraft has not been an issue because of it's low speed and usage as a private aircraft. So, the compliance of the bird strike regulation is limited to large fixed-wing aircraft such as the commuter category in FAR Part 23 and the civil aircraft in FAR Part 25, generally. However, the forecast of dramatic increasing of VLJ(Very Light Jet) and (light time of general aviation due to Air-taxi for the point to point transportation, would rise up the need of bird strike regulations and a safety enhancement in normal and utility categorized aircraft. In this study, the safety enhancement concept using a crushable foam for the bird strike to small aircraft wing leading edge, and the evaluation about the safety of the bird strike to small aircraft are proposed using the explicit finite element analysis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.270-275
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• 2019

Mica capacitor is being adopted for high voltage firing unit of guided weapon system because of its superior impact enduring property relative to ceramic capacitor. Reliability of localized mica high voltage capacitors was verified through environmental test like terminal strength test, humidity test, thermal shock test and accelerated life test for application to high voltage firing unit. Failure mode of mica capacitor is a decrease of insulation resistance and its final dielectric breakdown. Main constants of accelerated life model were derived experimentally and voltage constant and activation energy were 5.28 and 0.805 eV respectively. Lifetime of mica capacitor at normal use condition was calculated to be 38.5 years by acceleration factor, 496, and lifetime at accelerated condition and this long lifetime confirmed that mica high voltage capacitor could be applied for firing unit.