• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2259-2264
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• 2013

In this paper, a selective multiple-input multiple-output(MIMO) transmission scheme is proposed in dual-hop MIMO relaying systems, in which orthogonal space-time block code(OSTBC) transmission and transmit antenna selection(TxAS) transmission are selectively used. Assuming independent Rayleigh fading channels, the outage probability is analyzed for a decode-and-forward(DF) relaying system using the selective MIMO transmission scheme. Also, through numerical investigation, the outage performance for the DF relaying system using the selective MIMO transmission scheme is compared with that for the conventional DF relaying system using OSTBC or TxAS. Moreover, from the performance comparison, it is shown that the proposed scheme can reduce the system overhead without outage performance degradation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1180-1183
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• 2011

In this paper, we present a design of AEM radome with frequency selective surface using unit-cell EM simulation method and verified the performance of AEM radome by the radiation pattern measurements of $16{\times}16$ array-antenna. Measured results under near-field condition showed a good agreement with the simulation and far-field measured ones. And there were no radiation pattern variation between antenna only and antenna with AEM radome. From these results, we verified that AEM radome with frequency selective surface can be a solution to reduce the RCS of conventional mast and radar.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.1004-1008
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• 2012

The effect of address discharge characteristics by selective reset method is investigated to prevent the weakness of address discharge in the middle of a TV-field without increase of the black luminance. To reduce black luminance in AC PDP usually, the first subfield during one TV frame adopted the conventional rising ramp-reset waveform, whereas the other subfields adopted the subsidiary reset waveform without rising ramp type. As the wall charge for the address discharge was accumulated by only the rising ramp waveform during the first reset period, the wall charge on three electrodes was disappeared as time passed and the address discharge would be weakened in the rear subfields. To prevent a reduction of the address discharge characteristics without decrease the black luminance, the modified rising ramp reset waveform was adopted only in the sixth subfield. As a result, a modified driving method could improve the address discharge characteristics compared with selective reset driving scheme with almost the same black luminance.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.371-376
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• 2015

The Internet of Things (IoT) significantly increases the amount of data. Database compression is important for big data because it can reduce costs for storage systems and save I/O bandwidth. However, it could show low performance for write-intensive workloads such as OLTP due to the updates of compressed pages. In this paper, we present practical guidelines for the performance improvement of database compression. Especially, we propose the SELECTIVE strategy, which compresses only tables whose space savings are close to the expected space savings calculated by the compressed page size. Experimental results using the TPC-C benchmark and MySQL show that the strategy can achieve 1.1 times better performance than the uncompressed counterpart with 17.3% space savings.

• Natural Product Sciences
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• v.10 no.3
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• pp.129-133
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• 2004

Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect in nonmalignant hepatic cells. Using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed tumorigenic cell line (BNL SV A.8), we evaluated the effects of quercetin on cell proliferation and apoptosis. As the results, our present study demonstrated that quercetin had a selective growth inhibition in normal versus tumorigenic hepatic cells such that BNL SV A.8 cells were very sensitive to the quercetin-mediated cytotoxicity. In particular, as evidenced by the increased number of positively stained cells in the TUNEL assay, the induction of characteristic nuclear DNA ladders, and the migration of many cells to sub-G1 phase in the BNL SV A.8 cells, quercetin treatment more sensitively induced apoptosis in BNL SV A8 cells than in BNL CL.2 cells. Collectively, our findings suggest that quercetin can be approached as a potential agent that is capable of inducing selective growth inhibition and apoptosis of hepatic cancer cells.

• Polymer(Korea)
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• v.34 no.3
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• pp.242-246
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• 2010

FTIR spectroscopy has been employed in order to quantitatively investigate the relationship between planar arrangements and selective reflectance of cholesteric liquid crystals. It was found that the selective reflection was enhanced as the amount of planar arrangements in cholesteric liquid crystals increased. Although the planar arrangements of cholesteric liquid crystals can be induced only by the shear force effect, it was more effective to use the alignment layer to obtain the perfect planar arrangements.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.517-522
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• 2010

Selective laser melting (SLM) is emerged as a new manufacturing technique to directly fabricate precise parts using metallic materials. The final characteristics of a component fabricated through the SLM process are strongly dependent upon various parameters such as laser power, scan rate and pulse duration, etc. This paper, therefore, focuses on the dimensional characteristics of melted $20{\mu}m$ Fe-Cr-Ni powder by fiber laser for the selective laser melting process. With energy density decrease, the height and depth were decreased. Although the conditions are of the same energy density, the shape is different by laser power and scan rate. The shapes at various laser parameters were divided into 3 groups based on depth over height. The smooth regular shape is obtained under the conditions of $50{\mu}m$ of powder height and $15-20{\mu}s$ of pulse duration. And the laser power influenced the variation of shape more significantly than the scan rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.87-93
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• 2016

In this paper, we propose a new method to enhance an android security by exploiting a selective management of application permission. To that purpose, we analyze behavior of the current android security, via which we draw out possible vulnerabilities. After that, we develop a tool to implement the selective management of the application permission, witch has a function to give a permission selectively for the application when we install a new application. Via experiment we show validity of the developed tool in solving the drawn vulnerability in the current android security.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.533-538
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• 2011

A plastic-compatible low-temperature metal deposition and patterning process is essential for the fabrication of flexible electronics because they are usually built on a heat-sensitive flexible substrate, for example plastic, fabric, paper, or metal foil. There is considerable interest in solution-processible metal nanoparticle ink deposition and patterning by selective laser sintering. It provides flexible electronics fabrication without the use of conventional photolithography or vacuum deposition techniques. We summarize our recent progress on the selective laser sintering of metals and metal oxide nanoparticles on a polymer substrate to realize flexible electronics such as flexible displays and flexible solar cells. Future research directions are also discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.85-85
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• 2013

Label-free, sensitive and selective detection methods with high spatial resolution are critically required for future applications in chemical sensor, biological sensor, and nanospectroscopic imaging. Here I describe the development of Plasmon Resonance Energy Transfer (PRET)-based molecular imaging in living cells as the first demonstration of intracellular imaging with PRET-based nanospectroscopy. In-vivo PRET imaging relied on the overlap between plasmon resonance frequency of gold nanoplasmonic probe (GNP) and absorption peak frequencies of conjugated molecules, which leads to create 'quantized quenching dips' in Rayleigh scattering spectrum of GNP. The position of these dips exactly matched with the absorption peaks of target molecules. As another innovative application of PRET, I present a highly selective and sensitive detection of metal ions by creating conjugated metal-ligand complexes on a single GNP. In addition to conferring high spatial resolution due to the small size of the metal ion probes (50 nm in diameter), this method is 100 to 1,000 folds more sensitive than organic reporter-based methods. Moreover, this technique achieves high selectivity due to the selective formation of Cu2+complexes and selective resonant quenching of GNP by the conjugated complexes. Since many metal ion ligand complexes generate new absorption peak due to the d-d transition in the metal ligand complex when a specific metal ion is inserted into the complex, we can match with the scattering frequency of nanoplasmonic metal ligand systems and the new absorption peak.