Percolation properties of growing networks under an Achlioptas process

We study the percolation transition in growing networks under an Achlioptas process (AP). At each time step, a node is added in the network and, with the probability $\delta$, a link is formed between two nodes chosen by an AP. We find that there occurs the percolation transition with varying $\delta$ and the critical point $\delta_c=0.5149(1)$ is determined from the power-law behavior of order parameter and the crossing of the fourth-order cumulant at the critical point, also confirmed by the movement of the peak positions of the second largest cluster size to the $\delta_c$. Using the finite-size scaling analysis, we get $\beta/\bar{\nu}=0.20(1)$ and $1/\bar{\nu}=0.40(1)$, which implies $\beta \approx 1/2$ and $\bar{\nu} \approx 5/2$. The Fisher exponent $\tau = 2.24(1)$ for the cluster size distribution is obtained and shown to satisfy the hyperscaling relation.Comment: 4 pages, 5 figures, 1 table, journal submitte

Low-bias Negative Differential Resistance effect in armchair graphene nanoribbon junctions

Graphene nanoribbons with armchair edges (AGNRs) have bandgaps that can be flexibly tuned via the ribbon width. A junction made of a narrower AGNR sandwiched between two wider AGNR leads was recently reported to possess two perfect transmission channels close to the Fermi level. Here, we report that by using a bias voltage to drive these transmission channels into the gap of the wider AGNR lead, we can obtain a negative differential resistance (NDR) effect. Owing to the intrinsic properties of the AGNR junctions, the on-set bias reaches as low as ~ 0.2 V and the valley current almost vanishes. We further show that such NDR effect is robust against details of the atomic structure of the junction, substrate and whether the junction is made by etching or by hydrogenation.Comment: The following article has been submitted to Applied Physics Letters (http://scitation.aip.org/content/aip/journal/apl). Copyright (2014) Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported Licens

A Study on the impact of FDI on economic growth in ASEAN

Thesis(Master) --KDI School:Master of Development Policy,2015This paper examines the impact of foreign direct investment (FDI) on economic growth of the Association of Southeast Asian Nations (ASEAN) countries, using the panel data of ASEAN 8 countries over the period of 2000-2012. Employing various social factors and macroeconomic indicators as independent variables for fixed effect model and random effect model, we find evidence for the positive impact of FDI on economic growth of the region in both estimations.masterpublishedSu Hyeon SON

Development of sensitizer peptide-fused endolysin Lys1S-L9P acting against multidrug-resistant gram-negative bacteria

The advent of multidrug-resistant (MDR) bacteria poses a major threat to public health, garnering attention to novel antibiotic replacements. Endolysin, a bacteriophage-derived cell wall-degrading enzyme, is a promising alternative to conventional antibiotics. However, it is challenging to control Gram-negative bacteria due to the presence of the outer membrane that shields the peptidoglycan layer from enzymatic degradation. To overcome this threshold, we constructed the fusion endolysin Lys1S-L9P by combining endolysin LysSPN1S with KL-L9P, a sensitizer peptide known to extend efficacy of antibiotics by perturbing the outer membrane of Gram-negative bacteria. In addition, we established a new endolysin purification procedure that increases solubility allowing a 4-fold increase in production yield of Lys1S-L9P. The sensitizer peptide-fused endolysin Lys1S-L9P exhibited high bactericidal effects against many MDR Gram-negative pathogens and was more effective in eradicating biofilms compared to LysSPN1S. Moreover, Lys1S-L9P showed potential for clinical use, maintaining stability at various storage temperatures without cytotoxicity against human cells. In the in vivo Galleria mellonella model, Lys1S-L9P demonstrated potent antibacterial activity against MDR Gram-negative bacteria without inducing any toxic activity. This study suggest that Lys1S-L9P could be a potential biocontrol agent to combat MDR Gram-negative bacteria

Efficient High-dimensional Quantum Key Distribution with Hybrid Encoding

We propose a schematic setup of quantum key distribution (QKD) with an improved secret key rate based on high-dimensional quantum states. Two degrees-of-freedom of a single photon, orbital angular momentum modes, and multi-path modes, are used to encode secret key information. Its practical implementation consists of optical elements that are within the reach of current technologies such as a multiport interferometer. We show that the proposed feasible protocol has improved the secret key rate with much sophistication compared to the previous 2-dimensional protocol known as the detector-device-independent QKD.Comment: 10 pages, 6 figure

Endophytic microorganisms as potential growth promoters of banana.

The potential of endophytic microorganisms in promoting the growth of their host plant was determined by artificially introducing five isolates (bacterial and fungal strains: UPM31F4, UPM31P1, UPM14B1, UPM13B8, UPM39B3) isolated from the roots of wild bananas into both healthy and diseased banana plantlets (Berangan cv. Intan). The response of the host plants to endophytic infection was assessed by measuring the change in four growth parameters: plant height, pseudostem diameter, root mass and total number of leaves. The endophytes tested as growth promoters were found to have a significant effect in both healthy and Fusarium-infected (diseased) plantlets. In both experimental systems, the bacterial isolate UPM39B3 (Serratia) and fungal isolate UPM31P1 (Fusarium oxysporum) showed promising growth-promoting properties. Isolate UPM39B3 (Serratia) induced the largest increases in all four growth parameters in healthy plantlets – 3.14 cm (height), 1.12 cm (pseudostem diameter), 2.12 g (root mass) and 1.12 (total number of leaves plant−1) – followed by isolate UPM31P1 (Fusarium oxysporum). The beneficial effect of UPM39B3 (Serratia) and UPM31P1 (Fusarium oxysporum) was also reflected in the diseased plantlets, where pre-treatments with the isolates either singly (T6: UPM31P1; T8: UPM39B3) or in a mixture (T7: UPM31P1 + UPM39B3; T9: UPM14B1 + UPM13B8 + UPM39B3) were able to sustain the growth of plantlets, with significantly higher growth values than those in diseased plantlets that were not infected with endophytes (T10: FocR4). These results demonstrate the economic significance of these endophytic isolates, particularly UPM39B3 (Serratia) and UPM31P1 (Fusarium oxysporum), both as potential growth promoters of banana and as agents rendering tolerance towards Fusarium wilt as a strategy in the management of Fusarium wilt of banana via improved vegetative growth

Comparison of air pollution and the prevalence of allergy-related diseases in Incheon and Jeju City

PurposeA high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area.MethodsSecond grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of NO2, CO2, O3, particulate matter (PM) PM10/2.5, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined.ResultsThe levels of outdoor CO, PM10, and PM2.5 were significantly higher in Incheon (P<0.01). The levels of indoor CO, CO2, PM10, PM2.5 were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01).ConclusionWe found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed