STRESS CONTROLLED FERROELECTRIC (BA0.5Sr0.5)TiO3 THIN FILMS PREPARED ON GD2O3/SRTiO3(001) BY A PULSED LASER DEPOSITION

ABSTRACT

Stress controlled epitaxial ferroelectric Ba_0.5Sr_0.5TiO₃ (BST) films have been deposited on Gd₂O₃/SrTiO₃ by pulsed laser deposition with oxygen background pressure of 200 mTorr at the deposition temperature of 750°C. In order to control the stress in BST films, oxygen pressures for Gd₂O₃ buffer layers have been varied from 0.1 to 100 mTorr, while that of BST films have been fixed at 200 mTorr. It has been found that the lattice parameters of the BST films deposited on Gd₂O₃ were changed. Furthermore, microwave properties of co-planar waveguide (CPW) fabricated on BST films were investigated by a HP 8510C vector network analyzer from 1–20 GHz. Large dielectric tunabilities were observed from the CPW's fabricated on BST films deposited on Gd₂O₃ layers deposited at low and high oxygen pressures, 0.1 and 100 mTorr, respectively.     

ANTIGENOTOXIC, FIBRINOLYTIC AND IMMUNOMODULATING ACTIVITY OF TRADITIONALLY FERMENTED SOY PRODUCT, CHUNGKUKJANG

Fibrinolytic, antigenotoxic and immunomodulating properties of chungkukjang were evaluated. The purified fibrinolytic enzyme was characterized as an alkaline serine protease with molecular weight of 22 kDa determined by fibrin zymography and stable over pH range 6.0–10.0 below 50C. The comet assay showed that N-methyl-N ' -nitro-N-nitrosoguanidine (MNNG)-induced DNA damage level (190.8 AU) in 3T3 cells was considerably decreased to 121.2 AU with chungkukjang extracts (CB) showing 49.7% of protection. Incubation of the 3T3 cells with CB significantly reduced the cytotoxicity of MNNG. [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay revealed that the addition of CB enhanced the proliferation of RAW 264.7 (mouse leukemic monocyte macrophage cell line) macrophages up to about 150% of the control levels. RAW 264.7 macrophages incubated with CB induced a strong increase in nitric oxide (NO), tumor necrosis factor -α (TNF-α) and interleukin-1α (IL-1α) with a dose-dependent manner. After 24 h incubation with 1 mg/mL of CB, NO, TNF-α and IL-1α showed the highest production of 511, 2.46 and 0.258 ng/mL, respectively.     

Measuring IP Performance Metrics on Mobile Network with Heterogeneous Wireless Technologies

The new measurement scheme of IP performance metrics is proposed for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes (MNs) inside the mobile network needs to understand the condition of multiple communication paths outside the mobile network, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the presence or absence of measurement functionality. At the same time, the proposed scheme does not require the MN to be involved in measuring IP performance metrics. The Multihomed Mobile Router (MMR) with heterogeneous wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP performance metrics from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and battery power since MNs don't measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injected testing traffic are reduced.     

FRIENDS AND NEIGHBORS: HOMEOWNERSHIP AND SOCIAL CAPITAL AMONG LOW‐ TO MODERATE‐INCOME FAMILIES

ABSTRACT: This research explores whether homeownership leads to increased individual social capital among low‐ to moderate‐income families. Social capital refers to social resources a person can access through contacts with others in his or her social networks. We theorize that homeownership can motivate interactions with others in one's neighborhood and therefore build social capital. Using a sample of low‐ and moderate‐income homeowners and a matched sample of renters, we collect data on overall social resources and neighborhood‐specific social resources. We find that homeowners have more total social capital resources and more neighborhood social capital resources than renters. Neighborhood group involvement has an indirect effect on social capital, but explains only a small amount of the influence of homeownership. These findings hold when controlling for household‐level and neighborhood‐level sociodemographic variables, as well as when using statistical models that account for endogeneity. Based on this evidence, we conclude that homeownership gives people access to social capital via increased social ties to others. We discuss the implications of this finding for housing policy and suggest new directions for research on social capital.     

Adaptive Step Size Control of LMS-based Interference Cancellationfor ICS Repeater in Wibro Environment

The use of repeater for the support of high rate data transmission and the extension of cell coverage is imperative for the Wibrc system,which based on the IEEE 8M.16e standardization.Generally,if the separation between transmitting and receiving antennas isnot sufficient,the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be ocerur.Hence,the Interference Cancellation System(ICS)should be implemented as the important part of the repeater system far the mobile cellular systems in order to eliminate unwanted signals from the corruptW signals in the receiver.In this paper,we propose an adaptive technique for the Least Mean Square(LMS)-based interference cancellation methods by changing the step size according to the variation of channel environment in order to improve the performance degradation which oceuurs by using the fixed step size approach.Simrlatim results show that the proposed sclxme attains a little lower Berafor Rate(BER)performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques.The proposed scheme can be applied to other Orthogonal Frequency Division Multiple(OFDM)-based cellular systems and also be expected to achieve a similar performance improvement to W17-advanced system,which is called as the next generation mobile communication standards.