Directional Monopole Antenna Using a Planar Lossy Magnetic (PLM) Surface

A directional monopole antenna using a planar lossy magnetic (PLM) surface is proposed in this paper. When a monopole antenna is designed vertically on the ground plane composed of a perfect electric conductor (PEC) and a perfect magnetic conductor (PMC), the surface current on the ground plane cannot flow on the PMC and only flows in one direction on the PEC. Therefore, the electromagnetic (EM) wave of such a monopole antenna can radiate in the direction perpendicular to the ground. Alternatively, a PLM surface such as a ferrite sheet with a high relative permeability was employed to achieve EM properties similar to the PMC. To verify the feasibility of the proposed antenna, a ferrite sheet with a relative permeability of 20 and a magnetic loss tangent of 10 at 2 GHz was utilized to implement the half PMC ground plane, and the monopole antenna was bent for miniaturization. The measured peak gain and the −10 dB bandwidth was about 1.3 dBi and 23% at the resonant frequency, respectively

Response projected clustering for direct association with physiological and clinical response data

<p>Abstract</p> <p>Background</p> <p>Microarray gene expression data are often analyzed together with corresponding physiological response and clinical metadata of biological subjects, e.g. patients' residual tumor sizes after chemotherapy or glucose levels at various stages of diabetic patients. Current clustering analysis cannot directly incorporate such quantitative metadata into the clustering heatmap of gene expression. It will be quite useful if these clinical response data can be effectively summarized in the high-dimensional clustering display so that important groups of genes can be intuitively discovered with different degrees of relevance to target disease phenotypes.</p> <p>Results</p> <p>We introduced a novel clustering analysis approach, <it>response projected clustering </it>(RPC), which uses a high-dimensional geometrical projection of response data to the gene expression space. The projected response vector, which becomes the origin in the projected space, is then clustered together with the projected gene vectors based on their different degrees of association with the response vector. A bootstrap-counting based RPC analysis is also performed to evaluate statistical tightness of identified gene clusters. Our RPC analysis was applied to the <it>in vitro </it>growth-inhibition and microarray profiling data on the NCI-60 cancer cell lines and the microarray gene expression study of macrophage differentiation in atherogenesis. These RPC applications enabled us to identify many known and novel gene factors and their potential pathway associations which are highly relevant to the drug's chemosensitivity activities and atherogenesis.</p> <p>Conclusion</p> <p>We have shown that RPC can effectively discover gene networks with different degrees of association with clinical metadata. Performed on each gene's response projected vector based on its degree of association with the response data, RPC effectively summarizes individual genes' association with metadata as well as their own expression patterns. Thus, RPC greatly enhances the utility of clustering analysis on investigating high-dimensional microarray gene expression data with quantitative metadata.</p

Compact zeroth-order resonator (ZOR) antennas

In this paper, we introduce and review the zeroth-order resonator (ZOR) antennas with outstanding characteristics including various applications that have been researched so far. Since the zeroth-order resonance frequency is independent of a physical length of antenna, the ZOR antenna can theoretically be designed quite small and have a possibility to apply to considerably lots of applications. First, we have presented the ZOR antennas implemented by double-negative (DNG), epsilon-negative (ENG), and mu-negative (MNG) transmission lines. Then, the research related on extremely small, wide beamwidth, wideband, and circularly polarized (CP) ZOR antennas have been continuously carried out. Based on a series of these studies, the ZOR antennas were utilized for various applications such as a wireless power transfer (WPT), a compact controlled reception pattern antenna (CRPA), a penta-band mobile antenna, and a wide steering array antenna

RUASN: A Robust User Authentication Framework for Wireless Sensor Networks

In recent years, wireless sensor networks (WSNs) have been considered as a potential solution for real-time monitoring applications and these WSNs have potential practical impact on next generation technology too. However, WSNs could become a threat if suitable security is not considered before the deployment and if there are any loopholes in their security, which might open the door for an attacker and hence, endanger the application. User authentication is one of the most important security services to protect WSN data access from unauthorized users; it should provide both mutual authentication and session key establishment services. This paper proposes a robust user authentication framework for wireless sensor networks, based on a two-factor (password and smart card) concept. This scheme facilitates many services to the users such as user anonymity, mutual authentication, secure session key establishment and it allows users to choose/update their password regularly, whenever needed. Furthermore, we have provided the formal verification using Rubin logic and compare RUASN with many existing schemes. As a result, we found that the proposed scheme possesses many advantages against popular attacks, and achieves better efficiency at low computation cost

Compact Penta-Band Dual ZOR Antenna for Mobile Applications

A compact penta-band dual zeroth order resonator (ZOR) antenna with band-stop filter is proposed for mobile applications. The ZOR antenna is designed with modified mushroom-like structures extended on nonground region to obtain good efficiency and broad bandwidth. This modified mushroom-like structure is confirmed as double negative (DNG) transmission line by full wave simulated dispersion relation. Moreover, a bended patch and a band-stop filter (BSF) are employed to increase efficiency and bandwidth, respectively. The length of each antenna is about λ0/10 at the resonant frequencies of 900 MHz and 1800 MHz, respectively. The overall dimension of the antenna is 54.4 mm (length) × 4 mm (width) × 5 mm (height). The total efficiencies in low and high bands are measured more than 40% and 70%, respectively

The Development of Recurrent Choroidal Neovascularization in a Patient with Choroidal Coloboma

We report a case of recurrent choroidal neovascularization (CNV) in an eye with chorioretinal coloboma. A 36-year-old woman presented complaining of decreased visual acuity (VA) in her left eye. Best corrected visual acuity (BCVA) was 20/200 and iris coloboma was observed. Funduscopy and fluorescein angiography (FA) showed CNV in the superior extrafoveal region with chorioretinal coloboma reaching just inferior to the optic disc. No other cause for CNV was observed except for the chorioretinal coloboma. BCVA improved to 20/30 after laser photocoagulation. She revisited our clinic for deteriorating VA (20/400) in the same eye 3 years after treatment. Funduscopy and FA demonstrated recurrent CNV with subfoveal hemorrhage. Photodynamic therapy (PDT) was followed by three consecutive intravitreal bevacizumab injections (IVB) for the subfoveally-located CNV. However, the CNV persisted with the appearance of a fresh subretinal hemorrhage. Additional PDT was combined with IVB on the same day 6 months after the initial PDT. The CNV regressed 3 months after treatment and has not recurred as of 8 months after the last treatment. The patient's BCVA improved to 20/60. This case suggests that PDT combined with IVB can be an alternative treatment for the management of recurrent CNV after laser photocoagulation in eyes with chorioretinal coloboma