Design of flexible GF(2/sup m/) elliptic curve cryptography processors

The design of flexible elliptic curve cryptography processors (ECP) is considered in this paper. Novel word-level algorithms and implementations for the underlying GF(2/sup m/) multiplication and squaring arithmetic which enable improved flexibility versus performance tradeoffs, are presented and employed in the design of an efficient flexible ECP architecture; corresponding field-programmable gate-array (FPGA) prototyping results for two different processor word lengths are also included for evaluation.     

Placement for large-scale floating-gate field-programable analog arrays

Modern advances in reconfigurable analog technologies are allowing field-programmable analog arrays (FPAAs) to dramatically grow in size, flexibility, and usefulness. Our goal in this paper is to develop the first placement algorithm for large-scale floating-gate-based FPAAs with a focus on the minimization of the parasitic effects on interconnects under various device-related constraints. Our FPAA clustering algorithm first groups analog components into a set of clusters so that the total number of routing switches used is minimized and all IO paths are balanced in terms of routing switches used. Our FPAA placement algorithm then maps each cluster to a computational analog block (CAB) of the target FPAA while focusing on routing switch usage and balance again. Experimental results demonstrate the effectiveness of our approach.     

Internal Geometry Variation of LTCC Inductors to Improve Light-Load Efficiency of DC-DC Converters

A low-profile power inductor fabricated using low-temperature cofired ceramic (LTCC) technology has been demonstrated to improve the light-load efficiency of a converter, without the use of additional control circuitry. This is brought about by the material and the geometry, which causes a change in inductance with load current. Variation in inductor geometry is performed experimentally to study the effects on the light-load efficiency of a converter. By decreasing the conductor width of the inductor, the light-load efficiency can be further improved by 30% in comparison with using commercial inductors of similar inductance. Sufficient core thickness is necessary to have sufficient inductance, since an inductance value which is too low is detrimental from the system power loss point of view, as demonstrated experimentally. From the circuit point of view, there seems to be a critical inductance value, whereby increasing the inductance further, does not result in significant improvement in power stage efficiency. Changing conductor thickness in the range of 260 to 550 mum does not result in significant improvement in the overall efficiency of the converter. Variation in the number of parallel conductors in a multiconductor structure does not have significant effect on light-load efficiency improvement.     

SHARE: seamless handover architecture for 3G-WLAN roaming environment

For the transition from 3G communication systems to 4G communication systems, 3G-WLAN interworking systems can be a reference model for 4G communication systems. In this paper, we identify challenging problems in 3G-WLAN interworking systems and propose a loosely coupled architecture called SHARE. In SHARE, each WLAN hotspot access point (AP) is equipped with a 3G radio transmission module to generate radio signals for control channels of 3G networks in addition to a WLAN radio module. Consequently, base stations of the 3G networks share their control channels with hotspot APs. By monitoring these channels, mobile nodes can easily detect available WLAN hotspots without probe delay for handovers.

Synthesis and electrochemical characterization of Li2MnO3–LiNixCOyMnzO2 cathode for lithium battery using co-precipitation method

The Li_xNi_0.23Co_0.12Mn_0.65O₂ electrode system with various compositions (x = 1.19, 1.33, 1.46, 1.58) was synthesized from a metal oxide precursor synthesized by co-precipitation method. The XRD patterns of the prepared powders revealed a hexagonal α-NaFeO₂ structure (space group: R-3m, 166) and the existence of a Li₂MnO₃ phase in the composite structure. In particular, the low Li content sample shows a three integrated structure (spinel, Li₂MnO₃, LiMO₂) for a Li/Metal(Ni/Co/Mn) mol ratio of 1.2. Scanning electron microscopy showed that all the synthesized samples contained spherical agglomerates with a size of 8–10 μm. Among the samples tested, Li_1.46Ni_0.23Co_0.12Mn_0.65O₂ shows relatively high charge and discharge capacity for the first cycle is 287, 192.9 mA h g^?1, respectively. Also, charge transfer resistance was also significantly improved compare with other samples.     

Characteristics of nano-sized (Pb, La)TiO3 powder synthesized at room temperature

We synthesized nano-sized (Pb, La)TiO3 powder using a high energy mechano-chemical technique at room temperature. By the results, nano-sized (Pb, La)TiO3 powder with perovskite structure was successfully synthesized from an oxide mixture using a high energy mechano-chemical technique without any post-annealing. The mechanically-synthesized (Pb, La)TiO3 powder consisted of nanometer sized particles and had very high homogeneity. According to increase of milling time, source phases such as Pb oxides and TiO2 disappeared and the perovskite PLT phase was formed by chemical reaction and the release of OH group.     

An extended graphical targeting technique for direct reuse/recycle in concentration and property-based resource conservation networks

Minimum flowrate targeting methods for resource conservation networks (RCNs) have been developed over the last decades. The existing methodologies still have certain drawbacks. Their design insights could be deepened and some steps should be more convenient for the users. A targeting tool called the material surplus composite curve (MSCC), which is an improvement of the surplus diagram for water and hydrogen networks is introduced. The approach is illustrated on several cases selected from the literature. Using this technique, it is possible to determine rigorous flowrate targets for different variants of the RCN problem.     

Antioxidant effect of grapevine leaf extract on the oxidative stress induced by a high-fat diet in rats

This study was conducted to investigate the effect of grapevine leaf extract (GLE) on the oxidative stress of rats fed a high-fat diet. Rats were divided into six groups: a normal diet with 0% (NC), 1.0% (NG1.0), and 1.5% GLE (NG1.5); and a high-fat diet with 0% (HFC), 1.0% (HFG1.0), and 1.5% GLE (HFG1.5). Treatment with GLE to the high-fat diet reduced lipid peroxide concentrations in plasma and liver compared to those of HFC rats. Total glutathione and GSH/GSSG of the groups with GLE were higher than those of untreated groups. Hepatic glutathione peroxidase, glutathione-S-transferase, and glutathione reductase activities along with catalase and glutathione peroxidase activities in erythrocytes increased after GLE treatment to high-fat diet compared with HFC rats. Hepatic retinol and tocopherol increased in HFG1.5 group compared to those of HFC group. These results indicate that GLE can protect against oxidative stress induced by a high-fat diet in rats.