Stability analysis of linear systems under state and rate saturations

In this paper, we provide a stability analysis for linear systems which have simultaneous saturations in the states and their rates (dynamics). The stability analysis is conducted via a formulation based on the polytopic representations of two saturation functions, state and rate saturation functions. Sufficient conditions to guarantee local and global asymptotical stability of such systems are derived. Furthermore, using the invariance analysis, we estimate the domain of attraction of the system when it is locally asymptotically stable. The stability conditions are formulated as an iterative LMI (ILMI) algorithm. Finally, numerical examples are presented to validate the proposed method.     

Security Analysis and Improvement of Authentication Scheme Based on a One-way Hash Function and Diffie-Hellman Key Exchange Using Smart Card

A new authentication scheme based on a one-way hash function and Diffie-Hellman key exchange using smart card was proposed by Yoon et al.in 2005.They claimed that the proposed protocol is against password guessing attack.In this paper,the author demonstrate that Yoon's scheme is vulnerable to the off-line password guessing attack by using a stolen smart card and the DoS attack by computational load at the remote system.An improvement of Yoon's scheme to resist the above attacks is also proposed.     

Temperature stability and phase transition of Li0.02(KxNa1−x)0.98NbO3 ceramics

Li_0.02(K_xNa_1?x)_0.98NbO₃(x = 0.35–0.55) ceramics were prepared using the conventional solid state sintering method. The thermal behaviors of Li-modified (K_xNa_1?x)NbO₃ ceramics were investigated from ?30 to 150 °C, and the effect of Na/K ratio in (K_xNa_1?x)NbO₃ ceramics on thermal behavior and electrical properties was also studied. In the case of Li_0.02(K_xNa_1?x)_0.98NbO₃ ceramics with 0.5 wt.% ZnO, the transition temperature was sharply decreased because of a phase transition as the composition range of x was 0.425–0.475. From the results of the temperature dependence of piezoelectric properties, it is assumed that the Na-rich phase is less stable than the K-rich phase for temperature change.     

Safety distance analysis of dimethylether filling stations using a modified individual risk assessment method

The physical properties of dimethylether (DME) are similar to conventional fuels such as LPG and diesel, so DME has been recently considered one of the most promising candidates for a substitute for them. Equipment failures in gas stations lead to accidents that pose significant threats to people and property. Therefore, prior to commercialization, safety standards for DME need to be developed based on risk analysis. In this study, we focused on safety distance in DME filling stations. A hypothetical DME filling station was modeled based on a DME-LPG mixed filling station designed by KOGAS, and safety distances were suggested from a semi-quantitative risk estimation approach using individual risk calculations. Modified individual risk calculations were performed with consequence analysis and failure mode under varying accident scenarios. Compared with existing individual risk analysis, the modified-individual risk approach is supplemented with a weighting factor to graduate each accident scenario by historical analysis. Subsequently, the outcome shows the individual risk that suggests a safety distance. To compare with conventional fuel, we also performed a comparative study on the filling station fuels LPG and DME. According to the quantitative risk estimation results, we propose a separation distance based on accident scenarios for each facility. In conclusion, safe distances for DME facilities are lower than those that dispense LPG. Therefore, a DME filling unit can be placed at conventional gas stations without increasing the safety distance. The results will also be useful in determining the standard for safety management of renewable and sustainable energy.     

A high-precision spread spectrum clock generator based on a fractional-N phase locked loop

A low jitter Spread Spectrum Clock Generator (SSCG) based on a fractional-N Phase Locked Loop (PLL) capable of generating various Electromagnetic Interference (EMI) reduction levels is proposed. A digital compensation filter is fully integrated in the design to prevent various triangular modulation profiles from being distorted by the prohibitively small PLL loop bandwidth. A simple but comprehensive logic design included in the digital filter provides independently controllable modulation frequency, f _m, and modulation ratio, δ_m within all modulation modes (up, down, center). The proposed SSCG is designed in a 0.18 μm CMOS standard cell library and operates at 72 MHz with f _m ranging from 58 to 112.5 kHz and δ_m ranging from 0.75 to 2 %.     

Strategy for Building Initial Trust in Click-Only Online Fashion Stores

The main purpose of this study is to propose practical and effective strategies for acquiring and building initial trust from online consumers that could be used by the Internet store selling fashion goods online. To achieve this purpose, this paper suggests a trust life cycle model, identifies various trusting cues by reviewing antecedent literature on trust, establishes an empirical research model based on the eleven cues identified, and tries to find the most salient trusting cues affecting the development of initial trust by empirically testing the model. The results show that the factors significant in developing initial trust in an Internet fashion store are perceived service reliability, perceived variety of options, perceived ease of use, and legal infrastructure.     

Oyster Shell Recycling and Plasma Bone Waste Treatment Using Pyrolysis

Investigations on the recycling plasma pyrolysis technique are presented in 25 kW was employed for the experiments. of oyster shells and bone waste treatment using the this paper. A arc based plasma torch operated at Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases.     

Sliding Wear Behavior of Plasma Sprayed Zirconia Coating on Cast Aluminum against Silicon Carbide Ceramic

1.IntroductionPlasma-sprayed zirconia ceramic coating is widelyused for heat engines,gas turbine parts,aerospace seals,and lubrication systems,because of its special mechani-cal,chemical,and thermal properties[1].Previous stud-ies of the friction and wear patterns of zirconia andits coatings have been reported[2~14].The wear be-havior of zirconia ceramics seemed to be very sensi-tive to the structure of the material,and to test pa-rameters such as temperature,environment,and slid-ing speed[2].…     

Growth of GaAs Nanowires on Si Substrates Using a Molecular Beam Epitaxy

Au-catalyzed GaAs nanowires were grown on Si substrates by vapor-liquid-solid growth method using a molecular beam epitaxy (MBE). The MBE growth could produce controlled crystalline orientation and uniform diameter along the wire axis of the GaAs nanowires by adjusting growth conditions including growth temperature and V/III flux ratio. Growths of GaAslang001rang as well as GaAslang111rang nanowires were observed by transmission electron microscopy and scanning electron microscopy. Epitaxially grown GaAslang111rang nanowires on a Si(111) substrate were verified through x-ray diffraction out-of-plane 2thetas/omega-scans. A strong room-temperature photoluminescence (PL) was observed from the epitaxially grown GaAslang111rang nanowires on a Si(100) substrate. Results of low-temperature (10 K) PL measurements and current-sensing atomic force microscopy indicated that the GaAs nanowires on a Si substrate were unintentionally doped with Si