Correlation-based subblock partition design for PTS approach

In order to exploit the capability of the peak-to-average power ratio（PAPR）reduction afforded by the partial transmit sequences （PTS）approach in orthogonal frequency division multiplexing（OFDM）systems, subblock partition schemes for the PTS approach are studied. The motivation is to establish the relationship between the subblock partition and the capability of PAPR reduction through the periodic autocorrelation functions （ACFs）of partial transmit sequences and the periodic cross-correlation functions（CCFs）of signal candidates.Let Q represent the variation of the square magnitudes of ACFs.It is found that the lower the Q-value is, the better PAPR performance can be achieved, which is introduced as a design criterion for subblock partition.Based on this criterion, four common partition methods are compared and an efficient partition strategy is proposed. It is shown that structured partition schemes with low computational complexity have a large Q-value, leading to a poor PAPR performance.The new strategy can be regarded as a trade-off between PAPR performance and computational complexity.The simulation results show that the strategy can achieve an optimal performance with a relatively low complexity and, moreover,does not increase the amount of side information.

Exploring suitable ZSM-5/MCM-41 zeolites for catalytic cracking of n-dodecane: Effect of initial particle size and Si/Al ratio

In this study,various ZSM-5/MCM-41 micro/mesoporous zeolite composites have been prepared by alkalidesilication and surfactant-directed recrystallization of ZSM-5.The effects of particle size and Si/Al ratio of initial ZSM-5 zeolites on the structure and catalytic performance of ZSM-5/MCM-41 composites are studied.The results of XRD,TEM N_2-adsorption-desorption,NH_3-TPD and in situ FT-IR revealed that ordered hexagonal MCM-41 mesopores with 3-4 nm pore size were formed around ZSM-5 crystals,and the specific surface area and mesopore volume of composites increased with increasing the Si/Al ratio of initial ZSM-5.Catalytic cracking of n-dodecane(550℃,4 MPa) showed that the ZSM-5/MCM-41 composites obtained from the high Si/Al ratio and nano-sized initial ZSM-5 zeolites exhibited superior catalytic performance,with the improvement higher than 87%in the catalytic activities and 21%in the deactivation rate compared with untreated zeolites.This could be ascribed to their suitable pore structure,which enhanced the diffusion of reactant molecules in pores of catalysts.

Radon Gas Measurements through Geiger and Sodium Iodide Scintillator——Study Efficiency Comparison

With the use ofa Geiger proportional counter with sensor tube of Russian and Chinese origin, a comparison was made in this work between measurements of environmental ionizing radiation with these detectors and a sodium iodide scintillator activated with TI （Thallium NaI）. Through measurements carried out in a room located inside a tower 25 meters high on the ITA （Technological Institute of Aeronautics） campus, it was possible to study the efficiency of the three instruments for the environmental measurement of ionizing radiations at that location. Between March 7th and June 2nd of 2017, in that region, nine intense and weak rains were observed with 12 cold fronts coming from southern Brazil. Radiation measurements and the local meteorology involved are analyzed in this work to verify possible correlations.

New Exact Solutions for （2＋1）-Dimensional Breaking Soliton Equation

New exact solutions in terms of the Jacobi elliptic functions are obtained to the (2+1)-dimensional breakingsoliton equation by means of the modified mapping method. Limit cases are studied, and new solitary wave solutionsand triangular periodic wave solutions are obtained.

Experiment and Modeling of Pure and Binary Adsorption of n-Butane and Butene-1 on ZSM-5 Zeolites with Different Si/Al Ratios

Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and butene-1 and their mixtures on these catalysts at 300K and p=0—100kPa were measured using the intelligent gra- vimetric analyzer.The experimental results indicate that the presence of Al can significantly affect the adsorption of butene-1 than that of n-butane on ZSM-5 zeolites.Then,the double Langmuir(DL)model was applied to study the pure gas adsorption on ZSM-5 zeolites for pure n-butane and butene-1.By combining the DL model with the ideal adsorbed solution theory(IAST),the IAST-DL model was applied to model the butene-1(1)/n-butane(2)binary mixture adsorption on ZSM-5 zeolites with different Si/Al ratios.The calculated results are in good agreement with the experimental data,indicating that the IAST-DL model is effective for the present systems.Finally,the adsorp- tion over a wide range of variables was predicted at low pressure and 300K by the model proposed.It is found that the selectivity of butene-1 over n-butane increases linearly with the decrease of Si/Al ratio.A correlation between the selectivity and Si/Al ratio of the sample was proposed at 300K and p=0.08MPa.

Comparison of two approximal proximal point algorithms for monotone variational inequalities

Proximal point algorithms （PPA） are attractive methods for solving monotone variational inequalities （MVI）. Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approximate versions ofPPA （APPA） are developed for practical applications. In this paper, we compare two APPA methods, both of which can be viewed as prediction-correction methods. The only difference is that they use different search directions in the correction-step. By extending the general forward-backward splitting methods, we obtain Algorithm Ⅰ; in the same way, Algorithm Ⅱ is proposed by spreading the general extra-gradient methods. Our analysis explains theoretically why Algorithm Ⅱ usually outperforms Algorithm Ⅰ. For computation practice, we consider a class of MVI with a special structure, and choose the extending Algorithm Ⅱ to implement, which is inspired by the idea of Gauss-Seidel iteration method making full use of information about the latest iteration. And in particular, self-adaptive techniques are adopted to adjust relevant parameters for faster convergence. Finally, some numerical experiments are reported on the separated MVI. Numerical results showed that the extending Algorithm II is feasible and easy to implement with relatively low computation load.

Effects of electrical parameters and their interactions on plasma electrolytic oxidation coatings on aluminum substrates

Based on orthogonal experiments,the effects of voltage,frequency,duty ratio and their interactions on the thickness and corrosion resistance of coatings prepared by plasma electrolytic oxidation(PEO)on aluminum in an alkaline silicate-containing electrolyte were investigated.The thicknesses of these coatings were obtained by measuring their cross-section using Image J software.Their corrosion resistances were evaluated in HCl and NaCl media through spot test and electrochemical test.The results show that the experimental design of this study is the key to investigate the interactions among these electrical parameters.Additionally,not only each independent factor,but also their interactions exhibit a remarkable influence on the coatings.The combination of high voltage,low frequency and large duty ratio significantly increases the coating thickness and content of the corrosion resistance phase,and thus improves the corrosion resistance of the coating in HNO3 medium.Conversely,the coating possessing the densest microstructure and best corrosion resistance in NaCl medium is obtained when low voltage and high frequency match with a small duty ratio.

Periodic Structures of Rossby Wave under Influence of Dissipation

A simple barotropic potential vorticity equation with the influence of dissipation is applied to investigate the nonlinear Rossby wave in a shear flow in the tropical atmophere. By the reduetive perturbation method, we derive the rotational KdV （rKdV for short） equation. And then, with the help of Jaeobi elliptie functions, we obtain various periodic structures for these Rossby waves. It is shown that dissipation is very important for these periodic structures of rational form.

Distribution and ultrastructure of pigment cells in the skins of normal and albino adult turbot, Scophthalmus Maximus

The distribution and ultrastructure of pigment cells in skins of normal and albino adult turbots were examined with transmission electron microscopy （TEM）. Three types of pigment cells of melanophore, iridophore and xanthophore have been recognized in adult turbot skins. The skin color depends mainly on the amount and distribution of melanophore and iridophore, as xanthophore is quite rare. No pigment cells can be found in the epidermis of the skins. In the pigmented ocular skin of the turbot, melanophore and iridophore are usually co-localized in the dermis. This is quite different from the distribution in larvae skin. In albino and white blind skins of adult turbots, however, only iridophore monolayer still exists, while the melanophore monolayer disappears. This cytological evidence explains why the albino adult turbot, unlike its larvae, could never resume its body color no matter what enviroumental and nutritional conditions were provided. Endocytosis is quite active in the cellular membrane of the iridophore. This might be related to the formation of reflective platelet and stability of the iridophore.

Specific Heat and Magnetic Susceptibility of Graphene:A Renormalization Group Study

In the present paper, we study effect of the long-range Coulomb interaction on the thermodynamic propertiesof graphene by renormalization group methods.Our calculations show that both the specific heat and the magneticsusceptibility of the material behave differently from the Landau Fermi liquid.More precisely, we find that thesequantities are logarithmically suppressed with respect to its noninteracting counterpart when temperature is low.

REDUCING THE PEAK-TO-AVERAGE POWER RATIO OF OFDM SYSTEM WITH LOW COMPLEXITY

This paper proposes a companding scheme, where small signals are enlarged and large signals are reduced, to reduce the Peak-to-Average Power Ratio(PAPR). Computer simulation results show that the proposed technique has two advantages at least when compared with the conventional methods such as partial transmit sequence, selective mapping and the previous companding. First, it gets better PAPR performances with a lower complexity. Second, the scheme achieves greater performances gain with hardly any damnification of OFDM signals in some degree.

Optical Fiber Pressure Sensor with Reference Channel

The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.

Peak-to-average power ratio reduction using selective mapping with unequal power distribution

A new approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems was proposed.This approach is based on assigning powers to the different subcarriers of OFDM using an unequal power distribution strategy.In addition,a reduced complexity selective mapping (RC-SLM) scheme was proposed.The proposed scheme is based on partitioning the frequency domain symbol sequence into several sub-blocks,and then each sub-block is multiplied by different phase sequences whose length is shorter than that used in the conventional SLM scheme.Then,a kind of low complexity conversions is used to replace the IFFT blocks.The performance of the proposed RC-SLM scheme along with the new approach was studied with computer simulation.The obtained results show that the proposed RC-SLM scheme is able to achieve the lowest computational complexity when compared with other low complexity schemes proposed in the literature while at the same time improves the PAPR reduction performance by about 0.3 dB.

Teleportation of an Arbitrary Two-Particle State via a Single Cluster-Class State

Teleportation of an arbitrary two-qubit state with a single partially entangled state,a four-qubit linearcluster-class state,is studied.The case is more practical than previous ones using maximally entangled states as thequantum channel.In order to realize teleportation,we first construct a cluster-basis of 16 orthonormal cluster states.We show that quantum teleportation can be successfully implemented with a certain probability if the receiver can adoptappropriate unitary transformations after receiving the sender's cluster-basis measurement information.In addition,animportant conclusion can be obtained that a four-qubit maximally entangled state (cluster state) can be extracted froma single copy of the cluster-class state with the same probability as the teleportation in principle.

Dynamic Energy Saving Subcarrier, Bit and Power Allocation in OFDMA Relay Networks

To reduce energy consumption while maintaining users＇ Quality of Service （QoS） in Orthogonal Frequency Division Mul- tiplex Access （OFDMA） relay-enhanced net- works, an adaptive energy saving subcarrier, bit and power allocation scheme is presented. The optimal subcarrier, bit and power alloca- tion problems based on discrete adaptive modula- tion and coding scheme have been previously formulated for relay-enhanced networks, and have been reformulated into and solved by integer programming in optimization theory. If the system still has a surplus of subcarriers after resource allocation, we carry out Band- width Exchange （BE） to enable more subcar- riers to participate in transmission to save en- ergy. In addition, as the relay selection scheme is closely linked with heuristic energy saving resource allocation, a relay selection scheme is proposed. Simulation results indicate that the proposed algorithm consumes less energy when transmitting the same number of bits than greedy energy saving schemes, although its spectrum efficiency is worse.

Discussions about the differences and credibility on grape wine scoring

The scores of grape wine given by wine critics have differences, therefore, for which its credibility differs. Firstly, our paper analysis differences of overall and individual for the two groups of raters. The analysis method is： first check the score whether meets the normal distribution or not by Chi-square and then test whether the mean of the two group＇s ratings is equal or not, through t-test, to illustrate the differences of the two groups＇ ratings. Secondly this paper respectively characterizes the credibility of each group＇s rating with the variance and gray correlation. Both the results are highly consistent on the credibility, so they can support each other. This score comparison method can be further extended to a similar scoring system.

Gillnet Selectivity and Length at Maturity of Nile Tilapia （Oreochromis niloticus L.） in a Tropical Reservoir （Amerti： Ethiopia）

The selectivity of gillnets for Oreochromis niloticus in Amerti reservoir （9°63′ N, 37°23′ E） was determined from gillnets with four mesh sizes （60, 80, 100 and 120 mm）. Four selectivity models （a normal model assuming fixed spread, a normal model assuming that spread is proportional to mesh size, a lognormal model and a gamma model） were fitted to the data by using the share each length＇s catch total （SELECT） method. A total of 657 specimens of Oreochromis niloticus were caught （12.0-35.5 cm total length, TD. The sizes at first sexual maturity were 21.5 cm TL and 18.9 cm TL, respectively, for male and female Oreochromis niloticus. The lognormal selectivity curve provided the best fit to the data according to model deviance estimates with optimum selectivity of 16.66, 22.26, 27.78 and 33.38 cm TL for the 60, 80, 100 and 120 mm mesh sizes, respectively.

Frequency Offset Compensation for Satellite Communication System with CE-OFDM

Constant envelope orthogonal frequency division multiplexing(CE-OFDM) is a waveform that can achieve 0d B peak-to-average power ratio and avoid the signal distortion caused by the nonlinear power amplifi er. However, the carrier frequency offset(CFO) in CE-OFDM systems can cause errors at phase unwrapper module. In this paper, a CFO estimation scheme is proposed for CEOFDM in satellite communication system. As the null subcarrier is inherent in the conjugate symmetric symbol structure at the transmitter, the proposed scheme uses the null subcarrier as prior information to estimate the CFO at the receiver. The ideal estimation range of normalized CFO is obtained by mathematical analysis. Simulation results show that the proposed scheme can estimate the CFO accurately under additive white Gaussian noise(AWGN) channel and multipath fading channel, especially for moderate and high signal-to-noise ratio(SNR).

Financial Development, Trade Openness, and Economic Growth in Zambia

This study investigates the causal relationship among financial development, trade openness, and economic growth in Zambia from 1965 to 2011. Two measures of financial development were used： broad money and domestic credit to the private sector, each as a ratio of gross domestic product （GDP）. In this regard, two models were developed for each indicator. The Augmented Dickey-Fuller （ADF） and Phillips-Perron （PP） tests were used to determine stationarity of all the variables. Furthermore, Johansen test was employed to ascertain possible cointegration among variables. The vector error correction model （VECM） was employed to examine the short-run and long-run dynamics among the variables in each model. The results indicate that the relationship among financial development, trade openness, and economic growth is sensitive to the financial development indicator chosen.