Transmit/receive beamformer design and power control in MIMO MC-CDMA systems

IEEE International Symposium on Circuits and Systems, Island of Kos, Greece, 21-24 May 2006In this paper, a joint transmitter and receiver beamformers design algorithm for downlink multiple input multiple output multicarrier code-division multiple access (MIMO MC-CDMA) system is proposed. The algorithm is iterative in nature where the transmitter beamformers and the receiver beamformers are determined alternately. The transmitter beamforming problem with a given receiver beamformer is formulated as a convex programming problem, which can be solved optimally using second order cone programming (SOCP), while the receiver beamforming problem is formulated as a constrained optimization problem with an analytical solution. The convergence of the algorithm is analyzed and the performance of the proposed algorithm is evaluated by computing simulation. © 2006 IEEE.published_or_final_versio

Design and multiplierless realization of digital synthesis filters for hybrid-filter-bank A/D converters

This paper studies the optimal least squares and minimax design and realization of digital synthesis filters for hybrid-filter-bank analog-to-digltal converters (HFB ADCs) to meet a given spurious-free dynamic range (SFDR). The problem for designing finite-impulse-response synthesis filters is formulated as a second-order cone-programming problem, which is convex and allows linear and quadratic constraints such as peak aliasing error to be incorporated. The fixed coefficients of the designed synthesis filters are efficiently implemented using sum-of-power-of-two (SOPOT) coefficients, while the internal word length used for each intermediate data is minimized using geometric programming. The main sources of error are analyzed, and a new formula of SFDR in terms of these errors is derived. The effects of component variations of analog analysis filters on the HFB ADC are also addressed by means of two new robust HFB ADC design algorithms based on stochastic uncertainty and worst case uncertainty models. Design results show that the proposed approach offers more flexibility and better performance than conventional methods in achieving a given SFDR and that the robust design algorithms are more robust to parameter uncertainties than the nominal design in which the uncertainties are not taken into account. © 2009 IEEE.published_or_final_versio

Reply to comment by Huntley on "isochron dating of sediments using luminescence of K-feldspar grains"

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Estimation of paleo-firing temperatures using luminescence signals for the volcanic lava baked layer in Datong, China

Eight paleo-fired samples from the baked layer in different depths under the lava and one unfired sample were collected from Datong, China. Fine quartz grains (4–11 μm) from samples were used for probing into relationship between luminescence signals and paleo-firing temperatures. Findings from the re-firing experiments indicated that using thermoluminescence (TL) and optically stimulated luminescence (OSL) sensitivity changes could estimate the paleo-firing temperatures of samples: (1) 110 °C TL sensitivity change rate against the re-firing temperature can tell whether the sample has been fired to temperatures above 500 °C or not; (2) 150 °C TL sensitivity against the re-firing temperature can indicate whether the sample has been fired to temperatures above 900 °C or not; (3) the more specific paleo-firing temperatures can be estimated by comparing the ratio of OSL and 150 °C TL sensitivities against re-firing temperatures. Results showed that the paleo-firing temperatures of the eight lava-baked samples decreased exponentially with the distance from the lava. Based on the estimated temperature profile, the temperature of the lava was estimated to be about 1100 °C.postprin

Luminescence dating of volcanic eruptions in Datong, northern China

In this study, fine-grain quartz was used for luminescence dating for lava baked samples from different sites in Datong. Optical stimulated luminescence (OSL), thermal transferred OSL (TT-OSL)/recuperated OSL (Re-OSL) and thermoluminescence (TL) dating protocols were applied. For these samples, the OSL signals saturate at about 300–400 Gy, which limits their age to less than 100 ka based on their ambient dose rates. The TT-OSL/Re-OSL method has poor dose recovery. TL dating gives reliable results, and multiple-aliquot regenerative-dose TL method with sensitivity change correction based on the 325 °C TL peak of a test dose can be applied for samples up to 400 ka. The results indicate that the ages of the volcanoes in Datong are from 380 ka to 84 ka. The volcanic activity started earlier in the southeast area than those in the northwest part, which is consist with the literature data.postprin

Some debating points of investment promotion in the form of public–private partnership.

Стремительный рост необходимости развития транспортной инфраструктуры потребовал значительных финансовых средств на ее развитие и поддержание. Традиционных источников финансирования транспортной инфраструктуры с каждым годом становится недостаточно. В связи с этим нестандартные формы финансирования, подразумевающие привлечение внебюджетных средств в сферу транспортных коммуникаций, с каждым годом набирают все большую популярность. Государственно–частное партнерство (ГЧП) имеет много преимуществ по сравнению с другими формами привлечения средств. На сегодняшний день оно является одной из актуальных тем для обсуждения. Однако при наличии различных целей партнеров, партнерство должно быть выгодным как для государства, так и для частного инвестора. В настоящее время механизм ГЧП приходит в экономику Республики Беларусь. В этой статье автор указывает на основные разногласия партнеров, с которыми может столкнуться Беларусь при реализации транспортных проектов в рамках ЧГП. = The urgent necessity of transport infrastructure development requires significant financial resources for its construction and maintenance. There are no sufficient traditional sources for these purposes. There-fore the use of innovative forms of financing implying obtaining of extra budgetary resources for the transportation sphere becomes more and more popular year after year. Public–private partnership (PPP) has many advantages over other forms of fundraising. Today it is one of the most pressing topics for discussion. But goals of partners are different. However, partnership should be beneficial for both state and private investors. At present the mechanism of PPP becomes more and more relevant for the economy of Belarus. The author of this paper defines the main disagreements between the partners which the Republic of Belarus may face in implementation of transport projects within the PPP. Key words: financing of transport infrastructure; public–private partnership (PPP); possible disagree-ments between partners; Republic of Belarus

Neoproterozoic Mafic-Ultramafic Intrusions from the Fanjingshan Region, South China: Implications for Subduction-Related Magmatism in the Jiangnan Fold Belt

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iIRSL dating of K-feldspar and its application to Fajiagouwan, Salawusu site in Central China

Dating Protocols Improvements: abstract no. P19published_or_final_versio

High-yield cellulase production in solid-state fermentation by Trichoderma reesei SEMCC-3.217 using water hyacinth (Eichhornia crassipes)

In this study, the strain Trichoderma reesei SEMCC-3.217 was used for producing cellulase in solid-state fermentation with water hyacinth (Eichhornia crassipes). The results of fractional factorial design showed that, the addition amount of wheat bran, (NH4)2SO4, CaCl2 and Tween 80 had significant effect on the cellulase production. Then, these four factors were selected for further optimization by central composite design for the yield of cellulase. The statistical analysis of the results showed that, the optimum composition were: 5 g of substrate containing 3.9 g water hyacinth, 1% corn steep liquor, 1% soybean meal, 0.2% NH4NO3, 0.2% KH2PO4, 0.08% MgSO4·7H2O, 2.8% (NH4)2SO4, 1.5% urea, 13.9% wheat bran, 0.08% ZnSO4·7H2O, 0.08% FeCl2 0.05% CaCl2, 0.08% NaNO3, 0.08% KCl and 0.27% (v/v) Tween-80. Under these conditions, the cellulase production was 4-fold increased (13.4 FPIU/g dry solid) compared with the initial level (3.4 FPIU/g dry solid) after 7 days of fermentation in a 250 ml Erlenmeyer flask.Key words: Cellulase, solid-state fermentation, optimization, water hyacinth, Trichoderma reesei

High sensitivity cymbal-based accelerometer

Author name used in this publication: Cheng-Liang SunAuthor name used in this publication: K. H. LamAuthor name used in this publication: S. H. ChoyAuthor name used in this publication: H. L. W. ChanAuthor name used in this publication: X.-Z. ZhaoAuthor name used in this publication: C. L. Choy2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe