排序方式: 共有69条查询结果,搜索用时 421 毫秒
31.
List-based algorithms for. decoding block turbo Codes (BTC) have gained popularity due to their low computational complexity. The normal way to calculate the soft outputs involves searching for a decision code word D and a competing codeword B. In addition, a scaling factor /spl alpha/ and an estimated reliability value /spl beta/ are used. In this letter, we present a new approach that does not require /spl alpha/ and /spl beta/. Soft outputs are generated based on the Euclidean distance property of decision code words. By using the new algorithm, we achieve better error performance with even less complexity-for certain BTCs. 相似文献
32.
Shayan Farhikhteh Amir Maghsoudipour Babak Raissi Babak Mozaffari 《Journal of Sol-Gel Science and Technology》2009,49(1):60-65
In this study high specific surface area yttria-stabilized zirconia (ZrO2–8Y2O3) nanocrystalline powder have been synthesized through “modified polymerized complex (MPC) method”. Zirconium chloride, yttrium
nitrate, citric acid and ethylene glycol were polymerized at 80 °C to produce a gel-like mass in which metallic ions were
uniformly distributed. During the thermal treatment of dried gel, nanocrystalline YSZ powder was formed. Thermal reactions
and phase formation of dried gel were investigated through thermal analysis (DTA/TG) and X-ray diffraction (XRD) analysis,
respectively. Chemical bonding and thermal decomposition behavior of dried gel was investigated by FTIR analysis. During decomposition,
the nature of the bonding between carboxylate groups and the cations changed from unidentate to bridging at 370 °C and carbonate
species were detected at 470 °C. Morphology of powder calcined at 650 °C was analyzed by scanning electron microscope (SEM).
YSZ powder with high specific surface area was prepared successfully by this method. 相似文献
33.
The reaction of CH3OH with the O2 on the triplet and singlet potential energy surfaces (PES) was carried out using the B3LYP, MP2, and CCSD(T)//B3LYP theoretical approaches in connection with the 6-311++G(3df–3pd) basis set. Three pre-reactive complexes, 1C1, 1C2, and 3C1, on the singlet and triplet PES were formed between methanol and molecular oxygen. From a variety of the complexes, seven types of products are obtained, of which four types are found to be thermodynamically stable. Results reveal that there exists one intersystem crossing between triplet and singlet PES. For P4 adduct that is the main and kinetically the most favorable product, the rate constants are calculated in the temperature range of 200–1,000 K in the reliable pathway. 相似文献
34.
Ana Snchez‐Grande Jos I. Urgel Ale Cahlík Jos Santos Shayan Edalatmanesh Eider Rodríguez‐Snchez Koen Lauwaet Pingo Mutombo Dana Nachtigallov Reed Nieman Hans Lischka Bruno de la Torre Rodolfo Miranda Oliver Grning Nazario Martín Pavel Jelínek David cija 《Angewandte Chemie (International ed. in English)》2020,59(40):17594-17599
We report on the synthesis and characterization of atomically precise one‐dimensional diradical peripentacene polymers on a Au(111) surface. By means of high‐resolution scanning probe microscopy complemented by theoretical simulations, we provide evidence of their magnetic properties, which arise from the presence of two unpaired spins at their termini. Additionally, we probe a transition of their magnetic properties related to the length of the polymer. Peripentacene dimers exhibit an antiferromagnetic (S=0) singlet ground state. They are characterized by singlet–triplet spin‐flip inelastic excitations with an effective exchange coupling (Jeff) of 2.5 meV, whereas trimers and longer peripentacene polymers reveal a paramagnetic nature and feature Kondo fingerprints at each terminus due to the unpaired spin. Our work provides access to the precise fabrication of polymers featuring diradical character which are potentially useful in carbon‐based optoelectronics and spintronics. 相似文献
35.
A BiCMOS digital logic gate is analyzed for input voltages with a finite rise or fall time. A new gate delay model to account for the input slope is developed. A set of accurate yet simple closed-form delay expressions are derived for the first time in terms of the input signal slew rate as well as circuit and device parameters. SPICE simulations are used to verify the accuracy of the analytical delay model. The BiCMOS circuit is characterized in terms of the input slew rate, the fan-in, fan-out, and the circuit delay constants. The model can be incorporated in timing simulators and timing analyzers for BiCMOS ULSI circuit design 相似文献
36.
Coupled photonic oscillators and resonators are sensitive to unavoidable nanoscale disorder, and localization in periodic structures induced by disorder leads eventually to a complete collapse of the bandwidth, which is generally considered problematic for device applications. Here, we investigate the dependence of bandwidth collapse on the interresonator coupling coefficient, a parameter controllable by lithography or device operation. 相似文献
37.
Zhu Y Shayan A Zhang W Chen TL Jung TP Duann JR Makeig S Cheng CK 《IEEE transactions on bio-medical engineering》2008,55(11):2528-2537
38.
A coal burning power plant is considered. Its components are grouped into appropriate modules so that the whole unit is a series systems of 7 modules. Exponential distributions are used for life time and repair time of all components according to real data. A model is developed which generates: i) the reliability of components, modules, and the unit, and ii) the average amount of power generated by the unit at any given time and over a period of time. Result agrees with a simulation model and past data. The model can be used in planning, design. It can be adopted for production systems. 相似文献
39.
Sanei A. Ghrayeb A. Shayan Y. Duman T.M. 《Wireless Communications, IEEE Transactions on》2006,5(7):1579-1585
In this paper, we study the performance of space-time trellis codes (STTCs) with receive antenna selection over fast fading channels. Specifically, we derive upper bounds on the pairwise-error probability (PEP) with antenna selection. In performing the selection, we adopt a criterion that is based on using L out of the available M receive antennas that result in maximizing the instantaneous signal-to-noise ratio (SNR) at the receiver, where L les M. We show that the diversity order resulting from antenna selection deteriorates significantly and is actually dictated by the number of selected antennas. The implication of this result is that adding more receive antennas, while maintaining the same number of selected ones, will have no impact on the diversity order, but it does, however, provide some additional coding gain. This is unlike the case for quasi-static fading channels in which the diversity order is always preserved with antenna selection when the underlying STTC is full-rank. We present numerical examples that support our analysis 相似文献
40.
Multidimensional Systems and Signal Processing - In this paper we discuss recovering two signals from their convolution in 3 dimensions. One of the signals is assumed to lie in a known subspace and... 相似文献