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101.
102.
A new table of constant weight codes   总被引:8,自引:0,他引:8  
A table of binary constant weight codes of length n⩽28 is presented. Explicit constructions are given for most of the 600 codes in the table; the majority of these codes are new. The known techniques for constructing constant weight codes are surveyed, and a table of (unrestricted) binary codes of length n⩽28 is given  相似文献   
103.
In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient.  相似文献   
104.
Through time domain observation, typical wireless signal strength values seems to exhibit some forms of mean-reverting and discontinuous “jumps” behaviour. Motivated by this fact, we propose a wireless link prediction and triggering (LPT) technique using a modified mean-reverting Ornstein–Uhlenbeck (OU) jump diffusion process. The proposed technique which we refer as OU-LPT is an integral component of wireless mesh network monitoring system developed by ICT FP7 CARrier grade wireless MEsh Network project. In particular, we demonstrate how this technique can be applied in the context of wireless mesh networks to support link switching or handover in the event of predicted link degradation or failure. The proposed technique has also been implemented and evaluated in a real-time experimental testbed. The results show that OU-LPT technique can significantly enhance the reliability of wireless links by reducing the rate of false triggers compared to a conventional linear prediction technique and therefore offers a new direction on how wireless link prediction, triggering and switching process can be conducted in the future.  相似文献   
105.
Wan  Guang  Lin  Eric 《Wireless Networks》1999,5(4):245-256
This paper introduces a dynamic paging scheme based on the semirealtime movement information of an individual user, which allows a more accurate predication of the user location at the time of paging. In general, a realtime location tracking scheme may require complex control schemes and incur unacceptably high computation and messaging cost. Our proposed approach, namely the velocity paging scheme, relaxes the realtime constraints to semirealtime to provide a good combination of cost reduction and ease of implementation. The proposed velocity paging scheme utilizes semirealtime velocity information, namely velocity classes, of individual mobile terminals and dynamically calculates a paging zone (a list of cells to be paged) for an incoming call. Therefore, the total paging cost can be reduced due to the paging area reduction. Much consideration also has been given to reduce the complexity of the proposed scheme. As a result, it only requires minimal extra overhead and is feasible to implement in current cellular/PCS networks. The velocity paging can be combined with the movementbased registration or other registration schemes. Analytical and simulation results of the velocity paging and movementbased registration combination are provided to demonstrate the cost effectiveness of the scheme under various parameters in comparison with the location area scheme.  相似文献   
106.
计算机原设备制造商(OEM)正面对商业、环保和法规等多方面的压力,需要体现他们产品的能效,提供更“绿色”的台式个人电脑(PC)和服务器。这使设计这些产品的工程师需要设计出符合诸如美国80 PLUS、“能源之星”(ENERGYSTAR)和计算产业拯救气候行动计划(CSCI)等能效标准的PC电源。  相似文献   
107.
Understanding transport in Zintl compounds is important due to their unusual chemistry, structural complexity, and potential for good thermoelectric performance. Resistivity measurements indicate that undoped Ca5Al2Sb6 is a charge‐balanced semiconductor with a bandgap of 0.5 eV, consistent with Zintl–Klemm charge counting rules. Substituting divalent calcium with monovalent sodium leads to the formation of free holes, and a transition from insulating to metallic electronic behavior is observed. Seebeck measurements yield a hole mass of ~2me, consistent with a structure containing both ionic and covalent bonding. The structural complexity of Zintl compounds is implicated in their unusually low thermal conductivity values. Indeed, Ca5Al2Sb6 possesses an extremely low lattice thermal conductivity (0.6 W mK?1 at 850 K), which approaches the minimum thermal conductivity limit at high temperature. A single parabolic band model is developed and predicts that Ca4.75Na0.25Al2Sb6 possesses a near‐optimal carrier concentration for thermoelectric power generation. A maximum zT > 0.6 is obtained at 1000 K.Beyond thermoelectric applications, the semiconductor Ca5Al2Sb6 possesses a 1D covalent structure which should be amenable to interesting magnetic interactions when appropriately doped.  相似文献   
108.
Vaccine adjuvants that can induce robust protective immunity are highly sought after for the development of safer and more effective vaccines. Vaccine formulation parameters that govern efficacy are still far from clear, such as the diverse impacts of codelivering agonist molecules for innate cell receptors (e.g., pattern recognition receptors). In this study, a mesoporous silica‐templating approach is used to fabricate protein antigen (ovalbumin) particles covalently functionalized with agonists for NOD‐like receptor 2 (NOD2) and Toll‐like receptor 9 (TLR9). Particle‐induced combinatorial NOD2/TLR9 signaling results in synergistic inflammatory cytokine secretion by mouse macrophages (RAW 264.7). Administration of NOD2/TLR9 particles in mice results in adaptive immune responses that are both quantitatively and qualitatively different than those resulting from administration of particles conjugated with either NOD2 or TLR9 agonists alone. While delivery of NOD2 agonists alone activates T helper 2 (Th2)‐type responses (and no CD8+ T cell activation) and delivery of TLR9 agonists alone activates CD8+ T cell and T helper 1 (Th1)‐type responses, codelivery of NOD2 and TLR9 agonists enhances Th1‐type responses and abrogates CD8+ T cell activation. The results illustrate that in the particle‐based system, NOD2 activation plays different roles in polarizing adaptive immune responses depending on coactivation of TLR9.  相似文献   
109.
Through the use of the logic programming language PROLOG, digital logic circuitry can be conveniently represented in predicate calculus in a manner amenable to various forms of computation. Axioms define the behavior of primitive gates in a given technology, and implications hierarchically characterize the behavior of non-primitive modules.Simulation of circuitry proceeds by theorem proving, viewed as constraint satisfaction. A PROLOG-based simulator is presented for the investigation of heuristics to efficiently solve problems of ‘backward’ simulation which arise in a number of areas, such as reasoning about fault isolation. The heuristic simulator can also serve as the basis for an elegant implementation of Roth's D-algorithm.  相似文献   
110.
传统制导弹药自动驾驶仪的设计要求精确的气动模型,并依赖于变增益(gainschedule),以说明系统的非线性.本文给出了一种简化自动驾驶仪设计程序的方法:在单一飞行条件下设计逆控制器,将逆控制器与在线神经网络组合,以说明因近似逆引起的误差,这样减少了大量设计程序及精确的气动数据.这些数据在大攻角或其它情况下很重要,因为这些领域中的空气动力特征变得高度非线性化.研究发现:逆的选择在其实现的过程中很重要,所以详细讨论.最后,给出该方法在非线性6自由度制导弹药中的模拟结果.  相似文献   
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