A fuzzy multi-objective model for capacity allocation and pricing policy of provider in data communication service with different QoS levels

Data communication service has an important influence on e-commerce. The key challenge for the users is, ultimately, to select a suitable provider. However, in this article, we do not focus on this aspect but the viewpoint and decision-making of providers for order allocation and pricing policy when orders exceed service capacity. It is a multiple criteria decision-making problem such as profit and cancellation ratio. Meanwhile, we know realistic situations in which much of the input information is uncertain. Thus, it becomes very complex in a real-life environment. In this situation, fuzzy sets theory is the best tool for solving this problem. Our fuzzy model is formulated in such a way as to simultaneously consider the imprecision of information, price sensitive demand, stochastic variables, cancellation fee and the general membership function. For solving the problem, a new fuzzy programming is developed. Finally, a numerical example is presented to illustrate the proposed method. The results show that it is effective for determining the suitable order set and pricing policy of provider in data communication service with different quality of service (QoS) levels.     

Structural and vascular permeability abnormalities associated with lacunes of the human brain

Histopathological and immune-histochemical studies were carried out in four cases with multiple lacunes of the central grey matter and in control cases without such lesions. Routine light microscopic techniques were applied on paraffin-embedded material to identify lesions that may represent developing lacunes. In addition, polyclonal antisera to human albumin, IgG, fibrinogen and fibronectin were chosen as markers for extravasated plasma proteins. The brain tissue between lacunes contained several forms of focal injuries which may represent precursors of lacunes. Such lesions included foci of status spongiosus and status cribrosus, regions with dilated extracellular spaces and astrocytic gliosis, and multi-locular cysts. These "lacune-associated lesions" often included albumin immune-reactivity in extracellular spaces, nerve cell bodies and astrocytes. Less frequently signs of extravasated IgG, fibrinogen and fibronectin were identified. Thus, lacunes of the human brain frequently showed signs of antigenic sites to albumin. The extracellular deposits probably represent extravasated material from the blood. Vasogenic and cytotoxic oedema combined with other factors probably play important roles during the formation of some of the lacunes.     

Discovering patterns of online purchasing behaviour and a new‐product‐launch strategy

Spurred by rapid development of computers and Internet technology, online shopping is gradually overtaking in‐store shopping, because of advantages such as convenience, more choice of products or services etc. Online stores must devote a great deal of time and resources to locating and attracting new customers. Growing a customer base requires first understanding customers and then providing the products or services they need, thus encouraging customers to purchase more. This paper develops a system to analyse customers’ purchasing behaviour and track shifts in their interests. Customers’ purchasing behaviour is measured using proposed standard product loyalty status and standard brand loyalty status. Using these metrics, together with the preference map established for each customer, a marketing specialist can easily locate potential customers to target when a company launches a new product. The new‐product‐launch strategy proposed in this paper can be used to create a list of potential customers for a product being launched under a variety of conditions. A prototype system has been built to test the feasibility of the proposed new‐product‐launch strategy. The result shows almost 40% of potential customers respond to the recommendation positively.     

联合网络编码与HARQ的中继传输协议及跨层优化设计

为了进一步提高中继系统的可靠性和频谱效率,提出了联合固定网络编码与混合自动重传请求(DNC-HARQ)和联合随机网络编码与混合自动重传请求(ONC-HARQ)2种传输协议,分析了这两种传输协议的系统中断概率和频谱效率.以最大化系统频谱效率为优化目标进行跨层优化设计,并利用迭代算法求解.仿真结果表明,DNC-HARQ和ONC-HARQ传输协议比只采用网络编码的传输协议具有更高的系统可靠性,比仅采用HARQ的传输协议具有更高的频谱效率;所提出的基于最大化频谱效率的跨层优化算法能有效地最大化系统频谱效率.     

面向富互联网应用的数据传输策略研究

针对富互联网应用系统需要传输较大数据量而导致速度慢这一问题,研究了一种基于上下文感知的数据传输策略,通过感知用户的浏览记录和当前行为,系统可以自动预测用户下一步对数据的需求,并充分利用用户交互过程中的网络空闲时间传输数据,以提高系统的响应性.实验结果表明,该数据传输策略大大缩短了用户的等待时间,特别是在比较复杂的场景中,效果更为显著.     

Strength of single-phase high-entropy carbide ceramics up to 2300°C

The mechanical properties of single-phase (Hf,Zr,Ti,Ta,Nb)C high-entropy carbide (HEC) ceramics were investigated. Ceramics with relative density >99% and an average grain size of 0.9 ± 0.3 µm were produced by a two-step process that involved carbothermal reduction at 1600°C and hot pressing at 1900°C. At room temperature, Vickers hardness was 25.0 ± 1.0 GPa at a load of 4.9 N, Young's modulus was 450 GPa, chevron notch fracture toughness was 3.5 ± 0.3 MPa·m^1/2, and four-point flexural strength was 421 ± 27 MPa. With increasing temperature, flexural strength stayed above ~400 MPa up to 1800°C, then decreased nearly linearly to 318 ± 21 MPa at 2000°C and to 93 ± 10 MPa at 2300°C. No significant changes in relative density or average grain size were noted after testing at elevated temperatures. The degradation of flexural strength above 1800°C was attributed to a decrease in dislocation density that was accompanied by an increase in dislocation motion. These are the first reported flexural strengths of HEC ceramics at elevated temperatures.     

定粒配茧缫丝中不同茧层的茧粒数分布

在定粒缫丝工程中采用粗细茧丝搭配的方法进行配茧缫丝时，需要根据落绪茧及茧丝粗细搭配状况选择适当的接绪茧接绪，以保持厚薄茧型的搭配，减小生丝纤度方差。本文从理论上对这一缫丝动态过程建立差微分方程组，得到定粒配茧缫丝时不同茧层茧粒数的分布。通过对定粒缫丝动态过程的计算机模拟，对得到的理论结果进行了讨论，为缫丝工程管理提供了新的理论结果及管理基准。     

Vector quantisation codebook initialisation for discrete multiwavelet transform

A novel vector quantisation codebook initialisation method called vector component difference is proposed for image coding using the discrete multiwavelet transform. Simulation results show that it is superior to the currently available methods when using with the Linde-Buzo-Gray codebook generation algorithm.     

Generalized Discrete Multiwavelet Transform With Embedded Orthogonal Symmetric Prefilter Bank

Prefilters are generally applied to the discrete multiwavelet transform (DMWT) for processing scalar signals. To fully utilize the benefit offered by DMWT, it is important to have the prefilter designed appropriately so as to preserve the important properties of multiwavelets. To this end, we have recently shown that it is possible to have the prefilter designed to be maximally decimated, yet preserve the linear phase and orthogonal properties as well as the approximation power of multiwavelets. However, such design requires the point of symmetry of each channel of the prefilter to match with the scaling functions of the target multiwavelet system. It can be very difficult to find a compatible filter bank structure; and in some cases, such filter structure simply does not exist, e.g., for multiwavelets of multiplicity 2. In this paper, we suggest a new DMWT structure in which the prefilter is combined with the first stage of DMWT. The advantage of the new structure is twofold. First, since the prefiltering stage is embedded into DMWT, the computational complexity can be greatly reduced. Experimental results show that an over 20% saving in arithmetic operations can be achieved comparing with the traditional DMWT realizations. Second, the new structure provides additional design freedom that allows the resulting prefilters to be maximally decimated, orthogonal and symmetric even for multiwavelets of low multiplicity. We evaluated the new DMWT structure in terms of computational complexity, energy compaction ratio as well as the compression performance when applying to a VQ based image coding system. Satisfactory results are obtained in all cases comparing with the traditional approaches.     

On the Handover Performance of a Tri‐threshold Bandwidth Reservation CAC Scheme

A dynamic tri‐threshold call admission control scheme has been developed. This scheme supports voice, data, and multimedia services and it complies with the universal mobile telecommunications system. The performance of the proposed scheme is evaluated under varying handover rates. The QoS performance–including channel utilization, call dropping probability, and blocking probability–is investigated. The performance of the developed scheme is found to be encouraging.