考虑通信质量的网络最小主控集生成算法

无人移动平台无线ad hoc网络在实际应用中经常会出现由于电磁环境、干扰等因素导致通信质量不稳定的情况,在上述条件下传统的基于节点覆盖度的最小主控集（MCS）生成算法难以获得具有较好稳定性、健壮性的最小主控集。为此,提出了一种考虑通信质量的网络最小主控集生成算法,将链路的通信质量纳入网络最小主控集构造的考虑因素,使网络拓扑与链路通信质量特性保持一致;并通过对候选节点集及拟覆盖节点集的压缩,有效控制了网络最小主控集的节点数目。仿真表明,对敏感于通信质量的应用,该算法较基于节点覆盖度算法能取得更好效果。     

基于m序列的宽间隔跳频序列的生成

为了克服对偶法生成宽间隔跳频随机序列的缺点,基于m序列,提出非线性模d法,利用非连续抽头模型,生成宽间隔跳频随机序列.比较了对偶法生成的跳频序列和非线性模d法生成的跳频序列的自相关性能和互相关性能等.计算结果表明,非线性模d法是对偶法的明显改进,其生成序列的随机性、抗干扰性都有明显改善,且相关性能接近于最佳跳频序列的相关性能.     

Welfare and quality improvement in an international market

This paper analyzes the optimal uniform and discriminatory quality requirements under Cournot competition when two firms produce high-quality and low-quality products, respectively, in an international market. The quality requirements in our paper are not set for the foreign firm but are set to regulate products of different qualities, since in the real world a domestic firm could be a high- or low-quality producer. We find that whether the government should raise the quality requirements depends on the type of competition in which firms engage and the adopted quality requirements. By and large, the government should always set quality requirements raising both firms’ quality directly or indirectly, regardless of the quality of the product of the domestic firm. However, if the domestic firm is a high-quality producer, the government should set a quality requirement that enables the domestic firm to monopolize the market when a discriminatory quality requirement is adopted, and should not set any quality requirement when a uniform quality requirement is adopted. Moreover, we show that the quality requirement can actually improve global welfare in most cases.     

A safe speed guidance model for highways

ABSTRACT

This paper presents a fuzzy logic model to support decisions for the suggested speed limit for sections of highways as they become affected by adverse road conditions, environmental factors and differing traffic levels. The definition of the main factors, and their weight, that reduce safety on highways was conducted by the Delphi method, consulting traffic engineering experts. The survey served as a basis for structuring indicators and indexes in a soft decision tree, structured by a fuzzy logic system. The system can be used to support the decisions of those that manage the roads, indicating to drivers’ speeds, by visual, audible or combined systems.     

Category management and consumer choice

This paper shows the results of an exploratory analysis of the structure of a complex product category: Wine. In complex categories, a usual strategy of consumers is the partitioning of alternatives into homogeneous subsets and the sequential eliminations of subsets until a product/brand is chosen from among few homogeneous alternatives in the last subset. To identify if there is such a kind of strategy and the product attributes involved is of great interest for the retailer. After a discussion of the different modelling alternatives of the choice process, the authors provide an application of the additive trees (ADDTREE) model to explore the hierarchical structure. The ADDTREE results provide a first overview of the competitive market structure of the wine category: competition becomes more intense as the wine category is partitioned by, first, the type of wine criteria and, second, the designation of origin (DO) criteria.     

一种考虑稳定性的动态综合评价新模型

针对动态综合评价需要考虑被评对象的稳定性问题,提出了一种综合考虑指标权重、时间权 重和稳定性的动态综合评价模型。定义了稳定因子来表征被评对象指标的稳定程度,采用离 差最大化的方法确定指标权重,提出了一种基于极小范数时间权重确定方法。将所提模型应 用于军事IP网络评价,结果表明该模型能够把被评对象的稳定性反映到评价结果中。     

Does trade size restriction affect trading behavior? Evidence from Indian single stock futures market

Algorithmic traders use their advantage of speed to execute a large number of small-sized trades in a very short time. In the presence of a minimum trading unit (MTU) restriction, they are forced to trade at the smallest possible sizes, often restricted by the MTU. Using a novel data set of single stock futures market obtained from the National Stock Exchange of India, we show that the MTU restriction acts as a binding constraint for traders while optimizing trade sizes. Contrary to expectation, we find weak evidence that liquidity is positively impacted by the contract size revision.     

一种动态加权的LDPC译码方法

为了加快低密度奇偶校验（LDPC）码的译码速度,有效改善LDPC码的译码性能,针对校验节点更新过程中的对数似然比（LLR）值的大小,设计了一种LDPC码的动态加权译码方法。以IEEE 802.16e标准的奇偶校验矩阵为例,根据LLR值的变化规律,利用增长因子和抑制因子对和积译码算法和最小和译码算法进行动态加权。仿真结果显示,基于动态加权的译码方法相对于传统译码方法误码率都有明显改进,译码复杂度也有所降低。     

Globally networked: Intraorganizational boundary spanning in the global organization

Multinational corporations (MNCs) need to sense, source, and mobilize knowledge when and where it arises, whether at home, or elsewhere in the world. For this reason, MNCs benefit from employee networks of relationships that span across intraorganizational barriers, allowing for the efficient mobilization of knowledge across boundaries. Yet, which organizational members are more likely to be able to develop these boundary spanning networks? We leverage a unique data set from a large multinational corporation to empirically test a comprehensive model that captures the effect of an employee’s mandate, expertise, and behavioral orientations on her likelihood to span intraorganizational boundaries that manifest themselves in the form of hierarchies, intra-functional domains, and geographic territories. We find that the employees that are more likely to be boundary spanners are those having mandates with a global impact, high levels of expertise, and a collaborative orientation in their networking behaviors. In addition, we find that these effects are stronger for those employees that have large formal workflow networks.     

The evolution of world trade from 1995 to 2014: A network approach

This paper employs network analysis to study world trade from 1995 to 2014. We focus on the main connective features of the world trade network (WTN) and their dynamics. Results suggest that countries’ efforts to attain the benefits of trade have resulted in an intertwined network that is increasingly dense, reciprocal, and clustered. However, these features do not correspond to a linear aggregation of the characteristics of its constituents (trade sectors). Trade linkages are distributed homogeneously among countries, but their intensity (i.e. their value) is highly concentrated in a small set of countries. The main connective features of the WTN were not affected by the 2007–2008 international financial crisis. However, we find that the crisis marks a turning point in the evolution of the WTN from a two-group (led by the US and Germany) to a three-group (led by the US, Germany, and China) hierarchical structure.