一类双环网络的最优路由算法

设2>hn.双环网络),(hnD是如下定义的有向图:其结点集是}1,,1,0{-=nZnL,边集是}10:)(mod),(mod1{-++=ninhiiniiE.设rhrqhwhrrqhn/)/()1(,11,+-=-+=又设这里.本文提出了),(hnD中源结点到目的结点的最短路径算法,该算法至多只要两次算术运算和一次比较,并且除了q,h,r和w外,各结点不必预先存储网络中别的信息.

Cloning and Analysis of a Disease Resistance Gene Homolog from Soybean

Conserved domains e.g. nucleotide binding site (NBS) were found in several cloned plant disease resistance genes. Based on the NBS domain, resistance gene analogs (RGAs) have been isolated previously and were used as probes to screen a soybean (Glycine max L. Merr.) cDNA library. A full-length cDNA, KR3, was obtained by screening the library and rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that the cDNA is 2 353 bp in length and the open reading frame (ORF) codes for a polypeptide of 636 amino acids with a Toll-Interleukin-1 receptor (TIR) and a NBS domain. Sequence alignment showed that it was similar to N gene of tobacco. The phylogenetic tree analysis of R proteins with NBS from higher plants was performed. The KR3 gene has low copies in soybean genome and its expression was induced by exogenous salicylic acid (SA).

某些广播图的构作

1.引言 广播图G的广播方式见文,在讨论广播问题时,我们使用下述定义: 定义1 图G中某结点u的广播时间t(u)是完成以u为源结点的广播所需要的最少单位时间数。 定义2 图G的广播时间t(G)是指G中结点广播时间的最大值。即 定义3 若n阶广播图G满足t(G)=[logn],则称G为n阶合格广播图。 定义4 若n阶合格广播图G的任一真生成子图G′,有t(G′)】t(G)。

Antecedents and performance consequences of governance structures in R&D alliances

Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research and development（R D） alliances.Therefore,the first objective of this study is to investigate why there exist different organizational governance structures in managing R D alliances;the second objective of this study is to give strategic advice in choosing appropriate forms with respect to various characteristics of R D alliances.Through the theoretical lens that integrate both transaction cost economics（TCE） and the resource-based view（RBV）,a model that focuses on six major factors is developed for determining governance structure choices,namely,technological uncertainty,cultural difference,asset specificity,technology complementarity,appropriability of the individual firm＇s know-how,and trust.An R D alliance with higher technological uncertainty,larger cultural differences,and greater concerns for protecting an individual＇s know-how is more likely to adopt non-integrated alliances as the governing structure.An R D alliance with a higher degree of asset-specificity,greater technology complementarity and greater trust among partnering organizations is more likely to adopt integrated alliances as the governing structure;an R D alliance in the face of lower technological uncertainty will tend to adopt integrated alliances.The more aligned the choice of the governance structure with its determinants,the better the R D alliance will perform,and vice versa.

JOINT SOURCE-CHANNEL DECODING OF HUFFMAN CODES WITH LDPC CODES

In this paper, we present a Joint Source-Channel Decoding algorithm (JSCD) for Low-Density Parity Check (LDPC) codes by modifying the Sum-Product Algorithm (SPA) to account for the source redun-dancy, which results from the neighbouring Huffman coded bits. Simulations demonstrate that in the presence of source redundancy, the proposed algorithm gives better performance than the Separate Source and Channel Decoding algorithm (SSCD).

Analysis on Refinery System as a Complex Task-resource Network

Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in which nodes represent various tasks and edges denote the resources exchanged among tasks. Using the properties of node degree distribution, strength distribution and other weighted quantities, we demonstrate the heterogeneity of the network and point out the relation between structural characters of vertices and the functionality of correspond- ing tasks. The above phenomena indicate that the design requirements and principles of production process contrib- ute to the heterogeneous features of the network. Besides, betweenness centrality of nodes can be used as an impor- tance indicator to provide additional information for decision making. The correlations between structure and weighted properties are investigated to further address the influence brought by production schemes in system con- nectivity patterns. Cascading failures model is employed to analyze the robustness of the network when targeted at- tack happens. Two capacity assignment strategies are compared in order to improve the robustness of the network at certain cost. The refinery system displays more reliable behavior when the protecting strategy considers heteroge- neous properties. This phenomenon further implies the structure-activity relationship of the refinery system and provides insightful suggestions for process system design. The results also indicate that robustness analysis is a _promising applicat!on of methodologies from complex networks to process system engineering..

Joint routing and resource allocation in optical transport networks

A layered network model for optical transport networks is proposed in this paper,which involves IP,SDH and WDM layers.The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description are also presented for the proposed layered network model.DJRRA optimizes the bandwidth usage of interface links between different layers and the logic links inside all layers.The simulation results show that in contrast to the classical separate sequential routing and resource allocation solutions,DJRRA can reduce the blocking probability and increase network throughput effectively.

A sink moving scheme based on local residual energy of nodes in wireless sensor networks

In the application of periodic data-gathering in sensor networks,sensor nodes located near the sink have to forward the data received from all other nodes to the sink,which depletes their energy very quickly.A moving scheme for the sink based on local residual energy was proposed.In the scheme,the sink periodically moves to a new location with the highest stay-value defined by the average residual energy and the number of neighbors.The scheme can balance energy consumption and prevent nodes around sink from draining their energy very quickly in the networks.The simulation results show that the scheme can prolong the network lifetime by 26%-65%compared with the earlier schemes where the sink is static or moves randomly.

CCS in China:Opportunities, Challenges and Solutions

The economic growth, energy structure and environmental capacity in China determine that CCS (carbon capture and storage) is an important strategic approach for China to confront the climate changes. In this paper, current status in China is firstly presented regarding policy making, technology research and development, pilot project and international cooperation. Then the opportunities of exploring CCS are analyzed from the viewpoint of application potentials, cost and China's circumstances. The challenges to CCS are pointed out with respect to energy consumption, technologies, funding and environment. Finally some suggestions are put forward on CCS development.

Spatial Structure and Development of Tourism Resources based on Point Pattern Analysis: A Case Study in Hainan Island, China

Tourism resources are the basic materials of tourism development, and they also provide the support for regional tourism spatial competition. The development of tourism depends on the degree to which tourism resources are utilized, and it is of great guiding significance for their development and utilization to study their spatial structure. Based on a large sample of data on tourism resources, and starting from the characteristics of multi-type,multi-level and multi-combination, this paper puts forward a framework and method for analyzing the spatial structure of tourism resources. Taking Hainan Island as an example, this paper describes the spatial structure of tourism resources in Hainan Island by using the method of point pattern analysis, identifies the tourism resource development zones, and puts forward some suggestions for the development of tourism resources. The results are as follows:(1) The characteristic scale of the spatial structure of tourism resources in Hainan Island is 30.5 km, and there are significant differences in the distributions of all kinds of tourism resources.(2) Through the spatial structure map of tourism resources, the tourism resource development zones are identified, including three tourist central city levels, “one horizontal and three vertical” tourist belts and four tourist combination areas.(3) By combing the distribution of tourism resources and the development zones in Hainan Island, the cross-border characteristics of the tourism resources and development zones are obvious. In order to give full play to the spatial combination and superposition effect of tourism resources, a change from a single isolated development mode to the overall combined development between regions is suggested. On the provincial scale, it is relatively accurate to describe the spatial structure of tourism resources for point data with a large sample size. However, the method of point pattern analysis can not only accurately describe the spatial structure of tourism resources, but it can also provide reference for other types of regional spatial analyses. The research results provide a scientific basis for the spatial planning of regional tourism resources and have practical significance for the development of regional tourism.