Synthesis of Closed Queueing Networks with Several Classes of Messages on the Basis of Their Optimization and Balancing

The optimization and balancing problems formulated in the author's previous works are theoretically investigated for queueing networks with several classes of messages. The necessary and sufficient conditions of the global optimal solution of these problems are obtained. It is shown that the method of Lagrangian multipliers can be used in solving them.     

动态无线传感网中低延迟高可靠的数据查询机制

查询处理作为大规模无线传感器网络中智能服务的一个重要操作,可以根据用户需求对网络中的感知数据进行检索和回传.然而,部署在恶劣环境中的无线传感网络,节点容易遭受外力破坏,或者自身资源(能量、存储等)有限,可能会导致节点发生位移和故障,从而造成网络拓扑不断改变以及部分节点的感知数据失效.同时,由于节点感知数据容量大、传输带宽有限以及网络链路不可靠等情况,可能会造成网络通信时延大大增加.这些因素使得快速、可靠的数据查询处理成为无线传感网中一个难题.为了解决这个难题,提出一种动态网络中低延迟高可靠的数据查询机制.该机制是一种非聚合随机查询方式,通过将传感节点划分为源节点和查询节点来实现数据查询.首先,根据监测事件将网络划分为若干个子区域,每个子区域中的源节点相互协作,并按照时间顺序依次轮流监听该区域的事件信息;接着,源节点根据预估的平均节点故障概率,计算出一个合理的备份数量,并将源数据按照该数量存储到邻居节点中,以降低源数据的失效概率;然后,为了加快数据查询速度,源节点定期对源数据块进行编码压缩,并选取剩余能量和存储空间较小的多个邻居节点作为下一跳接收节点.这些接收节点基于局部区域中节点个数大小,决定是否接收存储该报文.重复上述过程,直至压缩数据均匀地分布在网络中.另一方面,查询节点接收到查询请求时,也使用负载均衡多路分发方式将查询请求传输到部分节点上.为了避免目标数据的冗余回传,当查询请求成功查询到目标数据时,目标节点先修改访问位,再选取与查询节点距离最近的邻居节点作为下一跳接收节点,迭代执行上述操作,直到用户获得所需要的事件信息.在以上过程中,为了节省节点能量,在保证高成功查询率的条件下,建立通信能耗最小化的优化模型,计算出最优的压缩数据副本数和查询消息副本数,之后,源节点和查询节点分别按照该数量进行副本数据分发.最后,理论分析和实验结果表明,与其它四种查询算法相比,提出的查询机制具有更高的查询成功率、更低的通信能耗和通信时延.     

无线异构网在油气生产物联网的应用

油气生产物联网（A11）系统是《中国石油＂十二五＂信息技术总体规划》的重要建设项目,分为三个子系统：生产数据采集与控制子系统、数据传输子系统、现场监控与管理子系统。本文主要介绍一种由无线网桥＋LTE230无线异构网络构建的数据传输子系统应用方案,该方案既利用了230MHz频段LTE系统的信号传播距离远、稳定性高、绕射能力强和广覆盖的特点,同时发挥了网桥点到点通信灵活、低成本和高传输速率的优势,可以完全满足福山油田油气生产物联网对生产数据、控制数据和视频图像实时传输的需求。     

Parametric Amplification of Signals by Noise in Neurons and Neural Networks

The positive role of parametric noise in neural systems is shown. In analogy with transistor effect the weak input signals control the intensive response of nonlinear neurons to parametric noise. As a result gigantic amplification of input signals can be obtained. The mechanism of amplification is simple and robust. It can relate both to biological and artificial neural networks. Such amplification was first investigated in a model of overdamped Kramers oscillator [1,2].     

遥感波段与样本组合及贝叶斯网络结构变化分析

贝叶斯网络表达了输入数据与分类结果之间的依赖关系,网络结构则表达了节点之间的条件概率状态。遥感数据的贝叶斯网络结构训练涉及先验知识和样本数量两个方面,是贝叶斯网络结构分类的重要环节。该文以应用目标和遥感数据波段的物理意义为先验知识指导,进行了贝叶斯网络结构建立中的遥感数据波段数和样本数的优化组合实验,为贝叶斯网络在遥感数据分类方面提供了基础性实验结果。     

Networks of Science and Technology in India: The Elite and the Subaltern Streams

The paper investigates the structure and functioning of the science and technology (S&T) system in India as it has evolved in the post-independence period (1947 onwards). The networks of entities involved in S&T actions, the paper argues, can be categorised, in terms of adopted approaches to agenda and priority setting and accounting for actions, into two streams. The origins and expansion of the two streams are traced. One, the ‘Elite’ stream (high profile and visibility linked to big industry), adopting what the paper has generically termed the ‘Nehruvian’ model of development, is shown to have emerged as a dominant network. The other socially powerful ‘Subaltern’ stream (less visible, closer to ground realities and linked to village and cottage industry), adopting the ‘Gandhian’ model of development, still remains dispersed and outside the consideration of high-level decision-making bodies. The paper stresses the importance of moving the support and attention from the dominant stream to efforts that attempt a synthesis between the dominant and the subaltern.     

Biochemical oscillations in delayed negative cyclic feedback: Existence and profiles

In this paper, we propose a theoretical framework to systematically analyze the existence and the profiles of chemical oscillations in gene regulatory networks with negative cyclic feedback. In particular, we analytically derive the existence conditions and the profiles of oscillations in terms of reaction kinetic parameters and reveal dimensionless quantities that essentially characterize the oscillatory dynamics. These discoveries then allow us to provide general biological insights that are useful for the design of synthetic gene circuits and wet-lab experiments. We point out that time delays due to splicing and transport play an important role for both of the existence and the profiles of oscillations. To this end, we first show that local instability leads to oscillations in cyclic gene regulatory networks, and we derive the existence conditions based on local instability analysis. Then, we analyze the period, phase and amplitude of oscillations using multivariable harmonic balance analysis. These results are demonstrated with two existing biochemical networks, the Pentilator and a self-repression network of a Hes protein.