Channel Mismatching in Sidelobe Canceler: Limitations and Remedies

After a brief recall of the Sidelobe Canceler (SLC) working principle, including the derivation of a general formula for the Cancellation Ratio (CR), the effects of channel mismatching are investigated. In particular, curves providing CRvalues as a function of amplitude and phase channel mismatching, radar bandwidth, and jammer direction of arrival (JDOA) are provided for the cases of one and two auxiliary antennas. Subsequently, a time -space processor for performance restoration is analyzed in detail. In addition to the above mentioned quantities, the attainable CR value is expressed as a function of the space-time processor parameters. The contribution of the paper is related to the derivation of a number of mathematical equations of CR for several cases of practical interest for the radar engineer. In addition, several curves are presented to assist design of SLC systems.     

SENSITIVITY ANALYSIS OF THE KNAPSACK PROBLEM： TIGHTER LOWER AND UPPER BOUND LIMITS

In this paper, we study the sensitivity of the optimum of the knapsack problem to the perturbation of the profit of a subset of items. We propose a polynomial heuristic in order to establish both lower and upper bound limits of the sensitivity interval. The aim is to stabilize any given optimal solution obtained by applying any exact algorithm. We then evaluate the effectiveness of the proposed solution procedure on an example and a set of randomly generated problem instances.     

基于网络药理学研究厚朴-杏仁治疗哮喘的潜在作用机制

本研究采用网络药理学方法分析厚朴-杏仁配伍治疗哮喘的潜在作用机制。通过BATMAN-TCM数据库检索厚朴、杏仁的中药化学成分及靶标信息，PALM-IST数据库搜索疾病靶标信息，string数据库构建靶标的蛋白质相互作用网络，利用Cytoscape v3.5.1对药物靶标相互作用进行可视化分析，DAVID数据库和Cytoscape v3.5.1的ClueGO+CluePedia插件对药物关键靶标进行GO生物功能富集分析和KEGG信号通路富集分析。共检索到厚朴-杏仁化合物51个，靶标435个，哮喘疾病相关靶标415个，进而分析得到药物治疗疾病关键靶标14个，包括肿瘤坏死因子、过氧化氢酶、白介素13、β2肾上腺素能受体等；GO基因功能分析主要涉及应激反应调控、先天性免疫反应调控、防御反应、急性炎症反应、刺激反应、凝血止血调节、自我内稳定、活性氧代谢过程等生物过程；KEGG分析主要参与NF-κB、IL-17、FcεRI、Toll受体及FoxO等信号通路。厚朴-杏仁能通过多个靶点、多种途径、多条通路对哮喘的气道慢性炎症、气道重塑和气道高反应起潜在治疗作用。     

化学:物质的科学与艺术

化学不会自我炫耀,但没有它,一些真正令人瞩目的成就不可能达成,如治疗疾病上的突破、太空探索和技术奇迹等。它在食品和药品、衣服和住房、能源和原材料、交通和通讯等     

SOME INITIAL-OBLIQUE DERIVATIVE BOUNDARY VALUE PROBLEM FOR QUASILINEAR PARABOLIC EQUATIONS WITH UNBOUNDED COEFFICIENTS

1 IntroductionThis paper is concerned with the a priori estimates and the ekistence of solutions of theinitiaLoblique derivative boundary value problem for quasilinear non-divergence parabolic equa-tions as follows:where O is a bounded domain in R"(N > 2) with smooth boundary 0a e C' ', QT =[o,T) x a be the parabolic domain in H" ,, ST = [o,T) x aa is the lateral boundary, andarQT is the parabolic boundary of QT' The repeated indices means summatiOns from 1 to N.In [11, the first bounda…     

QUEUEING NETWORKS WITH INSTANTANEOUS SEQUENTIAL TRANSITIONS

1 IntroductionQueueing networks have been one of the most importallt techniques in the modeling andanalysis of computer, communication, transportation, and Iogistics systems. The first queueingnetwork model was introduced by J..k,..[i'2], in which Jackson considers a network with Nnodes, and transitions of the typex -- x -- ej ek5 i,k = 0,1,'',N, (1)where x = (x1, x2)'' 5 XN) denotes the number of customers at the N nodes, ej is the unitvector with a 1 at the j-th position and 0 elsewh…     

20世纪70年代的中国

美国电影《阿甘正传》中有一句话让我们记忆深刻,多年不忘。故事说得是20世纪70年代初的事情,阿甘作为美国乒乓球队员访华,当他回国后,记者问他对中国的最深印象是什么,阿甘回答说:他们什么也没有。也就是说中国人非常贫穷。这句话深深地刺痛着我们的自尊心。作为20世纪60年代出生的人,我们亲身经历了那段困难的时期,虽然儿时的印象里家家户户都不富裕,但是我们并没有穷困不堪的感觉,精神生活也是非常地充实。当90年代我们成人时,却听到一个外国人对自己儿时的中国那种评价,的确心里很不舒服。