Application of Rollout Strategy to Test Points Selection for Integer-Coded Fault Wise Table

Test points selection for integer-coded fault wise table is a discrete optimization problem. The global minimum set of test points can only be guaranteed by an exhaustive search which is eompurationally expensive. In this paper, this problem is formulated as a heuristic depth-first graph search problem at first. The graph node expanding method and rules are given. Then, rollout strategies are applied, which can be combined with the heuristic graph search algorithms, in a computationally more efficient manner than the optimal strategies, to obtain solutions superior to those using the greedy heuristic algorithms. The proposed rollout-based test points selection algorithm is illustrated and tested using an analog circuit and a set of simulated integer-coded fault wise tables. Computa- tional results are shown, which suggest that the rollout strategy policies are significantly better than other strategies.

Continuous Selections and Fixed Points forφ-maps with Their Applications to Section Problems

The concept of finitely continuous topological space is introduced and the basic properties of the space are given. Several continuous selection theorems and fixed point theorems for Ф-maps are established, and as applications of the above fixed point theorems, some section problems are discussed. The results generalize and improve many corresponding conclusions.

Data point selection for weighted least square fitting of cavity decay time constant

For the accurate extraction of cavity decay time, a selection of data points is supplemented to the weighted least square method. We derive the expected precision, accuracy and computation cost of this improved method, and examine these performances by simulation. By comparing this method with the nonlinear least square fitting （NLSF） method and the linear regression of the sum （LRS） method in derivations and simulations, we find that this method can achieve the same or even better precision, comparable accuracy, and lower computation cost. We test this method by experimental decay signals. The results are in agreement with the ones obtained from the nonlinear least square fitting method.

Genes for the high life： New genetic variants point to positive selection for high altitude hypoxia in Tibetans

People living on the high plateaus of the world have long fascinated biological anthropologists and geneticists because they live in ＂thin air＂ and epitomize an extreme of human biological adaptation.

CONTINUOUS SELECTION THEOREMS FOR FAN-BROWDER MAPPINGS IN TOPOLOGICAL SPACES AND THEIR APPLICATIONS

The concept of Fan-Browder mappings was first introduced in topological spaces without any convex structure. Then a new continuous selection theorem was obtained for the Fan-Browder mapping with range in a topological space without any convex structure and noncompact domain. As applications, some fixed point theorems, coincidence theorems and a nonempty intersection theorem were given. Both the new concepts and results unify and extend many known results in recent literature.

Selection of Minimal Test Points Set for Integer-Coded Fault Wise Table

Test points selection for integer-coded fault wise table is a discrete optimization problem. On one hand, traditional exhaustive search method is computationally expensive. On the other hand, the space complexity of traditional exhaustive is low. A tradeoff method between the high time complexity and low space complexity is proposed. At first, a new fault-pair table is constructed based on the integer-coded fault wise table. The fault-pair table consists of two columns： one column represents fault pair and the other represents test points set that can distinguish the corresponding faults. Then, the rows are arranged in ascending order according to the cardinality of corresponding test points set. Thirdly, test points in the top rows are selected one by one until all fault pair are isolated. During the test points selection process, the rows that contain selected test points are deleted and then the dimension of fault-pair table decreases gradually. The proposed test points selection algorithm is illustrated and tested using an integercoded fault wise table derived from a real analog circuit. Computational results suggest show policies are better than the exhaustive strategy.

Use of Rough Sets Theory in Point Cluster and River Network Selection

In this paper, we applied the rough sets to the point cluster and river network selection. In order to meet the requirements of rough sets, first, we structuralize and quantify the spatial information of objects by convex hull, triangulated irregular network (TIN), Voronoi diagram, etc.;second, we manually assign decisional attributes to the information table according to conditional attributes. In doing so, the spatial information and attribute information are integrated together to evaluate the importance of points and rivers by rough sets theory. Finally, we select the point cluster and the river network in a progressive manner. The experimental results show that our method is valid and effective. In comparison with previous work, our method has the advantage to adaptively consider the spatial and attribute information at the same time without any a priori knowledge.

Spatially localized and joint access point selection for Wi-Fi indoor positioning

Wi-Fi indoor positioning system has received increasing interest in pervasive computing applications due to its low cost and satisfactory accuracy. To obtain high positioning accuracy based on source limited devices, various AP selection strategies have been proposed to select the most discriminant APs for positioning. In this paper, we propose a spatially localized AP selection method based on joint location information gain. In contrast to traditional AP selection methods which measure the discriminant ability of APs independently, we consider choosing APs jointly. By considering the correlation of the discriminant ability between different APs, more accurate measure of the discriminant ability of APs can be taken. Furthermore, since the optimal AP selection solution varies spatially, we incorporate a location clustering method to localize AP selection and subsequent positioning process. Finally, support vector regression (SVR) algorithm is combined to estimate the location. Experiments are carried in a realistic Wi-Fi indoor environment. Experimental results show that, by using the localized joint AP selection strategy, the proposed positioning method achieves a high-level accuracy while reducing the energy consumption on client devices significantly.

A Machine Learning-Based Distributed Denial of Service Detection Approach for Early Warning in Internet Exchange Points

The Internet service provider(ISP)is the heart of any country’s Internet infrastructure and plays an important role in connecting to theWorld WideWeb.Internet exchange point(IXP)allows the interconnection of two or more separate network infrastructures.All Internet traffic entering a country should pass through its IXP.Thus,it is an ideal location for performing malicious traffic analysis.Distributed denial of service(DDoS)attacks are becoming a more serious daily threat.Malicious actors in DDoS attacks control numerous infected machines known as botnets.Botnets are used to send numerous fake requests to overwhelm the resources of victims and make them unavailable for some periods.To date,such attacks present a major devastating security threat on the Internet.This paper proposes an effective and efficient machine learning(ML)-based DDoS detection approach for the early warning and protection of the Saudi Arabia Internet exchange point(SAIXP)platform.The effectiveness and efficiency of the proposed approach are verified by selecting an accurate ML method with a small number of input features.A chi-square method is used for feature selection because it is easier to compute than other methods,and it does not require any assumption about feature distribution values.Several ML methods are assessed using holdout and 10-fold tests on a public large-size dataset.The experiments showed that the performance of the decision tree(DT)classifier achieved a high accuracy result(99.98%)with a small number of features(10 features).The experimental results confirmthe applicability of using DT and chi-square for DDoS detection and early warning in SAIXP.

A Plea for Commonality Without Common Points --With Reference to The Planet of the Apes

In the science fiction novel titled The Planet of the Apes （1963）, Pierre Boulle tells a story about a completely reversed world where the apes dominate the humans. Coming from the normal world that is ours, a small group of people is totally embarrassed and confused by observing this strange world. On the planet of the apes that they have discovered, it is the apes that are more intelligent than the humans. On the earth, it was the other way around. That observation results in their perplexity. The two communities, human and simian, bear with one another the relationship that corresponds to what Lotman calls ＂enantiomorphic pairings＂. In this context, a series of questions deserves to be raised： Is a ＂common language＂ possible between the two communities in the enantiomorphic pairings？ If the answer is yes, under what conditions could they succeed in opening up a space where they can have something in common？ In rereading The Planet of the Apes with reference to Lotman＇s semiotics of culture, we would like to formulate a response to those questions. Our claim is that the experience of finitude of one＇s own language can make possible an access to the new form of universality requisite for the cross-cultural communication： commonality without common points.

Optimal Test Points Selection Based on Multi-Objective Genetic Algorithm

A new approach to select anoptimal set of test points is proposed. The described method uses fault-wise table and multi-objective genetic algorithm to find the optimal set of test points. First, the fault-wise table is constructed whose entries are measurements associated with faults and test points. The selection of optimal test points is transformed to the selection of the columns that isolate the rows of the table. Then, four objectives are described according to practical test requirements. The multi-objective genetic algorithm is explained. Finally, the presented approach is illustrated by a practical example. The results indicate that the proposed method can efficiently and accurately find the optimal set of test points and is practical for large scale systems.

Analysis of environmental selection pressure of superoxide dismutase in deep-sea sea cucumber

Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in mitochondria.In a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is essential for the survival of sea cucumbers.Six MnSODs were identified from the transcriptomes of deep and shallow-sea sea cucumbers.To explore their environmental adaptation mechanism,we conducted environmental selection pressure analysis through the branching site model of PAML software.We obtained night positive selection sites,and two of them were significant(97F→H,134K→V):97F→H located in a highly conservative characteristic sequence,and its polarity c hange might have a great impact on the function of MnSOD;134K→V had a change in piezophilic a bility,which might help MnSOD adapt to the environment of high hydrostatic pressure in the deepsea.To further study the effect of these two positive selection sites on MnSOD,we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and PyMOL.Results show that 97F→H,134K→V might improve MnSOD’s efficiency of scavenging superoxide a nion and its ability to resist high hydrostatic pressure by moderately reducing its stability.The above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity,piezophilic behavior,and local stability.This study revealed the correlation between MnSOD and extreme environment,and will help improve our understanding of the organism’s adaptation mechanisms in deep sea.

Study on the Rule of Acupoint Selection in Acupuncture and Moxibustion Treatment of Stomachache

A systematic collection of relevant literature on acupuncture and moxibustion treatment of stomach pain,and a summary of the rule of acupoints selection for acupuncture treatment of stomach pain.In conclusion,Zusanli,Zhongwan,Neiguan,and Liang Qiu are selected as the main acupoints.At the same time,according to the different syndrome types,dyspepsia hurt a stomach syndrome is compatible with Burong,Chengman,Tianshu and Shangjuxu acupoints.Cold evil invading the stomach syndrome is compatible with Shenque and Qihai acupoints.Liver-Qi attacking stomach syndrome is compatible with Danzhong,Zhangmen,and Qimen acupoints;for blood stasis to stop the stomach,it is compatible with Xuehai,Geshu,and Pishu acupoints.Adopting this rule of acupoints selection has a significant effect on acupuncture treatment of stomach pain,and it also provides a reference for other doctors to treat stomach pain.

Physical and numerical investigations of target stratum selection for ground hydraulic fracturing of multiple hard roofs

Ground hydraulic fracturing plays a crucial role in controlling the far-field hard roof,making it imperative to identify the most suitable target stratum for effective control.Physical experiments are conducted based on engineering properties to simulate the gradual collapse of the roof during longwall top coal caving(LTCC).A numerical model is established using the material point method(MPM)and the strain-softening damage constitutive model according to the structure of the physical model.Numerical simulations are conducted to analyze the LTCC process under different hard roofs for ground hydraulic fracturing.The results show that ground hydraulic fracturing releases the energy and stress of the target stratum,resulting in a substantial lag in the fracturing of the overburden before collapse occurs in the hydraulic fracturing stratum.Ground hydraulic fracturing of a low hard roof reduces the lag effect of hydraulic fractures,dissipates the energy consumed by the fracture of the hard roof,and reduces the abutment stress.Therefore,it is advisable to prioritize the selection of the lower hard roof as the target stratum.

去蜂窝大规模MIMO-NOMA上行链路用户分组及AP选择

针对去蜂窝大规模MIMO-NOMA系统上行链路的用户分组和AP选择问题,提出了一种最大信道相关性用户分组方案和基于有效信道增益的AP选择方案。首先,最大信道相关性用户分组方案通过统计学和皮尔逊相关系数分别计算出任意2个用户之间的有效信道增益差和信道线性相关性。然后,以任意2个用户差值最小化为目标对用户进行分组。在用户分组结果的基础上,先根据用户信道质量对用户进行排序,再基于有效信道增益为每个用户选择可连接的AP。实验结果表明,基于最大信道相关性的用户分组方案能够降低多用户间的干扰水平,显著提高系统总频谱效率和通信的公平性。同时,基于有效信道增益的AP选择方案能够减少用户间干扰和降低系统计算的复杂度,有效提高了系统总频谱效率。

基于人工蜂群算法的去蜂窝大规模MIMO系统AP选择技术

为了提升去蜂窝大规模多输入多输出(multiple input multiple output,MIMO)系统中接入点(access point,AP)选择方案的性能,结合迫零(zero forcing,ZF)预编码技术和人工蜂群算法,提出了针对去蜂窝大规模MIMO系统用户端的AP选择算法。基于各个用户所需接收的信号,采用ZF预编码算法,使得所有AP都参与预编码,从而获得预编码信号;针对每个用户,利用人工蜂群算法,在优化目标为最大化用户的信道容量的前提下,求解相应的AP选择方案。仿真结果表明,相比于不进行AP选择的方案,提出的去蜂窝大规模MIMO系统的AP选择方案在信道容量性能方面表现更优。当用户数量为5、信噪比(signal to noise ratio,SNR)为40 dB、AP数量为40时,提出的AP选择算法对应的信道容量为14.8 bit/(s·Hz),与不进行AP选择的算法相比,信道容量提高5 bit/(s·Hz)。

基于信息区分度的AP有效集构建方法

随着无线网络的广泛应用,面向接受信号强度(RSS)指纹定位的接入点(AP)日益增多,导致一些AP的作用是冗余的,甚至对定位产生不利影响,同时也增加了定位计算的开销。通过对AP进行适当筛选可以一定程度上去除冗余AP,但定位效果会随着AP数量发生较大变化,甚至会增大误差。本文提出一种基于信息区分度的AP有效集构建方法(EID),充分利用指纹信号在不同空间的差异,实现了准确的位置估计。首先,用信息区分度评估AP的定位能力,有效反映出每个AP在不同采样点的区别,展示AP对空间位置的分辨程度。然后,基于AP信息区分度设计更加符合现实环境的增量聚类算法,能根据AP的定位能力得到不同类别的集合并具有较好的鲁棒性。最后,利用点集距离最大原则提出AP有效集选择策略,根据聚类结果和选择要求,选择出合适的AP集合。本文在真实场景下进行实验验证,并与现有的AP选择方法,即基于组判别(GDB)算法、基于软件定义网络(SDN)算法和基于非均匀量化RSS熵(NQRE)算法对比,在减少不低于40%AP数量的情形下,EID将定位精度分别提升了18.7%、11.2%和14.6%。与此同时,本文方法具有更好的稳定性,在95%的情形下定位误差低于1.2 m。

APS在萧燃电厂机组中的应用

燃气-蒸汽联合循环机组作为电网调峰机组,具有启动快、燃烧效率高等特点,在我国电力生产行业中的地位日益提高。然而机组启停频繁,给安全运行带来一定的挑战。以萧燃电厂9F联合循环机组自动启停控制系统(APS)为例,对APS设计思想、结构和断点以及实现进行分析。研究表明APS能够实现机组从启动准备工作到燃气轮机、汽轮机启动到发电机并网带满负荷的一键功能,使得机组在启停过程中实现重要控制回路全程化、启动条件自优化、启停标准化、切换操作自动化和参数控制智能化,有效提高了机组启停的安全性、经济性。

无线流媒体应用中端系统切换触发机制和AP选择策略的研究与实现

对无线局域网(WLAN)中节点(Station)切换过程进行了研究,提出了一种适合流媒体应用的端系统快速切换解决方案.该方案在3个方面进行了改进:通过设置动态切换阈值避免节点的频繁切换;使用平滑因子降低无线信号强度的时变不确定性;利用探询时延选择合适的接入点(AP).该方案无需对现有AP进行修改,具有较强的可扩展性能.在实际WLAN环境下进行了实现和测试分析,表明该方案能有效地减小切换时延,改善了流媒体在WLAN中的应用.

高效选择性捕收剂AP的应用

AP是一种高效选择性铜捕收剂 ,对铜具有良好的选择性捕收能力 ,对硫捕收力弱 ,可以在部分优先浮选作业或快速浮选作业实现对单体解离铜矿物的早收 ,获得大部分高品位铜精矿 ,从而能提高最终铜精矿品位。