随机多元基量子安全直接通信

根据量子通信系统安全性要求较高的特点,提出了单光子的随机多元基的偏振校正方案,可以完成各个偏振角度误差的补偿。与利用强光的补偿方案相比,窃听者更难获得基的信息,因此保密性更好。在测量基校正的基础上,针对传统多态量子通信系统筛选后有效信息少的缺点,设计了随机多元基的量子安全直接通信协议。该协议与窃听者Eve的互信息量很低;结合校验序列和一次一密,在信道不安全的情况下,窃听者不能得到有效信息,具有安全性好、易于实现、通信距离远等优点。

随机径向基函数神经网络的收敛性分析

为了探究随机径向基函数神经网络的函数逼近能力,运用随机权重前馈神经网络收敛性分析的方法对其进行收敛性分析。首先利用广义δ函数的性质构建一个被近似函数的极限积分表达式;其次用蒙特卡罗方法计算这个表达式中的积分,证明随机径向基函数神经网络可以逼近任意连续函数。同时,从理论上分析了随机径向基函数神经网络的收敛特性,发现其收敛误差随着隐藏层神经元节点的增加而逐渐减少,表明其是一个高效的函数逼近器,并且具有处理大数据问题的潜力。

带Brown运动的随机奇异积分的存在性

在轨迹二阶导数具有Hlder连续的条件下,利用高阶奇异积分思想和概率极限的理论,研究了在Brown运动下的随机奇异积分.得到了以Brown运动为积分元的随机奇异积分是存在性定理.

Elimination Mechanism and Equilibrium Model about Complete Linkage of Panmixis Based on Fitness

[Objective]The aim was to discuss elimination mechanism and equilibrium model about complete linkage gene of panmixis based on fitness.[Method]A mathematical model that gsgenerational evalution of frequency of panmixis two pairs of complete linkage gene under difference fitness was built by using difference equations to study elimination mechanism and genetic equilibrium state of panncticcoinplete linkage gene.[Result]The panmixis is different from Hardy-Weinberg Equilibrium which reached the equilibrium just by one generation.A method that by using linear equation to calculate the frequency of four gametes and the fitnessed of panmixis was established after detormining is the fitness of 10 genotypes the necessary and sufficient condition of the panmixis to reach balance.[Conclusion]The method is valuable for reference on linkage disequilibrium and hitchhiking effect study.

随机稀释基底上刻蚀模型动力学标度行为的数值模拟研究

表面界面动力学粗化过程是凝聚态物理领域重要的研究内容,为研究基底不完整性对刻蚀模型动力学标度行为的影响,本文采用Kinetic Monte Carlo(KMC)方法,分析研究了在随机稀释基底上刻蚀模型(Etching model)生长表面的动力学标度行为.研究发现:尽管随机稀释基底的不完整性会对刻蚀表面的动力学行为产生显著的影响,导致刻蚀表面粗糙度指数和生长指数有明显的增加,但其仍基本满足原有的动力学标度规律.此外,本文还对刻蚀表面动力学标度指数的有限尺寸效应进行了分析讨论.

Deprescribing antihypertensive treatment in nursing home patients and the effect on blood pressure

Background It is debatable whether treating multimorbid nursing home patients with antihypertensive drugs produces beneficial effects. Most cardiovascular guidelines promote treatment; few have advice on how to deprescribe when treatment may no longer be necessary. We investigated the effect of medication review on antihypertensive drug use and the association between cognition, blood pressure, and prescribing. Methods From August 2014 to December 2015, 765 patients from 72 units （clusters） in 32 Norwegian nursing homes were included in a 4-month, multicentre, cluster-randomized, controlled trial, with 9-month follow-up. Patients ≥ 65 years old with antihypertensive treatment （n = 295, 39%） were randomized to systematic medication review where the physician received support from peers （collegial mentoring） or were given care as usual （control condition）. Outcome measures were the number of antihypertensive drugs, systolic blood pressure, and pulse. We used hospitalizations and deaths as criteria to assess harm. Results At baseline, each patient used 9.2 ± 3.5 regular drugs, and 1.6 ± 0.7 antihypertensives. Mean blood pressure was 128/71 mmHg and 9% had a systolic pressure ≥ 160 mmHg. Between baseline and month four, antihypertensives were deprescribed to a significantly higher extent in the intervention group （n = 43, 32%） compared to control （n = 11, 10%）; Incidence Rate Ratio = 0.8, 95% CI = 0.7？0.9. In the intervention group, there was an immediate increase in systolic blood pressure when antihypertensives were reduced, from baseline 128 ± 19.5 mmHg to 143 ± 25.5 mmHg at month four. However, at month nine, the blood pressure had reverted to baseline values （mean 134 mmHg）. Deprescription did not affect pulse and systolic pressure. The number of hospitalizations was higher in control patients at month four （P = 0.031） and nine （P = 0.041）. Conclusion A systematic medication review supported by collegial mentoring significantly decreased the use of antihypertensive drugs in nursing home patients without an effect on the systolic blood pressure over time.

Nuclear magnetic resonance(NMR) microscopic simulation based on random-walk: Theory and parameters analysis

The microscopic response characteristics of nuclear magnetic resonance(NMR) are widely used for characterizing complex pore structures of rocks. Due to the prohibitive NMR experiment cost, numerical simulation was employed as an alternative approach to verify some theoretical aspects of NMR responses. Firstly, the basic principles of pore-scale NMR simulation based on random-walk method(RWM) were introduced. The RWM-simulated results were benchmarked with the analytical results for an ideal spherical pore model. Then, the effects of two numerical parameters, namely diffusion radius and walk numbers, were studied on the simulation accuracy. The simulation method is then applied to various pore models with different pore sizes and pore shapes filled with different fluids to study the microscopic NMR response characteristics. The numerical experiments are useful for understanding and interpreting NMR measurements and the simulation code provides a numerical tool to perform pixel-based digital rock analysis.

Toward an RSU-unavailable Lightweight Certificateless Key Agreement Scheme for VANETs

Vehicle ad-hoc networks have developed rapidly these years,whose security and privacy issues are always concerned widely.In spite of a remarkable research on their security solutions,but in which there still lacks considerations on how to secure vehicleto-vehicle communications,particularly when infrastructure is unavailable.In this paper,we propose a lightweight certificateless and oneround key agreement scheme without pairing,and further prove the security of the proposed scheme in the random oracle model.The proposed scheme is expected to not only resist known attacks with less computation cost,but also as an efficient way to relieve the workload of vehicle-to-vehicle authentication,especially in no available infrastructure circumstance.A comprehensive evaluation,including security analysis,efficiency analysis and simulation evaluation,is presented to confirm the security and feasibility of the proposed scheme.

Identity-based ring signature scheme based on quadratic residues

Identity-based （ID-based） ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.

Oil-gas reservoir lithofacies stochastic modeling based on one- to three-dimensional Markov chains

Stochastic modeling techniques have been widely applied to oil-gas reservoir lithofacies. Markov chain simulation~ however~ is still under development~ mainly because of the difficulties in reasonably defining conditional probabilities for multi-dimensional Markov chains and determining transition probabilities for horizontal strike and dip directions. The aim of this work is to solve these problems. Firstly~ the calculation formulae of conditional probabilities for multi-dimensional Markov chain models are proposed under the full independence and conditional independence assumptions. It is noted that multi-dimensional Markov models based on the conditional independence assumption are reasonable because these models avoid the small-class underestimation problem. Then~ the methods for determining transition probabilities are given. The vertical transition probabilities are obtained by computing the transition frequencies from drilling data~ while the horizontal transition probabilities are estimated by using well data and the elongation ratios according to Walther＇s law. Finally~ these models are used to simulate the reservoir lithofacies distribution of Tahe oilfield in China. The results show that the conditional independence method performs better than the full independence counterpart in maintaining the true percentage composition and reproducing lithofacies spatial features.

Random Vibration Analysis of Urban Underground Tunnels Under Vertical Earthquake Excitations Based on Mass–Damper–Spring Model

In this paper, the verticalseismic effects on tunnels are studied based on a classic mass–damper–spring model. An analyticaldiscrete modelof urban underground tunnels subjected to verticalearthquake excitations is proposed by considering the first verticalvibration mode. Taking a light railproject in Tianjin as an example, this study uses the proposed discrete modelto analyze the displacements of tunneland soilunder verticalearthquake excitations. The soildisplacement responses at different tunnellocations are analyzed with linear random vibration theory.The computationalcost is greatly reduced using the proposed model. It can be seen that different from the case of horizontalearthquakes, the displacement responses under verticalearthquake excitations keep growing after seismic acceleration reaches its peak for a short duration, and then,they begin to decay. The soils at different positions around the tunnels have large relative displacement under verticalearthquake excitations. Moreover, a finite-element modelis also established for displacement responses using ABAQUS.The comparison with the results of the finite-element modelshows that the results of the proposed discrete modelare available.

Balance of Datum Land Prices Among Cities Based on the City Gravitation Model and Stochastic Diffusion Equation

A balance of urban datum land prices is achieved to harmonize regional land prices and make the prices truly reflect different economic development levels and land prices among cities. The current piecewise linear interpolation balance method widely used has two drawbacks that always lead to an unsatisfactory balance among some cities. When the excess of land price in the central city to the surrounding zone reaches a certain degree, land price in the circumjacent city is not only consistent with the local land grade and land use level, but also influenced by the diffusion of land price in the central city. Thus, a new balanced scheme of datum land prices based on the city gravitation model and stochastic diffusion equation is brought forward. Finally, the new method is examined in the practice of datum land price balance in Hubei Province, China.

TP53 Arg72Pro polymorphism is associated with esophageal cancer risk:A meta-analysis

AIM:To investigate the association between TP53 Arg72Pro polymorphism and esophageal cancer(EC)risk using meta-analysis. METHODS:All eligible studies published before March 1,2010 were selected by searching PubMed using keywords"p53"or"TP53","polymorphism"or"variation", "esophageal"and"cancer"or"carcinoma".Crude odds ratios(ORs)with 95%confidence intervals(CIs)were assessed for EC risk associated with TP53 Arg72Pro polymorphism using fixed-and random-effects models. RESULTS:Nine case-control studies involving 5545 subjects were included in this meta-analysis.Significantly reduced risk of EC was associated with TP53genotypes for Arg/Arg+Arg/Pro vs Pro/Pro(OR= 0.73,95%CI:0.57-0.94,P=0.014).Subgroup analyses according to the source of controls and the specimens used for determining TP53 Arg72Pro genotypes or sample size showed that significantly reduced risk was observed only in studies which have populationbased controls(Arg/Arg vs Pro/Pro:OR=0.56,95% CI:0.47-0.66,P<0.001),and use white blood cells or normal tissue to assess TP53 genotypes of cases (Arg/Arg vs Pro/Pro:OR=0.56,95%CI:0.47-0.65,P <0.001)or include at least 200 subjects(Arg/Arg vs Pro/Pro:OR=0.56,95%CI:0.47-0.65,P<0.001). Analysis restricted to well-designed studies also supported the significantly decreased risk of EC(Arg/Arg vs Pro/Pro:OR=0.54,95%CI:0.46-0.64,P<0.001). CONCLUSION:TP53 Arg72 carriers are significantly associated with decreased EC risk.Nevertheless,more welldesigned studies are needed to confirm our findings.

A genetic algorithm for community detection in complex networks

A new genetic algorithm for community detection in complex networks was proposed. It adopts matrix encoding that enables traditional crossover between individuals. Initial populations are generated using nodes similarity, which enhances the diversity of initial individuals while retaining an acceptable level of accuracy, and improves the efficiency of optimal solution search. Individual crossover is based on the quality of individuals' genes; all nodes unassigned to any community are grouped into a new community, while ambiguously placed nodes are assigned to the community to which most of their neighbors belong. Individual mutation, which splits a gene into two new genes or randomly fuses it into other genes, is non-uniform. The simplicity and effectiveness of the algorithm are revealed in experimental tests using artificial random networks and real networks. The accuracy of the algorithm is superior to that of some classic algorithms, and is comparable to that of some recent high-precision algorithms.

New model for deducing directional extrema based on multivariate extremum statistical theory

The parameters of principal and directional extrema in a marine environment are important in marine engineering design, especially for appropriate construction of oceanic platforms and other structures. When designing wave walls and break water structures, the orientation of the breakwater or seawall depends mainly on the direction of the strongest waves. However, the strength of the breakwater and the elevation of the seawall depend on the magnitude of the biggest wave height of the strongest waves. Thus, identification of directional extrema plays an important role in the design of wave factors. When calculating the directional extremum, different materials may require different specific computational methods, yet few theoretical studies have been conducted in this field of research. Based on multivariate extremnm statistical theory, this paper utilizes a discrete random variable to build a joint probability model compounded by a discrete random variable and a multivariate continuous random variable. Furthermore, this paper provides the first investigation on the theories and methodologies to deduce wave directional extrema. The results provide tools for both creating the calculation method of the directional extremum value and providing the rational directional extremum parameters for marine engineering design.

P53 gene could be a new effective therapeutic target in triple-negative breast cancer: a Meta-analysis

Objective： The aim of this study was to explore the relationship between p53 gene and triple-negative breast cancer （TNBC）, and determine that whether p53 gene could be a new effective therapeutic target. Methods： We identified studies with quantitative data on the relation of p53 gene and TNBC through searching 12 databases online （Oct. 1999-Oct. 2012） and reviewing the references, which were written in English or Chinese. Summary estimates of odds ratio （OR） was calculated using the fixed-effects model or the random-effects model as appropriate. Results： We identified 12 eligible stud- ies with 1532 cases of TNBC patients and 6329 controls of non-TNBC patients. The test for homogeneity resulted in X^2 = 200.16 （P 〈 0.05）, it showed significant heterogeneity so that a random effect model was applied. Our results showed that the expression of p53 gene could be much stronger in TNBC group than that in non-TNBC group [OR = 2.10, 95% confidence interval （CI） = 1.21-3.65]. In ethnicity-subgroup analysis, we found that in Caucasian group, the expression of p53 gene were stronger in TNBC group （OR = 2.60, 95% CI = 1.21-5.57）, but there was no statistical significance in Asian group （OR = 1.69, 95% CI = 0.83-3.45）. Conclusion： P53 gene could be an effective predictor and a good therapeutic target for TNBC patients in the future, especially in Caucasian. Further researches focusing on p53 gene would gain a breakthrough in the treatment of TNBC.

Effects of telbivudine and entecavir for HBeAg-positive chronic hepatitis B: A meta-analysis

AIM:To compare the effects of telbivudine (LDT) and entecavir (ETV) in treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B by meta-analysis. METHODS:We conducted a literature search using PubMed, MEDLINE, EMBASE, the China National Knowledge Infrastructure, the VIP database, the Wanfang database and the Cochrane Controlled Trial Register for all relevant articles published before April 1, 2012. Randomized controlled trials (RCTs) comparing LDT with ETV for treatment of HBeAg-positive chronic hepatitis B were included. The data was analyzed with Review Manager Software 5.0. We used relative risk (RR) as an effect measure, and reported its 95% CI. Meta-analysis was performed using either a fixedeffect or random-effect model, based on the absence or presence of significant heterogeneity. Two reviewers assessed the risk of bias and extracted data indepen- dently and in duplicate. The analysis was executed using the main outcome parameters including hepatitis B virus (HBV) DNA undetectability, alanine aminotransferase (ALT) normalization, HBeAg loss, HBeAg seroconversion, drug-resistance, and adverse reactions. Meta-analysis of the included trials and subgroup analyses were conducted to examine the association between pre-specified characteristics with the therapeutic effects of the two agents. RESULTS:Thirteen eligible trials (3925 patients in total) were included and evaluated for methodological quality and heterogeneity. In various treatment durations of 4 wk, 8 wk, 12 wk, 24 wk, 36 wk, 48 wk, 52 wk, 60 wk and 72 wk, the rates of HBV DNA undetectability and ALT normalization in the two groups were similar, without statistical significance. At 4 wk and 8 wk of the treatment, no statistical differences were found in the rate of HBeAg loss between the two groups, while the rate in the LDT group was higher than in the ETV group at 12 wk, 24 wk, 48 wk and 52 wk, respectively (RR 2.28, 95% CI 1.16, 7.03, P = 0.02; RR 1.45, 95% CI 1.16, 1.82, P = 0.001; RR 1.45, 95% CI 1.11, 1.89, P = 0.006; and RR 1.86, 95% CI 1.04, 3.32, P = 0.04). At 4 wk, 8 wk, 60 wk and 72 wk of the treatment, there were no significant differences in the rate of HBeAg seroconversion between the two groups, while at 12 wk, 24 wk, 48 wk and 52 wk, the rate in the LDT group was higher than in the ETV group (RR 2.10, 95% CI 1.36, 3.24, P = 0.0008; RR 1.71, 95% CI 1.29, 2.28, P = 0.0002; RR 1.86, 95% CI 1.36, 2.54, P < 0.0001; and RR 1.87, 95% CI 1.21, 2.90, P = 0.005). The rate of drug-resistance was higher in the LDT group than in the ETV group (RR 3.76, 95% CI 1.28, 11.01, P = 0.02). In addition, no severe adverse drug reactions were observed in the two groups. And the rate of increased creatine kinase in the LDT group was higher than in the ETV group (RR 5.58, 95% CI 2.22, 13.98, P = 0.0002). CONCLUSION:LDT and ETV have similar virological and biomedical responses, and both are safe and well tolerated. However, LDT has better serological response and higher drug-resistance.

Natural history of heartburn:A 10-year population-based study

AIM： To study the natural history and prevalence of heartburn at a 10-year interval, and to study the effect of heartburn on various symptoms and activities. METHODS： A population-based postal study was carried out. Questionnaires were mailed to the same age- and gender-stratified random sample of the Icelandic population （aged 18-75 years） in 1996 and again in 2006. Subjects were classified with heartburn if they reported heartburn in the preceding year and/or week, based on the definition of heartburn. RESULTS： Heartburn in the preceding year was reported in 42.8% （1996） and 44.2% （2006） of subjects, with a strong relationship between those who experienced heartburn in both years. Heartburn in the precedingweek was diagnosed in 20.8%. There was a significant relationship between heartburn, dyspepsia and irritable bowel syndrome. IndMduals with a body mass index （BMI） below or higher than normal weight were more likely to have heartburn. Heartburn caused by food or beverages was reported very often by 20.0% of subjects. CONCLUSION： Heartburn is a common and chronic condition. Subjects with a BMI below or higher than normal weight are more likely to experience heartburn. Heartburn has a great impact on daily activities, sleep and quality of life.

oncausal spatial prediction filtering based on an ARMA model

Conventional f-x prediction filtering methods are based on an autoregressive model. The error section is first computed as a source noise but is removed as additive noise to obtain the signal, which results in an assumption inconsistency before and after filtering. In this paper, an autoregressive, moving-average model is employed to avoid the model inconsistency. Based on the ARMA model, a noncasual prediction filter is computed and a self-deconvolved projection filter is used for estimating additive noise in order to suppress random noise. The 1-D ARMA model is also extended to the 2-D spatial domain, which is the basis for noncasual spatial prediction filtering for random noise attenuation on 3-D seismic data. Synthetic and field data processing indicate this method can suppress random noise more effectively and preserve the signal simultaneously and does much better than other conventional prediction filtering methods.

Study on High Order Perturbation-based Nonlinear Stochastic Finite Element Method for Dynamic Problems

Several algorithms were proposed relating to the development of a framework of the perturbation-based stochastic finite element method (PSFEM) for large variation nonlinear dynamic problems. For this purpose, algorithms and a framework related to SFEM based on the stochastic virtual work principle were studied. To prove the validity and practicality of the algorithms and framework, numerical examples for nonlinear dynamic problems with large variations were calculated and compared with the Monte-Carlo Simulation method. This comparison shows that the proposed approaches are accurate and effective for the nonlinear dynamic analysis of structures with random parameters.