Performance Analysis of a DS-CDMA Cellular System with Effects of Soft Handoff in Log-Normal Shadowing Channels

Next generation wireless communication is based on a global system of fixed and wireless mobile services thatare transportable across different network back-bones,network service providers and network geographical boundaries.This paper presents an approach to investigate the effects of soft handover and perfect power control on the forward link ina DS-CDMA cellular system.Especially,the relationships between the size ofhandover zone and the capacity gain are e-valuated under the log-normal shadow channel.Then the optimization of maximum forward capacity is very necessary tobe done with the maximum size of soft handover zone to the various system characteristics.

Log-normal湍流信道中超奈奎斯特传输系统的误码性能

超奈奎斯特传输理论与调制技术相结合,可有效提高系统的频谱效率。本文将超奈奎斯特理论引入大气激光通信系统,构建了一种适合于log-normal湍流信道的超奈奎斯特光传输系统,推导了QPSK调制方式下超奈奎斯特大气光传输系统平均误码率的表达式,利用蒙特卡洛仿真进一步分析了该系统的误码性能及频谱效率。结果表明:采用超奈奎斯特技术方案可以较大幅度提升大气光传输系统的频谱效率,当SNR为18 dB,S.I.为0.4时其频谱效率可以达到1.7 Baud/Hz,而未采用超奈奎斯特技术时只有1.56 Baud/Hz。另一方面,大气湍流对超奈奎斯特系统误码性能的影响较明显,当S.I.为0.4,BER为3.8×10^-3时,信噪比恶化了约1 dB。相对于频谱效率的提升,误码性能的恶化是能够接受的。因此,可以将FTN技术引入大气光传输系统来提高系统的频谱效率。

Poisson Log-normal回归模型的影响评价(英文)

本文利用EM算法研究了来自于Lognormal分布权重的混合Poisson模型,即Poisson Lognormal回归模型,从而利用基于完全数据似然函数的条件期望进行影响评价.基于数据删除模型和局部影响分析方法,分别得到了广义Cook距离、Q距离和三种不同扰动模型下的正则曲率度量等诊断统计量.

变环境不同阶段下Log-normal分布缺失数据的可靠性估计

本文研究了变环境不同阶段Log-normal分布下,观测数据中包含缺失数据的情形下的可靠性估计问题。通过EM算法估计参数以及可靠性,最后通过模拟研究验证了本文方法的可行性。

一种估算三参数log-normal分布参数的近似方法

三参数（ｌｏｇ－ｎｏｒｍａｌ）分布在可靠性工程中有广泛应用，但其分布参数的估计较为困难。为解决这一问题，本文将极大似然法引入其概率图。

A new car-following model yielding log-normal type headways distributions

Modeling time headways between vehicles has attracted increasing interest in the traffic flow research field recently, because the corresponding statistics help to reveal the intrinsic interactions governing the vehicle dynamics. However, most previous micro-simulation models cannot yield the observed log-normal distributed headways. This paper designs a new car-following model inspired by the Galton board to reproduce the observed time-headway distributions as well as the complex traffic phenomena. The consistency between the empirical data and the simulation results indicates that this new car-following model provides a reasonable description of the car-following behaviours.

Efficient Mean Estimation in Log-normal Linear Models with First-order Correlated Errors

In this paper, we propose a log-normal linear model whose errors are first-order correlated, and suggest a two-stage method for the efficient estimation of the conditional mean of the response variable at the original scale. We obtain two estimators which minimize the asymptotic mean squared error （MM） and the asymptotic bias （MB）, respectively. Both the estimators are very easy to implement, and simulation studies show that they are perform better.

Linear Maximum Likelihood Regression Analysis for Untransformed Log-Normally Distributed Data

Medical research data are often skewed and heteroscedastic. It has therefore become practice to log-transform data in regression analysis, in order to stabilize the variance. Regression analysis on log-transformed data estimates the relative effect, whereas it is often the absolute effect of a predictor that is of interest. We propose a maximum likelihood (ML)-based approach to estimate a linear regression model on log-normal, heteroscedastic data. The new method was evaluated with a large simulation study. Log-normal observations were generated according to the simulation models and parameters were estimated using the new ML method, ordinary least-squares regression (LS) and weighed least-squares regression (WLS). All three methods produced unbiased estimates of parameters and expected response, and ML and WLS yielded smaller standard errors than LS. The approximate normality of the Wald statistic, used for tests of the ML estimates, in most situations produced correct type I error risk. Only ML and WLS produced correct confidence intervals for the estimated expected value. ML had the highest power for tests regarding β1.

Suppression of Log-Normal Distributed Weather Clutter Observed by an S-Band Radar

We have observed weather clutter containing targets (ships) using an S-band radar with a frequency 3.05 GHz, a beam width 1.8°, and a pulsewidth 0.5 μs. To investigate the weather clutter amplitude statistics, we introduce the Akaike Information Criterion (AIC). We have found that the weather clutter amplitudes obey the log-normal, Weibull, and log-Weibull distributions with the shape parameters of 0.308 to 0.470, 4.42 to 4.51, and 15.91 to 16.44, respectively, for small data within the beam width of an antenna. We have proposed the log-normal/CFAR circuit modified a Cell-Averaging (CA) LOG/CFAR circuit. It is found that weather clutter is suppressed with improvement of 51.58 dB by log-normal/CFAR. As a result, we have showed that weather clutter observed by S-band radar does not obey the Rayleigh distribution and our log-normal/CFAR circuit has an effect on suppression of clutter and detection of target, while conventional LOG/CFAR circuit does not. In addition, if our circuit can be realized, we will have an advantage economically.

View of thermodynamic phase transition of the charged Gauss-Bonnet AdS black hole via the shadow

We examine thermodynamic phase transition(PT)of the charged Gauss-Bonnet Ad S black hole(BH)by utilizing the shadow radius.In this system,we rescale the corresponding Gauss-Bonnet coefficientαby a factor of 1/(D-4),and ensure thatαis positive to avoid any singularity problems.The equation derived for the shadow radius indicates that it increases as the event horizon radius increases,making it an independent variable for determining BH temperature.By investigating the PT curve in relation to shadows,we can observe that the shadow radius can be used as an alternative to the event horizon radius in explaining the phenomenon of BH PT.Furthermore,the results indicate that an increase in the parameterαcorresponds to a decrease in the temperature of the BH.By utilizing the relationship between the temperature and the shadow radius,it is possible to obtain the thermal profile of the Gauss-Bonnet AdS BH.It is evident that there is an N-type variation in temperature for pressures P<P_(c).Additionally,as the parameterαincreases,the region covered by shadow expands while the temperature decreases.The utilization of BH shadows as a probe holds immense significance in gaining a deeper understanding of BH thermodynamic behavior.

An Interactive Collaborative Creation System for Shadow Puppets Based on Smooth Generative Adversarial Networks

Chinese shadow puppetry has been recognized as a world intangible cultural heritage.However,it faces substantial challenges in its preservation and advancement due to the intricate and labor-intensive nature of crafting shadow puppets.To ensure the inheritance and development of this cultural heritage,it is imperative to enable traditional art to flourish in the digital era.This paper presents an Interactive Collaborative Creation System for shadow puppets,designed to facilitate the creation of high-quality shadow puppet images with greater ease.The system comprises four key functions:Image contour extraction,intelligent reference recommendation,generation network,and color adjustment,all aimed at assisting users in various aspects of the creative process,including drawing,inspiration,and content generation.Additionally,we propose an enhanced algorithm called Smooth Generative Adversarial Networks(SmoothGAN),which exhibits more stable gradient training and a greater capacity for generating high-resolution shadow puppet images.Furthermore,we have built a new dataset comprising high-quality shadow puppet images to train the shadow puppet generation model.Both qualitative and quantitative experimental results demonstrate that SmoothGAN significantly improves the quality of image generation,while our system efficiently assists users in creating high-quality shadow puppet images,with a SUS scale score of 84.4.This study provides a valuable theoretical and practical reference for the digital creation of shadow puppet art.

Color-polarization synergistic target detection method considering shadow interference

Aiming at the problem of shadow interference in UAV's ground reconnaissance,a color and polarization synergistic target detection method is proposed for anti-shadow interference,based on the influence of two physical characteristics(wavelength and polarization)under different illuminations.A valid fusion strategy is proposed via integrating two separate detection results on color and polarization images.Moreover,a local enhancement and recognition module(LER)is introduced to boost the performance.Based on our built dataset,experimental results show that our method achieves mAPof 87.76%,and12.37%higher than that of color image and 14.68%higher than that of polarization image.

Langzhong Shadow Play

LANGZHONG shadow play has been popular in 36 counties and cities in the vicinity of Langzhong in southwest China’s Sichuan Province,and is one of three major styles of Sichuan shadow play.Around 350 years ago,a puppeteer named Wang Yuansheng created the Langzhong shadow play by combining the unique characteristics of different styles of shadow play with north Sichuan’s folk customs.In 2008,the art of Sichuan shadow play which Langzhong shadow play is affiliated to was listed as a national intangible culture heritage item.

Energy efficiency aware dynamic rate and power adaptation in carrier sensing based WLANs under Rayleigh fading and shadowing

We consider the problem of energy efficiency aware dynamic adaptation of data transmission rate and transmission power of the users in carrier sensing based Wireless Local Area Networks(WLANs)in the presence of path loss,Rayleigh fading and log-normal shadowing.For a data packet transmission,we formulate an optimization problem,solve the problem,and propose a rate and transmission power adaptation scheme with a restriction methodology of data packet transmission for achieving the optimal energy efficiency.In the restriction methodology of data packet transmission,a user does not transmit a data packet if the instantaneous channel gain of the user is lower than a threshold.To evaluate the performance of the proposed scheme,we develop analytical models for computing the throughput and energy efficiency of WLANs under the proposed scheme considering a saturation traffic condition.We then validate the analytical models via simulation.We find that the proposed scheme provides better throughput and energy efficiency with acceptable throughput fairness if the restriction methodology of data packet transmission is included.By means of the analytical models and simulations,we demonstrate that the proposed scheme provides significantly higher throughput,energy efficiency and fairness index than a traditional non-adaptive scheme and an existing most relevant adaptive scheme.Throughput and energy efficiency gains obtained by the proposed scheme with respect to the existing adapting scheme are about 75%and 103%,respectively,for a fairness index of 0.8.We also study the effect of various system parameters on throughput and energy efficiency and provide various engineering insights.

Dragons Leap with Each Passing Year, Intangible Heritage Grows Fragrant Beijing Shadow Puppetry Outreach Activities

Since ancient times,the Chinese New Year has been the most important festival for the Chinese nation,and"celebrating the Chinese New Year in museums"has gradually become a new trend in recent years.To enrich the cultural offerings during the holiday period and let the general audience experience the strong festive atmosphere in museums,on February 22 and 23,2024,on the eve of the Lantern Festival,the China Arts and Crafts Museum(China Intangible Cultural Heritage Museum)successfully held the"Encounter with Intangible Heritage""Capital Colors Shadow Play:Bejing Shadow Puppetry Outreach Activities."

A Tale of Light and Shadow Chinese shadow puppetry seeks to explore new avenues

Accompanied by music,a turtle and a crane fight in a humorous story created by the simple interplay of light and curtain.This Chinese shadow puppetry performance makes the audience laugh.Backstage,Lu Baogang,a national-level inheritor of Beijing shadow puppetry art,and the other performers of the shadow puppetry troupe manipulate the silhouettes with great skill.

Nanyang Shadow Puppetry-Inheritance and Challenges

Nanyang shadow puppetry has a long history.It originated in the Han Dynasty and grew from folk rap art,combining various art forms like painting,sculpture(雕塑),and opera.In the past,rural cultural life in Nanyang was rare;shadow puppetry was a key form of entertainment(娱乐).During festivals,temple fairs,or slack farming seasons,troupes would visit villages to give wonderful shows.

An Overview of the Achievements of Modern Research on the Flying Shadow Pavilion Pictorial

The current academic research on the Dian Shi Zhai Pictorial founded in 1884 has been perfected,but there is very little research on the Flying Shadow Pavilion Pictorial,which can be said to be derived from Dian Shi Zhai Pictorial terms of both content and form,and which was founded by the Haiist painter Wu Youru in 1890 in order to reward the increasing number of admirers,but it is still in the initial stage.Flying Shadow Pavilion Pictorial consisted of four parts:pictures of ladies in Shanghai costumes,news about current affairs,pictures of animals,and compilations of women,each of which was accompanied by the then popular notebooks,which were popular at the time among the then readers because of the matching of pictures with text and the mixing of narratives and discussions.This paper takes Flying Shadow Pavilion Pictorial as the main object,summarizes the existing literature about Flying Shadow Pavilion Pictorial,points out the deficiencies of the current research on this basis,and points out the development trend of Flying Shadow Pavilion Pictorial in the future research.

一种基于Shadow Mapping的阴影生成改进算法

Shadow Mapping算法是目前广泛应用的阴影渲染方法,但该方法容易产生走样,特别是不能满足大规模场景中阴影的真实性和实时性要求。对此,提出一种利用平行面分割的改进Shadow Mapping算法,减少了算法运行时的缓冲空间,提高了阴影质量,尤其适合于动态大规模环境中实时阴影的生成。并用VS2005和OpenSceneGraph实现了算法的绘制过程,达到满意的视觉效果和生成速度。

Numerical simulation of seismic low-frequency shadows and its application

Strong low-frequency energy beneath a hydrocarbon reservoir is called a seismic low-frequency shadow and can be used as a hydrocarbon indicator （Tarter et al., 1979） bu the physical mechanism of the observed low-frequency shadow is still unclear. To stud） the mechanism, we performed seismic numerical simulation of geological models with a hydrocarbon-bearing zone using the 2-D diffusive-viscous wave equation which car effectively model the characteristics of velocity dispersion and transform the seismic dat~ centered in a target layer slice within a time window to the time-frequency domain by usinl time-frequency signal analysis and sort the frequency gathers to common frequency cubes. Then, we observe the characteristics of the seismic low-frequency shadow in the common frequency cubes. The numerical simulations reveal that the main mechanism of seismic lowfrequency shadows is attributed to high attenuation of the medium to high seismic frequency components caused by absorption in the hydrocarbon-filled reservoir. Results from a practical example of seismic low-frequency shadows show that it is possible to identify the reservoir by the low-frequency shadow with high S/N seismic data.