Efficient Evaluation of Monitoring Top-t Most Influential Places

The continuous top-t most influential place (CTtMIP)query is defined formally and solved efficiently in this paper.A CTtMIP query continuously monitors the t places with the maximum influence from the ...     

异形玻璃幕墙安装测量精度分析

随着玻璃幕墙在建筑中的广泛应用，各种异形玻璃幕墙的出现对安装测量方法提出了更高的要求。本文结合唐山人民大厦的实例，介绍了采用免棱镜全站仪进行玻璃幕墙三维测量的方法，并提出了相应的精度控制措施。     

Analysis for vertical velocity of seismic waves

Abstract

Presented here are the results of seismic wave velocities analyzed using the acceleration time‐histories recorded at the downhole strong motion array of the Lotung large scale seismic test site during the May 20, 1986 Hualien earthquake. The spectral ratios between the surface and downhole accelerograms were used to identify the frequencies of maximum amplification of soil layers, and an elastic 1‐D wave propagation model was proposed to estimate the wave velocities of the ground during the earthquake. The results obtained indicate that significant reduction of shear wave velocity as well as soil modulus was induced by earthquake excitation as compared to the values obtained from low strain level soil testings.     

A Modified Method Based on the Discrete Sliding Norm Transform to Reduce the PAPR in OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is a modulation technique that allows the transmission of high data rates over wideband radio channels subject to frequency selective fading by dividing the data into several narrowband and flat fading channels. OFDM has high spectral efficiency and channel robustness. However, a major drawback of OFDM is that the peak‐to‐average power ratio (PAPR) of the transmitted signals is high, which causes nonlinear distortion in the received data and reduces the efficiency of the high power amplifier in the transmitter. The most straightforward method to solve this problem is to use a nonlinear mapping algorithm to transform the signal into a new signal that has a smaller PAPR. One of the latest nonlinear methods proposed to reduce the PAPR is the L₂‐by‐3 algorithm, which is based on the discrete sliding norm transform. In this paper, a new algorithm based on the L₂‐by‐3 method is proposed. The proposed method is very simple and has a low complexity analysis. Simulation results show that the proposed method performs better, has better power spectral density, and is less sensitive to the modulation type and number of subcarriers than L₂‐by‐3.     

Self‐employment and local economic performance: Evidence from US counties*

This study explores the relationship between self‐employment and income growth, employment growth, and change in poverty in metro and non‐metro areas in the United States using county‐level panel data. We investigate the impact of the relative size of the self‐employment sector measured by the share of non‐farm proprietorships (NFPs) in total full and part‐time employment on three key economic performance indicators. We first estimate an income growth model to analyse the effects of self‐employment on income growth. Then we investigate the independent effects of self‐employment on employment growth and changes in family poverty rates. Our results indicate that higher self‐employment rates are associated with statistically significant increases over time in income and employment growth, and reductions in poverty rates in non‐metro counties. We find similar effects on metro county income and employment, but not on poverty dynamics.     

A new manufacturable filter design approach for spectral reflectance estimation

Selection of the best possible filter set among a set of available filters is the obvious method of increasing dimension of camera signals for spectral reflectance reconstruction. There are also methods that are focusing on the filter design regardless of noticing to the constructability of the designed filters. This study shows that direct optimization of physical variables of filter manufacturing technique is more reliable than indirect approach of designing and then physical manufacturing of the designed filters. Direct optimization of the transmission‐controlling primaries in filter manufacturing process would guarantee having the designed filters in reality. Combination of some solvent dyes was used as the spectral transmission matching system for filter manufacturing. As a conventional technique, filters were designed and best possible dye concentrations that match the desired filters were calculated. As an alternative approach, filters were also designed using direct optimization of dyes concentrations. The results showed that direct optimization of dye concentrations exhibits better performance in comparison with the conventional technique. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 316–326, 2017     

中国（上海）自由贸易试验区配套服务设施优化探讨--基于对自由贸易试验区现状与需求特征的分析

上海自贸试验区由外高桥保税区、浦东机场保税区和洋山保税港区3大区域组成，作为自贸试验区的主体功能，金融、贸易、会展等商务设施快速发展，建树显著。但与其主体功能相辅的配套服务设施，则由于三区不同的阶段和特征都各不相同，在一定程度上影响着自贸试验区的软实力提升。探讨如何结合自贸试验区的特殊性，从特征分析和需求调查出发，寻求适合于当前需求及发展形势的配套服务优化之路。     

Decomposing regional business change at plant level in Italy: A novel spatial shift‐share approach

In this paper, spatial shift‐share decomposition is analysed when applied to Italian data on regional business change at plant level, over the period 2004–2009. A new type of spatial decomposition, which looks more effectively at neighbourhood influence, is introduced here. Notable results emerge from the empirical investigation. First, it can be seen that the spatial level of aggregation greatly affects results. Second, evidence of neighbourhood advantage in the Southern NUTS 3 regions is found, together with opposite results for the Central‐Northern NUTS 3 regions. Finally, evidence of positive industrial mix effects is only found in Central‐Northern Italy.     

Stochastic response of fractionally damped beams

This paper aims at introducing the governing equation of motion of a continuous fractionally damped system under generic input loads, no matter the order of the fractional derivative. Moreover, particularizing the excitation as a random noise, the evaluation of the power spectral density performed in frequency domain highlights relevant features of such a system.Numerical results have been carried out considering a cantilever beam under stochastic loads. The influence of the fractional derivative order on the power spectral density response has been investigated, underscoring the damping effect in reducing the power spectral density amplitude for higher values of the fractional derivative order. Finally, the fractional derivative term introduces in the system dynamics both effective damping and effective stiffness frequency dependent terms.     

Life Prediction Based on Transient Dynamics Analysis of Van Semi-trailer with Air Suspension System

The early fatigue damage in the van-body of the semi-trailer is often caused by the unique mechanical characteristics and the dynamic impact of the loads.The traditional finite element method with static strength analysis cannot support the fatigue design of van-body;thus,the dynamics analysis should be adopted for the endurance performance.The accurate dynamics model to describe the transient impacts of all kinds of uneven road and the proper system transfer functions to calculate the load transfer effects...