A human-sensitive frequency band vibration isolator for heavy-duty truck seats

In this study,a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS)characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven roads.First,the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle,and are validated through the prototype restoring force testing.Second,the harmonic balance method(HBM)is used to obtain the dynamic responses under harmonic excitation,and further the influence of pre-stretching on the dynamic characteristics and transmissibility is discussed.Finally,the experimental prototype of the HFBVI is fabricated,and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP)of the proposed vibration isolator.The experimental results indicate that the HFBVI can effectively suppress the frequency band(4-8 Hz)to which the human body is sensitive to vertical vibration.In addition,under real random road spectrum excitation,the HFBVI can achieve low-frequency vibration isolation close to 2 Hz,providing new prospects for ensuring the health of heavy-duty truck drivers.

TRAMO/SEATS在危机事件中对旅游影响研究的应用

国内外对旅游危机事件的研究集中于管理方面,近年相关热点转向对旅游影响的研究。以往定性研究多,从经济数量模型进行定量分析研究的较少。本文使用在经济金融领域使用广泛的ARIMA改进版——TRAMO/SEATS方法评估危机事件,如疾病、地震等突发事件对中国旅游业的影响。作为欧盟各国统计局主要统计方法,TRAMO/SEATS方法能够最大程度地反映旅游业季节性波动的特点。通过该方法对2003年在中国内地和香港地区爆发的SARS进行实证研究,分析评估该危机事件的长期影响。在此基础上提出,国家短期内应当通过提高产品质量和拓展高质量的细分市场实现旅游效益型增长;恢复后期才可以推出更为直接的促销手法实现旅游数量型增长,采取刺激旅游人数快速增长的政策和措施。

监管政策对商业银行行为选择的冲击效应研究——基于H省若干家商业银行的TRAMO/SEATS检验

根据《巴塞尔协议》等国际公约的要求,中国的银行监管部门于2004年1月开始,在全国的银行系统推行严格的资本充足性管理。作为国际银行界主流的监管政策,资本充足性管理对商业银行的行为选择产生了深远的影响。本文选取了中国中部某省份2002年至2006年的商业银行数据,针对包括贷款对象结构、贷款期限结构和风险偏好结构三个表征商业银行行为特征的24个数据序列,运用TRAMO/SEATS的技术方法,实证检验了所有序列的结构性变动点以及监管政策的冲击效果。研究显示,当监管当局开始实施严格的资本充足性监管时,大多数商业银行都降低了风险偏好,说明监管政策的冲击效应十分明显;但是经过大约一年后,几乎所有的商业银行又选择恢复到初始状态,开始增加风险偏好,说明存在商业银行的资本约束软化效应。因此,若要保持资本监管政策的长期效果,还需不断完善相关制度体系建设。本文从商业银行行为变化的特征出发,提出了我国应对《巴塞尔协议Ⅲ》挑战的若干建议。

基于TRAMO/SEATS的北京月度入境游预测模型研究

本文运用在经济金融领域使用广泛的方法—TRAMO/SEATS方法对北京入境旅游人数开展短期预测研究。作为欧盟各国统计局主要统计方法,TRAMO/SEATS模型由于能有效提取时间序列数据中的信息,不仅预测精度高,而且稳定,能够最大程度地反映旅游业季节性波动的特点。实证分析表明,TRAMO/SEATS模型在北京入境旅游人次的短期预测方面预测能力极佳,能够为北京市入境旅游的短期经营策略提供良好的预测数据。

Ghana＇s Presidential Seats and Sword of State： Aesthetic Manifestation of Kwame Nkrumah＇ s Cultural Policy on Ghana＇s Political Culture

This study explores the aesthetic dimensions of Kwame Nkrumah＇s cultural policies in the creation of Ghana＇s Presidential Seats and the State Sword. The study is an Art Historical research situated within the qualitative research paradigm. It had a population of a defmed class of cultural policy makers, art historians, traditional rulers, nationalists, visual artists and Ghanaians resident both in and outside Ghana. The study examined how the creation of Ghana＇s Presidential Seats and the State Sword were influenced by Kwame Nkrumah＇s cultural policies and the cultural significance of the aesthetic interplay of ethnic insignias used in capturing the Ghanaian concept of Political authority. The study revealed that, Nkrumah recognised the cultural art forms and elements of ethnic Ghana as assets for national development. In line with his policy of building the Nation State of Ghana, he used ethnic cultural art forms and elements. At independence, Nkrumah commissioned some visual artist to create some artistic pieces （politico-cultural artefacts） for the Ghanaian political authority with inspiration or based on what pertains in the traditional authority （Chieftaincy） of Ghana. Politico-cultural artefacts as used in this study refer to the artefacts produced based on the cultural concepts of the ethnic states for the use of the political authority of the Republic of Ghana. Among these artistic pieces are the three Presidential Seats, The State Sword, The President＇s Personal Standard Pole and the State Mace.

Experimental study on the working performance of different milling tools for multistage fracturing ball seats

To achieve the secondary production in multistage fracturing wells of tight oil,milling tools are usually used to remove the multistage fracturing ball seats to achieve production with a large diameter in later.In this paper,first of all,the working mechanism of milling tools for multistage fracturing ball seats was studied and a mechanical analysis model of single abrasive grain was established.Then,an experimental system for milling tools was developed,and the experimental tests of the flat,the blade,and the slope milling tool were conducted in order.Besides,the morphology of chips and the surface morphology of the workpiece after the experiment were analyzed.Also,the working performance of milling tools was evaluated from the perspectives of working safety,working efficiency,and wear resistance of the milling tool.The results show that the torque of the milling tool increases nonlinearly with the increase in the cutting depth of the abrasive grain and increases linearly with the increase in the cutting width.Also,the chips are irregular particles and the size is mainly from 10 to 50μm.So,the chips should be pumped up with a small pump pressure and a large displacement.Besides this,the cutting depths of the abrasive grains are from 216.20 to 635.47μm and the bottom surface of the milling tool should be eccentric to avoid the zero point of cutting speed.Furthermore,the torque of the slope milling tool is 23.8%larger than that of the flat milling tool,which is also 30.4%smaller than that of the blade milling tool.Compared with the flat milling tool,the working efficiency of the blade milling tool improves by 79.9%and the slope milling tool improves by 111.1%.Also,the wear resistance of the blade milling tool decreases by 102.7%,while the slope milling tool declines by 32.6%when compared with the flat milling tool.Therefore,the slope milling tool has the characteristics of moderate torque,stable working conditions,the highest working efficiency,and fine wear resistance,which is preferably used to mill multistage fracturing ball seats.This study provides a theoretical basis and guidance for milling multistage fracturing ball seats on-site and realizing production with a large diameter in later stages of multistage fracturing wells.

A fully solid-state cold thermal energy storage device for car seats using shape-memory alloys

Thermal energy storage has been a pivotal technology to fill the gap between energy demands and energy supplies.As a solid-solid phase change material,shape-memory alloys(SMAs)have the inherent advantages of leakage free,no encapsulation,negligible volume variation,as well as superior energy storage properties such as high thermal conductivity(compared with ice and paraffin)and volumetric energy density,making them excellent thermal energy storage materials.Considering these characteristics,the design of the shape-memory alloy based the cold thermal energy storage system for precooling car seat application is introduced in this paper based on the proposed shape-memory alloy-based cold thermal energy storage cycle.The simulation results show that the minimum temperature of the metal boss under the seat reaches 26.2°C at 9.85 s,which is reduced by 9.8°C,and the energy storage efficiency of the device is 66%.The influence of initial temperature,elastocaloric materials,and the shape-memory alloy geometry scheme on the performance of car seat cold thermal energy storage devices is also discussed.Since SMAs are both solid-state refrigerants and thermal energy storage materials,hopefully the proposed concept can promote the development of more promising shape-memory alloy-based cold and hot thermal energy storage devices.

基于X-12-ARIMA与TRAMO/SEATS季节调整技术的销售量研究

首先说明了季节调整技术的发展及应用，并对X-12-ARIMA与TRAMO／SEATS方法进行了比较；其次应用x-12-ARIMA方法对苏宁电器的销售量进行季节调整，并改进了X-12-ARIMA方法中假日效应部分；最后应用改进的模型对苏宁电器的销售量进行了预测，均取得较好效果．

Design and Implementation of Library Seating Management System

The library seating management system is an important part of the library’s modern services. The system is based on the Spring and Spring Boot framework, and the system realizes a series of functions such as real-time query, reservation, and cancellation of seat resources, providing users with great convenience. With a simple operation, users can know the availability of seats in the library in real time and reserve them according to their needs. At the same time, the system also provides rich management functions, enabling administrators to easily configure and manage seat resources. The addition, deletion, modification and review of users, the generation of seats, the viewing of user usage records, and the addition or deletion of points for users’ usage can also be carried out. This not only improves the management efficiency, but also provides more scientific and accurate data support for the management of the library. The system not only optimizes the user experience, but also promotes the scientific management and efficient utilization of library resources, and provides strong support for the modern services of the library.

Design of Fully Automatic Specification Selection System for Resistance Welding Equipment

A system for fully automatic selection of welding specifications in resistance welding equipment has been developed to address the problem of workers frequently choosing the wrong specifications during manual welding of multiple parts on a single machine in automobile factories. The system incorporates an automatic recognition system for different workpiece materials using the added machine fixture,visual detection system for nuts and bolts,and secondary graphical confirmation to ensure the correctness of specification calling. This system achieves reliable,fully automatic selection of welding specifications in resistance welding equipment and has shown significant effects in improving welding quality for massproduced workpieces,while solving the problem of specification calling errors that can occur with traditional methods involving process charts and code adjustments. This system is particularly suitable for promoting applications in manual welding of multiple parts on a single machine in automobile factories,ensuring correct specification calling and welding quality.

Design of noise-reduction seats for high-speed trains

Noise-reduction seats have been successfully used in concert halls, theaters, and other places that reduce noise. In this study, a new noise-reduction seat design was proposed for high-speed trains, which have unique interior noise spectral characteristics. First, before the noisereduction seat models were fabricated, the parameters of high-performance sound-absorbing materials and perforated plates were selected by conducting a standing-wave tube test. The sound-absorption effects of the noisereduction seats and normal seats were investigated and compared in a reverberation chamber. Test results showed that, compared with normal seats, the noise-reduction seats obtained a significantly improved sound-absorption coefficient in the entire frequency band. Furthermore, the test results were used to establish a simulation model for calculation, and the simulation results proved that the noise-reduction seats substantially reduced the noise in an entire train car. Finally, the noise-reduction seats were fabricated and installed in a full train car of an actual highspeed train. The test results showed that, compared with the normal seats, the noise-reduction seats decreased the noise level at a standard point in the passenger car by 1.5 dB. Therefore, the noise-reduction seats are effective in noise reduction.

Guaranteed Seats for Women

Hainan Province has revised its villager committee election methods and procedures to ensure women’s participation in local government wang Saixiao was happy about being reelected as the village head. For six years, Wang, 34, has served as the head of Baotang Village, Lin’gao County of south China’s Hainan Province.

Numerical study on erosion behavior of sliding sleeve ball seat for hydraulic fracturing based on experimental data

The sleeve sealing ball seat is one of the important components in the multistage fracturing process of horizontal wells.The erosion and wear of the surface will decrease the sealing performance of the fracturing ball and the ball seat.This leads to pressure leakage during the fracturing process and fracturing failure.In this paper,combined with the actual ball seat materials and working conditions during the fracturing process,the erosion tests of ductile iron and tungsten carbide materials under different erosion speeds,angles,and mortar concentrations are carried out.Then the erosion test results were analyzed by mathematical fitting,and a set of erosion models suitable for sliding sleeve setting ball seat materials were innovatively established.For the first time,this paper combines the erosion model obtained from the experiment and the computational fluid dynamics(CFD)with Fluent software to simulate the erosion of the ball seat.Based on the simulation results,the morphology of the sliding sleeve seat ball after erosion is predicted.Through analysis of the test and simulation results,it is showed that the erosion rate of tungsten carbide material is lower and the wear resistance is better under the condition of small angle erosion.This research can offer a strong basis for fracturing site selection,surface treatment methods,and prediction of failure time of ball seats.

“营改增”的影响效应研究——以上海市的改革试点为例

本文选取上海市的交通运输业、通讯业和建筑业与地方财政收入相关的24个序列,利用TRAMO/SEATS方法对"营改增"结构性减税政策效应进行实证检验。结果表明,"营改增"对交通运输业发展的促进作用在短期来看有限,"营改增"对通讯业和建筑业的改革红利预期较低,说明本轮较窄范围内的试点改革对产业发展的影响效应还未充分显现。最后,以分析结论为基础,就今后"营改增"的实施路径提出相关的政策建议。

居民消费价格指数季节调整实证研究

文章首先对居民消费价格指数季节调整的原因、季节调整方法的发展过程和应用进行了说明,着重介绍了国际上最新流行的X-12-ARIMA和TRAMO/SEATS季节调整方法,然后用X-12-ARIMA方法对上海市居民消费价格指数序列进行季节调整、分析和预测,并结合使用TRAMO/SEATS方法解决中国与国外明显不同的春节假日因素的调整问题,最后提出我国季节调整面临的问题。

季节调整方法综述及比较

Seasonal adjustment has been widely used in statistic analyses.Nowadays,the research on seasonal adjustment methods mainly concentrates on X-11,X-12 etc in China,lacking the whole understanding of foreign seasonal adjustment methods,and the latest progress of seasonal adjustment methods has been less introduced.In this article,various seasonal adjustment methods were introduced,and a comparison of their characteristics and applications was made.It is helpful that statistical organizations can develop appropriate seasonal adjustment methods,concerning different kinds of data.

Real-Time CNN-Based Driver Distraction&Drowsiness Detection System

Nowadays days,the chief grounds of automobile accidents are driver fatigue and distractions.With the development of computer vision technology,a cutting-edge system has the potential to spot driver distractions or sleepiness and alert them,reducing accidents.This paper presents a novel approach to detecting driver tiredness based on eye and mouth movements and object identification that causes a distraction while operating a motor vehicle.Employing the facial landmarks that the camera picks up and sends to classify using a Convolutional Neural Network(CNN)any changes by focusing on the eyes and mouth zone,precision is achieved.One of the tasks that must be performed in the transit system is seat belt detection to lessen accidents caused by sudden stops or high-speed collisions with other cars.A method is put forth to use convolution neural networks to determine whether the motorist is wearing a seat belt when a driver is sleepy,preoccupied,or not wearing their seat belt,this system alerts them with an alarm,and if they don’t wake up by a predetermined time of 3 s threshold,an automatic message is sent to law enforcement agencies.The suggested CNN-based model exhibits greater accuracy with 97%.It can be utilized to develop a system that detects driver attention or sleeps in real-time.

盐城麋鹿生态旅游区游客变化特征及预测

生态旅游区的发展受到诸多确定性因素和随机性因素的共同作用,并反映于旅游区游客观测序列。通过构建游客序列分析框架,提出了游客序列分析的理论模型。并以江苏盐城麋鹿生态旅游区为例,集成多种数学方法,进行了游客序列的分解、调整和综合预测的实证分析。运用Tramo/Seats方法进行季节调整分析可有效提取时间序列各组分,从而获得了不同尺度的作用模式,所获得的去噪序列为预测研究提供了基础资料。基于ARIMA模型、Winter加法模型、Winter乘法模型和Tramo/Seats模型的综合预测表明,麋鹿生态旅游区未来两年年平均新增游客数量在1.95-3.14万人次之间。各方法预测结果间的差异与其建模思路及实现方法有关,因此集成多种方法进行预测,并进行对比分析,有助于获得对游客波动变化更为全面的认识,同时所提供的多种可能预测方案,可为生态旅游区容量控制、旅游环境资源的保护与开发及旅游区的管理决策提供参考依据。

居民消费价格指数的季节调整及短期预测

文章首先论述了季节调整方法的发展过程;然后把居民消费价格指数的同比数据转换为定基比数据,运用国际上最新流行的X-12-ARIMA程序对我国居民消费价格指数时间序列进行季节调整;再运用TRAMO/SEATS方法剔除中国特有的春节假日因素;最后对CPI进行短期预测,得出了我国的通货膨胀可能还会持续一段时间的结论。

基于ARIMA模型的春节因素调整方法研究

目的研究基于ARIMA模型的春节因素调整方法。方法构建通用的春节因素变量,将其作为回归变量纳入季节性ARIMA回归模型(regARIMA或TRAMO),采用AIC或BIC对模型的效果进行判断,确定最优模型。采用广义最小二乘法或最大似然法进行参数估计,并根据估计出的回归系数计算春节因素的影响程度。通过实例分析对上述方法进行实证。结果实例分析表明,引入春节因素变量后的季节调整方法能有效地消除春节因素对时间序列的影响,并能定量分析春节因素的影响程度。结论构建的春节因素变量具有较好的适用性,基于ARIMA模型的春节因素调整方法能有效地运用于时间序列的季节调整,为分析春节因素的影响提供了一种新的方法。