智能化小区中的家庭安全管理系统(收端)

随着科学技术的发展和普及 ,智能化住宅已开始在国内出现 ,国际上则以相当快的速度发展。本文仅讨论其中家庭安全防范的实现手段 ,并提供设计原理图供参考。

OFDM系统收端仿真

本文概述了正交频分复用(OFDM)系统的基本原理和数学模型,然后在具有白噪声的信道中进行了仿真,从仿真中可以看出OFDM系统有较好的系统性能。

清除客户端收发文库旧文件小秘笈

人行公文传输系统几年来在客户端收文库和发文库积累了大量旧文件.这些旧文件大多已经没有继续保存的价值,但利用常规的办法又不能予以清除.为达到既有效清除废旧文件,又能保存有用文件的目的,笔者经过摸索,总结出一套利用归档库解决问题的方法.

超声引导下远端收肌管阻滞在胫骨骨折患者术后镇痛中的应用效果观察

目的:观察超声引导下远端收肌管阻滞在胫骨骨折患者术后镇痛中的应用效果。方法:选择2019年8月-2021年12月大理市第一人民医院收治的80例胫骨骨折患者作为研究对象,随机分为研究组与对照组,各40例。研究组实施超声引导下远端收肌管阻滞,对照组实施静脉病人自控镇痛。比较两组住院时间、自控镇痛按压次数、不良反应发生率以及镇痛后1 h、12 h、24 h的视觉模拟评分法(VAS)评分。结果:研究组住院时间短于对照组,自控镇痛按压次数少于对照组,差异有统计学意义(P<0.05)。研究组不良反应发生率低于对照组,差异有统计学意义(P<0.05)。镇痛后1 h、12 h、24 h,研究组VAS评分均低于对照组,差异有统计学意义(P<0.05)。结论:超声引导下远端收肌管阻滞对胫骨骨折术后患者的镇痛效果较好,可缩短患者住院时间,减少不良反应的发生,提高患者围术期的舒适度。

内收肌腱断端固定治疗髌脱位16例临床分析

目的 :探讨急慢性髌骨不稳定患者采用重建方法的疗效。方法 :对急性髌脱位 ,采取将断裂的内侧髌韧带重新复位 ,原位缝合及长收肌断端固定到髌骨内侧缘。对慢性髌骨不稳定者 ,主要采取紧缩内侧髌韧带及支持带 ,将长收肌断端固定到髌骨内侧缘 ,并将髌韧带内移以改变伸膝装置的力线[1] 。结果 :对髌脱位采取重建方法手术治疗 16例 ,14例优 ,2例良。结论 :采用内收肌腱断端固定治疗髌脱位效果较满意。

内热式回转窑加料端收灰系统的设计改造

经过不断改进,目前内加热回转窑焙烧钼精矿的工艺已由燃煤加热改为天然气加热,再改为“无碳焙烧”。焙烧生产灵活,产量稳定,大大节约了能源。在焙烧生产过程中,回转窑进料端物料容易泄漏,收集不方便,粉尘飞扬,造成金属钼损失,存在环境风险。因此,合理布置回转窑给料端设施,对解决给料端漏料造成的漏尘问题具有重要意义。基于此,本篇文章对内热式回转窑加料端收灰系统的设计改造进行研究,以供参考。

对OTU提供1+1保护的实现

为保证光分插复用(OADM)节点设备工作的可靠性,需在设备中采用1+1或1:n光通道保护技术。文章采用了FPGA、光开关和单片机配合实现对OTU提供1+1保护功能的光倒换单元盘(OPSW)的方案,使其具有成本低和研发周期短的优点。

可编程误码仪的设计与实现

误码仪(biterrorratetester,BERT)是数字通信系统性能测试的重要仪器。本文设计的可编程误码仪主要由发端设备和收端设备两部分构成:发端设备主要完成序列产生和时钟产生;收端设备主要完成序列同步和序列比对。误码仪选用了单片机和FPGA作为核心器件,提高它的再升级和可移植能力。本文设计的可编程误码仪具有使用简单、测试内容丰富、误码测试结果显示直观、准确等特点。

A 12-Channel,30Gb/s,0.18μm CMOS Front-End Amplifier for Parallel Optic-Fiber Receivers

This paper presents a 12-channel,30Gb/s front-end amplifier realized in standard 0.18μm CMOS technology for parallel optlc-fiber receivers. In order to overcome the problem of inadequate bandwidth caused by the large parasitical capacitor of CMOS photo-detectors,a regulated-cascode structure and noise optimization are used in the design of the transimpedance amplifier. The experimental results indicate that, with a parasitical capacitance of 2pF,a single channel is able to work at bite rates of up to 2.5Gb/s,and a clear eye diagram is obtained with a 0. 8mVpp input. Furthermore, an isolation structure combined with a p^＋ guard.ring （PGR）, an n^＋ guard-ring （NGR）,and a deep-n-well （DNW） for parallel amplifier is also presented. Taking this combined structure, the crosstalk and the substrate noise coupling have been effectively reduced. Compared with the isolation of PGR or PGR ＋ NGR,the measured results show that the isolation degree of this structure is improved by 29.2 and 8. ldB at 1GHz,and by 8. 1 and 2. 5dB at 2GHz,respectively. With a 1.8V supply,each channel of the front-end amplifier consumes a DC power of 85mW,and the total power consumption of 12 channels is about 1W.

基于卫星链路的远程管理控制系统的设计

利用卫星网络的TCP/IP技术 ,设计一种高度自动化的遥感地面接收站的远程管理控制系统 ,并讨论了网内数据传送的控制流程。

Energy-efficient data transmission with non-ideal circuit power for downlink cellular networks

The downlink energy-efficient transmission schedule with non-ideal circuit power over Wreless networks involving a single transmitter and multiple receivers was investigated. According to the special structure of the problem, a novel algorithm called OOSCPMR （the optimal offine scheduling with non-ideal circuit power for multi-receivers） is proposed, and the optimal offine solutions to optimize the energy- efficient transmission policy are found. The packets to be transmitted can be divided into two types where one type of packet is determined to be transmitted using the enrgy- efficient tansmission time, and the other type of packet is determined by the ID moveright algorithm. Finally, an energy-efficient online schedule is developed based on te proposed OOSCPMR algoriAm. Simulation results show that the optima offline transmission schedule provides te lower bound performance for the online tansmission schedule. The proposed optimal offline and online policy is more energy efficient than the existing schemes tat assume ideal circuit power.

Trajectory tracking and obstacle avoidance method for robots based on fast terminal sliding mode

For accurate trajectory tracking and obstacle avoidance in finite time of a nonholonomic mobile robot,a trajectory tracking controller based on global fast terminal sliding mode method is proposed,which has the advantages of chattering-free and adjustable convergence time.First of all,the kinematics model of the robot is established in mobile carrier coordinates.Secondly,the global structure including terminal attractor and exponential convergence of the fast terminal sliding mode trajectory tracking controller is proved by Lyapunov stability theory,ensuring that the trajectory and heading angle tracking error converges to a smaller zero range in finite time.Finally,the artificial potential field obstacle avoidance method is introduced to make the robot not only track the reference trajectory strictly,but also avoid the obstacles.The simulation results show that the proposed method can achieve a stable tracking control in finite time for a given reference trajectory.

Study of Signal Processing Algorithm in the Receiving End of Through-the-Earth Communications of Elastic Wave

In the research of elastic wave signal detection algorithm, a method based on adaptive wavelet analysis and segmentation threshold processing of the channel noise removal methods is suggested to overcome the effect of noise, which is prcduced by absorption loss, scattering loss, reflection loss and multi-path effect during the elastic wave in the transmission undelgroound. The method helps to realize extraction and recovery of weak signal of elastic wave from the multi-path channel, and simulation study is carded out about wavelet de-noising effects of the elastic wave and obtained satisfactory results.

内侧柱植骨结合PHILOS钢板治疗老年肱骨近端内收型骨折的体会

目的探讨内侧柱植骨结合PHILOS钢板内固定治疗老年肱骨近端内收型骨折的治疗效果。方法对2013年8月至2016年12月舟山顾鹤传骨伤医院创伤关节科治疗的26例老年肱骨近端内收型骨折患者进行回顾性分析,其中男性11例,女性15例;年龄61～89岁,平均(75±14)岁。均因外伤至肩部疼痛入院,X线片示肱骨近端骨折。其中植骨组14例,未植骨组12例。14例植骨组采用内侧柱植骨结合PHILOS钢板内固定治疗,12例未植骨,单纯使用PHILOS钢板内固定治疗。术后定期门诊复查并摄X线片,通过肩关节功能Constant-Murley评分、手术时间、骨性愈合时间以及骨性愈合时颈干角丢失角度等相关指标综合判断治疗效果。结果所有患者末次随访时骨折均骨性愈合,植骨组肩关节功能Constant-Murley评分优良率高于未植骨组[13(92.86%) vs 9(75%),P<0.05]、植骨组骨性愈合时间短于未植骨组[(10.05±3.04) vs (13.03±2.85),P<0.05]、植骨组骨性愈合时颈干角丢失角度低于未植骨组[(5.12±4.51) vs (11.63±7.04),P<0.05],差异有统计学意义(P<0.05)。两组手术时间差异无统计学意义(P>0.05)。结论相对于不植骨,内侧柱植骨结合PHILOS钢板治疗老年肱骨近端内收型骨折可取得更满意的临床疗效。

A 10Gb/s combined equalizer in 0.18μm CMOS technology for backplane communication

This paper presents a lOGb/s highspeed equalizer as the frontend of a receiver for backplane communication. The equalizer combines an analog equalizer and a twotap decisionfeedback equal izer in a halfrate structure to reduce the intersymbolinterference （ISI） of the communication chan nel. By employing inductive peaking technique for the highfrequency boost circuit, the bandwidth and the boost of the analog equalizer are improved. The decisionfeedback equalizer optimizes the size of the CMLbased circuit such as D flipflops （DFF） and multiplex （MUX）, shortening the feedback path delay and speeding up the operation considerably. Designed in the 0. 181μm CMOS technology, the equalizer delivers 10Gb/s data over 18in FR4 trace with 28dB loss while drawing 27mW from a 1.8V supply. The overall chip area including pads is 0. 6 -0.7mm2.

Adaptive terminal sliding mode control for high-order nonlinear dynamic systems

An adaptive terminal sliding mode control (SMC) technique is proposed to deal with the tracking problem for a class of high-order nonlinear dynamic systems. It is shown that a function augmented sliding hyperplane can be used to develop a new terminal sliding mode for high-order nonlinear systems. A terminal SMC controller based on Lyapunov theory is designed to force the state variables of the closed-loop system to reach and remain on the terminal sliding mode, so that the output tracking error then converges to zero in finite time which can be set arbitrarily. An adaptive mechanism is introduced to estimate the unknown parameters of the upper bounds of system uncertainties. The estimates are then used as controller parameters so that the effects of uncertain dynamics can be eliminated. It is also shown that the stability of the closed-loop system can be guaranteed with the proposed control strategy. The simulation of a numerical example is provided to show the effectiveness of the new method.

Environmental Impact of Climate Change on Agricultural Production in Ekiti State, Nigeria

Climate change will impact agriculture and food production around the world due to the effects of elevated CO2 in the atmosphere, higher temperature, altered precipitation and transpiration regimes, increased frequency of extreme events, and modified weed, pest and pathogen pressure. Data of this study were collected from primary and secondary sources. Primary sources of data were collected using two sets of structured questionnaires. A total number of three hundred （300） questionnaires were administered on categories of respondents in this study. Results of this study revealed that food crops are the major crops cultivated in the study area, and the effects of climate change on agricultural production results in soil loss, plant nutrient loss, textural change, increase in pest and diseases and poor yield germination etc.. This study therefore recommended that cover trees should be planted, which will provide shade and reduce heat, due to climate change and the preservation of underground water.

Factors Determining the Development of Non-cash Payments in Rural Areas in Poland

This article aims at characterization and assessment of the financial behaviors of rural dwellers on non-cash payment markets and identification of factors determining the intensity of using individual methods of payment by the inhabitants of rural areas. The main source of data used for analysis and inference was information originating from the authors＇ own investigations conducted in 2013 on a group of 500 rural households and on a group of 150 trade and service points operating in non-urbanized areas. This work made use of statistical summary measures and Z2 independence test. According to the results of the conducted studies, forms of payment used by rural dwellers depend on many variables, of demographic, economic, and psychological character. Cash payments are more frequently used by persons possessing vocational or secondary education, elderly people, old-age pensioners, annuitants, or households with lower incomes. Also, persons who do not trust financial institutions or do not perceive benefits resulting from the use of non-cash instruments prefer cash. It is a group of households which require urgent educational activities in the area of non-cash payment instruments. A significant barrier to using non-cash payment instruments by rural dwellers was a limited access to non-cash channels. It is connected in the first place with a poorer development of financial infrastructure in rural areas （banks or cash points）, insufficient Internet access conditioning a possibility to use electronic banking points, and also a worse development of credit card acceptance network. As has been demonstrated by the results of conducted studies, the main reason for a lack of point of sale （POS） terminals in retail and service-providing points operating in rural areas, in the opinion of their owners, is the very high interchange fee （50% indications）, which under Polish conditions is one of the highest in the European Union （EU）.

Studies on Thermal Contraction of Crankshaft Bearings under Extreme Low Temperatures

This paper presents how the contractions of the main components of a V6 motor with low engine displacement are determined for the cold-start phase under extreme low temperature. Internal combustion engine components have complex geometries and to obtain the thermal contractions, in the research, used the method of finite element analysis. The phenomena of thermal contractions are studied for the cold-start situations at extreme low temperature, knowing that the cold-start phase of an internal combustion engine is the main factor that determines moving rotational and translational parts wear life. Checking the proper choice of clearance is particularly important, as the use of inappropriate values of it leads to rapid operation destruction of the engine group components. The results obtained for the thermal clearances of crankshaft bearings are mathematically modeled and the relations can be used for calculating the clearances. The mathematical models are also useful for implementing in different software tools.