AAMI/ANSI ES60601-1:2005/A1:2012(通标3.1版)中美国国家差异性要求浅析

据市场调查公司Espicom Business Intelligence统计数据,2012年美国的医疗器械市场额估计为1204亿美元,是世界上最大的,对于我国医用电气设备制造商有着至关重要的地位。2013年6月30日以后,准备在美国市场新注册的医用电气产品必须符合AAMI/ANSI ES60601-1:2005/A1:2012(修改采用IEC60601-1:2005+A1:2012)的要求。为此,本文针对该标准中美国国家差异要求做了较为详尽的分析。

AAMI/ANSI ES60601-1:2005/A1:2012(通标3.1版)中美国国家差异性要求浅析

据市场调查公司Espicom Business Intelligence统计数据,2012年美国的医疗器械市场额估计为1204亿美元,是世界上最大的,对于我国医用电气设备制造商有着至关重要的地位。2013年6月30日以后,准备在美国市场新注册的医用电气产品必须符合AAMI/ANSI ES60601-1:2005/A1:2012(修改采用IEC60601-1:2005+A1:2012)的要求。本文对该标准中美国国家差异要求做了较为详尽的分析。

通标标准技术服务有限公司向全球客户提供无与伦比的服务

成为世界上最具竞争力和生产力的服务机构,一直是SGS的目标。1991年,SGS通标标准技术服务有限公司(以下简称“SGS通标”)在中国成立,致力于在擅长的检验、鉴定、测试和认证服务领域不断改进、力臻完美,始终如一地向全球客户提供无与伦比的服务。

Traffic Sign Detection Model Based on Improved RT-DETR

The correct identification of traffic signs plays an important role in automatic driving technology and road safety driving.Therefore,to address the problems of misdetection and omission in traffic sign detection due to the variety of sign types,significant size differences and complex background information,an improved traffic sign detection model for RT-DETR was proposed in this study.Firstly,the HiLo attention mechanism was added to the Attention-based Intra-scale Feature Interaction,which further enhanced the feature extraction capability of the network and improved the detection efficiency on high-resolution images.Secondly,the CAFMFusion feature fusion mechanism was designed,which enabled the network to pay attention to the features in different regions in each channel.Based on this,the model could better capture the remote dependencies and neighborhood feature correlation,improving the feature fusion capability of the model.Finally,the MPDIoU was used as the loss function of the improved model to achieve faster convergence and more accurate regression results.The experimental results on the TT100k-2021 traffic sign dataset showed that the improved model achieves the performance with a precision value of 90.2%,recall value of 88.1%and mAP@0.5 value of 91.6%,which are 4.6%,5.8%,and 4.4%better than the original RT-DETR model respectively.The model effectively improves the problem of poor traffic sign detection and has greater practical value.

高温固态填料除氨技术在水泥厂烟气超低排放CEMS中的应用研究

随着水泥行业超低排放改造升级的持续推进,NO_(x)排放限值逐渐降低,脱硝剂的过量投加造成了突出的氨逃逸问题。逃逸氨除了直接贡献PM2.5并造成大气环境污染外,还对污染源废气在线监测系统(CEMS)造成了很大的负面影响,尤其是造成了标气通全程的T_(90)示值误差及响应时间超标。研究并测试了探头处滴加液态磷酸和高温固态填料除氨两种CEMS除氨技术,结果表明高温固态填料除氨技术的除氨效果良好、运行稳定、运维工作量低,彻底解决了SO_(2)标气通全程时监测数据超标的问题,为企业自证清白提供依据,并保证了CEMS监测数据的“真、准、全”。

节能改善效果有了准确评价

2009年3月24日,全球领先的第三方检验、鉴定、测试及认证公司SGS集团在中国的合资公司——SGS-CSTC通标标准技术服务有限公司(以下简称SGS通标公司)宣布,SGS目前已经成为国内首家,也是唯一一家在中国获得国际能效组织(以下简称EVO)授权的代表机构,准许在中国(包括香港、澳门地区)使用EVO的名义和相关资料,进行国际能效检测与确认规程(以下简称IPMVP)的推广。

Traffic sign recognition algorithm based on shape signature and dual-tree complex wavelet transform

A novel traffic sign recognition system is presented in this work. Firstly, the color segmentation and shape classifier based on signature feature of region are used to detect traffic signs in input video sequences. Secondly, traffic sign color-image is preprocessed with gray scaling, and normalized to 64×64 size. Then, image features could be obtained by four levels DT-CWT images. Thirdly, 2DICA and nearest neighbor classifier are united to recognize traffic signs. The whole recognition algorithm is implemented for classification of 50 categories of traffic signs and its recognition accuracy reaches 90%. Comparing image representation DT-CWT with the well-established image representation like template, Gabor, and 2DICA with feature selection techniques such as PCA, LPP, 2DPCA at the same time, the results show that combination method of DT-CWT and 2DICA is useful in traffic signs recognition. Experimental results indicate that the proposed algorithm is robust, effective and accurate.

Multi-objective evolutionary approach for UAV cruise route planning to collect traffic information

Unmanned aerial vehicle(UAV)was introduced as a novel traffic device to collect road traffic information and its cruise route planning problem was considered.Firstly,a multi-objective optimization model was proposed aiming at minimizing the total cruise distance and the number of UAVs used,which used UAV maximum cruise distance,the number of UAVs available and time window of each monitored target as constraints.Then,a novel multi-objective evolutionary algorithm was proposed.Next,a case study with three time window scenarios was implemented.The results show that both the total cruise distance and the number of UAVs used continue to increase with the time window constraint becoming narrower.Compared with the initial optimal solutions,the optimal total cruise distance and the number of UAVs used fall by an average of 30.93% and 31.74%,respectively.Finally,some concerns using UAV to collect road traffic information were discussed.

Reliability of Substation Protection System Based on IEC61850

Although the new technology of protection and automation system of substation based on IEC61850 standard has developed rapidly in China,reliability measures depending on this technology need to be further researched.By taking advantage of convenient information sharing,two kinds of new schemes,shared backup protection unit(SBPU)and signal backup(SB),have been proposed to solve the failure problem of protective devices and current/voltage transducers respectively,and the working principle of these two schemes are also described.Furthermore,the key technologies of on-line diagnosis of protective devices'failure and on-line status diagnosis of optical or electronic current/voltage transducers to realize the two schemes are proposed.

Assessment Index Structure of Mine Ventilation System and Application

Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the point of 8 aspects such as mine ventilation power, ventilation network, ventilation equipments, ventilation quality, ventilation monitoring, capacity of preventing and fighting disaster, ventilation consumption of power, and the capacity of ventila- tion system. A new assessment index system is put forward and has a good effect after being applied in coal mines.

Weight Based Channel Selection Towards 5G in the Unlicensed Spectrum

The growth of the wireless and mobile communication data traffic has brought severe challenges to the present telecommu- nication systems. To meet the ever-increasing mobile traffic demand in the next 5th generation （SG） communication systems, deploying 5G in the unlicensed spectrum （SG-U）, has been regarded as a promising technology. The Third Generation Partnership Project （3GPP） has specified the standardization of the Li- censed Assisted Access （LAA） and its extension enhanced LAA （eLAA）, to opportunistically transmit in the unlicensed spectrum. The LAA/eLAA systems share unlicensed spectrum resource with other networks, e.g., the Wi-Fi systems. In this article, we analyze the coexistence between the eLAA and the Wi-Fi systems in the unlicensed spectrum. We firstly establish the system model where the eLAA coexists with the Wi-Fi systems. Then, we theoretically derive and figure out the unfairness in the multi-channel occupancy rate between the eLAA and the Wi-Fi systems. After that, we propose a weight based channel selection method to improve the fairness of the coexistence. The numerical results demonstrate that by avoiding contentions and declining collisions, our method not only enhances the fairness, but also improves the overall unlicensed spectrum usage rate.

Energy-Efficient Target Channel Sequence Design for Spectrum Handoffs in Cognitive Radio Networks

Cognitive radio is considered as an efficient way to improve the spectrum efficiency. As one of its key technologies,spectrum handoff can guarantee the transmission continuity of secondary users(SUs). In this paper,we address a new and more generalized spectrum handoff problem in cognitive radio networks(CRNs),by considering simultaneously energy efficiency,multiple spectrum handoffs and multiple channels. Furthermore,effects of the primary users'(PUs')arrival and service rate on the target channel sequence selection are also considered. In order to obtain the energy-efficient target channel sequence,we firstly analyze the energy consumption and the number of delivered bits per hertz in the spectrum handoff process,and formulate a ratio-type energy efficiency optimization problem,which can be transformed into a parametric problem by utilizing fractional programming. Then,we propose an algorithm combining dynamic programming with bisection(DPB)algorithm to solve the energy efficiency optimization problem. Our simulation results verify that the designed target channel sequence has better performance than the existing algorithms in terms of energy efficiency.

Relationship between speed and traffic accident and speed limit on freeway

To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation and accident rate per 100,000,000 vehicle kilometers by regression analysis. The model shows that the more discrete is the speed distribution, the higher is the accident rate, which provides theoretical gist for speed limit on freeway. It is suggested that speed limit should be set according to 85th percentile speed obtained by the relationship between 85th percentile speed and RCCs (curvature change rate of single circular curve), and different speed limits should be set for cars and trucks. Through analyzing spot speed data of eight freeways in China, regression models were established between 85th percentile speed and RCCs and 15th percentile speed and RCCs. Reasonable speed limit suggestion values are put forward through these models.

Handling Label Noise in Air Traffic Complexity Evaluation Based on Confident Learning and XGBoost

Air traffic complexity is a critical indicator for air traffic operation,and plays an important role in air traffic management(ATM),such as airspace reconfiguration,air traffic flow management and allocation of air traffic controllers(ATCos).Recently,many machine learning techniques have been used to evaluate air traffic complexity by constructing a mapping from complexity related factors to air traffic complexity labels.However,the low quality of complexity labels,which is named as label noise,has often been neglected and caused unsatisfactory performance in air traffic complexity evaluation.This paper aims at label noise in air traffic complexity samples,and proposes a confident learning and XGBoost-based approach to evaluate air traffic complexity under label noise.The confident learning process is applied to filter out noisy samples with various label probability distributions,and XGBoost is used to train a robust and high-performance air traffic complexity evaluation model on the different label noise filtered ratio datasets.Experiments are carried out on a real dataset from the Guangzhou airspace sector in China,and the results prove that the appropriate label noise removal strategy and XGBoost algorithm can effectively mitigate the label noise problem and achieve better performance in air traffic complexity evaluation.

A Fully Integrated 60GHz Four Channel CMOS Receiver with 7GHz Ultra-Wide Bandwidth for IEEE 802.11ad Standard

In this paper, a fully integrated CMOS receiver frontend for high-speed short range wireless applications centering at 60GHz millimeter wave （mmW） band is designed and implemented in 90nm CMOS technology. The 60GHz receiver is designed based on the super-heterodyne architecture consisting of a low noise amplifier （LNA） with inter-stage peaking technique, a single- balanced RF mixer, an IF amplifier, and a double-balanced I/Q down-conversion IF mixer. The proposed 60GHz receiver frontend derives from the sliding-IF structure and is designed with 7GHz ultra-wide bandwidth around 60GHz, supporting four 2.16GHz receiving channels from IEEE 802.1lad standard for next generation high speed Wi- Fi applications. Measured results show that the entire receiver achieves a peak gain of 12dB and an input 1-dB compression point of -14.SdBm, with a noise figure of lower than 7dB, while consumes a total DC current of only 60mA from a 1.2V voltage supply.

Traffic jam in signalized road network

Traffic jam in large signalized road network presents a complex nature.In order to reveal the jam characteristics,two indexes,SVS(speed of virtual signal) and VOS(velocity of spillover),were proposed respectively.SVS described the propagation of queue within a link while VOS reflected the spillover velocity of vehicle queue.Based on the two indexes,network jam simulation was carried out on a regular signalized road network.The simulation results show that:1) The propagation of traffic congestion on a signalized road network can be classified into two stages:virtual split driven stage and flow rate driven stage.The former stage is characterized by decreasing virtual split while the latter only depends on flow rate; 2) The jam propagation rate and direction are dependent on traffic demand distribution and other network parameters.The direction with higher demand gets more chance to be jammed.Our findings can serve as the basis of the prevention of the formation and propagation of network traffic jam.