Local dimming原理及在车载中的应用

Local dimming(局部调光)是一种低成本提升车载显示器对比度和清晰度的技术。在目前OLED技术尚无法突破严苛的汽车环境要求的状况下,局部调光是一种首选的成本和性能兼顾的技术。在满足汽车环境要求的同时,大幅提升了显示器的清晰度,提高了显示内容的辨识度,同时成本的上升也在合理范围内。它能给客户带来更好的体验,使驾驶更为安全。本文对它的工作原理以及如何应用进行了阐述,给读者提供了一种思路和方法来提升车载显示器的对比度。

Local dimming高亮节能恒流控制算法的研究与应用

介绍了local dimming(区域调光)技术对LED背光亮度及整机功率的影响,通过实验数据分析了PWM(脉冲宽度调制)调光控制方式和DC(直流)调光控制方式引起的亮度变化、功率损耗、器件温升等问题,并结合实际案例给出了具体的改善对策。通过实验及大批量的生产验证表明,提出的具有创新性的恒流动态幅值控制算法对LED背光亮度、整机能效、器件温升等都有极大改善,对local dimming恒流控制方案的设计具有重要的借鉴和参考意义。

Local dimming效果与分区数的关系研究

Local dimming(区域背光调控)是改善被动发光的液晶显示器性能的重要技术。采用一套自主开发的仿真算法,在充分验证其准确性后,对液晶显示器的对比度和光晕指数随分区数的变化关系进行了计算仿真与分析,最终形成背光分区数设计指引。分析结果表明:对比度随分区数的增加而增加,RTINGS棋盘格图片最大价值点(导数为1的点)为300分区,要达到足够接近最大对比度,则需要1600分区左右;背光行列分区数为8的倍数时有更好的对比度体现;光晕指数与对比度随分区数变化的趋势相似,RTINGS十字架图片最大价值点(导数为1)为500分区。

一种基于STM32的Local Dimming检测工装

本文针对目前Local Dimming没有专门的检验提出了一种基于STM32的Local Dimming检测工装。此工装兼容多种Local Dimming背光模组控制方案,使用STM32F103RBT6芯片配合简单的外部电路和8421型按键开关实现了Local Dimming背光模组的检测,具有结构简单、性能稳定、成本低廉等特点。

The Implications of Fluorescent Lamp Electronic Ballast Dimming —An Experimental Study

In recent years, fluorescent lamp dimming controls are an integral part of daylight artificial light integrated schemes intended for realization of energy savings. However, dimming, like any lighting option, presents its own particular challenges and potential tradeoffs. In view of this, the present manuscript depicts the preliminary work progress carried out to arrive at a comprehensive idea on dimming implications on key factors: electrical characteristics, photometric distributions of lighting systems and influence on quality as well as quantity of visual environment. The objective is to experimentally establish the acceptable range of dimming control voltage that would satisfy both electrical and photometric performance of luminaire. The vital part of the paper is devoted towards presentation of measurement results. For the experimental analysis, three representative samples of different commercial analog 1-10VDC electronic dimmable ballasts and fluorescent fixtures are compared and evaluated over their control voltage dimming range.

Design of a Novel Multi-Mode LED Dimming and Color Control System

Aiming at the needs of different lighting applications, combined with the characteristics of LED dimming and color control, and using MSP430 digital control technology, a novel LED intelligent dimming and color control system was designed. The system integrated Bluetooth remote, human infrared sensor, voice/gesture control and other control modes, which could achieve LED multi-mode dimming and color intelligent control. System hardware and software were designed to develop a prototype to experimental verification. The designed method proposes new ideas and information for LED control.

Integrated Off-Line Ballast for High Brightness LEDs with Dimming Capability

This paper presents an off-line integrated full ballast to supply a 35W assembly of Power LEDs. The proposed solution integrates an input PFC stage (a flyback converter operating in DCM) and a DC-DC output converter (a buck converter) into a single switch power stage, operating with peak current control. As it will be shown, this control scheme maintains the current through the load constant, regardless of the instantaneous value of the DC link voltage. This issue allows the use of a small capacitor for the DC link, which enhances the overall system reliability. The complete ballast has full dimming capability, and all the analysis and design steps are presented, thus ensuring the fulfilling of the existing regulations. The novelty of the final solution comes from the simplicity and robustness of the control scheme in an integrated compact single-switch power stage. A final prototype of the ballast has been built and tested, and experimental results are shown in the last part of the paper. Finally, conclusions and future developments are shown.

Statistical study on the relationship between halo CME and coronal dimming

The data from SOHO/EIT and SOHO/LASCO observations are used to determine the relationship between coronal dimming and full halo CME (coronal mass ejection). The events of full halo CME examined in this study were observed by LASCO co-ronagraphs and taken from the CD AW CME catalog from 1996 to 2008. Dimming events are identified by using difference images taken by EIT at the 195 A passband. We found strong relationship between full halo CMEs and the coronal dimming events, with up to 93.3% of the front-side halo CMEs associated with the EIT 195 A dimming events. Full halo CMEs that show no clear signatures of dimming usually have lower sky plane velocities (<700 km/s) compared to the mean velocity of CMEs associated with dimming.

A Novel Sensing Imaging Equipment Under Extremely Dim Light for Blast Furnace Burden Surface:Starlight High-Temperature Industrial Endoscope

Blast furnace(BF)burden surface contains the most abundant,intuitive and credible smelting information and acquiring high-definition and high-brightness optical images of which is essential to realize precise material charging control,optimize gas flow distribution and improve ironmaking efficiency.It has been challengeable to obtain high-quality optical burden surface images under high-temperature,high-dust,and extremelydim(less than 0.001 Lux)environment.Based on a novel endoscopic sensing detection idea,a reverse telephoto structure starlight imaging system with large field of view and large aperture is designed.Combined with a water-air dual cooling intelligent self-maintenance protection device and the imaging system,a starlight high-temperature industrial endoscope is developed to obtain clear optical burden surface images stably under the harsh environment.Based on an endoscope imaging area model,a material flow trajectory model and a gas-dust coupling distribution model,an optimal installation position and posture configuration method for the endoscope is proposed,which maximizes the effective imaging area and ensures large-area,safe and stable imaging of the device in a confined space.Industrial experiments and applications indicate that the proposed method obtains clear and reliable large-area optical burden surface images and reveals new BF conditions,providing key data support for green iron smelting.

Dimming control scheme based on hybrid LACO-SCFDM for visible light communications

This paper proposes a hybrid layered asymmetrically clipped optical(HLACO) single-carrier frequency-division multiplexing(SCFDM) scheme for dimmable visible light communication. It designs a signal structure that combines layered asymmetrically clipped optical(LACO)-SCFDM and negative LACO-SCFDM in proportion for improving the inherent weaknesses of orthogonal frequency-division multiplexing(OFDM)-based dimmable schemes and further enhancing the system performance. Compared to the HLACO-OFDM-based dimming scheme, it obtains a lower bit error ratio and enables efficient communication over broader dimming range. Its spectral efficiency realizes 2.875 bit·s^(-1)·Hz^(-1) within the dimming range of 30%–70%, and the attainable average spectral efficiency gains exceed at least 19.21% compared to other traditional dimmable schemes.

基于激光点云批量化自动滤波分类技术研究

通过基于VC++6.0,OPENCV和GDAL/OGR自主开发数据处理软件来实现,直接读取点云数据的统计指标信息,如点密度、点云坐标最小值和最大值、标准差,根据统计的指标信息设置最大最小高程,进行高程异常滤波处理,自动滤除最大最小高程之外的点云,通过均值方差迭代滤波参数设置进行批量均值方差迭代高程异常滤波,进而可以进行批量粗分类,将植被、道路、房屋、水体等非地面点和地面点提取出来,实现激光点云的高效滤波并生成DEM。

基于Dim env-YOLO算法的昏暗场景车辆多目标检测

低照度的夜间路况复杂,现有夜间车辆识别相关研究较少,且存在识别方法实时性不高、过多占用硬件资源等不足。针对夜间场景车辆识别干扰因素较多、检测效果不佳的问题,提出一种基于YOLOv4的Dim env-YOLO车辆目标检测算法。利用MobileNetV3网络替换原始YOLOv4中的主干网络,以减少模型参数量。在改进的YOLOv4模型上使用图像暗光增强方法,提高车辆目标在昏暗环境中的可识别性。在此基础上,引入注意力机制加强特征信息选择,同时利用深度可分离卷积降低网络计算量。选取北京部分道路的夜间场景图片自制数据集并进行实验验证,结果表明,在存在高斯噪声、模糊扰动、雨雾夜晚等情况下,Dim env-YOLO算法的测试结果较稳定,对于照度低于30 lx的昏暗条件下的车流,其检测mAP值达到90.49%,对于最常见的轿车类别,mAP值达到96%以上,优于Faster-RCNN、YOLOv3、YOLOv4等网络模型在昏暗光照条件下的检测效果。

CD4阴性CD8弱阳性的罕见表型T幼稚淋巴细胞白血病伴肝转移1例

目的为临床医生了解和诊断罕见表型T幼稚淋巴细胞白血病提供参考依据。方法纳入1例罕见表型T幼稚淋巴细胞白血病,分析患者的临床病史、实验室检查结果及鉴别诊断,制订罕见表型T幼稚淋巴细胞白血病的诊断思路。结果患者全身多部位淋巴结肿大、肝脾肿大;外周血提示白细胞计数为101.8×10^(9)/L,淋巴细胞计数为81.9×10^(9)L;骨髓细胞形态学查见异常淋巴细胞约88.5%;骨髓流式细胞术检测和肝脏穿刺病理结果均查见CD4阴性/CD8弱阳性(CD4^(-)/CD8^(dim))异常幼稚T淋巴细胞。综合分析支持CD4^(-)/CD8^(dim)的罕见表型T幼稚淋巴细胞白血病诊断。结论认识和了解罕见表型白血病的特征,有利于临床医生更高效、准确的诊断。

2023年第6期导读

随着天津建造分公司业务的不断发展,公司在生产过程中面临着人工管理计划颗粒度比较粗,生产进度反馈不及时等问题。基于上述原因,天津建造分公司建立了一套完整的面向建造板块的设计、采办、施工信息一体化信息管控(DIMS)系统,并通过APS排程解决生产过程中多工序、多资源的优化调度问题。[DIMS系统与APS排程在海洋石油工程股份有限公司中应用研究]一文浅谈了临港智能化基地DIMS系统的各个模块及功能,详细介绍了APS排程在生产管理模块中的流程及应用,通过APS排程在天津建造分公司的实现,对天津建造分公司的现场智能化管理提升工作产生了非常显著的作用。

核电站实时风险管理系统部件重要度计算方法研究

在PSA中,重要度分析都是基于基本事件进行计算的,而在核电站实时风险管理系统Risk Moni- tor中,往往计算的是部件重要度,通常1个部件一般包括1个或多个基本事件,因而不能简单按照求解基本事件重要度的方法来进行。目前虽然有一些关于部件重要度的计算方法,但是均未得到广泛的认可。本文在分析了常用部件重要度计算方法基础上,引入了一种新的部件重要度即部件概率微分重要度CPDIM,该重要度主要基于微分重要度DIM,利用DIM的1个明显特性即可加性,来求解部件的概率微分重要度。通过实例证明该重要度可作为核电站关键风险部件选择的重要度依据。

我国科技成果转化效率的DIM分析

借用D IM的分析方法,从科技成果转化决策者、信息因素、动力机制等三个方面分析探讨了我国科技成果转化低效率的原因,并进一步提出了相应的对策。

连续化工生产过程CIPS的理论与实践

针对连续化工生产过程的具体特点，对它们的ＣＩＰＳ进行了一些研究，给出了相应的功能结构模型，阐明了严格在线模拟技术及在此基础上的信息综合集成问题，最后对ＣＩＰＳ的开发方法和建设策略作了一些探讨．

在VC环境下用Direct3 DIM Framework开发三维动画

介绍了DirectX的基本概念及Direct3DIMFramework的基本程序结构 ,通过一个例子程序 ,详细叙述了如何在VC +

GPS网络RTK流动站的电离层误差改正分析

结合实际数据,分析基准站双差电离层延迟与基线长度和时间的关系,并对各种内插算法进行比较。比较结果认为,LIM法的内插效果最好,基线长度小于100km时,内插精度优于3cm。

原因不明复发性流产患者蜕膜CD4^+CD25^+CD127^(dim/-) Treg细胞的表达频率和功能研究

目的:探讨原因不明复发性流产(URSA)患者母胎界面免疫耐受环境的变化。方法:留取URSA患者21例(URSA组)和30例正常早孕人流妇女(对照组)蜕膜组织,制备成单个核细胞悬液,流式细胞术分析CD4+CD25+CD127dim/-Treg细胞的表达频率;取两组蜕膜单个核细胞悬液各5例,用免疫磁珠分离法分离出CD4+CD25+CD127dim/-Treg细胞,流式细胞术分析CD4+CD25+CD127dim/-Treg细胞内IL-10和TGF-β的表达水平;体外增殖抑制试验分别检测用抗IL-10抗体和抗TGF-β抗体处理的CD4+CD25+CD127dim/-Treg细胞,和未用抗体处理的CD4+CD25+CD127dim/-Treg细胞对自身效应T细胞增殖的抑制作用。结果:URSA组蜕膜CD4+CD25+CD127dim/-Treg细胞的表达频率明显低于对照组(P=0.005);URSA组蜕膜CD4+CD25+CD127dim/-Treg细胞内IL-10和TGF-β表达频率均较对照组明显降低(P=0.04,P=0.01);URSA组CD4+CD25+CD127dim/-Treg细胞对自体效应性T细胞的增殖抑制作用显著低于对照组(P<0.05),且抗IL-10抗体和抗TGF-β抗体可部分阻断蜕膜CD4+CD25+CD127dim/-Treg细胞的免疫抑制功能(P均<0.05)。结论:URSA患者蜕膜CD4+CD25+CD127dim/-Treg细胞不仅表达频率降低,而且免疫抑制功能也减弱,且这种免疫抑制功能的减弱主要受IL-10和TGF-β介导,揭示CD4+CD25+CD127dim/-Treg细胞对URSA患者蜕膜局部免疫耐受环境产生影响。