An electronic travel guide for visually impaired – vehicle board recognition system through computer vision techniques

Abstract

Purpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.

Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.

Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.

Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.

• Implications for rehabilitation

• This proposed system will help the visually impaired to

• ensure secure navigation

• be independent of the others

• develop self confidence.

• overcome the training, affordability of wearable/ handheld devices.

     

基于组合不变量配准的数字减影算法

在现代医学中，DSA是X光片血管可视化技术的重要组成部分之一，在DSA中图像配准对消除运动伪影起着关键作用。运用一种基于组合不变量的相似度测量的模板匹配和弹性TPS算法配准减影方法，并根据实际情况有所改进。经过试验证明这种方法可以自动并有效地去除运动伪影，其速度和血管图像质量均比较理想。     

Simple,rapid, and accurate determination of deletion mutations by automated dna sequencing of heteroduplex fragments of the adenomatous polyposis coli (APC) gene generated by PCR amplification

Germline mutations in patients with familial adenomatous polyposis were analyzed by polymerase chain reaction (PCR) amplification of the adenomatous polyposis coli gene. PCR products from heterozygous patients for deletions of this gene formed four distinct bands on polyacrylamide gel electrophoresis. The four fragments were subsequently purified and both strands of each fragment were directly sequenced, using an automated DNA sequencer and the same primers as those for PCR amplification. It was found that the two slower migrating fragments were “bulge” heteroduplexes, while the other two were homoduplexes made up of two wild-type strands and two deletion-mutant strands, respectively. The sites of deletions in the adenomatous polyposis coli gene could be exactly determined in four of the five patients. In an attempt to identify deletion-carriers of familial adenomatous polyposis at the presymptomatic stage, a family study was also carried out, and two children were found to have the same mutations as those of their affected parents. The direct sequencing of heteroduplex fragments generated during PCR amplification is a potentially useful method for detecting mutations of not only the adenomatous polyposis coli gene but also many other genes of genetic diseases. © 1993 Wiley-Liss, Inc.     

室性早搏的快速检测方法

提出一种利用相关性和RR间期比相结合的快速室性早搏的检测算法.该算法具有一定的病人自适应性.通过MIT-BIH心律失常数据库的验证,该方法对Normal和PVC有很高的识别率.     

3D打印非共面模版引导125I粒子植入治疗头颈部肿瘤个体化设计与应用

目的 对比3D打印非共面模板引导¹²⁵I粒子植入治疗头颈部肿瘤的术前、术后计划的物理剂量学参数,探索头颈部肿瘤放射性粒子植入治疗用个体化模板设计方法的安全性、可行性、精确性。方法 2016年1月-2016年12月于北京大学第三医院接受3D打印模板辅助CT引导放射性¹²⁵I粒子植入的头颈部复发/转移恶性肿瘤的患者42例。处方剂量110~160Gy,设计制作3D打印非共面模板42块,对比术前、术后物理剂量学参数,包括D90、最小周边剂量(mPD)、V100、V150、V200、适形指数(CI)、靶区外体积指数(EI)、均匀性指数(HI)。结果 为42例患者设计、制作的42块导板术中就位良好,与术前计划相比,术后D90、V100、CI、EI、HI均相近(P=0.490、0.407、0.893、0.143、0.079),mPD、V150、V200不同(P=0.036、0.007、0.000)。结论 术后验证的主要剂量学指标较好地达到了术前计划要求,有良好的治疗精确性,可以满足临床需求。     

SnS2 Nanosheets as a Template for 2D SnO2 Sensitive Material: Nanostructure and Surface Composition Effects

Two-dimensional nanosheets of semiconductor metal oxides are considered as promising for use in gas sensors, because of the combination of a large surface-area, high thermal stability and high sensitivity, due to the chemisorption mechanism of gas detection. In this work, 2D SnO₂ nanosheets were synthesized via the oxidation of template SnS₂ nanosheets obtained by surfactant-assisted one-pot solution synthesis. The 2D SnO₂ was characterized using transmission and scanning electron microscopy (TEM, SEM), X-ray diffraction (XRD), low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and IR spectroscopy. The sensor characteristics were studied when detecting model gases CO and NH₃ in dry (RH₂₅ = 0%) and humid (RH₂₅ = 30%) air. The combination of high specific-surface-area and increased surface acidity caused by the presence of residual sulfate anions provides a high 2D SnO₂ sensor’s signal towards NH₃ at a low temperature of 200 °C in dry air, but at the same time causes an inversion of the sensor response when detecting NH₃ in a humid atmosphere. To reveal the processes responsible for sensor-response inversion, the interaction of 2D SnO₂ with ammonia was investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in dry and humid air at temperatures corresponding to the maximum “positive” and maximum “negative” sensor response.     

3D打印导航模板辅助椎弓根螺钉在脊柱侧弯矫形术中的置钉效果

目的:探讨3D打印导航模板辅助椎弓根螺钉在脊柱侧弯矫形术中的置钉效果.方法:回顾性分析2018年1月至2020年6月间采用椎弓根螺钉置钉法治疗的39例脊柱侧弯患者的病例资料,其中采用3D打印导航模板辅助置钉(3D组)18例,常规徒手置钉方法置钉(徒手组)21例.记录并比较2组的置钉时间、置钉出血量、置钉透视次数、置钉等...     

我国非处方药说明书范本中妊娠期和哺乳期女性用药信息调查分析

目的:评估国家药品监督管理局(NMPA)官网中非处方药说明书范本关于妊娠期和哺乳期女性用药信息标示的完整性和准确性。方法:收集截止到2018年11月11日NMPA官网中,非处方药化学药品说明书范本和非处方药中成药说明书范本,对范本的【禁忌】和【注意事项】中关于妊娠期和哺乳期女性用药信息标示情况进行统计分析。结果:我国非处方药说明书范本对妊娠期和哺乳期女性用药信息的标示情况仍存在较大空缺。非处方药化学药品说明书范本的用药信息标示率低于中成药(P<0.05),但其对妊娠期和哺乳期女性有指导意义的用药信息标示率明显高于中成药(P<0.01);对妊娠期女性有指导意义的用药信息标示率明显高于哺乳期女性(P<0.01)。结论:保障妊娠期和哺乳期女性用药的安全和有效,需要不断完善和规范说明书范本的用药信息,建立妊娠期和哺乳期女性用药信息数据库等措施。