某中学配电系统设计

本文主要介绍了某中学的配电设计,重点讲述了该学校实验室的配电设计及教室的照明设计。     

Effect of local background luminance on discomfort glare

The objective of this research is to propose a practical method of determining the background luminance in the evaluation of discomfort glare. Two experiments were conducted, a visual sensitivity test and a glare sensitivity test. The results show that the luminance of threshold and the luminance of discomfort glare are mainly determined by the luminance of the immediate background of the source, rather than by the average background luminance, which has previously been suggested by unified glare rating and visual comfort probability method. Consequently, when the background contains areas of differing luminance, the background luminance of a glare source should be determined by the local background luminance affecting the local adaptation.     

Test track evaluation of headlight glare associated with adaptive curve HID,fixed HID,and fixed halogen low beam headlights

Adaptive curve headlights swivel with steering input and are linked to reduced insurance claims and improved visual performance. This study assessed glare experienced from adaptive curve high-intensity discharge (HID), fixed (non-swiveling) HID and fixed halogen headlights – all tested in low beam mode. Twenty participants rated glare from vehicles’ headlights using the DeBoer visual discomfort scale as a test driver drove towards them from five approaches on a test track. Participants rated the fixed halogen condition as less glaring than the adaptive curve and fixed HID conditions. There was no significant difference in ratings between the HID low-beam conditions. Collapsing across roadway approaches, the mean subjective ratings for the fixed halogen, adaptive curve HID and fixed HID low-beam conditions indicated ‘satisfactory’ levels of glare. Differences between subjective ratings were supported by illuminance data. Differences among the three low-beam systems appear minor, relative to their differences from a benchmark high-beam condition.

Practitioner Summary: Insurance data indicates reduced claims associated with adaptive curve lighting. The current effort was to study how such lighting affects discomfort glare of oncoming drivers relative to conventional headlights. Participants rated halogen headlights as less glaring than fixed and adaptive curve HID low beams. Differences among systems were small and associated with acceptable levels of discomfort glare.     

Visual stress, its treatment with spectral filters, and its relationship to visually induced motion sickness

We review the concept of visual stress and its relation to neurological disease. Visual stress can occur from the observation of images with unnatural spatial structure and an excess of contrast energy at spatial frequencies to which the visual system is generally most sensitive. Visual stress can often be reduced using spectral filters, provided the colour is selected with precision to suit each individual. The use of such filters and their effects on reading speed are reviewed. The filters have been shown to benefit patients with a variety of neurological conditions other than reading difficulty, all associated with an increased risk of seizures.     

A study on overhead glare in office lighting conditions

Abstract— High‐intensity light sources illuminating the human eye may create discomfort glare, or at higher intensities even disability glare. In many office lighting conditions, light from overhead luminaires in the ceiling may deliver stray light into human eyes, and as such create discomfort glare, generally referred to as overhead glare. In this paper, overhead glare for a LED luminaire comprising a matrix array of small LED sources using subjective evaluation methodologies and theoretical models, commonly accepted to evaluate glare, were investigated. The perceived overhead glare of the LED luminaire is evaluated at various luminance levels and at different angles (i.e., between 55 and 90°) with respect to the line of sight of the viewer. The results show that a luminaire comprising a matrix of high‐intensity point sources can cause overhead glare and can become glary at lower averaged luminance levels than a luminaire with a uniform light source even at high evaluation angles with respect to the line of sight of the viewer. In addition, the conventional UGR model for predicting discomfort glare needs adaptation for a reliable prediction of perceived overhead glare of complex LED luminaires consisting of a matrix of small‐sized high‐intensity light sources.     

Evaluation of quantitative glare technique based on the analysis of bio-signals

Abstract

This laboratory study evaluated the effect of glare source (halogen, HID and LED) and its illumination levels (0.7, 2 and 5 lx) using a quantitative methodology. Pupil diameter and electroencephalography were measured using FaceLab and Biopac systems, respectively. The discomfort glare was assessed subjectively with Borg’s CR-10 scale. Twenty healthy subjects participated. Pupil size was significantly affected by the headlamp type and illumination condition. Pupil size was smaller when exposed to the LED headlamp than other headlamps (Halogen > HID > LED). In addition, when the illumination increased, pupil size decreased (0.7 lx > 2 lx > 5 lx). Also, driver’s discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver. These results can be applied to design and development of headlamps. Further investigation is necessary with adopted methodology to evaluate other headlamps in different illumination conditions.

Practitioner Summary: This study evaluated pupil size and electroencephalography under different glare source (halogen, HID and LED) and illumination levels (0.7, 2 and 5 lx). Driver’s discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver.     

不同条件透射眩光及色标缺口大小对抬头显示屏上色标辨识的影响

目的通过分析被试对抬头显示屏上色标判识的反应时变化,研究透射眩光强度和色标缺口大小对抬头显示屏上色标辨识的影响。方法本研究选取了11名大学生,设置强、中、弱三类透射眩光,采用系列目标按键任务研究透射眩光强度对于抬头显示屏上作业绩效的影响。结果结果显示,投射眩光强度以及色标缺口大小对于被试作业绩效均有显著影响,并且存在明显的交互作用。结论 (1)透射眩光强度对反应时具有显著影响,强透射眩光显著降低被试的作业绩效;(2)色标的缺口大小对于被试的反应时有显著影响,色标缺口越大,被试作业绩效越高;(3)透射眩光强度与色标缺口大小存在明显交互作用。     

首钢滑雪大跳台中心及制氧厂北区照明设计

首钢滑雪大跳台中心以建筑照明一体化为设计原则,结构预留灯具安装节点,避免灯具眩光对转播、运动员、裁判员、观众等造成干扰;制氧厂北区通过照亮建筑立面,为地面提供功能照明,用光朴素,为各种功能情境的植入预留空间。     

Exposure to and effects of glare from high mast lighting on workers at a timber terminal

High mast floodlighting at outdoor workplaces has economic advantages but suffers from shortcomings such as glare. This study was made to collect and evaluate data from a situation with glare from a physical and occupational health standpoint. When unloading timber, the worker's gaze is frequently directed upward, whereas conventional glare indexes for luminaires assume the gaze is diagonally downwards. It was found that reduced visual acuity could cause difficulty in normal working routines.     

基于煤矿井下的眩光防治与新型矿用防眩照明灯

眩光是煤矿井下照明设计中易出现又易被忽略的问题,眩光产生的原因主要有几种,高亮度的发光面、不合理的灯具选型、错误的灯具安装位置、过大的环境亮度比.所以煤矿照明设计时应该从上述几方面来避免眩光的出现.并介绍了一款新型矿用防眩照明灯--隔爆兼本质安全型LED照明灯.