An illuminance ratio model based on a luminance transfer function matrix

An illuminance ratio model of both single and multiple sources was proposed. The model tried to compensate for a lighting dimming system acting incorrectly as a result of an illuminance sensor aimed at a workplace sheltered by paper or a human body. The method was based on a luminance transfer function matrix, and the model parameters were estimated via the least squares method. Simulated and experimental results show the illuminance calculated using the model is consistent with the actual situation. The illuminance sensor setting based on this model can not only reduce difficulties associated with laying lines, but also avoid incorrect action caused by the illuminance sensor aimed at a workplace sheltered by paper or a human body. This research serves as a reference for the design of lighting dimming systems.     

Lighting quality indicators with space sense for urban lighting environment

In order to find out a space sense indicator that can present the real appearance of human and natural in urban lighting environment, three common used indicators are studied, which are ratio of vertical illuminance to semi cylindrical illuminance, ratio of vertical illuminance to horizontal illuminance and ratio of average cylindrical illuminance to horizontal illuminance.An on site test is taken at Three Gorges Square Pedestrian Street of Chongqing. The variation law of ratio of vertical illuminance to horizontal illuminance is approximate to ratio of average cylindrical illuminance to horizontal illuminance, which varies with the changing of measure point location and reach maximum at the axial central section of pedestrian street between two streetlamps. The change of ratio of vertical illuminance to semi cylindrical illuminance is small correspondingly and it is more appropriate to be as a lighting quality indicator with space sense for urban illuminance environment.     

A New Car Lighting and Signals Control System Based on Optical Fiber Communication

The control signals of conventional car lighting and signal control system which is not possess self-diagnosing function are transmitted via special wiring harness, with which the drivers are not able to discover a trouble and an accident may be occur when car running. To solve the problem, a new control system based on optical fiber communication is proposed. Its fundamental control function, self-diagnosing function, hardware designing and software developing are introduced.     

Research on Lighting Luminous Environment for Older People Living Areas in Residence

This paper probes into visual characters of older people, analyzes circumstance of lighting luminous environment under their living condition and then, beginning with visual physiology and visual psychology, it studies the illuminance and design methods of lighting luminous environment for older people living areas in residence.     

Conjugate Natural Convective Heat Transfer in an Enclosure with Discrete Protruded Heat Sources

The mathematic model on natural convection is proposed in a two-dimensional enclosure cavity with an isothermal heat sink at one vertical wall and five discrete protruded sources. Numerical study is performed to analyze the natural convection in the enclosure with a variety of aspect ratio, the range of which is from 3.0 to 12.22, Ra H is 10 7 and Pr is 30.The computed results show that the total heat transfer effect under the situation with discrete protruded heat sources is prior to that with flat wall heated. Moreover, when the aspect ratio is comparatively large, there is several secondary flow in the enclosure, which enhance the convective heat transfer. On the contrary, when the aspect ratio is small, the secondary flow weakened or disappeared, and the total convective heat transfer drop. Finally, the convective heat transfer criteria in the enclosure is obtained.     

Obtaining Outdoor Illuminance Values with Solar Irradiation Transformation Models

Daylighting is one of the important aspects of sustainable building, but architectural daylighting in China is obstructed because of shortage of daylight meteorological measurement record. However, there are many data of solar irradiation. Therefore solar irradiance values are used to calculate outdoor illumination values. Luminous efficacy is introduced to show the relation between solar irradiance and outdoor illumination. Sunny index is used to represent the meteorological states of the sky. On the basis of measurement data in Chongqing from 1991 to 1992, new luminous efficacy calculation model is built to obtain the outdoor global illuminance values and the diffuse illuminance values. Measurement data in Chongqing in 1993 is used to evaluate the proposed mode, which shows the proposed models are reliable. In order to prove possibility of calculating illuminance in other places in China, the measurement data records of annually average global illuminance values in 32 cites are used to examine the calculation results. If the real-time solar irradiation data was input, the real-time illuminance values could be obtained with this model in China, thus millions of illuminance values could be used in future daylighting design.     

Speed Ratio Matching Strategies of Metal V-belt Type CVT System

The ratio control strategy and the relevant pulley clamping control strategy of the Metal Pushing V-belt Type CVT C Continuously Variable Transmission are key technology of CVT system matching. The engine output torque model and oil consumption model are given in numerical table by cubic spline interpolation to fit engine test result. Based on the engine speed feature, the speed ratio changing strategy of CVT in the numerical table are given to realize the optimal fuel economy and optimal performance mode within the ratio range of the CVT system.     

Color Lapse by Halo Retreat for Night Landscape Lighting

This paper focused on making use of color change to incarnate hierarchy of floodlighting of the building facade in landscape lighting. Color lapse by halo retreat is a good method to reach this goal. The projection light source was chosen on the principle of building exterior color coordination. According to the computing method for chroma coordinates of object color, the magnitude of three stimulus values after reflection by external wall surface and the chroma coordinates were calculated. The purpose of this paper is to take account of the influence of difference between projecting light and reflecting light on external wall surface. At the same time, an approximating computing method is recommended, that is, first figure out the chroma coordinates of two points--the top and bottom points in vertical line of the building and then readjust the location of casting light lamp and lighting fitting or renewal the light source. Then let the chroma coordinate of ever point on the vertical line settle in or be near the line connecting the two points of chroma coordinates on CIE 1931 Chroma chart. It would yield good results due to the color lapse by halo retreat.     

隧道照明光源光色对驾驶员视觉功效的影响

目前,各国以及CIE的隧道照明设计规范和标准在隧道照明研究中都只考虑隧道路面的亮度或者照度水平,对于色温、显色性和光谱分布等因素对视觉效果的影响考虑不足,导致对隧道照明质量的评价不够科学。笔者从隧道照明光源光色对于驾驶员视觉功效的影响出发,选择两个隧道进行了小目标识别现场实验和不同色温反应时间测试实验,分析了驾驶员视觉功效受隧道照明光源的显色性和色温的影响情况。结果表明:隧道照明光源显色指数越高,驾驶员的视觉功效越好;对于光谱能量分布相似的光源,背景亮度相同时,含有短波成分多的光源照明效果更好,驾驶员的视觉功效也更好。     

The Effect of Aspect Ratio on Natural Convection in a Cavity with Discrete Heaters and a Vertical Heat Sink

SIMPLE method is used to study the influence of aspect ratio on the natural convection in an enclosure with five discrete heat sources on a vertical wall and an isothermal heat sink on another vertical wall. The range of aspect ratio is from 3. 0 to 12. 22. At high aspect ratio, multiple secondary flow cells can be found,which enhance heat transfer strongly and cause the highest heat transfer coefficient based on cooling area Nuc. With the decrease of aspect ratio,secondary flow cells become weaker gradually and finally reach the lowest Nuc at H/W = 7. 35. If H/W continues to decrease,natural convection is gradually developed,and heat transfer is improved. At H/W = 3. 67,Nuc becomes stable. Then the decrease of aspect ratio will not affect heat transfer. Besides, A heat transfer correlation including the influence of aspect ratio is .also provided.     

Analysis on the Illumination and Contrast of Imaging Deflection Measuring System

The principle of photoelectric imaging deflection measurement system are presented. The calculation of the image plane's illuminance and contrast are discussed. The relationship among the system's parameters are analyzed. The feasibility of high reflectivital material replacing the system's source are also discussed when illuminance on the ground is high. The result contributes to selecting the parameters of photoelectric imaging deflection measurement system and achieves the long online of deflection.     

Numerical analysis of indoor natural convection heat transfer under different heat source location

The research object is indoor natural convection heat transfer under different heat source location,using FVM numerical method to dispersed solving for mass conservation equation and energy conservation equation.Researched distribution of streamline and isotherm and variation of Nu in powerhouse with Ra among 10 3~10 6 when different heat source location.The results of analysis indicate that when Ra=10 3, the isotherms expand outward centring on the heat source and present shapely arcuation.When increasing Ra,isotherm shape changes gradually,thin boundary layers appear on cold wall and hot wall.The streamlines are two symmetrically reverse vortexs.As increasing Ra, the vortexs change in size and move. As Ra=10 3,Nu reaches maximum in the case of D=0. the effect of heat source location on heat transfer quantity is obvious.The curve of Nu is steepest when D=0.5 and smoothest.There is a power relationship between Nu and Ra, the linear correlation fitting 90%.The conclusion provides a theory basis for the research of complex indoor heat transfer mechanism.     

Analysis for Heat Transfer in Micro-annular Channel with Unsymmetrically Heated Walls in Slip Flow Regime

A theoretical analysis is presented for heat transfer in micro-annular channel with an adiabatic wall and a heated wall with uniform wall temperature in slip flow regime. The energy equations with the boundary conditions of temperature jump are solved for the hydrodynamical and thermal fully developed laminar flow of the incompressible fluid in this microchannel. The influences of the Kn number, the ratio of inner diameter to outer diameter on the heat transfer characteristics are discussed respectively. The results show that the Nusselt number in microchannel decreases with the increasing of Kn number comparing with that in macrochannel.     

Realization of Intelligent Vehicle System for Target Recognition and Tracking

After analyzing target recognition and tracking technique, a method of developing specifically target tacking system is proposed, which uses digital image manipulation to target recognition. Software and hardware design of intelligent vehicle are presented in detail. The system uses digital image manipulation technology to cognize the certain target through a pickup camera installed on the front of the intelligent vehicle. When the target is moving, singlechip receives the commands from the computer and then control the vehicle to trace target. The system can run by itself, regardless of artificial control. This design provides a platform for the research of Growing Machine Intelligence system.     

Calculation of Capacity of Vertically Loaded RC Joint of Local Transf er from Square Column to Straight Wall

On the basis of experimental results on four specimens of vertically loaded RC joints of local transfer from square column to straight wall, interaction between the transfer beam and the straight wall above it is analyzed. In the test, the effect of height of armpit on the transfer beam upon the behavior of the joint is specially studied. As a result, determination of the design shear force and shear capacity of the transfer beam and calculation of capacity of the straight wall are suggested, taking into account the effect of shear span ratio of the beam.     

地铁用间接蒸发冷却器换热性能影响因素

为解决地铁站冷却塔设置难题,提出了一种采用低速电机驱动旋转布水装置的间接蒸发冷却器,在两种布置方式下,对其换热性能进行了单因素实验,并运用正交实验法对较优布置方式下影响换热器换热的因素进行了分析。结果表明：两种布置方式下,喷嘴与蒸发冷却器的间距、两组换热管束间距均存在最佳值,喷嘴双侧旋转布水优于单侧旋转布水;换热器平行气流布置且喷嘴双侧旋转布水为较优布置方式,此时,换热器换热量随喷水量、转速、空气速度、冷却水进口温度的增加以及喷水温度、空气温度的降低而增大,其中,冷却水进口温度对换热器换热影响最为显著,其他因素对其换热的影响从主到次顺序为：喷水量、空气温度、空气速度、喷水温度、转速、冷却水流量。     

Are vegetation indices derived from consumer-grade cameras mounted on UAVs sufficiently reliable for assessing experimental plots?

Recent technological advances in UAV (unmanned aerial vehicle) technology offer new opportunities for assessing agricultural plot experiments using UAV imagery. Vegetation indices (VIs) based on aerial images derived from consumer-grade cameras are a simple and cheap alternative compared to VIs derived from proximal (on-ground) sensors. The objective of this study was to assess whether VIs derived from consumer-grade cameras mounted on UAVs are reliable and whether there are any shortcomings in image acquisition and analysis that need to be addressed before their general application. This objective was investigated using a rotary-wing and a fixed-wing UAV, true colour (RGB) and colour-infrared (CIR) cameras, four different VIs (ExG, NGRDI, NDVI and ENDVI), altitudes in the range of 30–100 m, different ambient lighting conditions and two different software packages for stitching images together. Results were compared with ground-based recordings by consumer-grade cameras and multispectral sensors. Field experiments in cereals were used to evaluate the assessments. The study showed that VIs based on UAV imagery have the same ability to quantify crop responses to experimental treatments as ground-based recordings with cameras and advanced sensors. However, there are shortcomings that need to be taken into consideration: (1) angular variation in reflectance (bidirectional reflectance), (2) stitching and (3) ambient light fluctuations. Bidirectional reflectance was so extensive that it could lead to misleading conclusions in sunny conditions and this effect could be amplified further by stitching. A procedure for avoiding impacts from bidirectional reflectance is demonstrated when plots were cropped from individual images and a procedure is suggested for stitching images. Camera, VIs and image acquisition altitude were of minor importance, but fluctuating ambient lighting conditions is an issue that should be addressed in future studies.     

Cluster Analysis of Hourly Usage Ratio of Lighting and Equipments Energy Use in Office Buildings

The hourly usage ratio is very important for lighting and equipment energy predicting of office buildings and energy saving calculation of energy efficient retrofit. 17 office buildings in Chongqing were selected to calculate daily usage ratio by using whole-year electrical consumption data of lighting and equipments energy system. According to the different hourly usage ratio, office buildings have been categorized into two main types by using cluster analysis method. Then, the typical hourly usage ratios of two types of office buildings were calculated.     

A preventive control model for static voltage stability considering the power constraints of weak branches

The voltage instability of power system often occurs when the active power on one or more weak branches exceeds its transfer capability. A preventive control model for static voltage stability is proposed using the active power transfer capability of weak branches as static voltage stability constraints. A local line based voltage stability index is used to determine the critical contingencies, weak branches and transfer capability of each weak branch. A static security analysis method, which is based on DC power flow equations, is used to establish the non linear active power flow expressions on weak branches following each critical contingency. The active power constraints on weak branches can be obtained from the active power flow expressions and transfer capabilities of weak branches. A quadratic optimal model for preventive control including the proposed active power constraints on weak branches is presented. The simulation results for IEEEE14 bus system and IEEE118 bus system demonstrate the correctness and effectiveness of the proposed preventive control model.     

密闭式植物种苗工厂的设计及其光环境研究

密闭式植物苗工厂具有节能、环保、控制精度高、生产成本低等特点,发展前景广阔。利用不透光的绝热材料建设人工光型密闭式植物工厂,设计开发了高精度的环境控制系统,为植物生长提供优化的物理环境。研制了种苗繁育LED光环境调控装置、光照距离可调式荧光灯板,有效地改善植物生长所需的光环境,提高植物的光能利用率。通过对环境控制系统的试验研究以及相关的生物学试验,为密闭式植物工厂以及人工光源在育苗领域的应用研究提供了理论和试验依据。LED、荧光灯与自然光条件下黄瓜育苗对比试验表明LED光环境下植株生长速率高于其他处理,表现出一定的生长优越性。