An Improved Convolutional Neural Network Based Indoor Localization by Using Jenks Natural Breaks Algorithm

With the rapid growth of the demand for indoor location-based services(LBS), Wi-Fi received signal strength(RSS) fingerprints database has attracted significant attention because it is easy to obtain. The fingerprints algorithm based on convolution neural network(CNN) is often used to improve indoor localization accuracy. However, the number of reference points used for position estimation has significant effects on the positioning accuracy. Meanwhile, it is always selected arbitraily without any guiding standards. As a result, a novel location estimation method based on Jenks natural breaks algorithm(JNBA), which can adaptively choose more reasonable reference points, is proposed in this paper. The output of CNN is processed by JNBA, which can select the number of reference points according to different environments. Then, the location is estimated by weighted K-nearest neighbors(WKNN). Experimental results show that the proposed method has higher positioning accuracy without sacrificing more time cost than the existing indoor localization methods based on CNN.

Application of Indoor Natural Ventilation Simulation in Residential Space Layout

Tatural ventilation of indoor air flow and thermal comfort space plays an important role, especial y in the interior design of passive cooling factors, indoor space layout, and the location of doors, windows and other factors on the indoor natural ventilation effect has great influence. Using the method of fluid mechanics, and Airpak3.0 software, indoor natural ventilation for residential buildings was simulated, and the thermal comfort of indoor natural ventilation in a residential building in Xuzhou City was analyzed to explore the effect of indoor spatial layout, location of doors, window opening types on indoor natural ventilation. The results showed that indoor spatial layout played an essential role in indoor natural ventilation, application of numerical simulation for the simulation of the indoor natural ventilation and assessment of indoor natural ventilation effect was a scientific instruction for the indoor spatial design.

Study on Model of Indoor Air Pollution Forecast for Decoration Under Natural Ventilation Condition

To establish the model of indoor air pollution forecast for decoration. Methods The model was based on the balance model for diffusing mass. Results The data between testing concentration and estimating concentration were compared. The maximal error was less than 30% and average error was 14.6%. Conclusion The model can easily predict whether the pollution for decoration exceeds the standard and how long the room is decorated.

Natural Gas and Indoor Air Pollution: A Comparison With Coal Gas and Liquefied Petroleum Gas

Objective The study was designed to compare the combustion products of coal gas, liquefied petroleum gas and natural gas in relation to indoor air pollution. Methods Regular pollutants including B(a)P were monitored and 1-hydroxy pyrene were tested in urine of the enrolled subjects. Radon concentrations and their changes in four seasons were also monitored in the city natural gas from its source plant and transfer stations to final users. To analyze organic components of coal gas, liquefied petroleum gas and natural gas, a high-flow sampling device specially designed was used to collect their combustion products, and semi-volatile organic compounds contained in the particles were detected by gas chromatograph-mass spectrograph (GC/MS). Results Findings in the study showed that the regular indoor air pollutants particles and CO were all above the standard in winter when heating facilities were operated in the city, but they were lowest in kitchens using natural gas; furthermore, although NO2 and CO2 were slightly higher in natural gas, B(a)P concentration was lower in this group and 1-hydroxy pyrene was lowest in urine of the subjects exposed to natural gas. Organic compounds were more complicated in coal gas and liquefied petroleum gas than in natural gas. The concentration of radon in natural gas accounted for less than 1‰ of its effective dose contributing to indoor air pollution in Beijing households. Conclusion Compared to traditional fuels, gases are deemed as clean ones, and natural gas is shown to be cleaner than the other two gases.

Application of natural ventilation of residential buildings in hot-humid regions

The current ventilation condition of the hot and humid regions was analyzed through on-site investigation. It is found that residents in this region expect to improve indoor thermal environment through natural ventilation as much as possible. Then,it comes to a conclusion by the field test that natural ventilation has certain practical effect on improving indoor thermal environment. CFD simulation software is employed to verify the test result. Based on PMV modified model,and according to norms,geography and climate combined with the measured and simulated results,the application of the time and effectiveness of natural ventilation in hot and humid region were analyzed,to some extent,providing a basis for reducing the air-conditioner's runtime with natural ventilation.

NATURAL BACKGROUND RADIOACTIVITY LEVELS IN THE TERRESTRIAL ENVIRONMENT OF HONG KONG

This paper analyses and summarizes the natural radionuclide contents of soil and building materials, radon concentrations and the penetrating radiation levels in Hong Kong. From these, a thorough and objective assessment for the terrestrial background irradiation level of Hong Kong was made. Finally, the annual effective dose equivalent received by Hong Kong people due to the natural background irradiation was calculated to be 3.2 mSv.

The Application of Natural Elements in Interior Landscape Design and its Principal Analysis

The rapid development of the decoration industry creates a good development space for interior decoration,and the public pays more attention to the integration of natural elements in the process of interior decoration.In this regard,this article introduces the ways in which natural elements are embodied in indoor landscapes,and expounds the principles of using natural elements in indoor landscapes,hoping to provide references for relevant personnel.

基于光环境仿真模拟的高校实验室竖向遮阳构件优化研究

以中国石油大学古镇口校区实验楼为例,以该校区实验楼的物理实验室为基础模型,将实验室外立面作为装饰构件的竖向外遮阳构件形体尺寸作为变量,结合相关建筑设计规范、绿色建筑设计规范和实际工程需求,设置试验的边界条件,试验方案设计采用正交试验法,以采光系数、空间天然采光百分比作为主要室内光照评价指标,结合其他相关光环境评价指标,使用三维建模软件Rhino建立基础实验模型,运用Grasshopper+Ladybug Tools设置变量并对实验室进行室内光环境定量模拟。优化结果使高校实验室的光环境得到改善。研究方法和思路有助于提高建筑项目落地实施的质量,同时为碳中和目标下的高校建筑设计提供参考。

遮阳方式及构造对室内自然通风的影响研究

遮阳方式及构造对室内风环境的营造有很大的影响,随着室内空气品质与热舒适要求的提高,室内自然通风越来越被重视。为了探究遮阳方式及构造对室内风环境的影响,以衡阳市某办公室为例,以计算机流体力学CFD(computational fluid dy-namics)技术为基础,分析了水平式、垂直式、综合式和挡板式遮阳板分别在400 mm、600 mm、800 mm、1000 mm和1200 mm长度下该办公室的进风量、测点风速和空气龄。当风向投射角为0°时,水平式、垂直式和综合式遮阳板长度每增加200 mm平均进风量分别增加135 m^(3)/h、110 m^(3)/h和125 m^(3)/h,挡板式板长每增加200 mm进风量平均减小365 m^(3)/h。通过对进风量、测点风速以及空气龄等评价指标的研究与分析,遮阳板对室内进风量影响较大,对室内空气流向和流速影响较小,合理利用各类遮阳板,可以达到改善室内自然通风的效果。

深凹立面建筑房间自然通风效果及污染物浓度分布

以西安地区某主导风向为侧向来风的深凹立面建筑房间为研究对象,通过过渡场模型对室外场到室内场进行了多尺度CFD模拟,研究了不同开窗方式下的室内空气质量。结果显示:全开窗对于排出室内产生的污染物有较好效果,但是对于室外污染物的抵抗能力不如单开平立面窗;当室内污染物集中于某个单个房间时,开窗形成的对流通风会造成其他无污染源房间内的污染物浓度增大;当污染物分散在各个房间时,对流通风则可以有效降低各房间污染物浓度,降低幅度约为50%;单开平立面窗能有效杜绝室外污染物进入室内,而增大出风口是排出室内污染物的最好方法。

自然通风、冷屋顶与外遮阳对室内热环境改善效果实验研究

对自然通风、冷屋顶与外遮阳3种被动技术在夏热冬冷地区的综合隔热降温作用及对室内热环境的改善效果进行了测试分析。结果显示:当三者协同作用时,外遮阳可以遮挡太阳辐射,有效降低窗户的得热量,实验房间玻璃外表面温度较对比房间最高降幅达到7.6℃;高反射涂料的应用使屋顶表面降温幅度达到10.3℃,有效减少了屋顶的温差传热;自然通风系统成功诱导了连续并具有周期性波动的气流,并对埋管内空气有着良好的预冷效果;实验房间室内温度稳定在26.8~27.9℃之间,室内热环境得到了明显的改善。

住宅室内甲醛污染健康危害及通风控制

以某高层新装修住宅室内空气甲醛污染为研究对象,采用现场实测与数值模拟方法,分析了甲醛污染对成人的健康安全危害及自然通风控制措施。结果表明:不开启门窗时甲醛浓度超过了我国室内空气质量标准,对成人的致癌风险较高,自然通风可以降低甲醛危害,尤其在安装有衣柜或书柜的房间要加强开窗开门通风;进风口的位置和数量对室内气流分布影响很大,导致不同房间甲醛浓度差异较大;相较于密闭房间,开窗开门通风可使甲醛浓度降低70%左右,仅开门通风可降低甲醛浓度45%左右。研究结果可为降低室内空气甲醛污染的健康安全危害提供一定参考。

天津既有住宅自然通风调控模式有效性研究

为提升既有住宅夏季自然通风有效性,设计了基于室内外温度变化的反馈开窗控制模式,对比无调控开窗和分时段开窗控制模式,利用FLUENT软件分别进行室内风环境模拟。以满足室内适应性平均热感觉指标(APMV)一级的时长百分比,和温度平均绝对偏差值(MAD)为评价指标,通过分析室内风热环境的仿真结果发现自然通风成效与开窗控制模式的规律,以及在不同调控策略下的差异化表现。实验结果显示,相较于无调控开窗和分时段开窗控制模式,温度反馈开窗控制模式下室内APMV一级百分比分别提高了9.09%和6.06%,MAD数值分别提高了0.19℃和0.1℃,温度反馈开窗控制模式能够更大幅度地提升自然通风有效性和室内热舒适度,但三种模式下住宅室内热舒适的分布规律相同。

地铁邻近高层住宅建筑振动分布规律及影响因素研究

通过有限元法建立轨道-隧道-土体-建筑大型精细化有限元模型,考虑轮轨激励的频率特性,结合源强原位测试验证模型的可靠性,在此基础上,系统研究建筑不同房间、楼板不同位置、不同楼层的振动分布规律,结合楼板的模态分析,重点研究不同房间振动水平差异的形成原因。结果表明,同一楼层不同房间振动差异受楼板一阶固有频率与输入源强卓越频率重叠关系影响,不同房间的振动水平仿真结果差异达到15.1 dB;当房间楼板一阶固有频率远低于源强卓越频率时,房间楼板振动极值点出现在房间楼板中央以外的位置,反之则出现在楼板中央;振动随楼层高度的增加表现为波动变化规律,不同房间的最大值可能出现的位置为首层、中间层或顶层。

北方滨海地区自然通风乒乓球馆冬季风热环境调查研究

文章通过现场测试及主观问卷调查,分析了初冬非采暖期青岛市某高校乒乓球馆在自然通风条件下运动人群在热舒适、室内空气品质、风速干扰性三方面的主观感受。研究发现:与非运动人群相比,运动人群感觉偏暖,可接受的舒适温度下限更低;运动人群可接受的CO_(2)浓度更高,但同时对CO_(2)浓度的变化表现出更高的敏感度;虽然乒乓球馆室内平均风速仅为0.09m/s,但仍有65.67%的运动者认为风速干扰较大。乒乓球资深运动人群有习惯性关窗的行为,避免运动区域的风场干扰是乒乓球馆中引入自然通风亟须解决的首要问题。

现代公共建筑中室内自然景观设计研究

室内自然景观设计是在室内环境中引入自然元素,以模拟室外的自然景观,提高空间的品质和人们的生活体验。室内自然景观设计在现代公共建筑中的应用,不仅是为了美化空间,更是为了创造更健康、更宜居的环境。结合实际案例对现代公共建筑中室内自然景观设计的应用进行了分析,探讨室内空间引入自然景观设计的方法。

Numerical simulation on exploringinfluencing factors of wind-driven naturalventilation effect in large indoor dock

The shipbuilding industry is booming and the health problems of workers caused by the harsh indoor dock environmentforce us to explore efficient and reasonable ventilation methods suitable for large workshops.Due to the strongspecificity of large workshops,general or local ventilation methods cannot be universally applied.It has great potentialand good economy to improve indoor environment by changing natural ventilation design.Computational fluiddynamics(CFD)has gradually become a powerful tool for predicting indoor and outdoor airflow organization andoptimizing indoor ventilation.This paper adopts CFD to study the effect of the inflow wind speed,the position of theside wall shutters,the area ratio and form of roof ventilators on the effectiveness of natural ventilation in a large shipyarddriven by wind pressure.The results show that the influence on total ventilation volume is more obvious whenthe intake side is shaded than the exhaust side.Different incoming wind speeds will affect the wind pressure at theventilation position,which is the decisive external factor affecting the natural ventilation of docks.When the area ratioof roof ventilators increases to a certain extent,its continued increase has an insignificant effect on the total ventilationvolume.The influence of changing the arrangement of the roof ventilator on the natural ventilation effect can beneglected when the area ratio is kept constant.

绿色建筑在提高室内空气质量方面的优势探讨

随着环保意识的不断提高,绿色建筑在全球范围内得到了广泛推广和应用,其中,其在提高室内空气质量方面的优势并未引起足够的重视。论文通过大量文献研究和案例分析,探讨了绿色建筑在提高室内空气质量方面的主要优势。首先,采用绿色建筑的设计原则,可以最大限度地提高室内的自然采光和通风,改善空气质量;其次,绿色建筑的用料考虑到环保和健康因素,大量使用的环保建材有助于减少室内的有害气体排放;最后,绿色建筑强调建筑与周围环境的和谐共生,一些绿色技术如绿化屋顶和绿色墙面也有助于改善室内空气质量。通过以上分析可知,绿色建筑通过技术、材料和设计等多方面因素,有效提高了室内空气质量。这为中国绿色建筑的进一步推广提供了理论支持和实践参考。

Impact of indoor heat load and natural ventilation on thermal comfort of radiant cooling system:An experimental study

Construction and operation of buildings are responsible for about 20%of the global energy consumption.The embodied energy of conventional buildings is high due to the utilization of energy-intensive construction mate-rials and traditional construction methodology.Higher operational energy is attributed to the usage of power-consuming conventional air-conditioning systems.Therefore,moving to an energy-efficient cooling technology and eco-friendly building material can lead to significant energy savings and CO 2 emission reduction.In the present study,an energy-efficient thermally activated building system(TABS)is integrated with glass fiber rein-forced gypsum(GFRG),an eco-friendly building material.The proposed hybrid system is termed the thermally activated glass fiber reinforced gypsum(TAGFRG)system.This system is not only energy-efficient and eco-friendly but also provides better thermal comfort.An experimental room with a TAGFRG roof is constructed on the premises of the Indian Institute of Technology Madras(IITM),Chennai,located in a tropical wet and dry climate zone.The influence of indoor sensible heat load and the impact of natural ventilation on the thermal comfort of the TAGFRG system are investigated.An increase in internal heat load from 400 to 700 W deteriorates the thermal comfort of the indoor space.This is evident from the increases in operative temperatures from 29.8 to 31.5℃ and the predicted percentage of dissatisfaction from 44.5%to 80.9%.Natural ventilation increases the diurnal fluctuation of indoor air temperature by 1.6 and 1.9℃ for with and without cooling cases,respectively.It reduces the maximum indoor CO 2 concentration from 912 to 393 ppm.

Field measurement of the impact of natural ventilation and portable air cleaners on indoor air quality in three occupant states

Natural ventilation(NV)has been considered a simple and effective method of ventilation.However,the intro-duction of NV does not achieve better indoor air quality(IAQ)when the outdoor atmospheric environment is polluted.Therefore,portable air cleaners(PACs)are increasing in use in recent years,but their effectiveness is highly dependent on the residents’habits.A typical residence in Xi’an,China was selected to examine the effects of the use of NV alone and the use of NV and PACs together on IAQ in the three occupant states,i.e.,unoc-cupied,sleeping and leisure.Parameters,such as temperature,relative humidity,CO_(2),and PM_(2.5)concentration were measured when changing the window opening and the position of the PAC.The results showed that in the unoccupied state,opening the inner door can promote a more uniform thermal and humid environment.In the sleeping state,the I/O ratio of the PM_(2.5)concentration was the lowest when the window opening of the bedroom was 1/2 or 3/4,with a mean value of 0.3.In the leisure state,only using NV,when the purification rate reaches 90%,the mean purification time of each window opening in the living room is 87.5 min.The mean purification time was reduced to 25 min when both NV and PAC were used.The on-site purification efficiencies were 91.0%and 94.5%,when the window opening was 1/2(i.e.,the PAC was placed in the center of the room)and 3/4(i.e.,the PAC was placed away from the outer window),respectively.