Perceptual Quality Assessment of Omnidirectional Images:Subjective Experiment and Objective Model Evaluation

Virtual reality(VR) environment can provide immersive experience to viewers.Under the VR environment, providing a good quality of experience is extremely important.Therefore, in this paper, we present an image quality assessment(IQA) study on omnidirectional images. We first build an omnidirectional IQA(OIQA) database, including 16 source images with their corresponding 320 distorted images. We add four commonly encountered distortions. These distortions are JPEG compression, JPEG2000 compression, Gaussian blur, and Gaussian noise. Then we conduct a subjective quality evaluation study in the VR environment based on the OIQA database. Considering that visual attention is more important in VR environment, head and eye movement data are also tracked and collected during the quality rating experiments. The 16 raw and their corresponding distorted images,subjective quality assessment scores, and the head-orientation data and eye-gaze data together constitute the OIQA database. Based on the OIQA database, we test some state-of-the-art full-reference IQA(FR-IQA) measures on equirectangular format or cubic formatomnidirectional images. The results show that applying FR-IQA metrics on cubic format omnidirectional images could improve their performance. The performance of some FR-IQA metrics combining the saliency weight of three different types are also tested based on our database. Some new phenomena different from traditional IQA are observed.

Improved Fuzzification Method for Multi-Objective Decision-Making and Its Application in Evaluation of Highway Planning

A new fuzzification method for multi-objective decision-making and selective sorting is proposed on the basis of the fuzzy consistent relation, and the specific algorithm is presented. The method is applied to the evaluation of highway planning of Zhanjiang city. To decrease the subjectivity in the process of decision-making, the LOWA operator is introduced, and a discussion on how to select appropriate weights involved in multi-objective sorting is made. It is concluded that it is feasible to apply the fuzzy consistent relation to multi-objective decision-making analysis, and the improved fuzzication method is workable.

Research on Demand Response Potential of Adjustable Loads in Demand Response Scenarios

To address the issues of limited demand response data,low generalization of demand response potential evaluation,and poor demand response effect,the article proposes a demand response potential feature extraction and prediction model based on data mining and a demand response potential assessment model for adjustable loads in demand response scenarios based on subjective and objective weight analysis.Firstly,based on the demand response process and demand response behavior,obtain demand response characteristics that characterize the process and behavior.Secondly,establish a feature extraction and prediction model based on data mining,including similar day clustering,time series decomposition,redundancy processing,and data prediction.The predicted values of each demand response feature on the response day are obtained.Thirdly,the predicted data of various characteristics on the response day are used as demand response potential evaluation indicators to represent different demand response scenarios and adjustable loads,and a demand response potential evaluation model based on subjective and objective weight allocation is established to calculate the demand response potential of different adjustable loads in different demand response scenarios.Finally,the effectiveness of the method proposed in the article is verified through examples,providing a reference for load aggregators to formulate demand response schemes.

Comprehensive Evaluation of Distributed PV Grid-Connected Based on Combined Weighting Weights and TOPSIS-RSR Method

To effectively quantify the impact of distributed photovoltaic(PV)access on the distribution network,this paper proposes a comprehensive evaluation method of distributed PV grid connection combining subjective and objective combination of assignment and technique for order preference by similarity to an ideal solution(TOPSIS)—rank sum ratio(RSR)(TOPSIS-RSR)method.Based on the traditional distribution network evaluation system,a comprehensive evaluation system has been constructed.It fully considers the new development requirements of distributed PV access on the environmental friendliness and absorptive capacity of the distribution grid and comprehensively reflects the impact of distributed PV grid connection.The analytic hierarchy process(AHP)was used to determine the subjective weights of the primary indicators,and the Spearman consistency test was combined to determine the weights of the secondary indicators based on three objective assignment methods.The subjective and objective combination weights of each assessment indicator were calculated through the principle of minimum entropy.Calculate the distance between the indicators to be evaluated and the positive and negative ideal solutions,the relative closeness ranking,and qualitative binning by TOPSIS-RSR method to obtain the comprehensive evaluation results of different scenarios.By setting up different PV grid-connected scenarios and utilizing the IEEE33 node simulation algorithm,the correctness and effectiveness of the proposed subject-object combination assignment and integrated assessment method are verified.

Investigation and analysis on indoor air quality of large commercial office building in summer

To study the indoor air qualities（IAQ）of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,is investigated.A questionnaire survey and field tests are used to collect data.According to the data of twelve rooms in this building,objective evaluation and the subjective evaluation of the IAQ are obtained.Almost all of the environmental parameters in these rooms basically meet the standards of the objective evaluation.But the average concentration of carbon dioxide in most rooms cannot reach the value of the cleanliness standards,1 255 mg/m^3.The average acceptability of the IAQ in these rooms is 71%,which is lower than the value of the ASHRAE 55—1992 standards,80%.The proper increase in the wind speed and the indoor fresh air supply can greatly improve the objective evaluation and the subjective evaluation of the IAQ.

Sense Estimation and Instrumental Evaluation of Fabric-Evoked Prickle

In this paper, the mechanism of fabric-evoked prickle is discussed, which indicates that the mechanical stimuli aroused by the fiber ends on the fabric surface to the skin-sensory receptors are responsible for prickle. The factors influencing the intensity of prickle are specialized and anatomized. Several means of sense estimate, including the corresponding statistical measures, are described. A few groping objective methods of evaluating prickle are analyzed, including the testing principles, the advantages and the disadvantages. At last, a new concept is proposed on the objective evaluation of prickle.

Study and Test on the Pressure Comfort of Shoe pad Based on Football Movement

Insole fabric made of cotton / spandex blended was selected ,and 30 female college students or graduate whose body close to 160/84A were choose. Combined with the objective assessment of pressure test and subjective stress method to evaluate pressure comfort of shoe pad based on football movement. The results show that the pressure produced in different activities is different from the parts of human body .Every parts which support the clothing pressure are different, and the threshold of buffer against stress shoe pad pressure comfort were concluded.

不同成像参数下CBCT的成像质量分析

目的:主观评价和客观评估不同成像参数下CBCT的图像质量,分析图像质量的主观评价和客观评价间的关系。方法:分别采用6台不同品牌CBCT扫描仪〔3D Accuitomo(Morita)、i-CAT(Kavo)、5G(NewTom)、Smart3D(北京朗视)、DCT Pro(Vatech)、VGi(NewTom)〕,在各个品牌的典型曝光条件下(电压和电流强度不同)扫描空间分辨率模体和高仿真头模,7位医师对拍摄的CBCT图像进行主观评价打分,比较不同CBCT扫描仪的空间分辨率和对常见口腔解剖结构的可见性。客观评价指标采用各仪器所获的图像空间分辩率(LP/mm)。结果:7位医师的组内一致性和组间一致性均无显著性差异。主观评价New Tom 5G为2分,i-CAT为5分,其余4个品牌匀为4分,客观评价i-CAT的LP/mm为1.8,Smart3D为2.0,其余4个品牌为1.0~1.7。在相同管电流条件下,不同管电压的图像主观质量有显著性差异。在相同管电压条件下,不同管电流的图像主观质量有显著性差异。结论:图像质量的主客观评价具有一定的一致性,不同品牌之间的客观评价差异可能与电压、电流强度不同有关。

腋拐的使用角度对人机舒适性的影响研究

目前单臂操作助行器具产品的舒适性评价标准体系不完善,产品设计过程中缺乏充分的生物力学及人机工程学分析,从而导致了诸如腋神经损伤、腕关节损伤等二次伤害的发生。结合人机工程学理论和实验,通过人体生理结构解剖分析、使用动作姿态分析、简易模型受力分析及使用舒适性主客观实验结合分析等方法,研究腋下拐杖各参数对人机舒适性的影响,得出腋下拐杖对人体使用舒适性产生影响的角度参数的最佳范围,为后续腋拐的设计与创新研究提供参考和借鉴。

基于主客观评价的社区生活圈公共服务设施优化策略研究——以南宁市中心城区为例

社区生活圈已成为当前“以人为本”理念下城市更新实施和评价的重要工具。然而传统的社区生活圈规划主要基于公共服务设施覆盖率和可达性等空间绩效评价方法,较少关注居民的实际生活体验和需求。以广西壮族自治区南宁市中心城区为例,通过社区居民满意度调查,根据客观评价(设施服务水平)和主观评价(居民满意度)之间的相关性程度,将公共服务设施分为强相关、中等相关、弱相关和不相关4种类型;进而根据各类设施的相关性特征及潜在影响因素,结合典型社区生活圈实地调研,提出社区生活圈公共服务设施的分类优化策略,以期为全国其他城市提供可借鉴的经验。

主客观方法的寒地传统村落生态治水韧性评价

本文以文献综述和实证研究为基础,运用耦合评价体系对村落人居空间生态韧性要素进行多维分析研究,在对寒地典型村落特征进行判定的基础上,引导形成现代治水防灾规划的启示。首先针对城乡空间环境韧性评价研究方法进行综述,得出了以多维模型耦合评价空间韧性的合理性与实操性;其次,总结不同研究方法结合模式梳理评价因子体系,通过多层筛选确定用于北方村落治水韧性评价方式与模型,通过观察测量无人机与三维模型数据处理技术得到评价数据,用熵值法与耦合协调度模型进行韧性评价,通过结合实例分析构建的评价体系与村落实际情况相符,证明体系的合理性;最后根据评价结果与调研数据综合分析,得出针对村落防灾生态规划建设的新思路。

基于结构CRITIC法的学术期刊评价指标的赋权方法及比较

在复杂、多元的期刊评价过程中经常涉及各评价指标的赋权问题。不同的评价指标赋权方案直接影响期刊评价的结果,因此如何确定指标权重是一个重要问题。文章基于CRITIC法的赋权原理,结合层次分析法,提出了一种全新的主客观赋权法相结合的权重确定方法,即结构CRITIC法。采用2022年《中国学术期刊影响因子年报(自然科学与工程技术)》中17种数学学术期刊的数据,使用包括原始的CRITIC法在内的其他三种赋权方法进行对比分析。结果表明,主观赋权法和客观赋权法赋权结果的差异性影响了评价结果的公认性;赋权方法的选择应当考虑其适用性;结构CRITIC法是在期刊评价中更能从主观和客观两个方面反映指标权重的计算方法。结构CRITIC法为学术期刊评价提供了一种新的赋权方法。

滑坡区输电塔线体系风振响应及主客观安全评价模型

滑坡区输电线路在边坡变形和风荷载共同作用下,极易产生断线、倒塔等事故。以滑坡区某输电线路为研究对象,建立2塔3线有限元模型,运用Kaimal谱建立风荷载模型,分析30°、45°、60°、90°风向角风荷载和15种边坡变形组合作用下,塔线体系的动力响应规律,提出应急加固建议。接着运用层次分析法和基于相关性指标权重法(CRITIC)分别确定主客观权重值,采用最小鉴别信息原理获得主客观组合权重,最终通过引入均化系数优化模糊综合评价法,建立塔线体系主客观安全性评价模型,并进行实例应用验证。结果表明:风荷载作用下输电塔线体系承受边坡变形能力总体上明显降低,且随着风向角的增大而减小,最不利于工况为单塔腿沉降叠加90°风向角,相对无风时抗变形能力降低69%。主客观安全性评价模型实例评价结果与实际一致,可用于滑坡区输电塔线体系的安全性评价。

噪声特性对言语可懂度评价的影响

言语可懂度是语言声房间和厅堂音质评价的重要指标,噪声特性是影响言语可懂度评价结果的重要因素之一。基于国内外相关文献就噪声特性对言语可懂度评价的影响进行系统研究,结果表明,噪声特性对言语可懂度的评价结果有显著影响(:1)噪声在时域上的波动起伏有利于言语理解,但会导致个体间差异增大并降低评价结果的稳定性;噪声频率范围和频谱分布与语言声越接近,在低频区的噪声量越大,对言语可懂度的影响越大;言语噪声能够导致额外的信息掩蔽,影响程度与言语噪声的数量、噪声和目标语之间的相似程度以及听者的个体因素等有关。(2)将当前基于稳态噪声的言语可懂度客观评价方法用于其他噪声时,可能造成对言语可懂度的低估或高估。非稳态噪声情况下的可懂度客观评价仍存在一些不确定的地方。结合当前的研究现状,进一步提出该领域的下一步研究方向。相关内容可为噪声环境中的言语可懂度主、客观评价提供参考。

基于主客观组合加权法的拖拉机座椅舒适度评价

拖拉机座椅是驾驶室人-机交互的主要界面。座椅是否舒适关系到驾驶员生理、心理以及作业效率等关键问题,因此对拖拉机座椅舒适性进行评价具有重要意义。为准确可靠地实现拖拉机座椅舒适性定量评价,提出一种基于主客观组合加权模型的拖拉机座椅舒适性综合评价方法。首先,通过文献调研和专家问卷,并结合作业中人体不舒适出现频率较多的部位,构建驾驶舒适性评价指标体系。其次,使用组合加权法平衡专家的主观评价和客观信息,得到综合权重。最后引用多级模糊综合评价理论将舒适性评价转换为定量评价,并进行实例分析验证组合加权法的有效性。结果表明:人体各部位对座椅舒适性影响程度不同,依次为臀部(0.355)、上背部(0.263)、下背部(0.199)和腿部(0.183)。验证试验表明使用组合赋权是有效的,该方法充分结合层次分析法与熵权法的优点,在保留专家主观意见的同时,很好地规避权重失衡的现象,对座椅舒适性评价以及优化设计具有重要的指导意义。

基于非线性空气弹簧模型的整车仿真与主客观评价

应用非线性空气弹簧模型,研究了空气悬架整车的动力学仿真和主观评价。结合空气弹簧频率、振幅相关性模型与Simulink仿真,给出了空气悬架整车7自由度模型,对比了不同路面情形下悬架动行程和簧上加速度的均方根值和功率谱密度。从时域和频率2个角度分析了不同速度、路面及减振器阻尼情形下空气悬架整车的动态特性。对装有不同空气弹簧的整车进行主、客观试验测试。结果表明:悬架动行程预测误差小于7%,簧上位置加速度共振峰值预测误差小于6%,共振频率预测误差小于6%;从而验证了所提模型的普适性和精确性;反映了带空气悬架整车的动态特性,解释了平顺性主客观试验的机理。

智能泊车辅助系统驾驶体验测评指标构建

针对当前行业内智能泊车辅助系统用户驾驶体验测试评价指标不完善的问题,提出了驾驶体验主客观测评指标并进行了试验验证及相关性分析。基于智能泊车辅助系统的功能逻辑,构建了智能泊车辅助系统驾驶体验闭环控制系统。结合闭环系统,采用体验阶梯金字塔模型构建主观评价指标体系,还采用GSM模型进行了客观指标构建。针对7款车型进行了实车测试,并利用皮尔逊相关性系数进行了分析。试验结果表明,所提出的评价指标可适用于测试对象的驾驶体验测评,且主客观相关性系数全部>0.5,能为智能泊车辅助系统的设计和测评提供参考。

基于电机电磁噪声的电动汽车声品质MNLR预测方法

为研究电动汽车电机电磁噪声对车内声品质的影响,建立声品质预测模型。采用等级评分法对车内噪声进行主观评价,作为预测模型因变量,计算总体噪声A计权声压级、粗糙度、AI指数等客观参量,作为预测模型自变量,此外通过阶次分析和滤波法得到电磁噪声并计算其尖锐度等客观参量,亦作为一组自变量,构建多元非线性回归(multivariate nonlinear regression,MNLR)模型。仿真实验结果表明,MNLR模型的预测结果与主观评价结果具有较高一致性,电磁噪声尖锐度提升会恶化车内噪声环境,同时还会增强AI指数对人主观感受的影响。本文预测模型对声品质优化具有一定的指导意义。

基于BWM-EWM的铁路综合客运枢纽站城融合发展水平评价研究

铁路综合客运枢纽站城融合发展已经成为城市高质量发展的重要催化剂,亟需科学决策铁路综合客运枢纽站城融合的开发规模和力度。通过铁路综合客运枢纽站城融合评价指标体系评价原则构建,从交通发展水平、土地利用水平和站城衔接水平3个准则层,提出铁路综合客运枢纽站城融合评价指标体系,建立基于BWM-EWM的铁路综合客运枢纽站城融合发展水平评价模型。以北京南站、上海虹桥站、南京南站、深圳北站和重庆沙坪坝站5个典型铁路综合客运枢纽进行实证分析,研究结果表明:南京南站具有较好的站城融合水平,还需要进一步强化枢纽统筹协调、提高站城衔接水平,集中开发枢纽用地、提高土地开发效益。

Carbon efficiency evaluation method for urban energy system with multiple energy complementary

Urban energy systems(UESs)play a pivotal role in the consumption of clean energy and the promotion of energy cascade utilization.In the context of the construction and operation strategy of UESs with multiple complementary energy resources,a comprehensive assessment of the energy efficiency is of paramount importance.First,a multi-dimensional evaluation system with four primary indexes of energy utilization,environmental protection,system operation,and economic efficiency and 21 secondary indexes is constructed to comprehensively portray the UES.Considering that the evaluation system may contain a large number of indexes and that there is overlapping information among them,an energy efficiency evaluation method based on data processing,dimensionality reduction,integration of combined weights,and gray correlation analysis is proposed.This method can effectively reduce the number of calculations and improve the accuracy of energy efficiency assessments.Third,a demonstration project for a UES in China is presented.The energy efficiency of each scenario is assessed using six operational scenarios.The results show that Scenario 5,in which parks operate independently and investors build shared energy-storage equipment,has the best results and is best suited for green and low-carbon development.The results of the comparative assessment methods show that the proposed method provides a good energy efficiency assessment.This study provides a reference for the optimal planning,construction,and operation of UESs with multiple energy sources.