A general framework to study the price‐color relationship in paintings with an application to Mark Rothko rectangular series

We propose a general framework to study the relationship between the price of a painting and its color‐related attributes. To this end we focus on four key aspects: dominant colors, features of the color palette, color harmony, and color emotions. We demonstrate the usefulness of this approach with an example based on Mark Rothko's post‐1950 paintings (the “rectangular” series), and auction data from the 1994 to 2018 period. We identify two distinct price‐color regimes in Rothko's market: (a) [1994‐2005], a period in which prices are explained mainly by the growing popularity of the artist regardless of the color attributes of the paintings sold; and (b) [2006‐2018], a period in which color‐related attributes explain most of the prices. Furthermore, we find that in this second period, the dominant colors and the diversity of the color palette, are by far the most relevant attributes that influence the price; color harmony and color emotions hold almost no explanatory power during this period. Finally, we propose a new metric based on the Herfindahl Index to describe color diversity; this metric seems to be promising at characterizing the effect of the color palette on the price of a painting.     

Electrolyte flow optimization and performance metrics analysis of vanadium redox flow battery for large-scale stationary energy storage

Vanadium redox flow battery (VRFB) is the best choice for large-scale stationary energy storage, but its low energy density affects its overall performance and restricts its development. In order to improve the performance of VRFB, a new type of spiral flow field is proposed, and a multi-physics coupling model and performance metrics evaluation system are established to explore the electrolyte distribution characteristics. The results show that the new spiral flow field can effectively improve the uniformity of electrolyte flow and alleviate the phenomenon of local concentration polarization as compared with the traditional serpentine flow field and parallel flow field. Due to the long flow channel and large pressure drop, the system efficiency is low. However, coulombic efficiency, voltage efficiency and energy efficiency are significantly better than the traditional flow fields. Therefore, the novel flow field has obvious advantages in the application of small stacks.     

APP软件性能效率研究

性能效率是APP软件的重要质量属性，但目前缺乏APP软件性能效率的通用模型。分析了APP软件的性能特征，基于ISO/IEC 25010标准提出了APP软件的性能效率模型，定义了APP软件性能效率的子特性和度量指标。基于提出的APP软件性能效率模型，通过实验对APP软件的性能效率进行了度量及相关分析。     

Analysis of the patent cooperation network in global artificial intelligence technologies based on the assignees

Studying the distribution of the patent cooperation networks from the perspective of assignees provides a very important reference to improve the analysis of the market situation, master the layout of industrial technology and seek partners or mergers and acquisitions. This study uses the Derwent patent database and the patent metric approach to investigate the cooperative network structure of the assignees. The overall patent output in the artificial intelligence field on a global scale exhibited a rapid growth, and the proportion of cooperative patents significantly increased; the cooperation structure between the assignees was loose, and the innovation efficiency was low.     

Real-world single image super-resolution: A brief review

Single image super-resolution (SISR), which aims to reconstruct a high-resolution (HR) image from a low-resolution (LR) observation, has been an active research topic in the area of image processing in recent decades. Particularly, deep learning-based super-resolution (SR) approaches have drawn much attention and have greatly improved the reconstruction performance on synthetic data. However, recent studies show that simulation results on synthetic data usually overestimate the capacity to super-resolve real-world images. In this context, more and more researchers devote themselves to develop SR approaches for realistic images. This article aims to make a comprehensive review on real-world single image super-resolution (RSISR). More specifically, this review covers the critical publicly available datasets and assessment metrics for RSISR, and four major categories of RSISR methods, namely the degradation modeling-based RSISR, image pairs-based RSISR, domain translation-based RSISR, and self-learning-based RSISR. Comparisons are also made among representative RSISR methods on benchmark datasets, in terms of both reconstruction quality and computational efficiency. Besides, we discuss challenges and promising research topics on RSISR.     

Comprehensive performance analysis of objective quality metrics for digital holography

Objective quality assessment of digital holograms has proven to be a challenging task. While prediction of perceptual quality of the recorded 3D content from the holographic wavefield is an open problem; perceptual quality assessment from content after rendering, requires a time-consuming rendering step and a multitude of possible viewports. In this research, we use 96 Fourier holograms of the recently released HoloDB database to evaluate the performance of well-known and state-of-the-art image quality metrics on digital holograms. We compare the reference holograms with their distorted versions: (i) before rendering on the real and imaginary parts of the quantized complex-wavefield, (ii) after converting Fourier to Fresnel holograms, (iii) after rendering, on the quantized amplitude of the reconstructed data, and (iv) after subsequently removing speckle noise using a Wiener filter. For every experimental track, the quality metric predictions are compared to the Mean Opinion Scores (MOS) gathered on a 2D screen, light field display and a holographic display. Additionally, a statistical analysis of the results and a discussion on the performance of the metrics are presented. The tests demonstrate that while for each test track a few quality metrics present a highly correlated performance compared to the multiple sets of available MOS, none of them demonstrates a consistently high-performance across all four test-tracks.     

Planning an ecological network of Xiamen Island (China) using landscape metrics and network analysis

Most Chinese municipal governments and urban planners have attempted to conserve and create urban greenspace in response to rapid urbanization. It is a major task for urban landscape planners to construct an effective and harmonious urban ecological network and maintain a sustainable urban development environment. In this paper, the present situation and a recent greenway augment plan of Xiamen Island were assessed using a series of landscape metrics. The results showed that the recent greenway augment plan could improve the present greenway system considerably. The improvements were indicated by decrease in patch density, and increase in total class area and edge density on the patch level, landscape diversity, landscape evenness and landscape connectivity on the landscape level. On the basis of these analyses, a number of alternative planning scenarios were designed by using network analysis methods for improving the ecological network of Xiamen Island. An alternative planning scenario was proposed to decrease the degree of landscape fragmentation, increase the shape complexity of greenway patches and enhance the landscape connectivity. The results indicated that methods which integrate landscape metrics with network analyses could not only quantitatively assess the present situation and the rationality of planning for urban greenway systems, but also facilitate the design of planning scenarios for urban ecological networks, enabling them to meet the principles of conformity, harmony, circulation, safety, diversity and sustainability. The principles and methods of landscape ecology, and the greenway concepts that have originated in the West can be useful for Chinese landscape planning and can be applied to greenway development in China.     

Evaluating the land use patterns of medium-sized Hellenic cities

Land use morphology has profound effects both on city functions and peri-urban areas. They can either lead to conflicts with negative side effects or generate positive synergies. This study focuses on land use spatial configurations and interprets the interactions among them. In order to evaluate spatial planning policies, the measurement of urban land use patterns is considered to play an important role in the urban development process and deserves further attention. A comparative analysis of the land use patterns of the medium-sized Hellenic cities is attempted, there are also used using pre-existing metrics, some new data from the European Environment Agency Urban Atlas 2006 geodataset and population and construction census data concerning the last decade from the national Hellenic Statistical Authority data set. The Larger Urban Zones of the medium-sized Hellenic cities are chosen as a suitable study level based both on population size and socio-spatial procedures. The results provide interesting information about the diversification among medium-sized cities, while some particularities concerning urban procedures appear to emerge for some of them. Many discussion points arise from this study concerning the data availability, the method, the functional city area delineation and the Larger Urban Zones definition.     

基于M-C 的高维SEA 方法

针对高维指标的系统效能分析(system effectiveness analysis,SEA)方法的应用难点,在系统数值仿真的基础上研究高维性能指标联合概率密度函数拟合,通过将联合概率密度函数应用于计算高维数值积分的蒙特卡罗平均值方法中,得到一种解决SEA中高维性能指标效能分析的蒙特卡罗数值方法,并用实例进行验证评估。结果表明：该方法是有效、实用的,能为SEA方法中涉及高维指标的分析提供一种行之有效的方法。