基于显著区域提取的红外图像舰船目标检测

针对复杂海面背景下红外图像舰船目标由于灰度不均匀、海杂波干扰大等因素造成的自动检测虚警率高、准确率低的问题，提出了一种显著区域提取和目标精确分割相结合的红外舰船目标检测方法。首先，利用基于图论的视觉显著性(Graph-based Visual Saliency ,GBVS)模型计算待检测图像的显著图，使得目标区域信息增强；其次，结合舰船目标先验信息（长短轴、面积等），利用多级阈值划分算法提取关注的显著区域，并确定原图中候选目标区域；最后，利用空间约束模糊C均值(Fuzzy C-Means,FCM)算法对候选区域进行分割，结合目标先验知识对分割区域筛选并输出目标位置。所提方法在公开数据集IRShips上与相关方法进行比较，结果表明，相比直接进行全图目标搜索的方法，所提方法不仅准确率高、执行速度快，且检测目标的位置更加精确。     

利用频移动态特征的辐射源目标盲分选

利用辐射源目标的频移动态特征进行盲分选时，针对已有的分选方法不能很好解决非合作接收数据非周期、间断、交叠的问题，提出了一种改进的逻辑回归分选算法,将信号分选转化为轨迹分类的问题来处理。首先，借鉴多目标航迹起始模型中的M/N逻辑法的框架，设计新的数据关联门限，以建立目标起始曲线；其次，采用最小二乘拟合方法替代卡尔曼滤波，设计新的外推规则，建立载频变化预测曲线；分析新的接收数据与预测曲线的关联性，不断迭代回归或形成新的分支，最后获得目标分选结果。仿真与实测试验表明，利用逻辑回归分选算法，对不同运动目标搭载的同频辐射源可进行自动分选，4个仿真目标与2个真实目标的分选正确率达到100%。同时，该方法拓展了辐射源目标盲分选中的动态频移特征应用，为辐射源个体识别提供了新的支持。     

Fuelled Power: Oil,Financiers and Central Bank Policy in Nigeria

While the literature on business power and global finance has illuminated the ways in which financial institutions limit the policy autonomy of states in developing countries, we know much less about the circumstances under which the power of financiers is undermined. In this article, I advance explanations of these circumstances by arguing that state access to natural resource revenues reduces the power of financial institutions and enhances the capacity of the state to pursue central bank policies which violate the interests of major financiers. I employ a case study of central bank policy in Nigeria to probe this argument and find evidence that supports the claim that whenever the Nigerian government's access to resource revenues increased, the state's capacity to diverge from financiers’ preferred central bank policies and to advance its own preferences increased as well. The analysis provides the basis for broader propositions about the policy space of developing countries vis-à-vis financial institutions and the variability of structural power.     

Firm performance and corporate finance in New Zealand

Low productivity growth in New Zealand has been a paradox. We study New Zealand firms’ profitability, in terms of profit margin and return on assets (ROA), from the viewpoints of productivity enablers using firm-level panel data. We find that tangible fixed investment and a research and development (R&D) tax incentive are associated with higher profitability performance. In addition, the firm size is found to be a key determinant of profit margin. By contrast, we do not find any evidence that intangible investment can improve the profitability. The global financial crisis has not changed the leverage effect on ROA in New Zealand, while the impact of R&D became more prominent after the crisis.     

The pricing of European airbnb listings during the pandemic: A difference-in-differences approach employing COVID-19 response strategies as a continuous treatment

The COVID-19 pandemic has been a major shock to the global tourism industry. Given its peculiarity, this paper analyzes one of the most intriguing questions in the Airbnb literature – the pricing of Airbnb listings – by taking advantage of a difference-in-differences methodology that largely draws on variations in country-level policy responses to the pandemic. Relying on a dataset containing weekly information from 130,999 continuously active listings across 27 European countries from 2019 to 2020, this study first investigates the exogenous impact of response policies (proxied by the COVID-19 Stringency Index) on demand. Secondly, accounting for the endogeneity of both demand and prices, this research analyzes pricing responses to demand variations. Results show that: i) increases in the COVID-19 Stringency Index cause significant declines in Airbnb demand; ii) increases in demand cause, on average, increases in Airbnb prices; and iii) pricing strategies between commercial and private hosts differ substantially.     

A decision support model for buying battery electric vehicles considering consumer learning and psychological behavior

Developments in battery electric vehicles (BEVs) have received more and more attentions in the last decades due to alleviating carbon emissions and energy crisis. Consequently, how to rank alternative BEVs to assist consumers make better purchasing decisions is a worthy research study. However, there are still some defects in the existing studies for ranking of BEVs: 1) the evaluation index system of BEVs is not comprehensive; 2) the determination of criteria weights cannot be well applied to the actual purchase scenarios; and 3) the psychological behavior of consumers is ignored. To address those shortcomings, this paper proposes a decision support model to assist with consumers to buy BEVs. First, a systematic evaluation criteria system of BEVs including quantitative and qualitative indicators from parameter configurations and online reviews is constructed. Then, a weight algorithm considering consumer learning is proposed to determine the criteria weights. Furthermore, a decision support process considering consumers' regret avoidance behavior is proposed. Finally, an actual BEV purchase case is given to illustrate the practicability of the decision support model. This can be seen in case studies the proposed support model can be well applied to consumers with different regret avoidance behaviours.     

Identifying the ‘knowledge base’ or ‘intellectual structure’ of research on international business, 2000–2015: A citation/co-citation analysis of JIBS

The purpose of this study consists in analyzing the existing literature on international business from all the research papers published in Journal of International Business Studies (JIBS) during the period of time comprised between 2000 and 2015. The authors apply bibliometric methods to that end –in particular, document citation and co-citation analyses (DCAs)– so that they can try and identify the main research lines within the aforementioned scientific field or domain; in other words, the ‘intellectual structure’ of the discipline examined. Social networks analysis was also used to carry out the representation or visualization of such structure or knowledge base. The highly interdisciplinary nature of the research undertaken, since the study field still keeps its characteristic diversity and interdisciplinarity or the need to integrate a variety of theoretical frameworks or approaches into the development of a widely-accepted theory about the field under study become evident. Amongst these theories would be the new institutional theory, the strategic theory or perspective or others such as the transaction cost theory or the agency theory, applied to the context of internationalization and to the field of international business, on whose integration the future development of this field may largely depend.     

Marx 200: The Abiding Relevance of the Labour Theory of Value

ABSTRACT

Marxist political economy is alive and well, and not just because of the habitual turn to Marx in response to any crisis of capitalism. Both through Capital and through the continuing evolution of Marxism, Marxist political economy offers valuable insights that can illuminate the modalities of social and economic reproduction and the relationships between (different aspects of) the economic and the non-economic. Marxism’s presence has been felt through its own internal debates and debates with other approaches to political economy, and even through its influence on those reacting against Marxism. The key to the continuing relevance and analytical strengths of Marxist political economy lies in its capacity to provide a framework of analysis for unifying disparate insights into and critiques of the contradictions of capitalism across the social sciences. The instrument for forging that unity is Marx’s theory of value, the potential of which is examined and illustrated with reference to the Sraffian critique and two key concepts in Marxian political economy: the value of labour power and financialisation. They are explored in the light of the processes of commodification, commodity form and commodity calculation.     

Using artificial neural network and multivariate analysis techniques to evaluate road operating conditions

Regional paved roads are low volume roads with a prevalence of heavy traffic. In the world, these roads concern about 80% of the total road network; however, the traffic that affects these roads is about 20%. Since regional roads are characterized by weak demand, budget for their management/maintenance is very low. This produces considerable difficulties in the choice of strategies for maintenance planning and scheduling. For this reason, the recurring topics of research in this field deal with typical roads issues and aim to develop low cost tools and methods. The study proposes a decision support system to evaluate regional paved roads operating condition in relation to the hydrogeological situation. In particular, the system allows to evaluate in a quick and easy manner, the operating conditions of the road, through low-cost tools (i.e. using low economic resources). This is very useful in the case of LVRs because administrations for these roads have a limited budget. The procedure is developed on a regional paved roads network based on more than 80 roads located in Southern Italy. Data is collected by direct surveys in the field and is integrated with cartography and information available in road agency records. From data analysis, obtained using two different techniques, an easy and quick use procedure is made. In particular, Model 1 is built through multivariate analysis and Model 2 using the artificial neural network (ANN) technique. The results show the validity of the two models in Regional paved roads operating conditions estimation in relation to hydrogeological situations of sites. Both models show good reliability. In particular, the first model (Model 1) is characterized by a high level of significance (p < 0.01) and by a coefficient of determination equal to 0.82. Comparative tests between the second model (Model 2) on which standard tests cannot be performed for obvious reasons, and the first model (Model 1). The results show that the ANN model (model 2), characterized by lower residual, simulates more accurately than the second (Model 1).     

战术面向服务架构概念及相关技术

战术面向服务架构（TSOA）是实现战术云平台服务基础设施的重要支撑概念。由于战术环境的复杂性，目前对TSOA实施过程中面临问题和相关实现技术的总结还较少。为此，开展了针对TSOA的概念以及相关技术的研究。首先，从战术环境下的TSOA架构需求背景出发，介绍了TSOA架构的组成以及适应性特征；然后，通过分析战术环境下设备和网络等多方面存在的限制性因素，明确实施TSOA架构所面临的挑战以及需要解决的关键问题，并对实现过程中涉及的服务发现、消息传输机制、网络状态自适应等相关技术进行归纳；最后，对国内外的相关研究工作进行总结，期望对推动TSOA架构的具体实施提供一定参考。