A saddlepoint approximation to the distribution of the sum of independent non‐identically uniform random variables

Calculating the probability of the corresponding significance point is important for finite sample sizes. However, it is difficult to evaluate this probability when the sample sizes are moderate to large. Under these circumstances, consideration of a more accurate approximation for the distribution function is extremely important. Herein, we performed a saddlepoint approximation in the upper tails for the distribution of the sum of independent non‐identically uniform random variables under finite sample sizes. Saddlepoint approximation results were compared with those for a normal approximation. Additionally, the order of errors of the saddlepoint approximation was derived. © 2014 The Authors. Statistica Neerlandica © 2014 VVS.     

Circular economy and the policy: A framework for improving the corporate environmental management in supply chains

The transition to the circular economy (CE) creates value through the closed-loop systems, reverse logistics, product life cycle management, and clean production in terms of corporate environmental management. During this transition process, the organization faces many barriers such as financial, organizational, technology-based, social, policy-related, market-based, and logistics-based barriers. The objectives of this study are to propose a framework highlighting policy-related barriers for a supply chain in the transition to CE and finally discuss potential implications on enhancing corporate environmental performance of a business. Further, this study evaluates the causal relationships between the policy-related barriers using fuzzy Decision-Making Trial and Evaluation Laboratory (DEMATEL) method. The application was conducted in an apparel firm in Turkey. From findings, lack of legislation for efficient CE (C4), lack of mandatory requirements and responsibilities for manufacturers/suppliers for the CE (C17), and lack of government support for environmentally friendly policies (C2) are revealed as the most important barriers, respectively. It is found that lack of attitude and awareness about CE in government institutions (C19) is the most influencing factor, whereas lack of effective recycling policies to achieve quality in waste management (C8) is the most influenced factor. The recommendations were developed for enhancing the corporate environmental performance of businesses through incentives and unique rewards, improving communication among stakeholders, the government's perception of CE and current linear economy, cooperation with nongovernmental organization (NGOs) and civil actions, the vision of government towards circular principles, the circular public procurement, the local governments in circular policymaking, and awareness of bureaucracy and government officials.     

Ad hoc网络中基于多波束天线的集中式低时延调度算法

UxDMA算法是一种高效的集中式算法，是用于时分多址、频分多址和码分多址信道分配的统一算法。在UxDMA的基础上，利用多波束天线的多波束形成能力，针对低时延定向ad hoc网络提出了一种集中式调度算法——CLSM(Centralized Low-delay Scheduling Algorithm Based on Multi-beam Antennas)。CLSM通过不同时延等级限制的报文来比较着色后发送链路的优先级，优先选择高优先级链路传输。通过仿真验证了CLSM的性能：与UxDMA相比，该算法在多时延限制的发送端调度中表现出了更好的吞吐量和时延性能。     

Local Powers of Optimal One‐sample and Multi‐sample Tests for the Concentration of Fisher‐von Mises‐Langevin Distributions

One‐sample and multi‐sample tests on the concentration parameter of Fisher‐von Mises‐Langevin distributions on (hyper‐)spheres have been well studied in the literature. However, only little is known about their behaviour under local alternatives, which is due to complications inherent to the curved nature of the parameter space. The aim of the present paper therefore consists in filling that gap by having recourse to the Le Cam methodology, which has recently been adapted from the linear to the spherical setup. We obtain explicit expressions of the powers for the most efficient one‐ and multi‐sample tests. As a nice by‐product, we are also able to write down the powers (against local Fisher‐von Mises‐Langevin alternatives) of the celebrated Rayleigh test of uniformity. A Monte Carlo simulation study confirms our theoretical findings and shows the empirical powers of the above‐mentioned procedures.     

多孔结构建筑材料力学性能的有限元分析

多孔材料是一种新兴的材料,制备较易,成本较低。相对于一般连续介质材料而言,多孔材料具有比强度高、比表面积高、相对密度低、重量轻、隔音、隔热等优点。它最大的特点是具有排列规则、大小可调的孔道结构,在建筑材料中也有很多的应用。因此,对非均匀孔洞与均匀孔洞建筑材料力学性能的研究是很重要的课题。论文通过建立非均匀孔洞和均匀孔洞的有限元模型,对比分析两种模型的受力性能,更好地进行多孔建筑材料的推广和使用。     

Sustainable consumption in China: New trends and research interests

China is currently the largest CO₂ emitter in the world and demonstrates one of the highest levels of energy consumption. The sustainable consumption behavior has increased in China, especially in urban cities. Some clear evidence of this includes food purchasing behavior. Recent studies have also suggested that considering full product information transparency, consumers are willing to pay premium prices for products. With this in mind, sustainable consumption must still be facilitated by related policies, regulations, and tools. This study focuses on sustainable consumption behavior in China and collects and analyzes the literature from the last decade (2007–2017) on the topic. In so doing, it highlights new trends and research topics against the background of circular economy development. The method of systematic review is applied. The review is categorized into several main groups: national policies and regulations, the green awareness of consumers, the definition of related concepts, the barriers between sustainable consumption and the circular economy, and the indicators for circular economy assessment in China. Future research directions are discussed. Furthermore, future challenges are addressed from three perspectives: sustainable consumption facilitating the circular economy, “cradle‐to‐cradle” practices, and the link between the European Union and China. This is a fundamental study in the research domain of sustainable consumption behavior. It provides added value that benefits both academic researchers and decision makers. It also sheds light on the further study of sustainable consumption behavior in China from a macroeconomic perspective.     

AKL9401TDP低平板半挂车道路通过性分析

以AKL9401TDP低平板半挂车为研究对象,建立道路通过性的计算模型,并基于解析方法分析最小转弯直径和转弯通道宽度两个参数。研究结果表明,整车道路通过性能满足使用要求。     

Designing business models in circular economy: A systematic literature review and research agenda

The concept of circular economy is increasingly receiving attention in different domains, including strategic management, operations management, and technology management. It requires companies to design their business model (i.e., the value network, the relationships with the supply chain partners, and the value propositions towards customers) around a new concept of sustainable development that reduces consumption of natural resources and preserves the environment. However, extant research falls short in terms of explaining how companies design their business model according to the circular economy principles. Starting from this premise, the present paper provides a systematic review of the literature on the design of business models in the context of circular economy, aiming to offer an overview of the state of research and outline a promising research agenda.     

Determinants of consumer demand for circular economy products. A case for reuse and remanufacturing for sustainable development

We investigate determinants of consumer demand for circular (reused and remanufactured) products. Based on exploratory choice-based conjoint experiments with a sample of 800 adults in the United Kingdom, we examine two types of premium segment electronic appliances: a mobile phone and a robot vacuum cleaner. We find that consumers prefer partly circulated products over fully or not at all circulated products and that circular products can likely successfully enter the existing market at the retail price of a new product. Interestingly, circular products compete for market share primarily with new products, leaving the market share of second-hand options less affected. The results show a promising path for firms considering a transition to circular business models.