Distributed ledger technology in supply chains: a transaction cost perspective

With the emergence of distributed ledger technology (DLT), numerous practitioners and researchers have proclaimed its beneficial impact on supply chain transactions in the future. However, the vast majority of DLT initiatives are discontinued after a short period. With the full potential of DLT laying far down the road, especially managers in supply chain management (SCM) seek for short-term cost-saving effects of DLT in order to achieve long-term benefits of DLT in the future. However, the extant research has bypassed grounding long-term as well as short-term effects of DLT on supply chain transaction with empirical data. We address this shortcoming, following an abductive research approach and combining empirical data from a multiple case study design with the corresponding literature. Our study reveals that the effects of DLT on supply chain transactions are two-sided. We found six effects of DLT solutions that have a cost-reducing or cost avoidance impact on supply chain transactions. In addition, we found two effects that change the power distribution between buyers and suppliers in transactions and a single effect that reduces the dependency of supply chain transactions on third parties. While cost-reducing and avoidance as well as dependency-reducing effects are positive effects, the change in power distribution might come with disadvantages. With these findings, the paper provides the first empirical evidence of the impact of DLT on supply chain transactions, which will enable managers to improve their assessment of DLT usage in supply chains.     

Analysis of Radio over Fiber system for mitigating four-wave mixing effect

In this paper, an efficient 8-channel 32Gbps RoF (Radio over Fiber) system incorporating Bessel Filter (8/32 RoF-BF) has been demonstrated to reduce the impact of non-linear transmission effects, specifically Four-Wave Mixing (FWM). The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t. channel spacing (75 GHz), input source power (0 dBm) and number of input channels (8). In comparison with the existing RoF system, the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.     

我国建筑石料用灰岩采矿权成交价变化分析

砂石资源采矿权出让收益是地方财政收入的重要来源。近年来,砂石资源供应紧张价格大幅上涨的背景下,本文以典型的砂石资源建筑石料用灰岩为例,分析了全国及部分典型省份建筑石料用灰岩采矿权成交价的变化特征,主要结论是2011～2018年我国建筑石料用灰岩采矿权平均成交单价与砂石市场供应价格均呈上升趋势但前者涨幅远高于后者,并且采矿权成交单价的区间分布结构年度变化差异也较大,不同区域平均成交单价年度变化规律分异明显,贵州、甘肃两省采矿权成交单价相对较低且变化幅度相对较小,山西、吉林、湖北、广西4省采矿权成交单价相对较高且变化幅度相对较大。最后,从平抑砂石价格过快上涨、加强矿业权市场建设、促进砂石资源区域供需平衡、维护良好砂石市场价格秩序的角度提出了有关政策建议。     

Winkler地基上有限板问题的计算

文献给出了Winkler地基上无限大板在集中力作用下的解。本文在此基础上,利用零阶柱函数的性质,导出了Winhler地基上无限大板在集中力偶作用下的解。对于有限板问题,采用补偿荷载法求解,可较好地解决此类问题。     

Transport in regional science: The “death of distance” is premature

Transport costs have always been an important dimension in regional science. It is therefore remarkable that regional science and transport economics have developed in a rather unconnected way. Although being distinct, the routes of the two were parallel, and there are signs that the two fields will get closer to each other. This paper further discusses long run trends in transport costs and the potential spatial consequences. The main conclusion is that although in terms of money and time, the performance of transport has improved enormously, many economic activities have not become footloose to the extent as expressed by the notion of death of distance. One of the reasons discussed is the role of transaction costs, some being clearly related with distance.JEL Classification: R0, R4The authors thank the guest-editors and an anonymous referee for helpful comments.     

农村工业化地区的城市更新:从破碎到整合——以佛山市南海区为例

空间破碎是农村工业化地区实施城市更新的主要制约,如何整合是重要的实践和学术课题。本文以“问题-对策”为分析框架,以佛山市南海区为例,从广度层面揭示出三类空间破碎及其对改造的约束机理和现有改造的整合特征,并通过深度的案例比较探究空间整合的关键所在。研究发现:物质和权属的空间破碎是该类地区的典型特征,改造又衍生出政策空间破碎;破碎增加交易成本,阻碍用地整合;现实中的整合改造是少数;在市场资本的驱动下,政府推动整合的效果显著。以“交易中间人”的角色统筹改造彰显出政府降低交易成本以协同市场的职能回归。     

多学科结合,实现裂缝控制——读《钢筋混凝土结构裂缝控制指南》

对《指南》中的一些观点进行了讨论,认为将补偿收缩混凝土等抗裂新材料排斥在《指南》之外,仅强调"好好打"存在局限性。赞赏"抗放兼施"的混凝土抗裂原则,提倡只有多学科结合,才能实现混凝土结构的裂缝控制。     

国典大厦地下室高强大体积混凝土裂渗控制

国典大厦地下室混凝土属于高强大体积抗渗混凝土,各层楼板混凝土还采用了空心管技术。工程重点控制楼板内部BDF空心管的上浮及混凝土超长施工不开裂的问题,通过严格精细的施工,达到了预期的目标。     

浅谈住宅楼地下室建设防水技术的创新与应用

就住宅楼地下室采用超长钢筋混凝土结构无缝设计新技术,对地下室结构自防水进行了分析,并在施工中采取了一定的防水技术措施,取得了良好的防水效果。     

长度投影变形计算的应用

在测绘大比例尺地形图、建筑施工放样、线路测量和井下贯通测量工作中,要求选择适合的投影面和投影带,其主要目的是解决长度变形问题,本文阐述了长度投影变形理论在实际测绘工作中的应用。