Effects of open trench siding on vibration-screening effectiveness using the two-dimensional boundary element method

The two-dimensional boundary element method in frequency domain is used to investigate the screening effectiveness of the open trench–wall barrier system on reducing vibration generated by a footing. Sheet piles or diaphragm walls are on both sides of the open trench as a vibration barrier in this study. The results showed that screening effectiveness of the open trench without siding is greater than that of the open trench–wall barrier system, which is essential for stabilizing the excavation surface in practice. The trench depth of the barrier system appears to govern the screening efficiency of the barrier, and increase in depth results in better vibration-screening effectiveness. The influence of the open trench width, the embedded length of the trench wall and the distance between the vibration source and the barrier are proven to be insignificant. The screening effectiveness of an open trench barrier with walls increases with the frequency of the vibration.     

Three-layer model for vertical velocity distribution in open channel flow with submerged rigid vegetation

Based on the detailed laboratory experiments and theoretical analysis, a new three-layer model is proposed to predict the vertical velocity distribution in an open channel flow with submerged vegetation. The time averaged velocity and turbulence behaviour of a steady uniform flow with fully submerged artificial rigid vegetation was measured using a 3D Micro ADV, and the vertical distribution of velocity and Reynolds shear stress at different vegetation height, vegetation density and measuring positions were obtained. The results show that the velocity profile consists of three hydrodynamic regimes (i.e. the upper non-vegetated layer, the outer and bottom layer within vegetation); accordingly different methods had been adopted to describe the vertical velocity distribution. For the upper non-vegetated layer, a modified mixing length theory combined with the concept of ‘the new vegetation boundary layer’ was adopted, and an analytical model was presented to predict the vertical velocity distribution in this region. For the bottom layer within vegetation, the depth average velocity was obtained by numerically solving the momentum equations. For the upper layer within vegetation, the analytical solution was presented by expressing the shear stress as a formula fitted to the experimental data. Finally, the analytical predictions of the vertical velocity over the whole flow depth were compared with the results obtained by other researchers, and the good agreement proved that the three-layer model can be used to predict the velocity distribution of the open channel flow with submerged rigid vegetation.     

Open innovation and its discontents

This paper critically synthesizes empirics and issues in discrete inter-disciplinary literatures to identify ‘open innovation’ as part of an emergent regime of accumulation, overlaying and co-existing with flexible production, and encompassing novel firm-level strategies, new forms of corporate networks, and a disturbing capital-labor relation that informalizes innovative work while cultivating entrepreneurial but self-exploiting subjects. I explain the novelty of open innovation, its genealogy, and the implications for people and conditions of work as much as for firms in a new topology of power relations. I cast the ensemble of strategies and tactics encompassed in open innovation as contingent, continually unfolding, and sometimes chaotic if not destructive for both firms and labor, in contrast to the celebratory tone in the business as well as geography and regional studies literatures regarding its benefits for competitiveness, innovativeness, value capture, and development. Open innovation – the externalization of innovation – entails long-run approaches to innovation and investment that are fraught with problems, prompting the development of short-term tactics to engage the challenges. One short-run strategy, crowdsourcing, bypasses the conventional web of inter-firm relations to connect digitally with individuals of the global crowd, enabling firms to reap the benefits of the crowd’s innovative talents, often without remuneration under circumstances that institutionalize informal work. These neoliberal subjects are best understood in terms of multiple subjectivities. I close by connecting the crowdsourcing of innovative with non-innovative work, both of which are parts of the emergent regime associated with new hiring and work practices that usher in new modes of exploitation.     

The Panama Ship Registry: 1917–2017

The Panama Ship Registry has its origins in the year 1917. Nowadays, Panama has the largest vessel registry in the world. The second placed registry in the world ranking is Liberia, which does not have even half the number of Panamanian ships. In this Centennial, the aim of this paper is to analyse the evolution of the Panamanian Registry, the structure of the Panamanian-flagged fleet and the level of compliance with international standards in relation to maritime safety and working conditions. To undertake the analysis, two different qualitative and quantitative approaches are compared and integrated for the evaluation of the Panama Ship Registry: the degree of ratification and enforcement of the Conventions and Recommendations of the International Maritime Organization and International Labour Organization, and the results of Panamanian flagged vessels in inspections carried out within the major Port State Control Memoranda of Understanding. This paper fills a research gap by discussing an approach to the concept of flag of convenience and flag State, Panama is more an international registry, whose role is becoming less important from the points of view of safety or working conditions. The fleet performance evolution has been very positive as evidenced by the data presented in this article regarding Port State Control.     

A general model of lateral depth-averaged velocity distributions for open channel flows

This paper reviews a model, developed by Shiono and Knight [Shiono K, Knight DW. Two-dimensional analytical solution for a compound channel. In: Proceedings of the 3rd international symposium on refined flow modelling and turbulence measurements, Tokyo, Japan, July 1988. p. 503–10; Shiono K, Knight DW. Turbulent open channel flows with variable depth across the channel. J Fluid Mech 1991;222:617–46 [231:693]], which yields analytical solutions to the depth-integrated Navier–Stokes equations, and includes the effects of bed friction, lateral turbulence and secondary flows. Some issues about the original model developed by Shiono and Knight (1988, 1991) are highlighted and discussed. Based on the experimental data concerning the secondary flow, two assumptions are proposed to describe the contribution of the streamwise vorticity to the flow. Two new analytical solutions are compared with the conventional solution for three simple channel shapes and one trapezoidal compound channel to highlight their differences and the importance of the secondary flow and planform vorticity term. Comparison of the analytical results with the experimental data shows that the general SKM predicts the lateral distributions of depth-averaged velocity well.     

基于ODC的国产卫星影像存储与应用研究

随着地球观测进入大数据时代,传统的数据管理技术已经难以适应大数据需求, Open Data Cube （ODC）作为新型的开源的地球观测数据管理与分析平台,适合进行时间序列数据的高性能计算和探索性数据分析,是亚大区域综合地球观测系统AOGEOSS的重要技术支撑平台。但当前ODC对国产卫星影像支持不友好,缺乏自动化管理和数据组织工具,使用ODC进行国产卫星影像数据管理的技术不成熟。因此,本文以高分一号卫星影像为例,通过开发ODC_GFTool中间件和自定义高分卫星影像产品格式探索ODC框架下国产影像数据自动化管理流程,最后以鄱阳湖为试验区,进行了基于ODC框架的水体提取应用实验,论证了ODC框架下国产卫星数据存取的可行性,研究结果表明相较于传统的数据处理工具ODC具有明显的效率优势,能够为AOGEOSS基础设施建设和国产卫星影像数据管理提供一定的参考。     

VRI photometry of M67 for CCD standardization at 2.3m VBT

We present the results from CCD photometry in theV, R andI bands, of the ‘Dipper Asterism’ region of the open cluster M67 based on observations carried out at the prime focus of the 2.3 m Vainu Bappu Telescope of the Vainu Bappu Observatory, Kavalur. The CCD parameters like the system gain and the readout noise are measured using several flatfield frames taken through the standardI filter. The CCD chip is calibrated using the photometric standards in the field and linear colour transformation relations are derived. Also a few newVRI photometric measurements are reported for the members of the cluster.     

嵌入式移动GIS的基本功能的实现

论述了目前国内外嵌入式移动GIS的发展状况,论述了嵌入式移动GIS的开发环境,对嵌入式移 动GIS专门的Hmap控件及所需的数据格式等进行了介绍,强调了在使用Hmap控件的特殊要求,最后用此控 件对移动GIS的基本功能如:打开地图、放大、缩小等功能给予了实现并展示了其实现结果。     

Controlling boundary conditions with a four-dimensional variational data-assimilation method in a non-stratified open coastal model

An innovative way to take the large-scale circulation influence into account in coastal primitive-equation models is explored by an inverse modelling approach. Restricted to barotropic external forcing, this work is a first step in the development of a four-dimensional variational (4DVAR) data-assimilation approach to estimate the best initial and open-boundary conditions that force a coastal model according to interior observations. This development is founded on the OPA modelling system which representation of barotropic coastal dynamics is restricted to motions of long time scales ( a day) due to its rigid lid approximation. Twin experiments are performed in an academic configuration of the Gulf of Lions (located in the northwestern Mediterranean Sea) to study the sensitivity of a remote barotropic forcing to different observational networks measuring surface currents deployed in this area. Three monitoring designs are tested for a large-scale barotropic perturbation in the hindcast mode. It is shown that the space and time distribution of observations acts on the efficiency of the 4DVAR method and then allows coarser datasets.Responsible Editor: Phil Dyke     

An open cellular caisson breakwater

Ａｎｏｐｅｎｃｅｌｌｕｌａｒｃａｉｓｓｏｎｂｒｅａｋｗａｔｅｒ￥ＬｉＹａｎｂａｏａｎｄＺｈａｎｇＸｉａｏｍｉｎｇ（ＲｅｃｅｉｖｅｄＪｕｌｙ１５，１９９５；ａｃｃｅｐｔｅｄＳｅｐｔｅｍｂｅｒ１，１９９５）Ａｂｓｔｒａｃｔ：Ａｎｏｐｅｎｃｅｌｌｕｌａｒｃ...