关于轨道交通声屏障结构优化的仿真分析

采用有限元—无限元耦合法,依据有关文献的声屏障模型进行有限元建模,验证基于有限元—无限元耦合法的Actran软件计算声屏障插入损失。在通过试验验证无声屏障时路基线路模型可靠性的基础上,进而对表面带有凸起的声屏障结构进行数值仿真计算分析;研究表面带有圆形凸起和表面带有三角形凸起的声屏障结构的扩散体宽度、间距及突出高度分别对其降噪效果的影响,并优化其各自结构参数,为设计效果达标、结构合理和外形美观的声屏障提供理论依据。     

海岸工程设计波要素推算方法探讨——以如东人工岛设计波要素推算为例

以如东人工岛设计波要素推算为例,分别利用历史台风天气图推算法和设计风速推算法推求不同重现期设计波要素并进行对比分析。结果表明,两种方法各有优劣,但历史台风天气图推算法的计算精度比设计风速推算法的精度差,为了安全起见,建议采用设计风速推算法。     

航运企业投资对码头运营效率的影响研究

随着港口投资结构多元化、航运企业向综合物流商转变,“港航合一”成为航运业未来的发展趋势.在此背景下,研究航运企业投资对码头的影响能够为码头健康发展提供一定的理论依据.本文先采用三阶段DEA模型对我国沿海集装箱码头2008–2012 年间的运营效率进行测度,其次依据投资结构将我国沿海62 个集装箱码头进行分组,最后重点分析投资结构与码头运营效率之间的关系.研究结果显示,有航运企业投资的码头运营效率普遍高于无航运企业投资的码头,两组码头的纯技术效率相差较小,而规模效率相差较大.航运企业参与码头建设经营可以实现自有船舶挂靠自有码头,提升码头设施的利用率,从而提升码头的规模效率,有利于码头的健康发展.     

A case study related to the improvement of working and rest hours of oil tanker deck officers

Navigation safety on coastal waters is an extremely important issue. Fatigue is an important factor threatening navigation safety. Considering that the vessel type is an oil tanker, such a threat is not posed only to the crew but also to the environment. Most of the tankers navigating coastal waters are in the small tanker category. Therefore, this study examined the working and resting hours of the deck officers in the oil tankers navigating coastal waters. The study utilized the ISF Watchkeeper 3 program for assessing and interpreting the working periods. The study reached the conclusion that the first and second officers in particular are working under unsuitable conditions. To improve the working conditions of the deck officers, effects of additional cargo officer on board was investigated. This study is in quality of recommendation. The study elucidated that the cargo officer practice determines the working and resting hours of deck officers, in the work on the oil tankers, and compliance with the related conventions.     

The Methodologies of Empowerment? A Systematic Review of the Deployment of Participation in the Coastal Zone Management Literature

Participation (e.g., stakeholder involvement) has become a central concept in the practice of environmental and coastal zone management. Research has shown that the integration of participation in coastal zone management has positive ecological and social outcomes. In the literature, however, participation is often reported in an unstructured and uncritical manner. Therefore, to find out whether and how there is a useful way to structure and characterize the way the coastal zone management literature deals with participation, we have conducted a literature review. The review was conducted and the literature structured through three central dimensions of participation, namely: power, knowledge, and (visions of) nature. The article concludes that this structured approach to participation enables us to study more systematically the role of participation and might facilitate the governance and learning processes of coastal networks.     

Managing Shoreline Change Under Increasing Sea-Level Rise in Ghana

Relative sea-level rise will affect vulnerable coastal communities globally. Quantifying this effect on the coastal environment and infrastructure provides critical information that enables coastal managers to develop sustainable mitigation and adaptation measures. Modeling applications have enabled the past, present, and future trends in shoreline morphology to be investigated in detail. Predictive numerical models depend largely on the reliability of the input data. This article reports on using the Soft Cliff and Platform Erosion (SCAPE) numerical model to simulate future shoreline evolution trend in the central Accra coast in Ghana. The model input parameters include historic shoreline recession rates, wave data, tidal data, bathymetry, beach volume, beach topography, historic relative sea-level rise rates, and the shoreline orientation. The data fed the SCAPE numerical model which simulated the emergence of soft rock shore profiles over timescale of decades to centuries, to project future positions of the central Accra shoreline for the next 100 years under different scenarios of climate change. Simulated future shoreline positions overlaid on a 2005 orthophoto map of Accra enabled vulnerable areas and infrastructure at risk to be identified. It emerged that a highly populated community in central Accra will be inundated by 2065, while the Rivera beach resort will be eroded from 2035. A natural fish landing site in Osu (suburb in Accra) will be lost from 2045. The study has demonstrated that considerable ecological, economic, social, and national losses should be expected within the next century. Shoreline change management options should be explored to help mitigate the expected impact of the sea-level rise.     

Use of GIS-Based Models for Integrating and Developing Marine Fish Cages within the Tourism Industry in Tenerife (Canary Islands)

Site selection is a key factor in any aquaculture operation, affecting both success and sustainability. Moreover, it can solve conflicts between different coastal activities, making a rational use of the coastal space. Geographical information systems (GIS) have become of increased significance for environmental planning and assessment mainly because of the need to compare a great number of spatially related data, and because it can be used to couple these spatial data with their attributes and overlay them. This study used GIS and related technology to build a spatial database using those criteria which were considered to have any influence in integrating marine fish-cage culture within the tourism industry in Tenerife. Criteria were grouped in three submodels (distance to beaches, nautical sports, and viewshed), which were combined to generate a final output showing the most suitable areas for cage culture development in coexistence with tourism. Most areas of the coastline of Tenerife were identified as being suitable (56%) or very suitable (46%), suggesting that marine cage aquaculture could be developed on the island in coexistence with the well-established tourism industry.     

Financing Beach Improvements: Comparing Two Approaches on the Georgia Coast

Fifty-five percent of Georgia's developed coastline has been armored with various types of erosion protection devices. This article is about beach improvement projects at Jekyll Island that would operate under (a) a nourishment policy or (b) a retreat policy. Benefits are calculated from an intensive, on-site survey of beach visitors and the costs are calculated from observable sources. Two financing methods are considered: general revenue and user fee financing. The analyses imply recommending beach improvement as an effective policy within the considered time frame.     

The Role of Spatial Data Management Strategies in ICZM in Ireland

This article explores how a fresh approach to integrated coastal zone management (ICZM) in Ireland might be forged through the identification of a number of key innovative cross-sectoral professional initiatives and interdisciplinary academic thinking in this sector. It includes three interlinked research themes that assess existing cross-sectoral data management issues (to include an assessment of readiness for the INSPIRE and compliance with the Re-use of Public Sector Information European Union Directives), the degree of cross-pollination between the various sectors involved in managing the Irish Coastal Zone (to identify the need (or otherwise) for capacity- building to encourage cross-fertilization of ideas, skills, and knowledge exchange), and cross-professional competencies (to assess the desire/need (if any) for those working in coastal zone management to add to their existing competencies through continuous professional development or lifelong learning opportunities). Indeed, the specific competencies for coastal practitioners are identified here and these further illustrate the need for professional recognition of the role, responsibilities, and therefore the requirement for an appropriately qualified “Coastal Manager” professional, one that is seen not merely as a nicety but rather a necessity—a core enabler in any future innovative and integrative management approach.