Factors Influencing Behavior in a Boating Speed Zone

The greatest source of human-related mortality for endangered Florida manatees is collisions with watercraft. Regulation of boat speeds is the principal management tool to minimize this threat. Demands on law enforcement limit their ability to monitor boater behavior and managers seek alternative strategies to increase compliance. The purposes of this study were to: (1) explore the effectiveness of an on-site sign to enhance boater compliance in a boating speed zone, and (2) examine the environmental and boating characteristics that influence the probability of compliance. Signs designed to increase compliance were posted halfway through the 18-week study period. The signs were not related to compliance level. Logistic regression models showed that only time of day and boat type were significantly related to compliance. Results suggest that passive methods of persuasion may not be an effective means of influencing boater behavior.     

Evaluating Boating Safety Risk in Intracoastal Waterways

Growth in the number of recreational vessels that use inland and coastal waterways, coupled with the diversity of boating activities, results in increased boating-related conflicts, accidents, and fatalities. This situation has led to numerous requests from boaters, shorefront property owners, waterfront businesses, and local governments for the imposition and enforcement of boating safety speed zones within Florida's Intracoastal Waterways. A decision-support framework that incorporates Geographic Information Systems (GIS)–based risk assessment was developed to assist the Florida Fish and Wildlife Conservation Commission's Division of Law Enforcement evaluate requests and applications for the establishment of boating safety zones, pursuant to the Florida Administrative Code Rule 68-D-23.105 “Criteria for Approval of Regulatory Markers.” The risk assessment uses geospatial data compiled from multiple government agencies, survey data from subject matter experts, and public input from participatory workshops. Relevant spatial data includes waterway features and marine infrastructure from field surveys, vessel traffic patterns observed and mapped from aerial reconnaissance, and indicators of boater behaviors extracted from accident and citation reports. The outcome is a characterization of waterway segments according to perceived risk to boating safety. The application was tested in two Florida counties and it helped guide the establishment of new, and the revision of existing, boating regulatory zones within their Intracoastal Waterways. The application design is such that it is adaptable to waterways beyond those in Florida.     

Developing a Spatially Enabled Inventory of Recreational Boats Using Vessel Registration Data

Effective waterway management requires information on the characteristics and locations of boats. A field-based boat census—a traditional method to obtain spatially accurate information—is relatively expensive, time-consuming, and restrictive in scope. Vessel registration data, maintained by all U.S. states, is potentially a more robust information source. This research evaluated the accuracy and reliability of vessel registration data to supply location and attribute information for boats. The study premise was to use vessel registration data, which includes the mailing address of registered boat owners, to develop a spatially enabled inventory of boats. The study area comprised 12,064 salt-water accessible property parcels in two Florida counties. An on-water census (OWC) provided location and characteristics for 5,023 vessels, which were compared to 8,681 vessel registration records linked to the study area. Discrepancies between the OWC and vessel registration data were explained by a stratified, random sample of 485 telephone survey respondents. Study results show that vessel registration data accurately located and characterized roughly 81% of the boat population; in contrast, the OWC accurately located less than 56%. A conclusion is that state vessel registration data is a better alternative than an OWC for locating and characterizing boats kept along waterways.     

Antecedents of safety-compliant behaviour on offshore service vessels: a multi-factorial approach

Procedure violations are commonly identified as an essential causal factor in maritime accidents. This also applies to the Norwegian offshore service vessel sector. This illustrates that there is a need to study compliance and non-compliance in a broad context and to explore the factors that affect the propensity to act in accordance with prevailing procedures. The aim of the present study was therefore to examine the antecedents of safety-compliant behaviour among workers on offshore service vessels operating on the Norwegian Continental Shelf. With reference to a survey of 1108 offshore service vessel workers, this was done by analysing the relationship between a set of predictor variables and a self-report measure of safety-compliant behaviour. Using binary logistic regression analysis, the present study revealed that the safety climate and the vessel workers’ age were positively related to safety compliance, whereas job experience and perceived procedure vagueness were negatively related to safety compliance. Theoretical and managerial implications are discussed. In sum, the findings indicate that shipowners, captains and other stakeholders within the offshore service vessel industry should consider a broad multi-factorial approach to increase safety compliance.     

Theme Issue 30(2): "Economics of Marine Protected Areas"

Most Florida manatees depend on localized warm-water refuges in the southern two-thirds of Florida to survive winter; about 60% use outfalls from 10 power plants, whereas 15% use 4 natural warm-water springs. Future availability of these refuges is in doubt; most of these power plants may be retired within the next 20 years and groundwater withdrawals for human use threaten natural springs. This article examines possible effects on manatees from losing major warm-water refuges and alternative management actions. Because of manatee site-fidelity patterns, plant retirements may increase cold-stress-related deaths and significantly decrease manatee abundance. A forward-looking management strategy is urgently needed before decisions are made to retire plants now used by large numbers of manatees. Possible management alternatives include: gradually weaning manatees off plant outfalls, maintaining the flow of springs now used by manatees, enhancing access to suitable warm-water springs now little used or unused by manatees, constructing new non-industry dependent warm-water refuges, and creating new thermal basins to retain warm-water pockets able to support overwintering manatees.     

Environmental Protection in Coastal Recreation Sites in Antalya,Turkey

This study was designed to evaluate different approaches to the protection of the environments of coastal recreation sites in and around Antalya, Turkey. Data was collected by means of a survey of coastal recreation sites and six categories were evaluated: environmental protection, infrastructure facilities, water conservation, energy conservation, waste management, and protection of the natural environment. The results indicated that there was a clear motivation among site managers or authorities for environmental protection (p < .05), infrastructure facilities (p < .001), water conservation (p < .05), energy conservation (p < .05) and the protection of the natural environment (p < .001) but waste management was not accorded a priority. The quality of coastal recreation largely relies on the attractiveness and naturalness of the environment. Although good quality site management largely depends on the awareness and willingness of individual site managers, more proactive approaches toward better environmental protection of recreation sites along the Turkish Mediterranean coast might be effective in improving their sustainable use, particularly in the absence of proper site planning.     

Evolutionary trajectory planning of ships in navigation traffic areas

By taking into account certain boundaries of the maneuvering region, along with navigation obstacles and other moving ships, the problem of avoiding collisions in navigation traffic areas was reduced to a dynamic optimization task with static and dynamic constraints. In heavy navigation traffic areas and within coastal zones, correct selection of a ship's speed, when accompanied by the necessary trajectory changes, is a crucial element of safe navigation. This paper presents a modernized version of the evolutionary ship trajectory planning system in which a new parameter was introduced, namely changes of the ship's speed along particular sections of the trajectory. Generally, a safe trajectory is estimated using specialized genetic operators for modifying the trajectory. Here, an additional operator was added to the system that mutates the ship's speed. Sample results present the safe trajectory for a ferry meeting other moving ships and navigational constraints on its way. Received for publication on Dec. 2, 1998; accepted on June 16, 1999     

基于集成仿真的灯光渔船艏部型线优化

针对我国现有渔船标准化建设中遇到的船体型线优化难的问题,提出一种基于集成仿真优化技术的船体型线优化方法,并以一艘灯光渔船的兴波阻力性能优化为例,通过半参数化方法提取10个控制参数用于艏部型线的变换,兴波阻力采用势流理论方法进行评估,并采用Sobol算法与梯度搜索算法相结合的优化算法。基于上述的船体型线优化方法最终得到兴波阻力性能最优的船型,优化结果表明,文中提出的船体优化技术是有效的,有助于加快推进渔船船型的标准化建设。     

An outline of R/V Kairei and recent activity of the multichannel seismic reflection survey system (MCS) and ROV Kaiko

The deep-sea research vessel Kairei was built in 1996 to carry out general deep-sea research, and is now active throughout the world. Kairei is the mother ship for the remotely operated vehicle (ROV) Kaiko, which is also equipped with deep-sea research systems. The role of the Kairei is to conduct detailed research on the tectonics of subduction zones and the sea bed in the deep ocean. A multichannel seismic reflection survey system (MCS) was developed in 1997 to investigate the focal mechanism of the huge earthquakes that occurr in subduction zones around Japan. In 1999, a new system was introduced into the MCS system. It took almost a year to improve the new towing assembly for the air gun array. Kaiko is currently the only ROV that can reach a depth of over 10 000 m. The system's ability was proved in various operating conditions, and Kaiko has continued to make new scientific discoveries. The Kairei's deep-sea observation system has become very powerful and stable. These systems will pursue the challenge to understand the unknown global deep-sea frontier. Received: February 5, 2001 / Accepted: April 26, 2001     

贵州省纳雍县滑坡易发性评价

以贵州省纳雍县为研究区,基于地理信息系统（GIS）平台,采用Logistic回归模型评价区域滑坡易发性。选取高程、坡度、坡向、地表曲率、岩性、到公路距离、到水系距离和到断层距离8项影响因子,应用Logistic回归模型拟合描述滑坡发生与各项因子关系的回归方程。在此基础上,预测研究区内滑坡易发性的概率值,并将研究区划分为5个易发级别。结合历史滑坡分布,对滑坡易发性分区的合理性进行验证,结果表明滑坡易发性分区图和实际滑坡分布情况吻合较好。此外,应用受试者工作特征曲线对模型结果进行评价,结果显示,曲线下面积AUC值为0.774,Logistic回归模型的预测精度较好。     

赤水河机动驳新船型快速性能试验研究

根据“赤水河航运新船型研究”科研项目的要求，研究并设计出赤水河航运的新船型。对设计的新船型进行了快速性能试验，同时选定了赤水河现有的1艘优秀机动驳作为对比船进行快速性能试验。两船试验结果对比表明新船型的阻力性能、推进性能优于对比船。在相同主机功率条件下，设计船的预报航速高于对比船。     

深水工程勘察船结构设计综述

深水工程勘察船是集各类先进勘察和分析设备于一体的综合性集群载体,既是工程勘察作业船,又是一个海上“实验室”。不仅要考虑船舶承受的常规载荷,还要为满足勘察作业要求,考虑众多设备的布置和加强以及控制评估船体结构的振动与噪音。     

内河电力推进船功能区振动响应分析

船舶总是会因其动力源、推进器、波浪以及其他外部激励的作用而产生振动,甚至有害振动。文章通过有限元方法对某电力推进内河船不同功能区结构进行螺旋桨和主机激励作用下的振动响应计算,对比螺旋桨和主机激励作用下不同功能区的振动响应,并判断振动产生的速度及加速度幅值是否符合CCS相关规定的要求。结果表明,在螺旋桨激励作用下,不同功能区振动响应远大于主机激励作用下的振动响应,电力推进装置所产生激振力对电力推进船舶的振动几乎没有影响。由此,对电力推进系统助推的船舶振动计算分析及该类船的设计提供一定的参考。     

机械和螺旋桨振动噪声作用下的物探船水下辐射噪声数值预报

探讨了考虑机械噪声和螺旋桨噪声共同作用下物探船水下辐射噪声有效计算方法,采用基于结构有限元-声学边界元的声固耦合模式直接一体化计算水下总辐射噪声级。建立了某物探船整船三维结构有限元模型以及流体声学边界元模型。在船体总振动响应分析基础上,将螺旋桨噪声以点声源的形式与机械振动源同时输入到统一声学环境中求解,对物探船水下辐射噪声进行数值预报,给出了物探船辐射噪声指向特性,并比较了两类噪声源一体化计算方法与直接叠加合成方法在物探船水下辐射噪声计算结果的差异。研究表明,采用机械噪声与螺旋桨噪声直接叠加合成总辐射声级的方法在工程精度上可接受,但一体化计算是更合理的处理方式。     

Evaluation of manatee habitat systems on the northwestern Florida coast

Abstract

Threats to the survival of West Indian manatees (Trichechus manatus) vary throughout their range so that protection of this endangered species requires careful planning on a regional and local basis. The importance and vulnerability of various components of manatee habitats in the Crystal River area of northwestern Florida were assessed, using an ordinal‐combination mapping technique similar to procedures practiced in urban and regional planning. Habitat components were mapped and evaluated in juxtaposition with relevant characteristics of human use of the area, to identify areas of existing and potential manatee/human conflicts in need of reconciliation. Areas evaluated as the most important manatee habitats within this region include Crystal Bay and River, Homosassa River, and the Suwannee River estuary. Existing overlap of human activities with important manatee habitats is most critical near the urban communities of Crystal River and, to a lesser degree, Homosassa Springs. The need for integration of this ecological information into coastal land‐use planning is discussed.     

风浪中螺旋桨水动力变化的实用计算方法

风浪中螺旋桨水动力变化规律是研究舰船在风浪中速航性能的重要方面。本文参照有关文献,提出了一种计算风浪中螺旋桨推力、转矩损失的实用定量计算方法,既可用于较精确地估算舰船在风浪中的增阻和失速,还可供提高舰船在风浪中速航性的研究和螺旋桨设计参考。     

三维物探船稳性优化设计

三维物探船因上层建筑面积大、重心位置高,其稳性问题是设计过程中需解决的重要问题。文章以国内首艘完全自主设计的6缆三维物探调查船为例,介绍其稳性优化设计方面的经验。首先对三维物探调查船的特点进行介绍;然后介绍总体布置优化、空船重量重心的控制对稳性的影响;最后分别就完整稳性和破舱稳性的计算特点及优化方法进行分析。该文总结了三维物探调查船的稳性特点和注意事项,为今后设计工作提供指导。     

Maritime security guidelines: a study of Swedish ports’ perceived barriers to compliance

ABSTRACT

Due to the constant risk of piracy and terrorist attacks which cause disturbances within international shipping of goods, barriers to the adoption of maritime security guidelines (MSGs) at European ports have become prevalent. In this paper, a conceptual framework was created to explore the perceived barriers that prevent compliance with MSGs. To verify the conceptual framework, empirical data were collected using a mixed-methods approach, which was comprised of interviews with national experts and a survey of 47% of Swedish ports involved in the shipping of goods. According to the presented framework, the perceived barriers of Swedish ports to compliance with MSGs were linked to collaborations within the Swedish Maritime Security stakeholder network, available resources and educational knowledge about security culture. In addition, the perceived barriers of smaller ports were linked to the adaptation to MSGs at different levels and the absence of specific tools of maritime security management. Due to an increased interest in international shipping of goods, this paper is currently one of few that addresses the barriers to compliance with MSGs. Moreover, the paper presents a general conceptual framework, novel managerial implications and recommendations for future research.     

South Carolina's diked tidal wetlands: The presisting dilemmas

Abstract

South Carolina has a significant stock of diked coastal wetlands, dating from the days of rice culture before the Civil War. A survey of those controlling these sites along the entire South Carolina coast reveals that many continue to be used for waterfowl hunting, with management practices becoming more intensive than they were when partial data were gathered a decade ago. It also suggests that most of the acreage involved is located in large fields, where management is more difficult and mosquito control problems are more likely. This survey also indicates that public access is limited, but that there is evidence of continuing conflict over ownership. This situation creates a persisting dilemma for coastal zone management, shaping conflicts between alternative strategies for the use of natural systems.     

一种崭新的船舶运行原理

这是一项原理性的发明,已获得22个国家的发明专利.该发明提出一种特别的船体浸湿面外形布局,可在不改变原推进系统及其推进功率的情况下,大大提高船艇的性能:船艇前进时激起水动推进力、附加水动升力和相应的水动力矩,从而大幅度提高航速和航向、横向、纵向的安全稳定性;转弯时激起水动助回转力矩和抗船体横向向心倾覆力矩,使船艇可以很小的回转半径和横向倾侧,安全迅速地完成回转;迎浪前进时激起水动反冲击力、附加水动升力和相应的水动力矩,可以抗颠簸失速、纵摇拍击和横摇摆动,使船艇平稳高速地前进,平稳安全地完成回转.应用该原理建造的小型船艇的实航试验证明了其确实具有上述性能.