A user‐resource planning framework for offshore recreational artificial reefs

Abstract

Artificial reefs have been used extensively in coastal waters to attract and enhance recreational fishery resources. In the United States, they have been traditionally built from “materials of opportunity”; using limited budgets. This paper explores some past planning philosophies and presents a recent artificial reef deployment case that demonstrates a lack of sensitivity to local and regional recreational demand. A systems framework is developed to guide future planning efforts in artificial reef development. The framework is intended to integrate previously fragmented knowledge and to demonstrate the interdisciplinary nature of artificial reef planning. Emphasis is given to advance planning, user dimensions, and the integral issue of reef access.     

Evaluating the energy performance of a SUV hybrid electric vehicle

This paper analyzes the energetic performance of the hybrid Lexus RX 400h, through on-board measurements. Several speed profiles were analyzed, for three driving types, successive stop and go cycles, three speed profiles, crossing an electronic toll collection booth, and a roundabout. In stop and go situations the internal combustion engine did not work (the torque needed to impulse the vehicle in the stop and go situations was only supported by the electric engines), as well as in the situations of constant low speeds (50 or 60 km h^?1). The auxiliary support given by the electric engines in the accelerations, as well as the importance of the energy regeneration system on the batteries’ load recovery is also demonstrated. When compared with similar conventional vehicles, the Lexus RX 400h has lower combined energy consumption between 1.2% and 60%.     

A risk model for the operation of container vessels

Commercial shipping of containerized goods involves certain risks for human safety and environment. In order to actively manage these risks, they must be identified, analyzed, modeled, and quantified. This requires a systematical analysis of design and operation of container vessels. Within the EU-funded research project SAFEDOR, a Formal Safety Assessment has been applied to establish the current safety level of generic container ships and to identify potential cost-effective risk control options. This paper describes a structured approach to develop the underlying high-level risk model. It is structured as risk contribution tree consisting of a series of fault trees and event trees for the major accident categories. Statistical analysis of casualty data is used to estimate the probability of occurrence. Finally, the summation overall individual risk contributions yields the current risk pro file for the operation of container vessels is presented as FN-curve.     

Development of hot stamped center pillar using form die with channel type indirect blank holder

The hot stamping process has been used in the automotive industry to reduce the weight of the body-in-white and to increase passenger safety via improved crashworthiness. However, defects such as fracture and wrinkle occur when hot stamping is performed using a conventional drawing or forming method. In this study, a channel-type indirect blank holder (CIBH) is proposed to develop a high-strength center pillar in form-type hot stamping, so that the aforementioned drawbacks are overcome. This type of blank holder plays an important role in reducing severe wrinkling at the flange; such wrinkling leads to folding after the completion of form-type hot-stamping. First, we investigated the effect of the channel shape on the indirect blank holding force by using a simplified two-dimensional plane-strain stamping process. Second, we selected the slope angle and corner radius of the channel as the main shape parameters by finite element analysis and artificial neural network (ANN). It is known that fracture at the hot formed wall and wrinkle at the flange are significantly affected by the slope angle of the channel, and the appropriate value for eliminating fracture and wrinkle is determined to be 99°. By performing hot stamping using a form die with the selected channel, we can manufacture a high-strength center pillar without wrinkle and fracture.     

Influence of load and inflation pressure on the tyre rolling resistance

Tyre load and inflation pressure are important factors controlling rolling resistance of road vehicles. The article presents results obtained in the Technical University of Gdańsk during laboratory and road measurements of different car tyres rolling on different pavements. The knowledge of rolling resistance characteristics is important for modelling car dynamics as well as fuel consumption. It is also necessary to establish proper test conditions in the future standardized on-road method of measuring rolling resistance. The results indicate that while an increase of load always leads to the increase of rolling resistance force, the influence on Coefficient of Rolling Resistance is more complicated and unpredictable. They also indicate that tyres with high rolling resistance are more sensitive to inflation pressure changes than low rolling resistance tyres.     

Implementation of discharging/charging current sensorless state-of-charge estimator reflecting cell-to-cell variations in lithium-ion series battery packs

This paper offers novel insights to the design and implementation of an innovative state-of-charge (SOC) estimator for the lithium-ion (Li-Ion) series battery pack. The most interesting feature of this approach is that it can utilize information from each filtered terminal voltage of the Li-Ion cells connected in series for SOC estimation of the battery pack. Without actual sensing each discharging/charging current (DCC) applied to the Li-Ion cells, it is possible to extract each DCC estimation from the corresponding filtered terminal voltages with an equivalent electrical circuit model (EECM) identification of all Li-Ion cells in the battery pack. There are two advantages to SOC estimation of the battery pack with this approach. First, the proposal can be implemented simply and effectively, reducing the computational steps required for SOC estimation. By reducing computational steps, the proposal is expected to be more cost-effective. Second, the approach guarantees an improved SOC performance, even if the battery pack results in inevitable cell-to-cell variation among Li-Ion cells. Accordingly, there are fewer differences to previously estimated DCCs among Li-Ion cells. Specifically, all values from the estimated DCCs are properly compensated for by simultaneous parameter modification according to each cell’s electrochemical characteristics. Experimental results clearly demonstrate that our DCC sensorless SOC estimator provides robust SOC performance for the battery pack. This approach considered an experimental battery pack (12S1P) connected in series using 2.6 Ah LiCoO2 cells produced by Samsung SDI.     

The importance of oceanographic fronts to marine birds and mammals of the southern oceans

During the last 30 years, at-sea studies of seabirds and marine mammals in the oceans south of the Subtropical Front have described an association with major frontal areas. More recently, the advancement in microtechnology has allowed the tracking of individuals and investigations into how these marine predators actually use the frontal zones. In this review, we examine 1) the relative importance to apex predators of the different frontal zones in terms of spatial distribution and carbon flux; 2) the processes that determine their preferential use; and 3) how the mesoscale dynamics of frontal structures drive at-sea foraging strategies of these predators. We review published results from southern waters and place them in a broader context with respect to what has been learned about the importance of fronts in oceans farther north.Some fronts constitute important boundaries for seabird communities in southern waters. At a mesoscale the maximum values of seabird diversity and abundance correspond to the location of the main fronts. At-sea surveys show a strong curvilinear correlation between seabird abundance and sea surface temperatures. High mean species richness and diversity for whales and seabirds are consistently associated with the southern water mass boundary of the Antarctic Circumpolar Current, the Subtropical Front and the Subantarctic Front; in the case of the Polar Front mean seabird densities are more variable. At small-scales, variation in seabird occurrence has been directly related to the processes at fronts in a limited number of cases. A significant positive relation was found between some plankton feeding species and frontal temperature gradient–phytoplankton variables.Telemetric studies have revealed that several apex predators (penguins, albatrosses, seals) perform long, directed foraging trips either to the Subtropical front or Polar Front, depending on locality. Seabirds with low flight costs, such as albatrosses, are able to reach fronts at long distances from colonies, showing variable foraging strategies as a function of the distances involved. Diving birds such as King penguins, that travel at a higher cost and lower speed, rely on the predictable spatial distribution of mesopelagic fish found close to the Polar Front. They may use the currents associated with eddies as oceanographic cues in the active search for frontal zones. Once in these areas they dive preferentially in and below the depth of the thermocline where catches per unit effort are high. Elephant seals concentrate foraging activity principally inside or at the boundary of cyclonic eddies. These mesoscale features appear to offer exceptional productivity favourable for foraging by various diving top predators.The connection between biophysical parameters at fronts and predators is likely to be made through biological enhancement. Top predators appear to forage at locations where prey are advected by physical processes and others where prey are produced locally. Long-term research on at-sea distributions and demographic parameters of top predators are essential to assess the consequences of potential shift in front distributions in relation to global warming. Such environmental changes would add to the impact of fish extraction by the industrial fisheries on the southern food webs.     

Longhaul feeder services in an era of changing technology: an Asia-Pacific perspective

Traditional liner carriers, operating in the highly competitive commercial environment of the last few years, have attempted to lower the marginal cost of each box carried. Technological improvements in both construction and propulsion systems have led to a steady growth in carrying capacity. Ships of 600+ TEUs are now in service and, as a result of this trend, have displaced 'smaller' ships from the major east-west trades. The more competitive environment of these trades has in turn led to a redeployment of ships in the 2500+ TEU range to the north-south trades. The result has been a rapid increase in north-south capacity, including feeder services and falling freight rates. Despite the current excess supply in shipping and historically low freight rates, significant developments in technology have created opportunities for new fast containerships. The paper analyses the key economic factors in the differentiation of the new fast ship technology from the traditionally designed containerships and demonstrates the potential financial viability to owners of these new 'greyhounds'.     

Conditional modelling of tanker market risk using route specific freight rates

This paper provides statistical evidence in support of the view, widely held in the tanker industry, that there are systematic differences in the degree of risk involved in investing in tankers of different sizes, and in operating tankers in spot and time charter markets. The industry view, broadly supported by the results of this paper, is that larger vessels are 'risker' assets than smaller vessels, and operating vessels in the time-charter market is less risky than employing them on a spot basis. The results are obtained by using a method derived from the financial economics literature, which models both the conditional mean and variance of a variable, known as GARCH modelling. Only one other paper has applied this method to the tanker market, and these results provide confirmatory support of those findings.     

Devising business strategy for railways

This paper presents a case study which tackles a general problem for railway management, namely the formulation of a strategy to improve business financial performance. This is prefaced, in Section 2, by discussion of general principles - concerning the type of information system required, investigations to be conducted and associated measurement needs. The case study, of Section 3, concerns our investigations of VicRail's total business and its constituents. The task of financial improvement is revealed from an assessment of sectors' current cost-recovery positions and the identification of system joint costs. For freight sectors, future traffic prospects, pricing possibilities and the scope for more efficient operations are then considered, and the implications traced for overall deficit reduction and the development of business strategy. The concluding section draws some general lessons for railway managements.A fuller discussion by the authors of the theoretical framework employed, and particularly of the case study application, is contained in a complimentary publication: Improving Railway Financial Performance, published by Gower in January 1985.Transmark is a subsidiary of the British Railways Board, acting as its international consultancy. The authors, who were respectively study director and manager, wish to thank Bernard Warner (an independent consultant), Richard Eccles (of Transmark) and Adrian Balkyn-Rackowe (of British Rail) for their valuable contributions. The study report, titled Rail Cost — Pricing Options, was released by the Minister in April 1981.