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Article
Publication date: 1 February 1992

GRANT HOCKING

This paper is concerned with the determination of the transient stress and deformational state of plate‐like discontinua subject to flexural cracking. Such a phenomenon…

Abstract

This paper is concerned with the determination of the transient stress and deformational state of plate‐like discontinua subject to flexural cracking. Such a phenomenon can be easily visualized as the type of fragmentation to floating sea ice impacted by an ice‐breaker or offshore platform. The discrete element method is used to solve the dynamic equilibrium equations for each distinct deformable body and the interaction between bodies. Each body may deform elastically and fracture into further pieces if a brittle failure criterion for flexure is exceeded. The discrete plate element is a hybrid thin‐plate (Kirchhoff) mode lumped at element boundaries with transverse shear deformation computed at element centroids. Errors in computed stresses near point loads and cracks by the current element warrant the use of an improved mixed mode plate element. A three‐dimensional application of the discrete element method is presented for the case of fragmentation of floating sea ice impacting an arctic offshore platform. A semi‐implicit solution scheme is introduced to overcome the stringent explicit time step stability conditions due to stiff members in the discrete element formulation.

Details

Engineering Computations, vol. 9 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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Book part
Publication date: 1 January 2005

John Weatherly

In the southern hemisphere, the Antarctic continent is also experiencing a net loss in ice from the extensive glaciers and ice sheets that cover it. However, the…

Abstract

In the southern hemisphere, the Antarctic continent is also experiencing a net loss in ice from the extensive glaciers and ice sheets that cover it. However, the connection between changes in Antarctic ice sheets and the global warming trend are much more uncertain than in the Arctic. The complex of changes in the Antarctic climate and the ice sheets are described in a later section of this chapter.

Details

Perspectives on Climate Change: Science, Economics, Politics, Ethics
Type: Book
ISBN: 978-0-76231-271-9

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Article
Publication date: 1 March 2004

Mark A. Hopkins

The ice pack covering the Arctic basin is composed of a multitude of ice parcels of different areas, ages, thicknesses, and deformation histories that are frozen together…

Abstract

The ice pack covering the Arctic basin is composed of a multitude of ice parcels of different areas, ages, thicknesses, and deformation histories that are frozen together into larger plates that combine and break apart in response to the demands of ever changing boundary conditions and forcing. Current Arctic sea ice models are Eulerian continuum models that use a plastic yield surface to characterize the constitutive behavior of the pack. An alternative is to adopt a discontinuous Lagrangian approach, based on a discrete element model and explicitly simulate individual ice parcels and the interactions between them. The mechanics of the Lagrangian sea ice model are outlined in detail along with the methods that will be used for validation.

Details

Engineering Computations, vol. 21 no. 2/3/4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 26 October 2020

Robin Robertson

This paper aims to present the physics of climate and climate change in an accessible manner to the layman in the context of shifting spheres.

Abstract

Purpose

This paper aims to present the physics of climate and climate change in an accessible manner to the layman in the context of shifting spheres.

Design/methodology/approach

This paper presents the physics of climate and climate change in an accessible manner to the layman in the context of shifting spheres. This is a viewpoint and more of a literature review than new findings.

Findings

Earth's climate is changing due to man's influence.

Social implications

Climate change will be a major factor in the future of our society.

Originality/value

The text is original. The information is not. There is recent information in this article. The author even updated things during the review process. The science is always improving.

Details

Kybernetes, vol. 50 no. 4
Type: Research Article
ISSN: 0368-492X

Keywords

Content available
Article
Publication date: 1 May 2000

Abstract

Details

Disaster Prevention and Management: An International Journal, vol. 9 no. 2
Type: Research Article
ISSN: 0965-3562

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Article
Publication date: 1 February 2000

Yaw A. Debrah and Ian G. Smith

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of…

Abstract

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.

Details

Management Research News, vol. 23 no. 2/3/4
Type: Research Article
ISSN: 0140-9174

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Article
Publication date: 31 March 2020

Tuomo Keltto and Su-Han Woo

The purpose of this study is to evaluate the profitability of the Northern Sea Route (NSR) as a shipping lane from the financial perspective of shipping companies under…

Abstract

Purpose

The purpose of this study is to evaluate the profitability of the Northern Sea Route (NSR) as a shipping lane from the financial perspective of shipping companies under post 2020 sulphur regulations.

Design/methodology/approach

This study develops profit estimation model, and the profitability of the NSR is assessed for a Handymax Medium Range (MR) tanker vessel using scenarios in combination with spot market earning levels, the regulation compliance method and destination ports. The required freight rates are calculated to justify the decision of shipowners to transit a tanker from the Baltic spot market to the NSR navigation.

Findings

Results suggest that the required freight rates from the Arctic trade to justify the transit to the NSR are higher than the actual agreed rates in the past, which implies low viability of the NSR as a regular shipping lane. It was also found that the required freight rates are affected by the spot market earning levels, compliance method and duration of the voyage.

Research limitations/implications

This study takes a new approach on assessing the NSR viability by comprehensively assessing the annual profitability and including the spot market trade as an opportunity cost for the NSR shipping. Despite various scenarios used in this study, a sensitivity analysis would be useful for future research.

Practical implications

This study suggests how much freight rates a shipping company would need to charge if it were to offer tanker shipping services to four major Asian ports while simultaneously operating at the Baltic Sea during the remainder of the year.

Originality/value

This study adopts a market-oriented approach by incorporating both earnings and costs (including opportunity costs) in the profitability model rather than merely analyzing the total cost of shipping via the NSR. This study also analyzes impact of IMO 2020 Sulphur regulation on the NSR profitability.

Details

The International Journal of Logistics Management, vol. 31 no. 2
Type: Research Article
ISSN: 0957-4093

Keywords

Content available
Article
Publication date: 15 December 2017

Po-Hsing Tseng and Nick Pilcher

The Northern Sea Route (NSR) could become viable in the near future. If this happens, it will radically reduce sailing times and distances on routes from Asia to Northern…

Abstract

Purpose

The Northern Sea Route (NSR) could become viable in the near future. If this happens, it will radically reduce sailing times and distances on routes from Asia to Northern Europe. However, although much has been written about the feasibility of the NSR, about the issues involved and about the possible opening of the route, the views of key stakeholders from companies who would potentially benefit from the route have been little explored. The purpose of this paper is to complement the existing literature on the feasibility of and issues related to the NSR by presenting and discussing the results from in-depth qualitative interviews with nine key stakeholders based in Shanghai and Taiwan who have extensive research, knowledge and practical experience of NSR.

Design/methodology/approach

Based on a grounded theory analysis, a total of nine key stakeholders knowledgeable about NSR and the majority with sailing experience of NSR are interviewed, including one government official, two professors, shipping experts in six liner and one bulk shipping companies.

Findings

The authors present interviewees’ thoughts regarding the feasibility of NSR at the current time in terms of practicalities, ships, costs, information and wider issues.

Practical implications

These thoughts show that whilst the potential of NSR is huge in theory, in practice the overall perception of it in terms of current feasibility from a company perspective is one of challenges and unknown issues. Shipping companies can benefit from the authors findings when considering the feasibility of NSR as a shipping route. Ultimately, the picture emerges that without one country, probably Russia, taking the lead on the route, it will remain only a theoretical one.

Originality/value

In-depth interviews with grounded theory are used to investigate current and actual thoughts on NSR. This paper highlights correlations and additions to show a fuller picture of current knowledge and adds views from Shanghai and Taiwan.

Details

Maritime Business Review, vol. 2 no. 4
Type: Research Article
ISSN: 2397-3757

Keywords

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Book part
Publication date: 1 January 2005

Jerry D. Mahlman

In 2001, the Intergovernmental Panel on Climate Change's Third Assessment Report revealed an important increase in the level of consensus concerning the reality of…

Abstract

In 2001, the Intergovernmental Panel on Climate Change's Third Assessment Report revealed an important increase in the level of consensus concerning the reality of human-caused climate warming. The scientific basis for global warming has thus been sufficiently established to enable meaningful planning of appropriate policy responses to address global warming. As a result, the world's policy makers, governments, industries, energy producers/planners, and individuals from many other walks of life have increased their attention toward finding acceptable solutions to the challenge of global warming. This laudable increase in worldwide attention to this global-scale challenge has not, however, led to a heightened optimism that the required substantial reductions in carbon dioxide (CO2) emissions deemed necessary to stabilize the global climate can be achieved anytime soon. This fact is due in large part to several fundamental aspects of the climate system that interact to ensure that climate change is a phenomenon that will emerge over extensive timescales.

Although most of the warming observed during the 20th century is attributed to increased greenhouse gas concentrations, because of the high heat capacity of the world's oceans, further warming will lag added greenhouse gas concentrations by decades to centuries. Thus, today's enhanced atmospheric CO2 concentrations have already “wired in” a certain amount of future warming in the climate system, independent of human actions. Furthermore, as atmospheric CO2 concentrations increase, the world's natural CO2 “sinks” will begin to saturate, diminishing their ability to remove CO2 from the atmosphere. Future warming will also eventually cause melting of the Greenland and Antarctic ice sheets, which will contribute substantially to sea level rise, but only over hundreds to thousands of years. As a result, current generations have, in effect, decided to make future generations pay most of the direct and indirect costs of this major global problem. The longer the delay in reducing CO2 and other greenhouse gas emissions, the greater the burden of climate change will be for future life on earth.

Collectively, these phenomena comprise a “global warming dilemma.” On the one hand, the current level of global warming to date appears to be comparatively benign, about 0.6°C. This seemingly small warming to date has thus hardly been sufficient to spur the world to pursue aggressive CO2 emissions reduction policies. On the other hand, the decision to delay global emissions reductions in the absence of a current crisis is essentially a commitment to accept large levels of climate warming and sea level rise for many centuries. This dilemma is a difficult obstacle for policy makers to overcome, although better education of policy makers regarding the long-term consequences of climate change may assist in policy development.

The policy challenge is further exacerbated by factors that lie outside the realm of science. There are a host of values conflicts that conspire to prevent meaningful preventative actions on the global scale. These values conflicts are deeply rooted in our very globally diverse lifestyles and our national, cultural, religious, political, economic, environmental, and personal belief systems. This vast diversity of values and priorities inevitably leads to equally diverse opinions on who or what should pay for preventing or experiencing climate change, how much they should pay, when, and in what form. Ultimately, the challenge to all is to determine the extent to which we will be able to contribute to limiting the magnitude of this problem so as to preserve the quality of life for many future generations of life on earth.

Details

Perspectives on Climate Change: Science, Economics, Politics, Ethics
Type: Book
ISBN: 978-0-76231-271-9

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Article
Publication date: 21 October 2019

Rui Wang, Xiangyang Li, Hongguang Ma and Hui Zhang

This study aims to provide a new method of multiscale directional Lyapunov exponents (MSDLE) calculated based on the state space reconstruction for the nonstationary time…

Abstract

Purpose

This study aims to provide a new method of multiscale directional Lyapunov exponents (MSDLE) calculated based on the state space reconstruction for the nonstationary time series, which can be applied to detect the small target covered by sea clutter.

Design/methodology/approach

Reconstructed state space is divided into non-overlapping submatrices whose columns are equal to a predetermined scale. The authors compute eigenvalues and eigenvectors of the covariance matrix of each submatrix and extract the principal components σip and their corresponding eigenvectors. Then, the angles ψip of eigenvectors between two successive submatrices were calculated. The curves of (σip, ψip) reflect the nonlinear dynamics both in kinetic and directional and form a spectrum with multiscale. The fluctuations of (σip, ψip), which are sensitive to the differences of backscatter between sea wave and target, are taken out as the features for the target detection.

Findings

The proposed method can reflect the local dynamics of sea clutter and the small target within sea clutter is easily detected. The test on the ice multiparameter imaging X-ban radar data and the comparison to K distribution based method illustrate the effectiveness of the proposed method.

Originality/value

The detection of a small target in sea clutter is a compelling issue, as the conventional statistical models cannot well describe the sea clutter on a larger timescale, and the methods based on statistics usually require the stationary sea clutter. It has been proven that sea clutter is nonlinear, nonstationary or cyclostationary and chaotic. The new method of MSDLE proposed in the paper can effectively and efficiently detect the small target covered by sea clutter, which can be also introduced and applied to military, aerospace and maritime fields.

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