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991.
Hyung Rim Choi Hyun Soo Kim Byung Joo Park Nam-Kyu Park Sang Wan Lee 《Maritime Policy and Management》2003,30(3):197-210
The major characteristics of ERP (Enterprise Resource Planning) are an enterprise-wide system that covers all the business functions and information resources, integrated database, built-in best industry practice, packaged software and open architecture. ERP enables reduction of system development time, flexibility, standardization of workflow and effective business planning capability. ERP is mainly for the manufacturing industry. However, the principles of ERP can also be applied to container terminal operating systems. This paper presents an ERP system approach for a container terminal. It has clustered the workflow of a container terminal and analysed the business process to generate the best workflows. The integrated database is designed to eliminate redundancy and keep integration. The core of ERP for container terminal is the planning facility such as berth planning and yard planning. The planning capability is very tightly coupled with data flow from client entities such as shipping companies. The ERP can handle the existing problems of container terminal operation that are mainly caused by lack of integration of a whole information resource in a container terminal, ad-hoc and poor planning capability, disconnected and incorrect data from client companies. The ERP approach can not only resolve the problems of container terminals but also promote adoption of information systems for container terminals in the world that have not yet implemented terminal operating systems. 相似文献
992.
This study developed a set of pictograms for lane control systems, to provide additional information to drivers on weather and traffic incidents. The results suggest that in the design of traffic signs, it is important to consider local context and not simply adopt standards and practices that are developed elsewhere. The differences in the social and cultural environments may affect the ease of reading and comprehension by local drivers. However, the study also showed that not all locally developed signs were rated higher for their ease of reading than others… Since some design characteristics are more salient, whereas others tend to be more dependent on the local context, it is important to conduct simple experiments and exploratory research to find the optimal designs to be used. 相似文献
993.
S. Mü ller M. Uchanski J. K. Hedrick 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,39(2):121-133
Summary Each vehicle on a section of highway is potentially a driving condition 'sensor.' For example, a vehicle's speed give can give a clue about the traffic conditions in its section of roadway. By 'cooperative estimation,' we mean a system that uses a communication network to combine the experience of many vehicles into parameter estimates that are more useful than the estimates that any individual vehicle could generate by itself. This paper demonstrates the cooperative estimation concept by showing how it can be used to estimate traffic conditions and road friction without using roadside sensors. 相似文献
994.
This study is based on a major container terminal operator in Hong Kong. Container terminals form a link in the transport chain for transhipment and temporary storage of containers. The service time for vessels including waiting time for berthing must be minimal in order to reduce costs for shipping lines. The use of heuristics and computer simulation to measure different allocation strategies is demonstrated. The existing performance measures of allocation are evaluated and prioritized. Three sets of allocation policies are developed to tackle the day-to-day allocation problems with a view to increasing operational efficiency and enhancing customer service levels. Results show that all three proposed allocation policies have substantial improvements over the existing policy. 相似文献
995.
This paper addresses a general stochastic user equilibrium (SUE) traffic assignment problem with link capacity constraints. It first proposes a novel linearly constrained minimization model in terms of path flows and then shows that any of its local minimums satisfies the generalized SUE conditions. As the objective function of the proposed model involves path‐specific delay functions without explicit mathematical expressions, its Lagrangian dual formulation is analyzed. On the basis of the Lagrangian dual model, a convergent Lagrangian dual method with a predetermined step size sequence is developed. This solution method merely invokes a subroutine at each iteration to perform a conventional SUE traffic assignment excluding link capacity constraints. Finally, two numerical examples are used to illustrate the proposed model and solution method. 相似文献
996.
Mixed assembly line rebalancing: A binary integer approach applied to real world problems in the automotive industry 总被引:1,自引:0,他引:1
F. S. Oliveira K. Vittori R. M. O. Russel X. L. Travassos 《International Journal of Automotive Technology》2012,13(6):933-940
Industrial organizations have increasingly sought to optimize the resources needed for the manufacture of its products from the competition, in order to maintain their profit margins. The search for balance of resources and balanced distribution of tasks in various types of industrial environments is called balancing. When adjustments are made and adequacy of an assembly line that is already in operation, this process is called rebalancing. This paper presents a case study involving a problem of rebalancing of automotive assembly line in an environment of arbitrarily mixed models of products, also known as mix. The proposed procedure for solving the rebalancing in the company in question is based on Binary Integer Programming, in particular the branch and bound algorithm. For comparison, we used a heuristic method based on precedence diagrams for solving the rebalancing of lines. To evaluate the results obtained between the two procedures were used performance indicators such as number of workstations created, average load of work and level of unbalance. The proposed algorithm has resulted in significant improvements in the production line capacity. 相似文献
997.
Malcolm A. Clarke 《WMU Journal of Maritime Affairs》2002,1(1):71-84
Consignors of goods in international trade want their containers to move door to door whether by land, sea or air — smoothly, seamlessly and at predictable cost. What they actually get from the law is at best a jerky roller coaster: a series of contracts, one for each mode or stage of the journey, contracts with various people and with liability that varies too. All agree that the law should change but attempts to agree on an entirely new multimodal regime have failed. Recently attempts have been not to start again but to expand an existing and established regime. The latest of these, the UNCITRAL draft, is essentially maritime: it applies to the sea phase but and goes further to apply door to door except when its path is blocked by compulsory unimodal law. Has Venus at last arisen from the waves? And what will happen when Beauty meets the Beast in the form of CMR? This article addresses the problems that will be encountered by an ambitious amphibious instrument of this kind. — problems of integration, of compatibility with local legal culture, and of methodology. 相似文献
998.
A. Alleyne P.D. Neuhaus J.K. Hedrick 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(5):309-320
This paper illustrates the use of nonlinear control theory for designing electro-hydraulic active suspensions. A nonlinear, “sliding” control law is developed and compared with the linear control of a quarter-car active suspension system acting under the effects of coulomb friction. A comparison will also be made with a passive quarter-car suspension system. Simulation and experimental results show that nonlinear control performs better than PID control and improves the ride quality compared to a passive suspension. 相似文献
999.
It is often advantageous to model a semi-enclosed estuarine or coastal embayment (e.g. fish farms or tidal inlets, or typhoon shelters) as a separate system within a larger water body connected to the outer sea. The water quality of the system depends crucially on its flushing time—the average time of a particle in the system. The flushing time is governed by the barotropic and baroclinic tidal exchanges between the system and the outer sea. We describe herein a general method to determine systematically the flushing time of a stratified water body via a numerical tracer experiment. Numerical solution of the 3D flow and mass transport equations for many practical problems show that the tracer mass removal process depends on the physical topography and bathymetry, tidal range and the degree of stratification in the outer sea. Field application suggests that the tracer mass variation can be well approximated by a double-exponential decay curve that can be described by three flushing coefficients. Using a simple analytical two-segment model, the flushing coefficients can be given a clear physical interpretation, and the flushing time can be easily determined in terms of the coefficients. The method is illustrated by application to a number of tidal inlets in Hong Kong, in both the dry and wet season. The connection between the numerically determined flushing time and the traditional bulk flushing time obtained from salt-balance methods is established. 相似文献
1000.
Peter M. P. Muirhead 《WMU Journal of Maritime Affairs》2004,3(2):139-158
This paper examines the impact of new technology on MET institutions in the 21st century and discusses to what extent global MET institutions can enhance and enrich traditional practices through access
to new technology and the use of innovative teaching and assessment methods within a sustainable and achievable framework.
It notes the diverse standards and access to new technology by MET institutions across the globe and discusses the implications
for them if they are to remain competitive and viable. The paper concludes that maritime institutions can benefit from the
use of new technology, but only through rational planning and sustainable staged growth. A series of continua of technical
development is provided to assist institutions, from the smallest to the largest, to plan for technical development and growth
in a rational and feasible way. 相似文献