Port strategic planning: Canadian port reform

Recent port reform established major commercial ports as Canadian Port Authorities (CPAs) as federal non-profit, business corporations. Canadian port reform was aimed at allowing CPAs to compete effectively. Canada's major ports operate in an increasingly competitive business environment. To gain advantage over their competition, Canadian ports must develop business strategies dealing with their organizational cultures, institutional structures, operations, and facility provision. Developing appropriate strategies involves creating a strategic plan that considers external and internal port environments. This paper outlines the evolution of strategic planning and its applicability to Canadian ports. The initial literature review is followed by a brief review of Canadian port reform and an analysis of external and internal port environments. This analysis determines the resources available to exploit external opportunities and defend against threats, and considers the internal strengths and weaknesses of Canadian ports. A list of strategic issues facing Canadian ports and how the Canada Marine Act affected them is derived from the analysis.     

Application of the VOF method based on unstructured quadrilateral mesh

To simulate two-dimensional free-surface flows with complex boundaries directly and accurately, a novel VOF (Volume-of-fluid) method based on unstructured quadrilateral mesh is presented. Without introducing any complicated boundary treatment or artificial diffusion, this method treated curved boundaries directly by utilizing the inherent merit of unstructured mesh in fitting curves. The PLIC (Piecewise Linear Interface Calculation) method was adopted to obtain a second-order accurate linearized reconstruction approximation and the MLER (Modified Lagrangian-Eulerian Re-map) method was introduced to advect fluid volumes on unstructured mesh. Moreover, an analytical relation for the interface’s line constant vs. the volume clipped by the interface was developed so as to improve the method’s efficiency. To validate this method, a comprehensive series of large straining advection tests were performed. Numerical results provide convincing evidences for the method’s high volume conservative accuracy and second-order shape error convergence rate. Also, a dramatic improvement on computational accuracy over its unstructured triangular mesh counterpart is checked.     

Time-domain simulation for water wave radiation by floating structures （Part A）

Direct time-domain simulation of floating structures has advantages： it can calculate wave pressure fields and forces directly; and it is useful for coupled analysis of floating structures with a mooring system. A time-domain boundary integral equation method is presented to simulate three-dimensional water wave radiation problems. A stable form of the integration free-surface boundary condition （IFBC） is used to update velocity potentials on the free surface. A multi-transmitting formula （MTF） method with an artificial speed is introduced to the artificial radiation boundary （ARB）. The method was applied to simulate a semi-spherical liquefied natural gas （LNG） carrier and a semi-submersible undergoing specified harmonic motion. Numerical parameters such as the form of the ARB, and the time and space discretization related to this method are discussed. It was found that a good agreement can be obtained when artificial speed is between 0.6 and 1.6 times the phase velocity of water waves in the MTF method. A simulation can be done for a long period of time by this method without problems of instability, and the method is also accurate and computationally efficient.     

Underwater hydraulic shock shovel control system

The control system determines the effectiveness of an underwater hydraulic shock shovel. This paper begins by analyzing the working principles of these shovels and explains the importance of their control systems. A new type of control system’s mathematical model was built and analyzed according to those principles. Since the initial control system’s response time could not fulfill the design requirements, a PID controller was added to the control system. System response time was still slower than required, so a neural network was added to nonlinearly regulate the proportional element, integral element and derivative element coefficients of the PID controller. After these improvements to the control system, system parameters fulfilled the design requirements. The working performance of electrically-controlled parts such as the rapidly moving high speed switch valve is largely determined by the control system. Normal control methods generally can’t satisfy a shovel’s requirements, so advanced and normal control methods were combined to improve the control system, bringing good results.     

Determining the hydrodynamic forces on a planing hull in steady motion

A combination of methods was developed that can determine hydrodynamic forces on a planing hull in steady motion. Firstly, a potential-based boundary-element method was used to calculate the hydrodynamic pressure, induced resistance and lift. Then the frictional resistance component was determined by the viscous boundary layer theory. Finally, a particular empirical technique was applied, to determine the region of upwash geometry and determine spray resistance. Case studies involving four models of Series 62 planing craft were run. These showed that the suggested method is efficient and capable, with results that are in good agreement with experimental measurements over a wide range of volumetric Froude numbers.     

Discomfort of vertical whole-body shock-type vibration in the frequency range of 0.5 to 16 Hz

Shock-type vibrations are frequently experienced in vehicles excited by impulsive input, such as bumps in the road, and cause discomfort. Current national and international standard weightings were primarily developed for assessing exposure to sinusoidal or random vibrations and not impulsive excitations or shocks. In this experimental study, various shock signals were systematically produced using the response of a one degree-of-freedom vibration model to hanning-windowed half-sine force input. The fundamental frequency of the shock was varied from 0.5 to 16 Hz at a step of 1/3 of an octave. The magnitude estimation method was used for fifteen subjects to compare the discomfort of shocks with various unweighted vibration dose values between 0.35 ms^−1.75 and 2.89 ms^−1.75 at each frequency. The equivalent comfort magnitude of shock showed greater sensitivity at frequencies less than 0.63 Hz and at the resonance frequency of the human body between 5.0 Hz and 6.3 Hz. The frequency weighting constructed by using both the equivalent comfort magnitude and the growth rate of discomfort obtained in this study was compared with the current standard weightings, W_b of BS 6841 and W_k of ISO 2631. The derived weightings for shock were applied to the acceleration of the shocks, and an enhanced correlation was proved between the magnitude estimations and the weighted physical magnitude of shock.     

Application of Optimal Control Theory to Inverse Simulation of Car Handling

The application of Optimal Control Theory to time-optimal inverse simulation of car handling was investigated. Time-optimal inverse simulation of car handling involves the calculation of driver actions required to perform specified manoeuvres, in as short a time as possible. Driver actions consist of time-histories of front wheel steer rate and longitudinal force. Optimal time-histories of these quantities were calculated using the Gradient method after formulating the problem as one of optimal control. Simulation results are presented for two different cars performing similar lane-changes. These results show significant differences in necessary driver actions for different cars and demonstrate the suitability of the approach taken.     

Inverse Heat Conduction and Data-Type Issues for Advanced Diagnostic Analysis

IlitroductlonNormallytemperaturemeasurementsareusedinaninverseheatconductionanalysis.lnarecelltinverseheatconductioninvestigation[ll,twodatatypes(temperatureandheating/coolingrate)weecomparedforthepurposeofinvestigatingtheireffectonpredictingthesurfaceheatfltixattheprojectedsurface.Itwasillustrated,vianumericalexample,thatthechoiceofinputdatainnuencesbOththeaccurasyandstabilityattheprojectedsurface.Thatis,thepredictionnotonlydePendsonthetemperaturedatabutimplicitlyitsillterpretedheating/cooli…