Torque control of a vehicle with electronic throttle control using an input shaping method

The shock-jerk phenomenon is usually observed in vehicles with manual transmission systems that are rapidly accelerating, and this phenomenon makes the passenger feel uncomfortable. This phenomenon can be minimized using torque control of the vehicle with throttle-by-wire or an ETC (Electronic Throttle Control) system. In this paper, the drivetrain of the vehicle is modeled to simulate the vehicle behavior, and the control strategy of ETC is studied to reduce shock and jerk characteristics using an input shaping method. The control logic is verified by using vehicle modeling and simulations.     

The Greening of Ports: A Comparison of Port Management Tools Used by Leading Ports in Asia and Europe

Abstract

From the policy and management perspective, this study aims to investigate the port management tools that port/public authorities have at their disposal and then to analyse to what extent the tools are used to enforce or encourage green port development at functional activities of port operations and development. We conduct an exploratory and comparative review based on two axes: on the one hand, the range of tools available to port authorities (pricing, monitoring and measuring, market access control and environmental standard regulation) and on the other hand, the functional activities in ports (shipping traffic, cargo handling and storage operations, intermodal connection, industrial activities, and port expansion). The situations in the leading ports in Asia and Europe, namely Singapore, Shanghai, Antwerp and Rotterdam are studied and compared, whereby the policies' effectiveness is discussed accordingly. Findings show that the ports are particularly mature in exercising environmental standard regulations which reveals that the enforcement approach is more prevalent. The most focused functional activity is shipping traffic which reflects that the ports are driven by the International Maritime Organisation. The respective port authorities in Antwerp and Rotterdam have a higher level of influence on devising green port policy in comparison to the two Asian ports.     

Optimizing the transportation of international container cargoes in Korea

This paper considers a multimodal transportation problem, which is the problem of determining the transportation flow, i.e. volume of container cargoes, and the transportation mode in each trade route, for the objective of minimizing the sum of shipping and inland transportation costs. The problem takes account of two restrictions: maximum cargo volumes capacitated at each seaport and maximum number of vehicles available at each transportation mode. To solve optimally the problem, this paper employs a mixed integer programming, which is an operations research technique. A case study is performed on the container cargo data in Korea and we draw several implications to improve efficiency in the transportation of international trade cargoes in Korea.     

Automatic FE modeler using stiffener-based mesh generation algorithm for ship structural analysis

Shipbuilding industries have started to employ 3D CAD systems to integrate all design and production processes by achieving seamless data transfer and data sharing. The emerging 3D CAD system brings a considerable change in FE analysis field. The availability of 3D geometry increased the recognition of the need for developing automatic FE modeling system consequently.

However, general automatic mesh algorithms developed by academic research field have a limitation. The difficulty in satisfying lots of line constraints and the absence of proper idealization of 3D geometry entities defined in CAD system hinders directly employing the general mesh algorithms.

In this research, an automatic FE modeling system has been developed for cargo hold FE modeling and whole ship FE modeling. The basic concept of the algorithm is to decompose surfaces using stiffener lines into subregions and generate mesh using a rule established based on FE modeling practice of ship structure. Since the decomposed subregions take simple polygon, they can be easily transformed into elements by decomposing the polygon according to the rule defined considering the shape of the polygon and mesh seed on its perimeter. The algorithm is also designed to treat appropriate geometry idealizations for bracket-type surface and stiffener connections. The idealization process is also completely customized based on FE modeling practice. The validity of the developed system is verified through illustrative examples.     

Improving the Performance of Loop-Sensor-Based Traffic-Information System by (M+PLL) Circuit

Conventionally a phase-shift detection method (PSDM) and a frequency-shift detection method (FSDM) have been used in loop detectors. The PSDM has a fast response time and is very effective in detecting vehicles traveling at normal speeds. However, it is well known that the detection results are erroneous for vehicles traveling at low speeds in heavy traffic conditions. On the other hand, the FSDM greatly improves the detector performance for heavy traffic conditions. However, this method is not effective in fast and normal traffic conditions. Thus, in order to collect accurate traffic data for all traffic conditions, this paper proposes combining two methods using the digital OR logic. In the developed circuit, a phase-locked loop (PLL) circuit is used for measuring the phase change. This paper also develops a new loop detector instrumentation method using the so-called M circuit for detecting frequency change. The developed method has been tested for various traffic conditions. Experimental results show that the new combined M and PLL detection method greatly improves the accuracy in all traffic conditions, reducing the error rate in measuring traffic flow by more than 83%, when compared to the PSDM.     

Multicommodity network flow model for Asia's container ports

This paper seeks to develop a multi-commodity network model to analyse the flow of containers within the Asia Pacific context. The model is used to evaluate the impact of container throughput in Asia's port by varying terminal handling charges and turnaround time. The three main regions analysed are north-east Asia, east Asia (Chinese port region) and south east Asia. Using the model, it could be shown that Busan port, which is an important transhipment hub in north-east Asia, could boost the container activities in the north-eastern part of China by improving its service quality. It is also found that the efficiency of the land link between Hong Kong and mainland China plays a crucial role for the future of Hong Kong port. While Singapore port maintains its position as a transhipment hub in south-east Asia, there would be expected competition from neighbouring low costs ports.     

Effects of the 1988/89 climatic regime shift on the structure and function of the southwestern Japan/East Sea ecosystem

In this study we compared the structure of the ecosystem and the role of major species before and after 1988/89 climatic regime shift (CRS) in the southwestern Japan/East Sea. The 1988/89 CRS event changed the biomass and production of fisheries resources in the southwestern Japan/East Sea. Total biomass of all species groups in the ecosystem increased by 59% after the CRS. These results indicate that there were substantial changes in the function of major species in the southwestern Japan/East Sea ecosystem. The relative contribution of walleye pollock, at trophic level (TL) III, to the total flow of energy decreased drastically from 33.0% in the pre-CRS period to 4.3% in the post-CRS period, while that of common squid, at the same TL, doubled from 34.2% to 72.2% during the periods.     

Evaluation of actuated control of diamond interchanges with advanced experimental design

Two three‐phase actuated control strategies at diamond interchanges were investigated for different ramp spacings and traffic patterns. An advanced experimental design, hardware‐in‐the‐loop control, was employed for the simulation study. Operational performance was identified in terms of cycle length, average delay and total stops. Experimental results showed that the two phasing strategies gave similar performance in terms of cycle length and average delay, but not stops. The cycle length of three‐phase operation increased slightly as the ramp spacing became wider. The delay of each strategy was dependent on the traffic pattern, but there was a distinct movement preference for each strategy. The total stops decreased as the spacing increased, and it was the most sensitive variable for the studied traffic demand level. It was also shown that the concept of the hardware‐in‐the‐loop control provides an effective way to evaluate the signal phasing and control strategies.     

String tyre model for evaluating steering agility performance using tyre cornering force and lateral static characteristics

The cornering force and lateral static characteristics of a tyre are fundamental factors that describe the steering feel for handling performance. However, it is difficult to justify the contribution of each factor when the tyre’s cornering motion is evaluated through subjective assessment. Currently, the relaxation length of Pacejka’s tyre model is close to describing these tyre motions. Therefore, this paper proposes a string tyre model based on the relaxation length in order to represent the steering performance. The proposed method provides a more accurate modelling of the steering agility performance. Therefore, it is possible to use this model to predict the steering response performance, and this is validated through comparison with a real relaxation length.