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41.
Lam Canh Nguyen 《Maritime Policy and Management》2019,46(1):24-42
This paper aims at defining generic characteristics of dry ports by carrying out an analysis using a large sample of dry ports from around the world. The dataset includes details on 107 inland terminals worldwide. All dry ports in the database have been selected from studies in the extant literature before being shortlisted to fit our research scope. Data collected include terminologies used, actors driving the development, terminal throughput, total area, services provided and the relation with the corresponding seaport(s). Using statistical analysis, the paper examines how dry port parameters are influenced by (1) a different terminal set up, like sea-driven and land-driven development, developed and developing system, dry port functions; (2) specifications of the seaport with which the dry port is connected, i.e. seaport traffic, connectivity, utilization, etc. and (3) the transport leg linking dry ports and seaports. The findings could be applied to the planning and development of inland nodes from the perspectives of different stakeholders. 相似文献
42.
Development of a low-noise cooling fan for an alternator using numerical and doe methods 总被引:1,自引:0,他引:1
W. Kim W. -H. Jeon N. Hur J. -J. Hyun C. -K. Lim S. -H. Lee 《International Journal of Automotive Technology》2011,12(2):307-314
An alternator, which converts mechanical rotational energy into electrical energy, is an important component of a vehicle.
Alternators operate over a broad range of rotational speeds, typically from 3,000 RPM to 18,000 RPM, which demands a cooling
fan producing sufficient airflow, ideally with a minimum of noise. In the current study, an optimized alternator-cooling fan
was developed through a linked DOE(Design OF Experiment) process and numerical analysis. The SC/Tetra and FlowNoise S/W programs were used to calculate flow rates and noise levels, respectively, for the newly developed fan. Compared with
original model, the numerical results predicted a 3 dBA noise reduction; the measured reduction was 4 dBA. 相似文献
43.
B. J. Yoon J. Y. Lee J. H. Kim C. S. Han 《International Journal of Automotive Technology》2011,12(1):111-118
A navigation algorithm is indispensable for Unmanned Ground Vehicles (UGVs). During driving, UGVs follow a global path. In
this study, we propose a navigation algorithm using Real Time Kinematic (RTK)-Differential Global Positioning System (DGPS)
units and encoders to complement global path planning. Sometimes GPS systems lose their signals and receive inaccurate position
data due to many factors, such as edifice and barrier obstructions. This paper shows that GPS deviations can be solved using
a Dead Reckoning (DR) navigation method with encoders and that position errors can be decreased through the use of RTK-DGPS
units. In addition to this method, we will introduce a new waypoint update algorithm and a steering algorithm using RTK-DGPS
units. 相似文献
44.
T. Y. Shin S. Y. Kim J. Y. Choi K. S. Yoon M. H. Lee 《International Journal of Automotive Technology》2011,12(1):103-110
This paper presents a modified lateral control method for an autonomous vehicle with both look-ahead and look-down sensing
systems. To cope with sensor noise and modeling uncertainty in the lateral control of the vehicle, a modified LMI-based H
lateral controller was proposed, which uses the look-ahead information of the lateral offset error measured at the front of
vehicle and the look-down information of the vehicle yaw angle error between the reference lane and the centerline of the
vehicle. To verify the safety and the performance of the lateral control, a scaled-down vehicle was developed, and the positioning
of the vehicle was estimated with USAT. The proposed controller, which uses both look-ahead and look-down information, was
tested for lane changing and reference lane tracking with both simulation and experiment. The simulation and experimental
results show that the proposed controller has better tracking and handling performance compared with a controller that uses
only the look-ahead information of the target heading angle error. 相似文献
45.
K. Jang I. Park J. Han K. Lee M. Sunwoo 《International Journal of Automotive Technology》2011,12(4):589-597
Because the FlexRay protocol has more than 70 configuration parameters and these parameters correlate with each other, designing
a FlexRay network is a complex and difficult task. In this study, we propose a design framework that optimizes the two main
FlexRay network parameters that are highly relevant to the application algorithm. The design process is composed of two steps
for optimizing parameters. In the first step, the static slot length is optimized using a frame-packing algorithm. This algorithm
binds network signals into static frames based on their periods and signal groups. In the second step, the communication cycle
length is optimally designed with frame-scheduling algorithm and worst-case reponse time analysis. Based on the frame-scheduling
algorithm, the response times are analyzed. The proposed design framework was applied to a unified chassis control system
as a case study, and the analytical results were verified. 相似文献
46.
Identifying the components of a vehicle’s interior noise is important in many phases of the noise, vibration, and harshness
(NVH) development process. Many test methods that have been widely used in the automobile industry to separate noise sources
are based on system identification methods in the frequency domain. However, none of the frequency response function-based
methods can directly estimate the wind noise component. In this article, an analytical model for the interior noise level
based on a simple power law was developed. It was assumed that the mean squared acoustic pressure for the interior noise could
be obtained by summing up those of the wind noise, road noise, and background noise. The wind noise and road noise were further
assumed to depend only on wind speed and the vehicle’s driving speed, respectively, and to follow a simple power law. The
resulting analytical model includes five parameters that can be optimized for the vehicle and the road. The validity of the
model was verified by using data obtained from cruise tests performed on a proving ground for cruise speeds ranging from 40
km/h to 130 km/h. The model is applied to the overall and 1/3-octave bands of interior noise and is shown to describe the
data trends fairly well. For the test vehicle used in the present work, the overall mean squared pressures for the wind and
road noise components are shown to be proportional to the wind speed to the 5.8 power and to the driving speed to the 3.4
power, respectively. 相似文献
47.
H. H. Lee H. W. Bang S. K. Kauh S. I. Kim 《International Journal of Automotive Technology》2011,12(3):351-358
The development of an inner-piston-chamber temperature measurement system is a necessary step in engine development or when
solving other fundamental problems related to automotive engines. There are various pre-existing measurement methods available,
e.g., the linkage method, piston telemetry, templog, and the electromagnetic induction method. In this study, we first redesigned
the coil sensor used in the electromagnetic induction method using PEEK and then used Taguchi methods to reduce the number
of experiments in the development process and finally utilized piston telemetry via Bluetooth to verify the precision and
accuracy of the redesigned PEEK coil sensor and electromagnetic induction method. The results displayed a reproducibility
within 0.5 degrees and an accuracy within 2 degrees Celsius. 相似文献
48.
D. H. Kim J. M. Lee E. H. Park J. H. Song S. I. Park 《International Journal of Automotive Technology》2011,12(3):409-416
A comprehensive study evaluating the performance of biobutanol-blended gasoline in passenger cars was conducted because biobutanol
is considered a better biofuel than bioethanol as it has no water solubility and it has a higher caloric value, giving it
a higher energy value. Several kinds of samples—suboctane gasoline, 8 volume percentage and 16 volume percentage biobutanol—blended
gasoline, and a 10 volume percentage MTBE-blended market sample (as the oxygencontaining gasoline)-were tested to evaluate
the engine performance in terms of the detergency of the intake valves and combustion chambers, power, emissions, and fuel
efficiency. Additionally, the toxicity of the emissions from these biobutanolblended samples was tested in order to assess
the viability of biobutanol as one of the competitive potential substitutes for MTBE as an oxygenator in the near future.
The results show that biobutanol-blended gasoline samples had relatively better detergency, relatively higher power, and similar
levels of emissions compared with those of MTBE-blended gasoline. Formaldehyde was emitted from all of the samples at almost
the same levels and within the error range, whereas biobutanolblended gasoline samples emitted approximately three times the
amount of acetaldehyde than did the suboctane gasoline. This study shows that biobutanol is one of the best alternative bioalcohol
fuels for use in the near future. 相似文献
49.
Y. Kim S. Choi J. Lee W. Yoo J. Sohn 《International Journal of Automotive Technology》2011,12(4):521-527
In this study, a large bus is tested to measure its dynamic response by the single-lane change test and the rapid stop test.
A full car model is established by ADAMS/Car for computer simulation. For multibody modeling of a large bus, user-defined
templates are used in the simulation. Simulation results of the single-lane change test and the rapid braking test are compared
to the results of the physical experiments, in which several sensors are installed to measure the vehicle’s responses. The
results obtained from the simulation show good agreement with the tests’ results. A dynamic model for the MR(magnetic-rheological)
damper is also developed by employing the Magic Formula model, which is widely used in the nonlinear modeling of a tire. Bump
simulation of a full car with the MR damper is carried out to verify the performance of the MR damper. The comparison of the
simulation results obtained with the MR damper model to the results obtained with the traditional passive damper model showed
improved response of the vehicle with the MR damper. 相似文献
50.
Competition and disruption in a dynamic urban supply chain 总被引:1,自引:0,他引:1
Terry L. Friesz Ilsoo Lee Cheng-Chang Lin 《Transportation Research Part B: Methodological》2011,45(8):1212-1231
Rapid changes and complexities in business environments have stressed the importance of interactions between partners and competitors, leading supply chains to become the most important element of contemporary business environments. There is a concomitant need for foresight in describing supply chain performance in all operating environments, including those involving punctuated disruptions. Furthermore, the urban metropolis is now widely recognized to be an environment which is especially vulnerable to supply chain disruptions and for which integrated supply chain decisions can produce very substantial net benefits. Accordingly, this paper presents a dynamic supply chain network model formulated as a differential variational inequality; the model is fashioned to allow consideration of supply chain disruption threats to producers, freight carriers, and retail enterprises. The DVI is solved using a fixed-point algorithm, and a simple numerical example, introduced to illustrate how the impacts of supply chain disruptions may be quantified, is presented. 相似文献