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381.
Hyung Rim Choi Jae Joong Kim Jae Kee Lee Kang Bae Lee Joong Jo Shin 《Maritime Policy and Management》2018,45(3):388-402
To ensure the successful implementation of China’s Belt and Road (B&R) Initiative, it is essential to enable the real-time monitoring of containers’ locations, prevent theft during cargo delivery, ensure more efficient logistics management and reduce carbon emissions. For this, it is vital to have an economic and effective system to track and control containers across multiple countries. However, this requirement cannot be met by today’s container tracking systems because they are either limited within the borders of each country or expensive to employ internationally. This study thus presents a framework for an IoT-based container tracking system that enables users not only to grasp the international flow of container movement with one check but also to achieve smooth cross-border procedures. To verify the system’s performance, an empirical test was made for an actual container shipped from Korea to Poland. The test results showed that the system could successfully track the location of the container in real time across international borders. Last, this study discusses the policy development and international cooperation that should take place to enable the introduction of this container tracking system. 相似文献
382.
Gunwoo Lee 《Maritime Policy and Management》2017,44(4):524-535
Recently, the number of foreign tourists to Korea via cruise ships has increased dramatically. We attempted to estimate the shore excursion expenditure function during cruise tourism in Korea. To this end, we collected data from a survey of foreign tourists who visited Korea via cruise ships and conducted the ordered probit model with sample selection to correct for the sample selection bias. Statistical tests indicate that the sample selection model provides unbiased estimates of the ordered probit model. The estimation results reveal that the coefficients of the experience of visiting Korea, job status, annual income, and nationality have statistically significant relationships with shopping expenditure. Further, it is likely that Chinese and Japanese passengers spend more money on shopping than passengers from other countries. This study is expected to provide the Korean government and port authorities with useful information for targeting passengers with high shore excursion expenditure. From a management perspective, the results of this analysis will enable cruise operators to design shore excursion programs that meet travelers’ needs. 相似文献
383.
Paul Tae-Woo Lee 《运输评论》2017,37(4):507-520
Port devolution and port governance are focal issues in port studies. This paper argues that the previous typology of port devolution and port governance, including port function matrix models, might have to be modified, in particular for Asian port cases, because they have not considered socio, economic, and political systems and historical aspects behind the port devolution continuum. This paper uses the “compound eyes” approach comprising of many similar, closely-packed facets called ommatidia, with a multiple angle view, to revisit and review previous port devolution and governance models. The paper aims to identify the limitations and rectify fallacies in previous port studies by conducting a critical review and taking a couple of Asian container port cases as examples. This paper contributes to the literature of port devolution and governance, illuminating crucial gaps that the previous studies have not addressed. 相似文献
384.
This paper suggests using a proportional hazard model to predict personal income, for the purpose of imputing missing income
data in household travel surveys. The model has a hazard function that comprises two multiplicative components: (1) a non-parametric
baseline hazard function that is dependent only on the income level and (2) a function that is dependent only on the other
personal attributes of the survey respondents (excluding income). To estimate and validate the model, data is drawn from a
travel characteristics survey conducted in Hong Kong in year 2001. The model is found to have a much higher accuracy when
compared with a conventional ordered probit model based on the assumption that the logarithm of income is normally distributed.
C.·O. Tong is an Associate Professor at the Department of Civil Engineering, The University of Hong Kong. He received his B.Sc. (Eng.) degree from the University of Hong Kong, M.Sc. (Transportation Engineering) degree from Leeds University and Ph.D. degree from Monash University. His research interests are in transport demand modeling and dynamic network modeling. Jackie K. L. Lee worked as a Research Assistant at the Department of Civil Engineering, The University of Hong Kong during the period from March 2004 to April 2005. She received her B.Eng. and M.Eng. degrees in Civil Engineering from the Hong Kong Polytechnic University. She is a Chartered Engineer and is also Corporate Members of the Hong Kong Institution of Engineers and the Institution of Structural Engineers. 相似文献
C. O. TongEmail: |
C.·O. Tong is an Associate Professor at the Department of Civil Engineering, The University of Hong Kong. He received his B.Sc. (Eng.) degree from the University of Hong Kong, M.Sc. (Transportation Engineering) degree from Leeds University and Ph.D. degree from Monash University. His research interests are in transport demand modeling and dynamic network modeling. Jackie K. L. Lee worked as a Research Assistant at the Department of Civil Engineering, The University of Hong Kong during the period from March 2004 to April 2005. She received her B.Eng. and M.Eng. degrees in Civil Engineering from the Hong Kong Polytechnic University. She is a Chartered Engineer and is also Corporate Members of the Hong Kong Institution of Engineers and the Institution of Structural Engineers. 相似文献
385.
Estimation of intersection turning movements is one of the key inputs required for a variety of transportation analysis, including intersection geometric design, signal timing design, traffic impact assessment, and transportation planning. Conventional approaches that use manual techniques for estimation of turning movements are insensitive to congestion. The drawbacks of the manual techniques can be amended by integrating a network traffic model with a computation procedure capable of estimating turning movements from a set of link traffic counts and intersection turning movement counts. This study proposes using the path flow estimator, originally used to estimate path flows (hence origin–destination flows), to derive not only complete link flows, but also turning movements for the whole road network given some counts at selected roads and intersections. Two case studies using actual traffic counts are used to demonstrate the proposed intersection turning movement estimation procedure. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
386.
While most aggregate studies of transit ridership are conducted at either the stop or the route level, the present study focused
on factors affecting Metro ridership in the Seoul metropolitan area at the station-to-station level. The station-to-station
analysis made it possible to distinguish the effect of origin factors on Metro ridership from that of destination factors
and to cut down the errors caused by the aggregation of travel impedance-related variables. After adopting two types of direct-demand
patronage forecasting models, the multiplicative model and the Poisson regression model, the former was found to be superior
to the latter because it clearly identified the negative influences of competing modes on Metro ridership. Such results are
rarely found with aggregate level analyses. Moreover, the importance of built environment in explaining Metro demand was confirmed
by separating built environment variables for origin and destination stations and by differentiating ridership by the time
of day. For morning peak hours, the population-related variables of the origin stations played a key role in accounting for
Metro ridership, while employment-related variables prevailed in destination stations. In evening peak hours, both employment-
and population-related variables were significant in accounting for the Metro ridership at the destination station. This showed
that a significant number of people in the Seoul metropolitan area appear to take various non-home-based trips after work,
which is consistent with the results from direct household travel surveys. 相似文献
387.
Justin S. Chang Soo Yon Cho Beom Shin Lee Yonghwan Kim Suk Kang Yun 《Transportation》2012,39(1):33-54
The total economic value for a transportation service consists of use, option, and non-use value. The use benefit is based
on a traveler’s willingness to pay for usual consumption of the service. The optional value, on the other hand, is related
to the possible use of the service for trips not yet anticipated or currently accommodated by other travel modes. The non-use
value, however, is derived from the intrinsic merit of the service, even though a trip-maker never actually or potentially
depends on the mode. A closed-ended contingent valuation method is considered for the quantification of the option and non-use
values. A survey of single- and double-bounded dichotomous choices is conducted with a case study of South Korean bus operations.
A logistic regression model and a survival analysis for the single- and double-bounded approaches, respectively, are applied.
The estimation result is examined according to the statistical property required and the behavioral validity expected. In
particular, three issues from the output are discussed. First, the results help to show the preferable framework between single-
and double-bounded surveys for addressing an individual’s option and non-use values. Second, the differences in the absolute
values of option and non-use values are compared. Thirdly, the relationship between trip-makers’ willingness to pay and the
level of service of their primary travel modes are investigated. In conclusion, the summary of research and the possibilities
for future studies are given. 相似文献
388.
Integrated expression method for technical mapping of traffic parameters using RGB color model
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In the field of traffic flow, speed, density, time, and distance are fundamental variables analyzed to predict traffic conditions. Reliable sources of information are gauged using tested mathematical approaches that have been developed. However, a fundamental diagram that could serve as a basis for expression techniques has not been devised. Red–green–blue (RGB) color modeling was used to overcome this limitation in traffic flow. The purpose of this study is to provide a way to understand traffic flow conditions based on features of three traffic flow elements simultaneously. The limitation of three‐dimensional expressions in two‐dimensional paper was extended to multi‐dimensional information. Information on speed, density, and flow were combined into a single RGB color and given the name RGB flow‐density space time‐distance space. This cancels out the effect of each individual's vehicular trajectories and contains five major components of a specific road section. The new gizmo aims to provide information on traffic flow conditions in transition and to stimulate further approaches related to the predictions and understanding of traffic flow. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
389.
Numerical study of a light-duty diesel engine with a dual-loop EGR system under frequent engine operating conditions using the doe method 总被引:1,自引:0,他引:1
J. Park K. S. Lee S. Song K. M. Chun 《International Journal of Automotive Technology》2010,11(5):617-623
Exhaust gas recirculation (EGR) is an emission control technology that allows for a significant reduction in NOx emissions
from light- and heavy-duty diesel engines. The primary effects of EGR are a lower flame temperature and a lower oxygen concentration
of the working fluid in the combustion chamber. A high pressure loop (HPL) EGR is characterized by a fast response, especially
at lower speeds, but is only applicable if the turbine upstream pressure is sufficiently higher than the boost pressure. On
the contrary, for the low pressure loop (LPL) EGR, a positive differential pressure between the turbine outlet and the compressor
inlet is generally available. However, a LPL EGR is characterized by a slow response, especially at low and moderate speeds.
In this study, of the future types of EGR systems, the dual-loop EGR system (which has the combined features of the high-pressure
loop EGR and the low-pressure loop EGR) was developed and was optimized under five selected operating conditions using a commercial
engine simulation program (GT-POWER) and the DOE method. Finally, significant improvements in the engine exhaust emissions
and performance were obtained by controlling several major variables. 相似文献
390.
S. H. Jeong C. G. Choi J. N. Oh P. J. Yoon B. S. Kim M. Kim K. H. Lee 《International Journal of Automotive Technology》2010,11(3):409-416
This paper presents a low cost design and implementation of a parallel parking assist system (PPAS) based on ultrasonic sensors.
Generally, a PPAS requires several types of sensors, such as an ultrasonic sensor, camera sensor, radar sensor and laser sensor
for parking space detection. However, our proposed PPAS only requires two ultrasonic sensors on the front and lateral sides
for parking space detection. Moreover, a steering angle sensor and wheel speed sensor installed in the vehicle are used to
obtain vehicle position information for localization in ultrasonic range data. The hardware architecture of the PPAS based
on an electronic control unit (ECU) module, sensor modules and a human machine interface (HMI) module was proposed. Moreover,
the software architecture of the PPAS is based on system initialization, scheduling, recognition and a control algorithm.
In particular, a novel sensor algorithm was proposed to minimize the vehicle corner error of the ultrasonic sensor. A prototype
of the PPAS based on the proposed architecture was constructed. The experimental results demonstrate that the implemented
prototype is robust and successfully performs parking space detection and automatic steering control. Finally, the low cost
design and implementation of the PPAS was possible due to the cheap ultrasonic sensors, simple hardware design and low computational
complexity of the proposed algorithm. 相似文献