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61.
I. Park J. Chung J. Youn W. Lee M. Sunwoo 《International Journal of Automotive Technology》2016,17(4):717-729
This paper presents an integration method of AUTOSAR-compliant ECUs which can evaluate resource constraints in an early-stage of development. There are three types of resources for an ECU (timing, memory, and interface) which should be carefully managed for successful ECU integration. The proposed method consists of three steps: measurement, prediction, and evaluation. In the first step, a method to measure resource factors for AUTOSAR-compliant software architecture is introduced. Based on the method, a worst-case execution cycle of a runnable, memory section usages of a software component, and interface of legacy ECUs can be obtained. In the second step, the obtained factors are quantitatively predicted according to the architectural designs of the integration ECU. In the case of the timing resource, the worst-case execution time of the integration ECU can be precisely predicted by a proposed empirical model. In the last step, the resource constraints such as CPU, memory, network utilizations can be evaluated with predicted resource factors before implementation. The proposed method was applied to the integration of an in-house engine management system composed of two ECUs. The method successfully provided quantitative measures to evaluate architectural designs of three different integration scenarios. 相似文献
62.
Seung-Ho Yang Sang-Beom Lee Jung-Ho Park Seung-Yoon Han Young-Myung Choi Jitae Do Sun-Hong Kwon Bernard Molin 《Journal of Marine Science and Technology》2016,21(4):715-728
An experimental study was performed on the piston- and sloshing-mode moonpool resonances of offshore structures. Two different geometries were considered to investigate the flow characteristics in a plain moonpool and a moonpool with a cofferdam. To examine the efficiency of a cofferdam for reducing the flow in a moonpool, three cofferdam geometries were tested. The plain moonpool presented violent flows as a result of the piston- and sloshing-mode resonances. However, the moonpool with the cofferdam introduced violent sloshing waves instead of the ascent and descent of the water column in the piston-mode moonpool resonance. Among three different cofferdam geometries, the model with a right triangle facing to the left on the top of the cofferdam was most effective in reducing the flow in the moonpool when compared with the other models. 相似文献
63.
Tae-Woo Lee Nam-Kyu Park John F. Joint Woong Gyu Kim 《Maritime Policy and Management》2000,27(2):133-144
There have been many efforts to develop a logistics information system in the Korean logistics industry. In spite of these efforts, there are many points which need improvement in the Logistics Information System, of which function is the electronic data communication without added value. This paper aims to describe some of the main problems and the successful factors which are being found in the evolution of the present EDI systems for clearing import/export container cargoes, with special reference to Singapore, Korea, and Japan. Following this, leaving legal issues aside, to suggest workable guidelines for designing a new efficient EDI system for container cargo logistics. As a result of the review, the following successful factors are drawn: (a) the planning, requirement analysis and design of EDI are critical, as it provides a framework for its implementation; (b) as the data of customs clearance are an integral part of a logistics EDI system, the inclusion of customs in the system design is essential; (c) the sharing system of cargo data as the framework of the logistics EDI is efficient for data interchange; (d) the EDI software for the user has been developed and provided by an EDI network operating company; and (e) to facilitate communication between trading partners and the transport sector, it is necessary to adopt a global message standard, such as EDIFACT. 相似文献
64.
In this paper, the basic architecture of an agent is proposed and a federated agent system based on the basic architecture
is implemented. The basic architecture consists of a knowledge query and manipulation language (KQML) handler, a knowledge
interchange format (KIF) interpreter, and design flow control codes. The KQML handler is a module for managing KQML performatives
received from an agent. The KIF interpreter provides the support services of content-based routing, translation using a matching
scheme, and simple inference. A Java template package was used for communication between agents. A federated agent system
was then applied to a preliminary ship design to show the handling process of the agent system and its applicability in a
distributed design environment.
Received: June 5, 2000 / Accepted: September 20, 2000 相似文献
65.
Becky P. Y. Loo 《Transportation》2007,34(4):471-486
Paratransit refers to urban transport services “somewhere between private passenger transport and conventional public transport in terms of cost and quality of service” [Rimmer (1980), Paratransit: A commentary. Environ. Plan. A 12, 937–944]. Since the 1980s, a new form of paratransit—residents’ coach, which provides exclusive transport services to residents living in private housing estates—has emerged in Hong Kong. What was the background underlying the emergence and subsequent growth of residents’ coach services? Also, what was the role of residents’ coach in the public transport system of Hong Kong? With the completion of more railway extensions, should residents’ coach services be replaced? If so, what are the potential impacts on people’s life? This paper addresses the above research questions through a large-scale questionnaire survey that examined not only people’s modal choice but also their residential choice, socio-economic background and attitudes. The findings suggest that transport policy makers should pay more attention to examine new forms of paratransit and the ways of integrating them into the overall public transport system, both spatially and temporally. It is only through the development of an efficient and multi-modal transport system can the maximum potential of paratransit in filling the transport gap between conventional mass transit and private cars be realized. 相似文献
66.
Y. S. Kim E. Y. Kim Y. W. Shin S. K. Lee 《International Journal of Automotive Technology》2010,11(5):759-765
This paper presents a multi-body flexible dynamic analysis of a centrifugal turbo blower for a fuel cell electric vehicle
(FCEV) based on the application of computer-aided engineering (CAE) to predict the acceleration at the mount position of the
blower. This predicted acceleration is validated by using the measured acceleration data. The numerical simulation for the
multi-body flexible dynamics of the blower is used not only to identify the most effective mount among four mounts in an FCEV
by controlling the complex stiffness of the isolator, but also to suggest the range of complex stiffness of the isolator at
the most effective mount. This numerical simulation technology can be useful for the estimation of the variation of vibration
transmission for the structural modification of the turbo blower. 相似文献
67.
H. J. Kim B. Han W. S. Hong W. H. Shin G. B. Cho Y. K. Lee Y. J. Kim 《International Journal of Automotive Technology》2010,11(4):447-453
A 3000 cc diesel engine attached to an engine dynamo was used to test three newly developed electrostatic Diesel Particulate
matter filtration Systems (DPS 1, 2, and 3) under four steady-state engine operating conditions: idle, 2000 rpm with no load,
and 2000 rpm under 25% and 50% loads. Of the two developed alternatives, DPS 1 and DPS 2, DPS 2 comprises an ionization section,
electrostatic field additional section and Flow-Through Filter (FTF), which achieved almost 90% removal of particulate matter
(PM) under the engine’s operating conditions, and the efficiency of the FTF was maintained between 20% and 50%. Comparing
the long-term performance of DPS 2 and DPS 3 (effectively a serial combination of two DPS 2s) with a commercially-available
Diesel Particulate Filter (DPF), the DPS 2 and DPS 3 achieved almost the same efficiency for removing PM as the DPF but had
significantly improved (75%∼90% lower) differential pressure drops. 相似文献
68.
Fault detection method for electric parking brake (EPB) systems with sensorless estimation using current ripples 总被引:1,自引:0,他引:1
C. W. Lee H. B. Chung Y. O. Lee C. C. Chung Y. S. Son P. Yoon 《International Journal of Automotive Technology》2010,11(3):387-394
A fault detection method with parity equations is proposed in this paper. Due to its low cost implementation, the velocity
of the motor is not measurable in electric parking brake (EPB) systems. Therefore, residuals are not reliable when estimating
the motor velocity with a low-resolution encoder. In this paper, we propose a fault detection method with sensorless estimation
using current ripples that estimates the position and velocity of the motor by detecting periodical oscillations of the armature
current caused by rotor slots. In addition, this method can estimate the position and velocity of the motor with less computational
effort than a state observer. Moreover, the method is less sensitive to motor parameters than model-based estimation methods.
The effectiveness of this method is validated with experimental data, and the simulation results show that various faults
have their own residual patterns. Therefore, we can detect the presence of faults by monitoring the residual signals. 相似文献
69.
Development of a new sound metric for impact sound in a passenger car using the wavelet transform 总被引:1,自引:0,他引:1
Vehicles can experience impacts due to harsh road conditions. Contact with an uneven road surface causes vehicles to vibrate,
which generates a loud impact sound. The attenuation of such noise is important because car passengers may complain about
the impact noise. However, perfect removal of impact noise is not possible because most of it is caused by external conditions.
More research is needed on the objective attributes of impact noise; however, the problem of impact noise is not a simple
matter because impact noise is transient in nature and reaches a high level instantaneously. In this paper, a new objective
attribute of impact noise is designed using the wavelet transform, which is appropriate for analyzing nonstationary signals,
such as an impact signal. The usefulness of the new objective attribute, which is a sound metric, is examined by comparing
the mean subjective ratings for real impact noise in passenger cars. The new sound metric has better correlation with the
mean subjective rating than currently existing sound metrics. 相似文献
70.
We investigated the effects of injection parameters such as injection pressure, ambient pressure, and ambient temperature
on spray characteristics. We calculated the turbulence occurring point (t
c
), defined as the time required to generate a vortex, and the deceleration point (t
b
), defined as the time when spray penetration begins to decelerate, to elucidate the breakup mechanism of the test injectors.
The spray velocity coefficient (Cv) was obtained to evaluate the spray characteristics. As the ambient pressure increases in the case of a slit injector, Cv decreases. We investigated the effects of nozzle tip shape according to injection pressure, ambient pressure, and fuel properties
on spray characteristics and provide a Cv value of 0.38 for the swirl injector with a spray angle of 60° and the slit injector under atmospheric conditions. The value
of Cv in the case of a slit injector was reduced by increasing the ambient pressure. Our results suggest that Cv of a swirl injector is constant regardless of changes in ambient pressure, injection pressure, and fuel properties. On the
other hand, Cv of a slit injector is altered by changes in ambient pressure. 相似文献