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111.
Quantitative assessment of hydrocarbon explosion and fire risks in offshore installations 总被引:1,自引:0,他引:1
Jeom Kee Paik Jerzy CzujkoBong Ju Kim Jung Kwan SeoHan Seong Ryu Yeon Chul HaPiotr Janiszewski Beata Musial 《Marine Structures》2011,24(2):73-96
A risk-based design framework should involve both risk assessment and risk management. This article introduces and describes a number of procedures for the quantitative assessment and management of fire and gas explosion risks in offshore installations. These procedures were developed in a joint industry project on the explosion and fire engineering of floating, production, storage and off-loading units (the EFEF JIP), which was led by the authors. The present article reports partial results, focussing on defining the frequency of fires and explosions in offshore installations. Examples of the aforementioned procedures’ application to a hypothetical floating, production, storage, and off-loading unit (FPSO) are presented. A framework for the quantitative risk assessment of fires and explosions requires the definition of both the frequency and consequences of such events. These procedures can be efficiently applied in offshore development projects, and the application includes the assessment of design explosion and fire loads as well as the quantification of effects of risk control options (RCO) such as platform layout, location and number of gas detectors, isolation of ignition sources etc. 相似文献
112.
Sang-Yeob Kim Kyong-Hwan Kim Yonghwan Kim 《Journal of Marine Science and Technology》2012,17(1):47-58
This paper considers a comparative study on model-scale sloshing tests. There are two primary scopes of this study: the comparison
of sloshing pressure measured in 1/50-scale model tests at Seoul National University (SNU) with (1) the data measured at the
other facility for the same model, and (2) the data measured on a smaller scale model. For the comparative study, model tanks
are excited with the same irregular motions with Froude scale, and sloshing pressure signals are measured at the same locations.
The statistical quantities of 1/50-scale model tests are compared with those of other facility and 1/70-scale model tests.
In this study, it is found that peak pressure measured at SNU are slightly lower than those of other facility, and this difference
may be due to different sensor types and sensing diameters. 相似文献
113.
114.
In this study, a control strategy for a dual mode power split-type hybrid electric vehicle (HEV) is developed based on the powertrain efficiency. To evaluate the transmission characteristics of the dual mode power split transmission (PST), a mechanical loss model of the transmission (TM loss) is constructed. The transmission efficiency, including the TM loss, is evaluated for the dual mode PST. Two control strategies for the dual mode PST are proposed. An optimal operation line (OOL) control strategy is developed to maintain a high engine thermal efficiency by controlling the engine operation point on the OOL. A speed ratio (SR) control strategy is proposed to obtain a greater transmission efficiency by shifting the engine operation point when the dual mode PST operates near the mechanical points. Using the TM loss and the proposed control strategies, a vehicle performance simulation is conducted to evaluate the performance of the two control strategies for dual mode PST. The simulation results demonstrate that, for the SR control strategy, the engine efficiency decreases because the engine operates beyond the OOL. However, the transmission efficiency of the dual mode PST increases because the PST operates near the mechanical point where the PST shows the greatest transmission efficiency. Consequently, the fuel economy of the SR control strategy is improved by 3.8% compared with the OOL control strategy. 相似文献
115.
D. O. Kang S. J. Heo M. S. Kim W. C. Choi I. H. Kim 《International Journal of Automotive Technology》2012,13(1):109-122
This study presents the robust design optimization process of suspension system for improving vehicle dynamic performance
(ride comfort, handling stability). The proposed design method is so called target cascading method where the design target
of the system is cascaded from a vehicle level to a suspension system level. To formalize the proposed method in the view
of design process, the design problem structure of suspension system is defined as a (hierarchical) multilevel design optimization,
and the design problem for each level is solved using the robust design optimization technique based on a meta-model. Then,
In order to verify the proposed design concept, it designed suspension system. For the vehicle level, 44 random variables
with 3% of coefficient of variance (COV) were selected and the proposed design process solved the problem by using only 88
exact analyses that included 49 analyses for the initial meta-model and 39 analyses for SAO. For the suspension level, 54
random variables with 10% of COV were selected and the optimal designs solved the problem by using only 168 exact analyses
for the front suspension system. Furthermore, 73 random variables with 10% of COV were selected and optimal designs solved
the problem by using only 252 exact analyses for the rear suspension system. In order to compare the vehicle dynamic performance
between the optimal design model and the initial design model, the ride comfort and the handling stability was analyzed and
found to be improved by 16% and by 37%, respectively. This result proves that the suggested design method of suspension system
is effective and systematic. 相似文献
116.
J. K. Park Y. S. Kim O. S. Seo M. G. Lee H. Y. Kim 《International Journal of Automotive Technology》2013,14(5):717-722
There are two types of hot-stamping processes, direct and indirect, depending on the sequence of the heating, forming, and quenching steps and the method used for each step. In this study, an indirect hot-stamping process consisting of forming at room temperature, heating, and water quenching was applied to develop a coupled torsion beam axle. The analysis results indicated that the application of the heat convection coefficient is critical in the simulations and must take into account the temperature and specific location in the model to ensure the accuracy of the heating and quenching analysis. The heat convection coefficients used in the analysis were directly measured at various positions of the tube (e.g., outside, inside, and bending region) using thermocouples, and the final values were determined through correlation between the actual tests and numerical analysis. The experimental and simulated final deformed shape and temperature distribution were in good agreement. 相似文献
117.
J. Son B. Reimer B. Mehler A. E. Pohlmeyer K. M. Godfrey J. Orszulak J. Long M. H. Kim Y. T. Lee J. F. Coughlin 《International Journal of Automotive Technology》2010,11(4):533-539
Driving demands significant psychomotor attention and requires even more when drivers are engaged in secondary tasks that
increase cognitive workload and divert attention. It is well established that age influences driving risk. Less is known about
how culture impacts changes in attention. We conducted parallel driving simulations in the US and Korea to measure the extent
to which age and culture influence dual-task performance. There were 135 participants divided into two groups: a younger group
aged 20∼29, and an older group aged 60∼69. Whereas some differences by culture appeared in absolute control measures, the
younger participants showed similar mean velocity and compensatory patterns associated with increased cognitive load in the
urban setting; however, the results from the older samples were less similar. 相似文献
118.
Although automobile crash test data have a comparatively large variation because of the complexity of the tests, only a limited
number of crash tests are usually conducted due to monetary and time limitations. Thus, it is necessary to control input variables
that cause the variation in test data to obtain consistent crash test results and to correctly assess the safety performance
of an automobile under development. In this study, a MADYMO model was validated deterministically to yield the head, chest,
pelvis deceleration pulses of anthropomorphic test devices and the belt load pulses similar to those from actual tests, and
it was also validated stochastically to yield means and standard deviations of the head and chest injury numbers, i.e., HIC
15
and 3 msec clip similar to those from actual tests. A stochastic analysis was conducted using the validated MADYMO model to calculate the
sensitivity of the standard deviations of the injury numbers to the standard deviations of influential input variables to
determine the most influential input variable that makes the largest contribution to the variation in the injury numbers.
Moreover, the Taguchi approach was used to determine the optimal values of the influential input variables to improve safety
performance. 相似文献
119.
S. Lee D. H. Lee M. H. Kim K. C. Lee 《International Journal of Automotive Technology》2010,11(4):525-531
The controller area network (CAN) is the dominant protocol for in-vehicle network (IVN) systems because it provides bounded transmission delay among electronic control units (ECUs) at data rates between 100 Kbps and 1 Mbps. Many automotive companies have chosen the CAN protocol for their chassis network system of intelligent vehicles. However, the increasing number of ECUs in intelligent vehicles and the need for more intelligent functions require a network system with more network capacity and real-time capability. As one approach to enhance the network capacity of a CAN system, this paper introduces a CAN system with dual communication channels. This paper also presents a traffic-balancing algorithm that predicts the traffic of each channel and allocates frames to the most appropriate channel. An experimental testbed using commercial off-the-shelf microcontrollers with two CAN controllers was used to demonstrate the feasibility of the traffic-balancing algorithm. 相似文献
120.
This paper deals with the lane assignment problem in the Automated Highway Systems (AHS). The purpose of lane assignment strategies
is to increase throughput on multi-lane highways with many entry and exit points, based on the itineraries of vehicles using
the highway (point of entry, time of entry and exit point) and the effects of maneuvers. Using partitioned lane assignment
strategies, the lane assignment problem is formulated as an optimization problem to find the proper positions of partitions.
Then the optimal problem is solved using a Genetic Algorithm (GA). The proposed algorithm has been validated by comparing
its solution with that of an all-cases algorithm for a simple case. Moreover, a traffic simulator with a realistic car-following
model as well as lane change logic has been developed. The simulation results show the efficiency of the proposed genetic
algorithm, compared with random assignment algorithms. 相似文献