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941.
Water hydraulic systems have provoked major interest because of the human friendly and environmental safety aspects. Piston pump is one of the most frequently used hydraulic units in recent engineering technique. In water hydraulic piston pump, poor lubrication is more likely to happen than in oil hydraulic one because of difference in properties between water and oil. So there are some key problems such as corrosive wear and erosion, which are investigated briefly. Many new materials have been developed, which give longer life expectancies with water without corrosion and erosion. A new type of seawater hydraulic piston pumps with better suction characteristics had been developed at HUST. Much of this research has concentrated on new materials, structure and experiments, which are also specially introduced.  相似文献   
942.
The energy distribution model of motion blurred star point is analyzed. The distribution of the star point approximates to a two-dimensional (2D) Gaussian distribution under degeneration. Two multi-parameter nonlinear Gaussian fitting methods (GFMs) are proposed, and the relationship between fitting parameters and motion blur parameters is analyzed. Estimation of the parameters of motion blur by fitting parameters is calculated to realize the error compensation of the motion blur. The simulation results show the effectiveness and accuracy.  相似文献   
943.
The dissolution of a relationship is a life event that often coincides with many other changes in life, such as a decline in income level or household size or a change in place of residence. This study aims to provide more insight into the ways in which circumstances shortly following the disruption of a relationship affect travel behaviour. Register data that combines information on the Dutch population, income and vehicle registration are used to understand how personal situations that are closely related to relationship disruption affect car ownership. The study shows that several characteristics of singles and single partners shortly after a breakup negatively affect car ownership. For instance, a relatively low income level, unemployment, living in a city or a residential move all affect car ownership negatively. This study focuses on the role of circumstances shortly after relationship disruption, demonstrating the importance of such an event.  相似文献   
944.

A large amount of information is required to model the complex trade-off processes between travel activities, non-travel activities and budget assignment at the individual level. This paper describes the development of a new survey design, which incorporates components of travel surveys, time use surveys and consumer expenditure surveys in an integrated format, which is expected to deliver a richer data set allowing deeper insights into individuals’ activity and consumption patterns. The survey procedure and the incentives paid, which were necessary to obtain acceptable response rates, are also described. Results from two pilot studies using a trip-based and an activity-based diary format are presented. The paper examines to which extent the diaries have been capable of collecting the required data with high quality and response rates. The innovative “Mobility–Activity–Expenditure-Diary” is introduced and results of the main survey using this design are presented. Travel behaviour and non-travel activities were reported at high quality. Expenditures would require longer observation periods (and preferably not only telephone but also personal support in the survey process) to reduce unsystematic variations and to better capture individuals’ long term equilibrium.

  相似文献   
945.
Transportation - The Netherlands seems to exhibit the unique conditions that allow cycling on the country level instead of only the city level. Moreover, the national transit system seemingly...  相似文献   
946.
The Second International Conference on New Survey Methods in Transport was held at Hungerford Hill, Australia in September 1983. The aims of the conference were to provide a focus for discussion of survey methodology and to establish bench‐marks with respect to the state of the art in various facets of transport surveys. The conference evolved around workshops in twelve key areas: sample design, survey needs for modelling, questionnaire design and piloting, perceptual studies, diary surveys, longitudinal studies, interactive survey methods, freight surveys, traffic surveys, total design concepts, response errors and data correction, and coding and computing.

A number of plenary keynote papers were also presented describing the state of the art in cross‐sectional, longitudinal and interactive survey methods. Emerging from the conference discussions, six key issues were prominent; the gap between the state of the art, as espoused by researchers, and the state of practice, as employed by practioners; the differences in results obtained when employing different survey methods to collect essentially the same data; the emerging use of the telephone for the conduct of interview travel surveys; the interaction between survey methods and demand modelling and the disparate levels of sophistication in the two areas; the role of microcomputers in the design, conduct and analysis of transport surveys; and the need for practitioners to engage in controlled experimentation, so that methodological advances may continue to be made in the field of transport surveys.  相似文献   
947.
Adam  Lukas  Jones  Tim  te Brömmelstroet  Marco 《Transportation》2020,47(2):503-527
Transportation - Urban utility cycling is being promoted widely due to various health, social, economic and environmental benefits. This study seeks to identify and rank which municipal-level...  相似文献   
948.
The high frequency of maritime accidents and incidents occurring at sea has been a major challenge for the maritime industry in the last decades. The majority of these accidents are attributed to seafarers’ poor performance. This, despite the fact that the international maritime domain continues to adopt and update conventions regulating maritime safety to mitigate these accidents from occurring. In this paper, utilising a qualitative research approach, we show through a socio-cultural contextual perspective that time constraints as a major influencing factor in causing task deviations at sea which leads to dangerous situations. We analyse how some of the present barriers in place to prevent accidents at sea are in effect prompt seafarers who are working under time pressure to deviate from their task. Moreover, the paper discusses the social constituents such as job insecurity and the seafarers’ viewpoint towards the ship operators’ commitment to safe ship operations are crucial in motivating seafarers’ deviating from the task at hand when faced with time pressure.  相似文献   
949.
Most efficient indeces and query techniques over XML (extensible markup language) data are based on a certain labeling scheme, which can quickly determine ancestor-descendant and parent-child relationship between two nodes. The current basic labeling schemes such as containment scheme and prefix scheme cannot avoid relabeling when XML documents are updated. After analyzing the essence of existing dynamic XML labels such as compact dynamic binary string (CDBS) and vector encoding, this paper gives a common unifying framework for the numeric-based generalized dynamic label, which can be implemented into a variety of dynamic labels according to the different user-defined value comparison methods. This paper also proposes a novel dynamic labeling scheme called radical sign label. Extensive experiments show that the radical sign label performs well for the initialization, insertion and query operations, and especially for skewed insertion where the storage cost of the radical sign label is better than that of former methods.  相似文献   
950.
Skin detection has been considered as the principal step in many machine vision systems, such as face detection and adult image filtering. Among all these techniques, skin color is the most welcome cue because of its robustness. However, traditional color-based approaches poorly perform on the classification of skin-like pixels. In this paper, we propose a new skin detection method based on the cascaded adaptive boosting (AdaBoost) classifier, which consists of minimum-risk based Bayesian classifier and models in different color spaces such as HSV (hue-saturation-value), YCgCb (brightness-green-blue) and YCgCr (brightness-green-red). In addition, we have constructed our own database that is larger and more suitable for training and testing on filtering adult images than the Compaq data set. Experimental results show that our method behaves better than the state-of-the-art pixel-based skin detection techniques on processing images with skin-like background.  相似文献   
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