Search results

The purpose of this paper is to design a robust tracking algorithm which is suitable for the real-time requirement and solves the mistake labeling issue in the appearance model of trackers with the spare features.

This paper proposes a tracker to select the most discriminative randomly projected ferns and integrates a coarse-to-fine search strategy in this framework. First, the authors exploit multiple instance boosting learning to maximize the bag likelihood and select randomly projected fern from feature pool to degrade the effect of mistake labeling. Second, a coarse-to-fine search approach is first integrated into the framework of multiple instance learning (MIL) for less detections.

The quantitative and qualitative experiments demonstrate that the tracker has shown favorable performance in efficiency and effective among the competitors of tracking algorithms.

The proposed method selects the feature from the compressive domain by MIL AnyBoost and integrates the coarse-to-fine search strategy first to reduce the burden of detection. This paper designs a tracker with high speed and favorable results which is more suitable for real-time scene.

The purpose of this paper is to investigate the influence of the oxidation on the cracks of DZ125L nickel-based superalloy thin-walled parts in laser metal direct forming (LMDF).

Thin-walled cylinders were fabricated in protective atmosphere with different oxygen contents in order to reveal the influence of oxidation on the morphology of cracks. The influence of oxidation on the cracks was investigated in detail by measuring the wall thicknesses of cylinders, the residual stress in the top surface of the cylinders and the composition of the cracks. Finally, the validity of the results was verified by fabricating a thin-walled turbine blade in protective atmosphere.

The experimental results showed that wall thickness fluctuation of cylinders, unequal residual stress distribution of cylinders and the oxides in the crack were all the critical factors which led to crack of DZ125L thin-walled parts. Thin-walled turbine blades with no cracks can be fabricated when the oxygen content was about less than 150 ppm in protective atmosphere.

The appropriate oxygen content in protective atmosphere is helpful for fabricating thin-walled parts of nickel-based superalloy like DZ125L, and the results can show what will happen at different oxygen levels. Moreover, the results show that the cracks can be eliminated as the oxygen content reduce to less than 150 ppm rather less than 10 ppm or even less, which can reduce the cost of protective gas as forming thin-walled parts of nickel-based superalloy such as DZ125L.

The appropriate oxygen content in protective atmosphere is helpful for fabricating thin-walled parts of nickel-based superalloy like DZ125L. However, when heavy solid parts of some other material other than DZ125L were fabricated, the oxygen content of less than 150 ppm may be not suitable.

The influence of oxidation on the cracks of DZ125L thin-walled parts in LMDF was investigated in detail, and a DZ125L thin-walled turbine blade with no cracks was fabricated by adjusting the oxygen content in protective atmosphere.

This study aimed to identify driving factors of safety attitudinal ambivalence (AA) and explore their influence. Construction workers' intention to act safely can be instable under conflicting information from safety management, co-workers and habitual unsafe behaviour. Existing research explained the mechanism of unsafe behaviours as individual decisions but failed to include AA, as the co-existence of both positive and negative attitude.

This study applied system dynamics to explore factors of construction workers' AA and simulate the process of mitigating the ambivalence for less safety behaviour. Specifically, the group model building approach with eight experts was used to map the causal loop diagram and field questionnaire of 209 construction workers were used to collect empirical data for initiating parameters.

The group model building identified five direct factors of AA, namely the organisational safety support, important others' safety attitude, emotional arousal, safety production experience and work pressure, with seven feedback paths. The questionnaire survey obtained the initial values of the factors in the SD model, with the average ambivalence at 0.389. The ambivalence between cognitive and affective safety attitude was the highest. Model simulation results indicated that safety experience and work pressure had the most significant effects, and safety experience and positive attitude of co-workers could compensate the pressure from tight schedule and budget.

This study provided a new perspective of the dynamic safety attitude under the co-existence of positive and negative attitude, identified its driving factors and their influencing paths. The group model building approach and field questionnaire surveys were used to provide convincible suggestions for empirical safety management with least and most effective approaches and possible interventions to prevent unsafe behaviour with tight schedule and budget.

The purpose of this paper is to study the condensation flow of wet steam in the last stage of a steam turbine and to obtain the distribution of condensation parameters such as nucleation rate, Mach number and wetness.

Because of the sensitivity of the condensation parameter distribution, a double fluid numerical model and a realizable k-ε-k_d turbulence model were applied in this study, and the numerical solution for the non-equilibrium condensation flow is provided.

The simulation results are consistent with the experimental results of the Bakhtar test. The calculation results indicate that the degree of departure from saturation has a significant impact on the wet steam transonic condensation flow. When the inlet steam deviates from the saturation state, shock wave interference and vortex mixing also have a great influence on the distribution of water droplets.

The research results can provide reference for steam turbine wetness losses evaluation and flow passage structure optimization design.

This paper aims to investigate the patterns of and reasons for regional differences in entrepreneurship among Chinese provinces (excluding Hong Kong and Taiwan).

The paper employs a linear regression model to examine determinants of regional entrepreneurship in China.

Evidence suggests that provincial differences in entrepreneurship were directly related to local business growth, but not to factors such as level of local business development, urbanisation rate, level of market economy, level of salary and ratio of unemployment. The differences among economic growth in various regions contributed directly to differences in entrepreneurship.

There is a need to determine the spatial patterns of entrepreneurship by using panel data in a more sophisticated econometric model. A further investigation of regional entrepreneurship in China is planned for the near future.

Active entrepreneurship in a region can contribute to the economic growth of the region, leading to more active enterprising activities. It is therefore argued that one of the effective ways to boost entrepreneurship and small business development is to advance the economic growth of a region.

The paper adopts an industrial location perspective on determinants of business growth and its links with regional entrepreneurship.

The purpose of this paper is to present ontology alignment as a basis for mobile service integration and invocation.

This paper presents an automated schema‐based approach to align the ontologies from interacting devices as a basis for mobile service invocation. When the ontologies are ambiguous about the services provided, compatibility vectors are introduced as a means of maintaining ontology quality and deciding which service to choose to reduce the ambiguity.

Both precision and recall measurements are applied in the evaluation of the alignment approach, with promising results. In addition, for the compatibility vector system, it is not only proved theoretically that the approach is both precise and efficient, but it also shows promising results experimentally.

In cases where sufficient resources are not available and only a certain number of mobile devices can be chosen for interaction, this approach increases the efficiency by choosing suitable mobile device(s).

This current approach makes use of a center ontology, but introduces the problem of how to handle the vulnerability issue inherent in this centralized solution. To analyze and solve this problem is a potential research direction.