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Small group detection and tracking in crowd scenes are basis for high level crowd analysis tasks. However, it suffers from the ambiguities in generating proper groups and in handling dynamic changes of group configurations. In this paper, we propose a novel delay decision-making based method for addressing the above problems, motivated by the idea that these ambiguities can be solved using rich temporal context. Specifically, given individual detections, small group hypotheses are generated. Then candidate group hypotheses across consecutive frames and their potential associations are built in a tree. By seeking for the best non-conflicting subset from the hypothesis tree, small groups are determined and simultaneously their trajectories are got. So this framework is called joint detection and tracking. This joint framework reduces the ambiguities in small group decision and tracking by looking ahead for several frames. However, it results in the unmanageable solution space because the number of track hypotheses grows exponentially over time. To solve this problem, effective pruning strategies are developed, which can keep the solution space manageable and also improve the credibility of small groups. Experiments on public datasets demonstrate the effectiveness of our method. The method achieves the state-of-the-art performance even in noisy crowd scenes. 相似文献
4.
Perfluorocarbon gas is widely used in the semiconductor industry. However, perfluorocarbon has a
negative effect on the global environment owing to its high global warming potential (GWP) value.
An alternative solution is essential. Therefore, we evaluated the possibility of replacing conventional
perfluorocarbon etching gases such as CHF3 with C6F12O, which has a low GWP and is in a liquid
state at room temperature. In this study, silicon oxynitride (SiON) films were plasma-etched using
inductively coupled CF4 +C6F12O+O2 mixed plasmas. Subsequently, the etching characteristics
of the film, such as etching rate, etching profile, selectivity over Si, and photoresist, were investigated.
A double Langmuir probe was used and optical emission spectroscopy was performed for plasma
diagnostics. In addition, a contact angle goniometer and x-ray photoelectron spectroscope were used
to confirm the change in the surface properties of the etched SiON film surface. Consequently, the
etching characteristics of the C6F12O mixed plasma exhibited a lower etching rate, higher SiON/Si
selectivity, lower plasma damage, and more vertical etched profiles than the conventional CHF3 mixed plasma. In addition, the C6F12O gas can be recovered in the liquid state, thereby decreasing
global warming. These results confirmed that the C6F12O precursor can sufficiently replace the
conventional etching gas. 相似文献
5.
This paper analyzes the problems existing in the teaching of data structure course, and puts forward the reform from the as-
pects of strengthening basic programming, visualized explanation of abstract theory, combination of C++, Java programming, ratio-
nal use of online platform, and stratification of exercises, aiming at improving students' practical ability, learning interest and self-
confidence. 相似文献
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While creativity is essential for developing students’ broad expertise in Science, Technology, Engineering, and Math (STEM) fields, many students struggle with various aspects of being creative. Digital technologies have the unique opportunity to support the creative process by (1) recognizing elements of students’ creativity, such as when creativity is lacking (modeling step), and (2) providing tailored scaffolding based on that information (intervention step). However, to date little work exists on either of these aspects. Here, we focus on the modeling step. Specifically, we explore the utility of various sensing devices, including an eye tracker, a skin conductance bracelet, and an EEG sensor, for modeling creativity during an educational activity, namely geometry proof generation. We found reliable differences in sensor features characterizing low vs. high creativity students. We then applied machine learning to build classifiers that achieved good accuracy in distinguishing these two student groups, providing evidence that sensor features are valuable for modeling creativity. 相似文献
8.
This paper is the second one of the two papers entitled “Weighted Superposition Attraction (WSA) Algorithm”, which is about the performance evaluation of the WSA algorithm in solving the constrained global optimization problems. For this purpose, the well-known mechanical design optimization problems, design of a tension/compression coil spring, design of a pressure vessel, design of a welded beam and design of a speed reducer, are selected as test problems. Since all these problems were formulated as constrained global optimization problems, WSA algorithm requires a constraint handling method for tackling them. For this purpose we have selected 6 formerly developed constraint handling methods for adapting into WSA algorithm and analyze the effect of the used constraint handling method on the performance of the WSA algorithm. In other words, we have the aim of producing concluding remarks over the performance and robustness of the WSA algorithm through a set of computational study in solving the constrained global optimization problems. Computational study indicates the robustness and the effectiveness of the WSA in terms of obtained results, reached level of convergence and the capability of coping with the problems of premature convergence, trapping in a local optima and stagnation. 相似文献
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AbstractModel order reduction is a common practice to reduce large order systems so that their simulation and control become easy. Nonlinearity aware trajectory piecewise linear is a variation of trajectory piecewise linearization technique of order reduction that is used to reduce nonlinear systems. With this scheme, the reduced approximation of the system is generated by weighted sum of the linearized and reduced sub-models obtained at certain linearization points on the system trajectory. This scheme uses dynamically inspired weight assignment that makes the approximation nonlinearity aware. Just as weight assignment, the process of linearization points selection is also important for generating faithful approximations. This article uses a global maximum error controller based linearization points selection scheme according to which a state is chosen as a linearization point if the error between a current reduced model and the full order nonlinear system reaches a maximum value. A combination that not only selects linearization points based on an error controller but also assigns dynamic inspired weights is shown in this article. The proposed scheme generates approximations with higher accuracies. This is demonstrated by applying the proposed method to some benchmark nonlinear circuits including RC ladder network and inverter chain circuit and comparing the results with the conventional schemes. 相似文献
10.
Combination of X-ray Digital Industrial Radiography (DIR) and Particle Tracking Velocimetry (PTV) techniques for local liquid velocity measurement (VLL) has been newly developed and successfully applied for trickle bed reactor (TBR). The technique was validated against newly developed fiber optical probe technique. This work attempts to highlight the applicability of this newly developed technique on a liquid–solid packed bed reactor. In this work, liquid was represented by water and solids were represented by EPS beads. The EPS beads were chosen because of its low density property. Three superficial liquid velocities (VSL) were applied to the system. The experiment was replicated four times. The digital industrial radiography (DIR) consists of a complementary metal oxide semiconductor (CMOS) digital detector and X-ray source. Results of this work suggest that the technique has been successfully applied and comparable with previous work that has been done in the literature. It also suggests that there will be a maximum measurable interstitial liquid velocity when it travel inside the packed bed. The measured VLL can have a maximum range that is between 4 and 4.7 times that of its VSL. For VSL=0.42±±2%, the VLL-Max is in between 1.7 cm/s and 1.9 cm/s, VSL=0.84±±2%, the VLL-Max is in between 3.6 cm/s and 4.0 cm/s, and for VSL=1.11±±2%, the VLL-Max is in between 4.3 cm/s and 4.8 cm/s. 相似文献