Hybrid modeling method of dust suppression efficiency for dry fog dust suppression process

The original mechanism model of dust suppression efficiency for dry fog dust suppression could not guide the actual process. In order to accurately predict the dust suppression efficiency in the process, a new mechanism model was established by my analysis of the process. But there were some factors that I could not establish the model. So a hybrid model combining mechanism model and support vector machine (SVM) was proposed. Using the data of dry fog dust suppression oval process, the hybrid model was simulated. The simulation results show that the hybrid model can accurately predict the dry fog dust suppression.

Stability and periodicity in a mosquito population suppression model composed of two sub-models

In this paper, we propose a mosquito population suppression model which is composed of two sub-models switching each other. We assume that the releases of sterile mosquitoes are periodic and impulsive, only sexually active sterile mosquitoes play a role in the mosquito population suppression process, and the survival probability is density-dependent. For the release waiting period T and the release amount c, we find three thresholds denoted by $$T^*$$ T ∗ , $$g^*$$ g ∗ , and $$c^*$$ c ∗ with $$c^*>g^*$$ c ∗ > g ∗ . We show that the origin is a globally or locally asymptotically stable equilibrium when $$c\ge c^*$$ c ≥ c ∗ and $$T\le T^*$$ T ≤ T ∗ , or $$c\in (g^*, c^*)$$ c ∈ ( g ∗ , c ∗ ) and $$T<T^*$$ T < T ∗ . We prove that the model generates a unique globally asymptotically stable T-periodic solution when either $$c\in (g^*, c^*)$$ c ∈ ( g ∗ , c ∗ ) and $$T=T^*$$ T = T ∗ , or $$c>g^*$$ c > g ∗ and $$T>T^*$$ T > T ∗ . Two numerical examples are provided to illustrate our theoretical results.

Human Eye Pupil Detection System for Different IRIS Database Images

The pupil detection system plays a vital role in ophthalmology diagnosis equipments because pupil has a center place of human eye to locate the exact position. To identify the exact human eye pupil region in near infrared (NIR) images, this work proposes the Center of gravity method and its real time FPGA hardware implementation. The proposed work involves global threshold method to segment the pupil region from human eye and the bright spot suppression process removes the light reflections on the pupil due to the IR (Infra red) rays then the morphology dilation process removes unnecessary black pixels other than pupil region on the image. Finally, center of gravity (COG) method provides the exact pupil center coordinate and radius of the human eye. CASIA IRIS V4 and UBIRIS iris database images used in this work and achieved 90-95% of recognition rate.

A Cascaded Ensemble of Sparse-and-Dense Dictionaries for Vehicle Detection

Vehicle detection as a special case of object detection has practical meaning but faces challenges, such as the difficulty of detecting vehicles of various orientations, the serious influence from occlusion, the clutter of background, etc. In addition, existing effective approaches, like deep-learning-based ones, demand a large amount of training time and data, which causes trouble for their application. In this work, we propose a dictionary-learning-based vehicle detection approach which explicitly addresses these problems. Specifically, an ensemble of sparse-and-dense dictionaries (ESDD) are learned through supervised low-rank decomposition; each pair of sparse-and-dense dictionaries (SDD) in the ensemble is trained to represent either a subcategory of vehicle (corresponding to certain orientation range or occlusion level) or a subcategory of background (corresponding to a cluster of background patterns) and only gives good reconstructions to samples of the corresponding subcategory, making the ESDD capable of classifying vehicles from background even though they exhibit various appearances. We further organize ESDD into a two-level cascade (CESDD) to perform coarse-to-fine two-stage classification for better performance and computation reduction. The CESDD is then coupled with a downstream AdaBoost process to generate robust classifications. The proposed CESDD model is used as a window classifier in a sliding-window scan process over image pyramids to produce multi-scale detections, and an adapted mean-shift-like non-maximum suppression process is adopted to remove duplicate detections. Our CESDD vehicle detection approach is evaluated on KITTI dataset and compared with other strong counterparts; the experimental results exhibit the effectiveness of CESDD-based classification and detection, and the training of CESDD only demands small amount of time and data.

Reward encourages reactive, goal-directed suppression of attention

Stimuli that signal large reward are more likely to capture attention and gaze than stimuli that signal lesser or no reward, even when capture counterproductively prevents reward delivery. This suggests that a stimulus’s signalling relationship with reward (the contingency between stimulus presentation and reward delivery) is a potent influence on selective attention. Recent studies have also implicated a stimulus’s response relationship with reward (the reward-related consequences of attending to a stimulus) in reducing capture by signals of reward. Here we show that this response pathway modulates capture by encouraging a reactive, goal-directed distractor suppression process. In a rewarded visual search task, participants demonstrated an oculomotor preference away from a distractor that had a negative response relationship with high reward (looking at the distractor caused reward to be cancelled) and towards a distractor that had no such negative response relationship, providing evidence for the role of the response relationship in suppressing capture by reward-related distractors. Analysis of the temporal dynamics of eye-movements suggests that this distractor suppression process operates via a reactive mechanism of rapid disengagement (Experiment 1). Consistent with a goal-directed mechanism, the influence of the response relationship was eliminated when reward was unavailable (Experiment 2). These findings highlight the multifaceted role of learned stimulus-reward relationships in attentional selection.

OPTIMAL SUPPRESSION OF TRANSVERSE VIBRATIONS OF SPINNING ELASTIC RODS

The process of suppressing transverse vibrations of an elastic rod spinning in a horizontal plane and fixed at one of its ends is studied. It is supposed that the rod spins around the vertical axis at a constant angular velocity and performs transverse vibrations in the vertical plane, the vibrations are assumed small in amplitude. Transverse vibrations of the spinning rod are performed under external mechanical action. Lateral vibrations are described by the displacement function and considered in a rotating plane by using the classical beam model. The necessary conditions of optimality are derived and applied for suppressing elastic vibrations on a finite time-interval. The problem of optimal suppression of lateral vibrations caused by initial disturbances is formulated as a variational problem with constraints that take into account the suppressing effects on the rod. The limiting restrictions are presented in the form of inequalities. With the introduction of an additional variable, these restrictions are reduced to standard integral equality, while taking into account the energy constraints imposed on the control actions. The proposed iterative algorithm for solving the formulated problem is a numerical-analytical algorithm and consists in minimizing the quadratic quality criterion. This criterion characterizes the vibration suppression process and allows the implementation of improving variations. As a result of the operations carried out, the dependence of the vibration suppression process on the determining parameters, such as the angular velocity of rotation, the isoperimetric energy constant, and the length of the considered process of vibration suppression in time, has been clarified. An example that illustrates the implementation of the proposed algorithm and shows the effectiveness of this method for suppressing lateral vibrations is given.

Active protection of work area against explosion of dust–gas mixture

Potentially explosive atmosphere can occur not only in the production systems of the food, energy, chemical and petrochemical industries but also in the production processes of the mining industry. Gases, vapours, mists and dusts arise can escape in an uncontrolled way during production, processing, transportation and storage of flammable substances. In combination with oxygen, they create explosive atmospheres that, if ignited, lead to an explosion causing catastrophic damage to people's lives and property. To protect against the results of hazardous dust–gas mixtures explosions in a confined work space, where employees can stay, various control and protection mechanisms are used in the form of an active explosion-proof system. The article presents the results of tests on an active system for limiting the effects of ignition of gas and/or dust based on a highly efficient explosion suppression system—equipped with an ignition detection system, high-pressure fire extinguisher and a power supply and trigger system. Smokeless powder was used as the explosive charge and sodium bicarbonate as the suppressive material. Tests of the effectiveness of the active explosion suppression system were carried out on two devices: a small-size dry dust collector and a zone extinguishing system adapted for direct explosion suppression in closed working spaces. In both cases, the explosion suppression process took place through the action of extinguishing powder blown out of the fire extinguisher after membrane perforation by compressed combustion products.

Predictive attenuation of touch and tactile gating are distinct perceptual phenomena

In recent decades, research on somatosensory perception has led to two important observations. First, self-generated touches that are predicted by voluntary movements become attenuated compared to externally generated touches of the same intensity (attenuation). Second, externally generated touches feel weaker and are more difficult to detect during movement compared to rest (gating). Researchers today often consider gating and attenuation to be the same suppression process; however, this assumption is unwarranted because, despite more than forty years of research, no study has combined them in a single paradigm. We quantified how people perceive self-generated and externally generated touches during movement and rest. We demonstrate that whereas voluntary movement gates the precision of both self-generated and externally generated touch, the amplitude of self-generated touch is selectively attenuated compared to externally generated touch. We further show that attenuation and gating neither interact nor correlate, and we conclude that they represent distinct perceptual phenomena.

Predictive attenuation of touch and tactile gating are distinct perceptual phenomena

In recent decades, research on somatosensory perception has led to two important observations. First, self-generated touches that are predicted by voluntary movements become attenuated compared to externally generated touches of the same intensity (attenuation). Second, externally generated touches feel weaker and are more difficult to detect during movement compared to rest (gating). Researchers today often consider gating and attenuation to be the same suppression process; however, this assumption is unwarranted because, despite more than forty years of research, no study has combined them in a single paradigm. We quantified how people perceive self-generated and externally generated touches during movement and rest. We demonstrate that whereas voluntary movement gates the precision of both self-generated and externally generated touch, the amplitude of self-generated touch is selectively attenuated compared to externally generated touch. We further show that attenuation and gating neither interact nor correlate, and we conclude that they represent distinct perceptual phenomena.