Wheel center detection based on stereo vision

As the location of the wheel center is the key to accurately measuring the wheelbase, the wheelbase difference and the wheel static radius, a high-precision wheel center detection method based on stereo vision is proposed. First, according to the prior information, the contour of the wheel hub is extracted and fitted as an ellipse curve, and the ellipse fitting equation can be obtained. Then, a new un-tangent constraint is adopted to improve the ellipse matching precision. Finally, the 3D coordinates of the wheel center can be reconstructed by the spatial circle projection algorithm with low time complexity and high measurement accuracy. Simulation experiments verify that compared with the ellipse center reconstruction algorithm and the planar constraint optimization algorithm, the proposed method can acquire the 3D coordinates of the spatial circle more exactly. Furthermore, the measurements of the wheelbase, the wheelbase difference and the wheel static radius for three types of vehicles demonstrate the effectiveness of the proposed method for wheel center detection.

室间隔缺损合并肺动脉高压1例报告

患儿女,12岁。因活动后气促、心悸半年余加重伴声音嘶哑一月余。入院前半年自觉活动后气促、心悸、乏力,无咳嗽、咯血。曾在当地医院诊治无效。

Effect of local thermal sensation on whole-body thermal sensation under stable non-uniform environment

To reveal the principles of human thermal responses and find out the effects of body parts on whole-body thermal sensation,through a subjective survey,experimental investigations on human responses are carried out when a single body part is thermally stimulated.Cooling airflow is sent to seven body parts,respectively.Totally 94 samples are tested.To eliminate the obvious multicollinearity of thermal sensation among different body parts,the principal component regression approach is adopted to obtain the principal components for the body parts under different experimental conditions.Through regression and analysis of principal components,the weighting factors of the seven body parts are obtained.A predictive model on whole-body thermal sensation is obtained based on the weighting factors.The results show that the different characteristics of trunk and limbs are clearly seen.The weighting factors of local thermal sensation are integrated values,and there is little difference among values of different body parts.

Evaluation of body weight of sea cucumber Apostichopus japonicus by computer vision

Apostichopus japonicus(Holothuroidea,Echinodermata) is an ecological and economic species in East Asia.Conventional biometric monitoring method includes diving for samples and weighing above water,with highly variable in weight measurement due to variation in the quantity of water in the respiratory tree and intestinal content of this species.Recently,video survey method has been applied widely in biometric detection on underwater benthos.However,because of the high flexibility of A.japonicus body,video survey method of monitoring is less used in sea cucumber.In this study,we designed a model to evaluate the wet weight of A.japonicus,using machine vision technology combined with a support vector machine(SVM) that can be used infield surveys on the A.japonicus population.Continuous dorsal images of free-moving A.japonicus individuals in seawater were captured,which also allows for the development of images of the core body edge as well as thorn segmentation.Parameters that include body length,body breadth,perimeter and area,were extracted from the core body edge images and used in SVM regression,to predict the weight of A.japonicus and for comparison with a power model.Results indicate that the use of SVM for predicting the weight of 33 A.japonicus individuals is accurate(R^2=0.99) and compatible with the power model(R^2=0.96).The image-based analysis and size-weight regression models in this study may be useful in body weight evaluation of A.japonicus in lab and field study.

Differential effects of physical activity and sleep duration on cognitive function in young adults

Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy(NIRS).Methods: A total of 23 healthy young adults(age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time(TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test(WCST), and the Continuous Performance Test—Identical Pairs(CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks(r = —0.602, p = 0.002; r = —0.446, p = 0.033,respectively), whereas TST was significantly correlated with % corrects on the 2-back task(r = 0.486, p = 0.019). Multiple regression analysis,including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks(b = —0.634, p = 0.002; b = —0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task(b = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area(r = 0.492, p = 0.017).Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.

Vision navigation for aircrafts based on 3D reconstruction from real-time image sequences

In this paper,we propose a novel vision navigation method based on three-dimensional(3D)reconstruction from real-time image sequences.It adapts 3D reconstruction and terrain matching to establish the correspondence between image points and3D space points and the terrain reference(by using a digital elevation map(DEM)).An adaptive weighted orthogonal iterative pose estimation method is employed to calculate the position and attitude angle of the aircraft.Synthesized and real experiments show that the proposed method is capable of providing accurate navigation parameters for a long-endurance flight without using a global positioning system or an inertial navigation system(INS).Moreover,it can be combined with an INS to achieve an improved navigation result.

Prediction of shelled shrimp weight by machine vision

The weight of shelled shrimp is an important parameter for grading process.The weight prediction of shelled shrimp by contour area is not accurate enough because of the ignorance of the shrimp thickness.In this paper,a multivariate prediction model containing area,perimeter,length,and width was established.A new calibration algorithm for extracting length of shelled shrimp was proposed,which contains binary image thinning,branch recognition and elimination,and length reconstruction,while its width was calculated during the process of length extracting.The model was further validated with another set of images from 30 shelled shrimps.For a comparison purpose,artificial neural network(ANN) was used for the shrimp weight predication.The ANN model resulted in a better prediction accuracy(with the average relative error at 2.67%),but took a tenfold increase in calculation time compared with the weight-area-perimeter(WAP) model(with the average relative error at 3.02%).We thus conclude that the WAP model is a better method for the prediction of the weight of shelled red shrimp.

Influences of olfactory ensheathing cells transplantation on axonal regeneration in spinal cord of adult rats

Objective: To observe whether olfactory ensheathing cells could be used to promote axonal regeneration in a spontaneously nonregenerating system.Methods: After laminectomy at the lower thoracic level, the spinal cords of adult rats were exposed and completely transected at T10. A suspension of ensheathing cells was injected into the lesion site in 12 adult rats, and control D/F 12 ( 1∶1 mixture of DMEM and Hams F 12) was injected in 12 adult rats. Six weeks and ten weeks after cell transplantation, the rats were evaluated by climbing test and motor evoked potentials (MEPs) monitoring. The samples were procured and studied with histologicl and immunohistochemical methods.Results: At the 6th week after cell transplantation, all the rats in both the transplanted and control groups were paraplegic and the MEPs could not be recorded. At the 10th week after cell transplantation, of 7 rats in the control group, 2 rats had muscles contraction of the lower extremities, 2 rats had hips and/or knees active movement; and 5 rats MEPs could be recorded in the hind limbs in the transplanted group (n=7). None of the rats in the control group had functional improvement and no MEPs recorded (n=7). Numerous regenerating axons were observed through the transplantation and continued to regenerate into the denervated host tract. Cell labelling using anti Myelin Basic Protein (MBP) and anti Nerve Growth Factor Receptor (anti NGFR) indicated that the regenerated axons were derived from the appropriate neuronal source and that donor cells migrated into the denervated host tract. But axonal degeneration existed and regenerating axons were not observed within the spinal cords of the adult rats with only D/F 12 injection. Conclusions: The axonal regeneration in the transected adult rat spinal cord is possible after ensheathing cells transplantation.

Global shape reconstruction of nano grid with singly fixed camera

Depth from defocus(DFD),as a typical shape reconstruction method,has been widely researched in most recent years.However,all the existing DFD algorithms require at least two defocused images with different camera parameters.Unfortunately,in micro/nano manipulation,any change on visual sensor's parameters is absolutely forbidden.Therefore,a novel DFD method to reconstruct the shape of a nano grid on micro/nano scale is researched in this paper.First,the blurring imaging model is constructed with the relative blurring and the diffusion equation.Second,the relationship between depth and blurring is discussed from four aspects.Subsequently,depth measurement problem is transformed into an optimization issue which is solved using the gradient flow algorithm.Finally,experiment results and error analysis are conducted to show the feasibility and effectiveness of the proposed method.

A Multiscale Superpixel-Level Salient Object Detection Model Using Local-Global Contrast Cue

The goal of salient object detection is to estimate the regions which are most likely to attract human's visual attention. As an important image preprocessing procedure to reduce the computational complexity, salient object detection is still a challenging problem in computer vision. In this paper, we proposed a salient object detection model by integrating local and global superpixel contrast at multiple scales. Three features are computed to estimate the saliency of superpixel. Two optimization measures are utilized to refine the resulting saliency map. Extensive experiments with the state-of-the-art saliency models on four public datasets demonstrate the effectiveness of the proposed model.

Ocular myasthenia gravis accompanied by anosmia

We report a case of ocular myasthenia gravis(MG)accompanied by anosmia. A 76-year-old man had idiopathic anosmia of 2-year duration. Four months before consultation, he began to have drooping in the right upper eyelid along with muscle soreness,distension, and pain in the nape. His tongue was dark-red with a thin and white coating; his pulse was wiry and slippery. According to Traditional Chinese Medicine, eyelid drooping and anosmia are the main signs of liver constraint and spleen deficiency. In Western Medicine, the diagnosis was ocular MG and idiopathic anosmia. Our patient, along with the literature, suggests that anosmia may be an early symptom before MG. MG accompanied by anosmia could be a special subtype of MG according to antibody production and symptoms.

Influences of Sense of Place on Farming Households' Relocation Willingness in Areas Threatened by Geological Disasters:Evidence from China

Scholars from environmental psychology,geography, disaster science, and sociology have recently focused attention on evacuation and relocation behaviors and influencing factors in hazard-threatened areas. However, existing studies are mainly focused on developed countries and the influence of individual characteristics,household characteristics, and the perception of risk of urban households on evacuation and relocation behaviors.Few studies examine developing countries and the influence of farmers' sense of place in geological hazardthreatened areas. Using statistics of farming households in an area threatened by landslides, this is a pilot study to explore the relationship of sense of place to the relocation willingness of farming households while controlling for other variables. The results show that:(1) Households with higher scores of place identity and place dependence are less willing to relocate, whereas place attachment has no significant relationship to household relocation willingness;(2) Risk perception dimensions, including probability,threat, and controllability have a significant relationship to household relocation willingness, while worry and fear of the unknown have no significant relationship;(3) Household characteristics, including income, whether a household has experienced economic loss from landslides, and social support are significantly correlated with household relocation willingness, while gender, age, experience, distance to hazard sites, size of household, children, older people, and housing material are not. The results for information and education are not robust. This study contributes to the current literature by improving the understanding of the relationship of sense of place to the relocation willingness of farming households in villages threatened by geological disasters in rural China.