An estimation-based approach for range image segmentation:on the reliability of primitive extraction

This paper presents a new algorithm for estimation-based range image segmentation. Aiming at surface-primitive extraction from range data, we focus on the reliability of the primitive representation in the process of region estimation. We introduce an optimal description of surface primitives, by which the uncertainty of a region estimate is explicitly represented with a covariance matrix. Then the reliability of an estimate is interpreted in terms of “measure of uncertainty”. The segmentation approach follows the region-growing scheme, in which the regions are estimated in an iterative way. With the probabilistic model proposed in this paper, surface homogeneity is defined and tested by an optimal criterion. A notable feature of the algorithm is that the order of merging is organized to lead the growth towards the most reliable representation of the merged region. Concerned with man-made objects in the scene, we restrict the class of surface primitives to be quadric or planar. The proposed algorithm has been applied to real data and synthetic data and demonstrated with experimental results

Recognition Technology for Four Arithmetic Operations

Numeral recognition is an important research direction in field of pattern recognition, and it has broad application prospects. Aiming at four arithmetic operations of general printed formats, this article adopts a multiple hybrid recognition method and is applied to automatically calculating. This method mainly uses BP neural network and template matching method to distinguish the numerals and operators, in order to increase the operation speed and recognition accuracy. Sample images of four arithmetic operations are extracted from printed books, and they are used for testing the performance of proposed recognition method. The experiments show that the method provides correct recognition rate of 96% and correct calculation rate of 89%

Wireless capsule endoscopy exploration for diseases of the small intestine in China

For small bowel diseases, it is difficult for the ordinary enteroscopy to reach due to its specific curvature and length. Capsule endoscopy (CE) is a unique tool to visualize the mucosa of the small intestine. The aim of this study was to evaluate the detection rate and diagnostic yield of CE in a large group of patients with suspected digestive diseases in China. One hundred and two consecutive patients (75 male, mean age 50 years, range 32-87 years) underwent CE in our Gastroenterology Units, for a total of 102 procedures. Referrals were obscure occult/ overt gastrointestinal bleeding group (19 patients) and suspected small bowel disease group (83). In our study, the whole detection rate was 92 % (94/102), with a definite diagnosis yield of 63 % of the patients in the obscure gastrointestinal bleeding and 39 % of the patients in the suspected small bowel diseases. None of the patients developed symptoms of signs of mechanical obstruction, although the capsule was retained in the stomach in 2/102 patients for their somatostatin taken. CE seems to be a very safe, painless and effective procedure with a high diagnostic yield. Accurate selection of indications and critical evaluation of the results are essential to explore these diseases

Institutional reform and economic growth of China: 40-year progress toward marketization

China has persevered its market-oriented economic transition since 1978. In this paper, we use the provincial-level NERI Index of Marketization from 1997 to 2014 and a panel data model to investigate the quantitative contribution of market-oriented reforms to China’s total factor productivity (TFP) and economic growth. Our results indicate that marketization reforms contributed 1.3 percentage points to China’s annual economic growth rate and accounted for 35 percent of the increase in TFP. This means that the institutional reforms significantly improved resource allocation. However, economic transition in China has not yet been completed and sustainability of future growth will depend on further market-oriented reforms

Neural Dynamics of Processing Probability Weight and Monetary Magnitude in the Evaluation of a Risky Reward

Risky decision-making involves risky reward valuation, choice, and feedback processes. However, the temporal dynamics of risky reward processing are not well understood. Using event-related brain potential, we investigated the neural correlates of probability weight and money magnitude in the evaluation of a risky reward. In this study, each risky choice consisted of two risky options, which were presented serially to separate decision-making and option evaluation processes. The early P200 component reflected the process of probability weight, not money magnitude. The medial frontal negativity (MFN) reflected both probability weight and money magnitude processes. The late positive potential (LPP) only reflected the process of probability weight. These results demonstrate distinct temporal dynamics for probability weight and money magnitude processes when evaluating a risky outcome, providing a better understanding of the possible mechanism underlying risky reward processing

Quantitative evaluation and models of hydrocarbon accumulation controlled by faults in the Pearl River Mouth Basin

The Pearl River Mouth Basin is the largest petroliferous basin in the northern South China Sea, where hydrocarbon accumulation is strongly controlled by fault activities. This study performed the quantitative evaluation of the effects of faults on hydrocarbon migration and accumulation in the basin. The results indicate that the critical values of vertical migration of middle-shallow hydrocarbon, including the active strength of faults and the ratio of fault throw to shale caprock thickness, were up to 10 m/Ma and 5, respectively. The lateral hydrocarbon migration efficiency of the unbreached relay zone was higher than that of the barely breached and strongly breached types. The lower critical value of shale gouge ratio for the clay sealing efficiency was 0.32. Additionally, the zones with the EW-trending transtensional faults were found to have unique dual functions of migration and stress sealing, suggesting that the linking fault positions play important roles in the lateral migration of hydrocarbons. Finally, seven hydrocarbon accumulation models controlled by faults in different tectonic settings were constructed to clarify the effects of faults on the vertical and lateral migrations of hydrocarbon. These models suggested that fine hydrocarbon exploration should be undertaken in the northeastern Baiyun Sag, and that middle-deep hydrocarbon exploration should be enhanced in the Enping, Huizhou, and southwestern Baiyun Sags.Cited as: Peng, G., Wu, Z., Dai, Y., Zhang, L., Yu, S., Wang, W., Pang, H. Quantitative evaluation and models of hydrocarbon accumulation controlled by faults in the Pearl River Mouth Basin. Advances in Geo-Energy Research, 2023, 8(2): 89-99. https://doi.org/10.46690/ager.2023.05.0

Conforming an Extracorporeal Lithotripter System for Video Urodynamic Studies

Objectives: This study aimed to evaluate the efficiency using existing fluoroscopic unit and lithotripter table of an extracorporeal lithotripter system for video urodynamic studies (VUDS) to determine anatomical abnormalities in patients with neurogenic lower urinary tract dysfunction (NLUTD). Methods: The extracorporeal lithotripsy system was adapted to obtain optimum fluoroscopic view according to body shape and observed organs of patients. We reviewed the VUDS data of 25 patients with NLUTD. Results: “Christmas tree bladder” (CTB) was found in 5 (20%) patients. Vesicoureteral reflux (VUR) and external detrusor sphincter dyssynergia (DESD) were detected in 3 (12%) and 4 (16%) patients, respectively. Four (16%) patients with normal coordination between detrusor contraction and external sphincter relaxation were proven by VUDS. CTB, VUR, or DESD was not observed in 10 (40%) patients with flaccid bladder. Hematuria, urinary tract infection, or autonomic dysreflexia did not occur in any of the patients. Conclusions: VUDS can discern anatomical abnormalities of the urinary tract, and patients in undeveloped areas of the world who have NLUTD can have easier access to VUDS because of the decreasing capital cost of VUDS

Enhancing LGMD-based model for collision prediction via binocular structure

IntroductionLobular giant motion detector (LGMD) neurons, renowned for their distinctive response to looming stimuli, inspire the development of visual neural network models for collision prediction. However, the existing LGMD-based models could not yet incorporate the invaluable feature of depth distance and still suffer from the following two primary drawbacks. Firstly, they struggle to effectively distinguish the three fundamental motion patterns of approaching, receding, and translating, in contrast to the natural abilities of LGMD neurons. Secondly, due to their reliance on a general determination process employing an activation function and fixed threshold for output, these models exhibit dramatic fluctuations in prediction effectiveness across different scenarios.MethodsTo address these issues, we propose a novel LGMD-based model with a binocular structure (Bi-LGMD). The depth distance of the moving object is extracted by calculating the binocular disparity facilitating a clear differentiation of the motion patterns, after obtaining the moving object's contour through the basic components of the LGMD network. In addition, we introduce a self-adaptive warning depth-distance, enhancing the model's robustness in various motion scenarios.ResultsThe effectiveness of the proposed model is verified using computer-simulated and real-world videos.DiscussionFurthermore, the experimental results demonstrate that the proposed model is robust to contrast and noise

A two-phase differential evolution for uniform designs in constrained experimental domains

open access articleIn many real-world engineering applications, a uniform design needs to be conducted in a constrained experimental domain that includes linear/nonlinear and inequality/equality constraints. In general, these constraints make the constrained experimental domain small and irregular in the decision space. Therefore, it is difficult for current methods to produce a predefined number of samples and make the samples distribute uniformly in the constrained experimental domain. This paper presents a two-phase differential evolution for uniform designs in constrained experimental domains. In the first phase, considering the constraint violation as the fitness function, a clustering differential evolution is proposed to guide the population toward the constrained experimental domain from different directions promptly. As a result, a predefined number of samples can be obtained in the constrained experimental domain. In the second phase, maximizing the minimum Euclidean distance among samples is treated as another fitness function. By optimizing this fitness function, the samples produced in the first phase can be scattered uniformly in the constrained experimental domain. The performance of the proposed method has been tested and compared with another state-of-the-art method. Experimental results suggest that our method is significantly better than the compared method in the uniform designs of a new type of automotive crash box and five benchmark test problems. Moreover, the proposed method could be considered as a general and promising framework for other uniform designs in constrained experimental domains