Efficient Parallel Implementation of Active Appearance Model Fitting Algorithm on GPU

The active appearance model (AAM) is one of the most powerful model-based object detecting and tracking methods which has been widely used in various situations. However, the high-dimensional texture representation causes very time-consuming computations, which makes the AAM difficult to apply to real-time systems. The emergence of modern graphics processing units (GPUs) that feature a many-core, fine-grained parallel architecture provides new and promising solutions to overcome the computational challenge. In this paper, we propose an efficient parallel implementation of the AAM fitting algorithm on GPUs. Our design idea is fine grain parallelism in which we distribute the texture data of the AAM, in pixels, to thousands of parallel GPU threads for processing, which makes the algorithm fit better into the GPU architecture. We implement our algorithm using the compute unified device architecture (CUDA) on the Nvidia’s GTX 650 GPU, which has the latest Kepler architecture. To compare the performance of our algorithm with different data sizes, we built sixteen face AAM models of different dimensional textures. The experiment results show that our parallel AAM fitting algorithm can achieve real-time performance for videos even on very high-dimensional textures

Impact of cage aquaculture on water exchange in Sansha Bay

Abstract(#br)Influence of cage aquaculture on the flow field and water exchange in Sansha Bay is investigated based on in situ current measurements and output from a two-dimensional shallow water hydrodynamic finite element model (SHYFEM). Without cage influence, the flow is relatively uniform in the vertical except a bottom Ekman layer. An asymmetry of tidal current speed is also observed in Sansha Bay with a dominance of the ebb tide. Near-surface current speed squared in cage-free area is typically larger than that within cage area by a factor exceeding three in deep channels, and by a factor of two in tidal flats. Current speed profiles suggest that cage-induced drag on the flow field can reach as deep as 20 m in the relatively deep channels of Sansha Bay. A set of numerical experiments are designed to quantify the relative effect of cages in tidal flats and channels, respectively, on water exchange using SHYFEM. It is shown that cage aquaculture weakens the local flow but seems to strengthen the flow adjacent to cages. Reducing the frictional drag in channels significantly increases the water exchange rate both locally and in the near-field tidal flats. Therefore, certain clearance or rearrangement of cage aquaculture in channels would be more effective in improving the water exchange in the entire Sansha Bay

The Chinese version of obsessive compulsive drug use scale: validation in outpatient methadone maintenance treatment program

Funder: Guangci Professorship Program of Ruijin Hospital and Shanghai Jiao Tong University School of Medicine 2018 International and Hong Kong, Macao and Taiwan Regional Research Cooperation ProjectAbstract: Background: The Obsessive Compulsive Drug Use Scale (OCDUS) measures the overall craving level within a period from a multidimensional perspective. However, no studies have addressed the validity of the new OCDUS factor structure, presented in 2016, in China. Additionally, there is lack of evidence on the interaction among risk factors for relapse. We aimed to assess the psychometric properties of the scores of the Chinese version of the OCDUS in patients with heroin dependence receiving methadone maintenance treatment (MMT). Further, we aimed to assess the correlations of the OCDUS scores with withdrawal symptoms, depression, anxiety, and nicotine dependence. Methods: We enrolled 113 adults (age 32–64 years) and administered them with the OCDUS, Subjective Opioid Withdrawal Scale (SOWS), Beck Depression Inventory-II (BDI-II), State-Trait Anxiety Inventory (STAI), and Fagerstrom Test for Nicotine Dependence (FTND). Results: Exploratory factor analysis identified a 3-dimensional component that included “Frequency of craving,” “Inference of heroin,” and “Control of heroin.” These factors showed acceptable internal consistency, adequate item-total correlations, and significant item-subscale correlations. There was no correlation between the OCUDS scores and age, education, duration of receiving MMT, and MMT dosages. However, there was a significant correlation between the OCDUS total scores and the SOWS, STAI, BDI-II, and FTND scores. The scores of all the subscales were associated with the SOWS scores; further, the scores of the first two subscales were associated with BDI-II scores while only the scores of the first subscale were associated with the FTND scores. Conclusions: Our findings support the reliability and structure validity of the OCDUS scores. Heroin craving, withdrawal symptoms, negative emotions, and nicotine dependence, which are considered as risk factors for heroin relapse, might interact with each other. There is a need for further studies on the underlying mechanism of these clinical phenomena

Resilience-Based Repair Strategy for Gas Network System and Water Network System in Urban City

In resilience-based frameworks, optimizing the repair strategy and approaches is important for the recovery of the function of gas network systems (GNS) and water network systems (WNS). According to the resilience quantification results of GNS and WNS for a real example urban city in China, the potential impact of utilizing different repair sequences and repair/replacement approaches was investigated. First, a Monte Carlo simulation-based method was proposed to search for the optimal repair sequence according to the skew of the recovery trajectory (SRT). Under high seismic intensity conditions, the significant difference between the repair sequence corresponding to maximum SRT and minimum SRT indicates that choosing the optimal repair sequence is important in the enhancement of repair efficiency, especially when the pipelines have experienced serious damage. We also discussed the parallel repair strategy, which is more consistent with the practice, and can greatly improve the recovery efficiency compared with the single pipeline repair strategy under large damage conditions; however, under minor damage levels, the parallel repair strategy may result in a certain degree of redundancy. Next, three different repair approaches were thoroughly compared, including the point-by-point repair approach, whole pipeline replacement, and hybrid repair approach. At the condition of high seismic intensity (e.g., macroseismic intensity IX), the resilience curves for the hybrid repair approach and the pipeline replacement approach are overall similar and take less time and economic cost than the point-by-point repair approach. However, when the seismic intensity is low, the point-by-point repair approach is most efficient and has the shortest recovery time. Therefore, the choice of repair approach should be determined by stakeholders based on the specific pipeline’s damage situation. Finally, we calculated the joint resilience curves by allocating different weight factors to GNS and WNS, to represent the proportion of water and gas supply that contributes to community resilience

Resilience-Based Repair Strategy for Gas Network System and Water Network System in Urban City

In resilience-based frameworks, optimizing the repair strategy and approaches is important for the recovery of the function of gas network systems (GNS) and water network systems (WNS). According to the resilience quantification results of GNS and WNS for a real example urban city in China, the potential impact of utilizing different repair sequences and repair/replacement approaches was investigated. First, a Monte Carlo simulation-based method was proposed to search for the optimal repair sequence according to the skew of the recovery trajectory (SRT). Under high seismic intensity conditions, the significant difference between the repair sequence corresponding to maximum SRT and minimum SRT indicates that choosing the optimal repair sequence is important in the enhancement of repair efficiency, especially when the pipelines have experienced serious damage. We also discussed the parallel repair strategy, which is more consistent with the practice, and can greatly improve the recovery efficiency compared with the single pipeline repair strategy under large damage conditions; however, under minor damage levels, the parallel repair strategy may result in a certain degree of redundancy. Next, three different repair approaches were thoroughly compared, including the point-by-point repair approach, whole pipeline replacement, and hybrid repair approach. At the condition of high seismic intensity (e.g., macroseismic intensity IX), the resilience curves for the hybrid repair approach and the pipeline replacement approach are overall similar and take less time and economic cost than the point-by-point repair approach. However, when the seismic intensity is low, the point-by-point repair approach is most efficient and has the shortest recovery time. Therefore, the choice of repair approach should be determined by stakeholders based on the specific pipeline’s damage situation. Finally, we calculated the joint resilience curves by allocating different weight factors to GNS and WNS, to represent the proportion of water and gas supply that contributes to community resilience

Weathering Process of In Situ Granite and Particle Breakage Characteristics of Compacted Weathered Granite

Quantificationally describing weathering process and characterizing particle breakage are important in predicting the behavior of coarse-grained soil (e.g., weathered granite). In order to comprehensively understand the mechanical properties of weathered granite and provide references for reasonable evaluation of the engineering properties of subgrade filling in mountains, a series of tests—X-ray diffraction, sieving, heavy compaction, large-scale triaxial, and field compaction tests—were carried out in this research. Based on the weathering process parameters (m and r) of in-situ granite samples at two typical sections of weathered granite mountains obtained by using previous grading equation, the mathematical model of weathering process with depth was proposed and the variation laws of weathering process with depth were described. The results show that, with an increase in burying depth of mountain profile (h) of weathered granite, the geological year’s parameter (m) decrease by power function, but the geometric progression constants (r) increase by power function. Some factors affecting the particle breakage properties of compacted weathered granite were evaluated by using relative breakage (Br). Especially, the effect of field compaction condition (such as thickness of loose paving layer and number of vibratory rolling passes) on particle breakage was analyzed creatively. Through laboratory and field tests, it was found that particle gradation, mineral composition, compaction effect, stress level, and number of rolling passes significantly affected the particle breakage characteristics of weathered granite. Furthermore, it is worthy of attention that the weathered granite in this paper showed obvious particle breakage characteristics under weak compaction effect and at low stress levels and over-compaction could result in a decrease in the degree of compaction of a certain thickness of loose paving layer filled with weathered granite. Findings in this research can provide a theoretical basis for evaluating the physical properties and mechanical behavior of weathered granite as subgrade fillings

3D Numerical Analysis of Synergetic Interaction between High-Rise Building Basement and CFG Piles Foundation

A strong bearing capacity and the satisfaction of strict settlement requirements are necessary for high-rise buildings. A single-raft foundation cannot meet certain settlement requirements, in which case CFG (cement/fly ash/gravel, an emerging and sustainable construction material) piles can be used in the foundation to set up a cushion between the top of the pile and the raft slab, where the piles act as settlement reducers. The rafts of disconnected piles (DPs) exhibit complex synergetic interactions involving the raft, cushion, pile, and soil under the load of the superstructure. Multiple piles in particular lead to an increase in the number of degrees of freedom of the problem, resulting in difficulty in solving it. However, when the number of piles is very large and the structure is complex—for example, many buildings are placed on the same raft with basement structures—even if the embedded pile element is used during numerical calculations, either the method remains prone to non-convergence or the time needed for numerical calculations is too long. It is, thus, difficult to satisfy the requirement of an efficient scheme of evaluation in practice. To solve this problem, a method that uses a simulation of the integral equivalent of the CFG pile reinforcement zone is proposed in this paper. In the CFG pile reinforcement zone, the effect of the pile is reflected in the enhancement of parameters of the soil in the strengthened zone, and the reinforcement zone (including the soil and the pile) is regarded as an anisotropic elastoplastic material. As the structure of the pile is no longer needed in the model, its elimination significantly reduces the complexity of the model and improves its calculation efficiency. An example of a numerical calculation is provided to verify the viability and accuracy of the integral equivalent simulation method in comparison with the embedded pile element simulation method. Finally, the proposed method is applied to the three-dimensional numerical analysis of a scheme for the treatment of foundations of high- and low-rise buildings with basements, and its effectiveness is further verified through comparison with theoretical results

Why do family firms dismiss their family CEOs? A perspective on kinship ties.

Existing studies have suggested that nonfamily CEOs are more likely to be fired from family firms, while we focus on why family CEOs are also fired from family firms. Using data from 455 listed Chinese family firms, we find that family CEOs with affinity ties are more likely to be dismissed as they are not genetically related to the family. The difference becomes greater when firm performance is poor or family ownership is high. These findings elaborate that business-owing family is not a group with aligned interests, that is, family members with different family identities are treated differently within family. Besides, existing studies have emphasized that the preservation of socioemotional wealth in family firms can affect firms' operations, while this study further proposes that the preservation of socioemotional wealth can also have an impact on the business-owning families themselves

Retrieving High-Resolution Aerosol Optical Depth from GF-4 PMS Imagery in Eastern China

Gaofen 4 (GF-4) is a geostationary satellite, with a panchromatic and multispectral sensor (PMS) onboard, and has great potential in observing atmospheric aerosols. In this study, we developed an aerosol optical depth (AOD) retrieval algorithm for the GF-4 satellite. AOD retrieval was realized based on the pre-calculated surface reflectance database and 6S radiative transfer model. We customized the unique aerosol type according to the long time series aerosol parameters provided by the Aerosol Robotic Network (AERONET) site. The solar zenith angle, relative azimuth angle, and satellite zenith angle of the GF-4 panchromatic multispectral sensor image were calculated pixel-by-pixel. Our 1 km AOD retrievals were validated against AERONET Version 3 measurements and compared with MOD04 C6 AOD products at different resolutions. The results showed that our GF-4 AOD algorithm had a good robustness in both bright urban areas and dark rural areas. A total of 71.33% of the AOD retrievals fell within the expected errors of ±(0.05% + 20%); root-mean-square error (RMSE) and mean absolute error (MAE) were 0.922 and 0.122, respectively. The accuracy of GF-4 AOD in rural areas was slightly higher than that in urban areas. In comparison with MOD04 products, the accuracy of GF-4 AOD was much higher than that of MOD04 3 km and 10 km dark target AOD, but slightly worse than that of MOD04 10 km deep blue AOD. For different values of land surface reflectance (LSR), the accuracy of GF-4 AOD gradually deteriorated with an increase in the LSR. These results have theoretical and practical significance for aerosol research and can improve retrieval algorithms using the GF-4 satellite

The Chinese version of obsessive compulsive drug use scale: validation in outpatient methadone maintenance treatment program.

BACKGROUND: The Obsessive Compulsive Drug Use Scale (OCDUS) measures the overall craving level within a period from a multidimensional perspective. However, no studies have addressed the validity of the new OCDUS factor structure, presented in 2016, in China. Additionally, there is lack of evidence on the interaction among risk factors for relapse. We aimed to assess the psychometric properties of the scores of the Chinese version of the OCDUS in patients with heroin dependence receiving methadone maintenance treatment (MMT). Further, we aimed to assess the correlations of the OCDUS scores with withdrawal symptoms, depression, anxiety, and nicotine dependence. METHODS: We enrolled 113 adults (age 32-64 years) and administered them with the OCDUS, Subjective Opioid Withdrawal Scale (SOWS), Beck Depression Inventory-II (BDI-II), State-Trait Anxiety Inventory (STAI), and Fagerstrom Test for Nicotine Dependence (FTND). RESULTS: Exploratory factor analysis identified a 3-dimensional component that included "Frequency of craving," "Inference of heroin," and "Control of heroin." These factors showed acceptable internal consistency, adequate item-total correlations, and significant item-subscale correlations. There was no correlation between the OCUDS scores and age, education, duration of receiving MMT, and MMT dosages. However, there was a significant correlation between the OCDUS total scores and the SOWS, STAI, BDI-II, and FTND scores. The scores of all the subscales were associated with the SOWS scores; further, the scores of the first two subscales were associated with BDI-II scores while only the scores of the first subscale were associated with the FTND scores. CONCLUSIONS: Our findings support the reliability and structure validity of the OCDUS scores. Heroin craving, withdrawal symptoms, negative emotions, and nicotine dependence, which are considered as risk factors for heroin relapse, might interact with each other. There is a need for further studies on the underlying mechanism of these clinical phenomena