This paper proposes an adaptive color-guided autoregressive (AR) model for high quality depth recovery from low quality measurements captured by depth cameras. We observe and verify that the AR model ...tightly fits depth maps of generic scenes. The depth recovery task is formulated into a minimization of AR prediction errors subject to measurement consistency. The AR predictor for each pixel is constructed according to both the local correlation in the initial depth map and the nonlocal similarity in the accompanied high quality color image. We analyze the stability of our method from a linear system point of view, and design a parameter adaptation scheme to achieve stable and accurate depth recovery. Quantitative and qualitative evaluation compared with ten state-of-the-art schemes show the effectiveness and superiority of our method. Being able to handle various types of depth degradations, the proposed method is versatile for mainstream depth sensors, time-of-flight camera, and Kinect, as demonstrated by experiments on real systems.
In this paper, we propose to introduce intrinsic image decomposition priors into decomposition models for contrast enhancement. Since image decomposition is a highly illposed problem, we introduce ...constraints on both reflectance and illumination layers to yield a highly reliable solution. We regularize the reflectance layer to be piecewise constant by introducing a weighted ℓ 1 norm constraint on neighboring pixels according to the color similarity, so that the decomposed reflectance would not be affected much by the illumination information. The illumination layer is regularized by a piecewise smoothness constraint. The proposed model is effectively solved by the Split Bregman algorithm. Then, by adjusting the illumination layer, we obtain the enhancement result. To avoid potential color artifacts introduced by illumination adjusting and reduce computing complexity, the proposed decomposition model is performed on the value channel in HSV space. Experiment results demonstrate that the proposed method performs well for a wide variety of images, and achieves better or comparable subjective and objective quality compared with the state-of-the-art methods.
A sparse representation-based classifier (SRC) is developed and shows great potential for real-world face recognition. This paper presents a dimensionality reduction method that fits SRC well. SRC ...adopts a class reconstruction residual-based decision rule, we use it as a criterion to steer the design of a feature extraction method. The method is thus called the SRC steered discriminative projection (SRC-DP). SRC-DP maximizes the ratio of between-class reconstruction residual to within-class reconstruction residual in the projected space and thus enables SRC to achieve better performance. SRC-DP provides low-dimensional representation of human faces to make the SRC-based face recognition system more efficient. Experiments are done on the AR, the extended Yale B, and PIE face image databases, and results demonstrate the proposed method is more effective than other feature extraction methods based on the SRC.
The power consumption of actuators is an important concern for the spacecraft attitude control system. This paper presents a power consumption reduction method for permanent magnet biased active ...magnetic bearings (AMBs) during torque output of control moment gyros (CMGs). For simplicity of analysis, a simple single degree-of-freedom (DOF) AMB system undergoing an external load force is first presented. An operating point adaptive regulation based on current-integral feedforward method is proposed to realize the coil current reduction with a reference position offset. Then the proposed method is extended to the case of the 4-DOF AMB-rotor system. In order to improve the dynamic response of the current-integral output, a dynamic regulator is incorporated into the feedforward loop. The parameter range for stability and dynamic properties of the AMB-rotor system with and without using the dynamic regulator have also be compared and discussed. Finally, experimental results on a developed magnetically suspended double-gimbal CMG prototype validate the effectiveness of the proposed method.
Cisplatin (CP) is the classical chemotherapeutic drug for various cancer, but it also accompanies reproductive toxicity and genotoxicity. Liuwei Dihuang Pill (LW) is the traditional Chinese medicine ...prescription for treating Kidney-Yin deficiency syndrome, which has been reported to prevent and treat various diseases. However, the protective effect of LW on CP-induced reproductive toxicity and genotoxicity has not been reported.
To investigate the potential protective effect and mechanism of LW on CP-induced reproductive toxicity and genotoxicity in male mice.
Mice were given LW (0.4, 1.2 and 3.6 g/kg) or Vitamin C (0.1 g/kg) once daily by oral gavage for thirteen consecutive days. Then, CP (3.00 mg/kg) was given intraperitoneal injection once daily for five consecutive days starting on the ninth day. The protective effects of LW against CP-induced reproductive toxicity and genotoxicity were evaluated by body weight, testis ratio, sperm count, sperm viability, sperm abnormal morphology type, micronuclei test, testicular histopathology, serum malondialdehyde (MDA), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) level.
The results demonstrated that LW could significantly increase CP-induced the reduction of sperm count and sperm viability, then decrease abnormal sperm type rate and micronucleus rate. Moreover, LW also could improve testicular abnormal histopathologic morphology induced by CP exposure. Meanwhile, LW decreased serum MDA level and increased T-SOD, GSH-Px and CAT level compared to CP group.
our findings show that LW has protective effects on CP-induced reproductive toxicity and genotoxicity. LW decreases serum MDA level and increases T-SOD, GSH-Px and CAT level, which indicates that antioxidant activity may be the potential mechanism of LW to resist reproductive toxicity and genotoxicity.
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Single image denoising suffers from limited data collection within a noisy image. In this paper, we propose a novel image denoising scheme, which explores both internal and external correlations with ...the help of web images. For each noisy patch, we build internal and external data cubes by finding similar patches from the noisy and web images, respectively. We then propose reducing noise by a two-stage strategy using different filtering approaches. In the first stage, since the noisy patch may lead to inaccurate patch selection, we propose a graph based optimization method to improve patch matching accuracy in external denoising. The internal denoising is frequency truncation on internal cubes. By combining the internal and external denoising patches, we obtain a preliminary denoising result. In the second stage, we propose reducing noise by filtering of external and internal cubes, respectively, on transform domain. In this stage, the preliminary denoising result not only enhances the patch matching accuracy but also provides reliable estimates of filtering parameters. The final denoising image is obtained by fusing the external and internal filtering results. Experimental results show that our method constantly outperforms state-of-the-art denoising schemes in both subjective and objective quality measurements, e.g., it achieves >2 dB gain compared with BM3D at a wide range of noise levels.
The tracking and data relay satellite (TDRS) in geosynchronous orbit (GEO) can provide ranging and communication services for user spacecraft in low Earth orbit (LEO) through the inter‐satellite link ...(ISL). The time delay of TDRS ISL transponder in orbit differs from its pre‐launch state and changes due to the complex space environment, adding significant errors to the user spacecraft's orbit determination based on four‐way ranging data. The authors have developed a calibration system and proposed an efficient on‐orbit calibration method for the ISL transponder's time delay in TDRS. Experimental results demonstrate the effectiveness of the authors’ method, and the RMS of calibration residuals is less than 0.5 m.
We have developed a calibration system and proposed an efficient on‐orbit calibration method for the ISL transponder's time delay in TDRS. Experimental results demonstrate the effectiveness of our method, and the RMS of calibration residuals is less than 0.5 meters.
Circular polarization memory is a well-known phenomenon indicating that the circular polarization light can persist better its polarization property during propagating through turbid media compared ...with the linear polarization light. Therefore, in principle, using circularly polarized light can probably improve the quality of image recovery in dense turbid media than using the linearly polarized light. In this paper, we propose a new polarimetric image recovery method in dense turbid media with the illumination light of circular polarization, and we realize the image recovery combining the circular polarization information and linearly polarization information. The real-world experiment results demonstrate that the proposed method is more effective than previous methods, including the traditional polarimetric image recovery method by Schechner's Appl. Opt.42, 511 (2003) based on linear polarization.
Abstract This paper focuses on the pressure resistance of underwater equipment. A shell structure that divided into multi-layer is proposed, the spaces between layers are filled with fluid medium, ...which is applied gradually decreasing pressure in outside-inside order that helps offsetting external pressure. Using the Finite Element Method, the Multi-layer Fluid-Solid-Coupling Shell Structure has been proved to be effective in improving the pressure resistance of underwater equipment without increasing the total thickness of material, in the scope of the study, the maximum equivalent stress of the whole structure decreased with increase of the number of layers without instability phenomenon.
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•Doxorubicin-loaded hyaluronic acid-glycyrrhetinic acid succinate nanoparticles presented higher liver and tumor targeting efficiency.•The higher glycyrrhetinic acid graft ratio on ...hyaluronic acid, the better liver and tumor targeting property.•The binding site of glycyrrhetinic acid on hyaluronic acid has significant influence on the liver and tumor targeting efficiency.
Liver-targeted nanoparticles is highly desired for better therapy of liver cancer. In this study, enhanced delivery of doxorubicin (DOX) to the liver cells through self-assembled nanoparticles formed via conjugation of glycyrrhetinic acid (GA) to the hydroxyl group of hyaluronic acid (HA) was investigated. The DOX loaded hyaluronic acid-glycyrrhetinic acid succinate (HSG) conjugates based nanoparticles (HSG/DOX nanoparticles) were sub-spherical in shape with particle size in the range of 180–280 nm, the drug loading was drug-to-carrier ratio and GA graft ratio dependent. In vitro release study suggested that the release of DOX from HSG nanoparticles was sustained and the release rate was pH and GA graft ratio dependent. MTT assay indicated the HSG/DOX nanoparticles presented a GA-dependent cytotoxicity to HepG2 cells. Pharmacokinetics study demonstrated the HSG/DOX nanoparticles could prolong blood circulation time of DOX and had a higher AUC value than that of DOX solution. Furthermore, tissue distribution study revealed the HSG/DOX nanoparticles significantly increased the accumulation of DOX in the liver and meanwhile decreased the cardiotoxicity and nephrotoxicity of DOX. Moreover, the liver targeting enhancing capacity was HSG conjugate structure dependent. The accumulation of HSG-20/DOX, HSG-12/DOX, and HSG-6/DOX nanoparticles in the liver was 4.0-, 3.1-, and 2.6-fold higher than that of DOX solution. In vivo imaging analysis further demonstrated HSG nanoparticles not only had better liver targeting effect, but also presented superior tumor targeting efficiency, and the tumor targeting capacity was also GA-dependent. These results indicated that HSG conjugates prepared via modifying the hydroxyl groups of HA have promising potential as a liver-targeting nanocarrier for the delivery of hydrophobic anti-tumor drugs.
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