LeNo: Adversarial Robust Salient Object Detection Networks with Learnable Noise

Pixel-wise predction with deep neural network has become an effective paradigm for salient object detection (SOD) and achieved remakable performance. However, very few SOD models are robust against adversarial attacks which are visually imperceptible for human visual attention. The previous work robust salient object detection against adversarial attacks (ROSA) shuffles the pre-segmented superpixels and then refines the coarse saliency map by the densely connected CRF. Different from ROSA that rely on various pre- and post-processings, this paper proposes a light-weight Learnble Noise (LeNo) to against adversarial attacks for SOD models. LeNo preserves accuracy of SOD models on both adversarial and clean images, as well as inference speed. In general, LeNo consists of a simple shallow noise and noise estimation that embedded in the encoder and decoder of arbitrary SOD networks respectively. Inspired by the center prior of human visual attention mechanism, we initialize the shallow noise with a cross-shaped gaussian distribution for better defense against adversarial attacks. Instead of adding additional network components for post-processing, the proposed noise estimation modifies only one channel of the decoder. With the deeply-supervised noise-decoupled training on state-of-the-art RGB and RGB-D SOD networks, LeNo outperforms previous works not only on adversarial images but also clean images, which contributes stronger robustness for SOD.Comment: 8 pages, 5 figures, submitted to AAA

The study of the feasibility of segmental bone defect repair with tissue- engineered bone membrane: a qualitative observation

The objective of the study was to investigate the feasibility of intramembranous osteogenesis from tissue-engineered bone membrane in vivo. Bone marrow mesenchymal stem cells (MSCs) of rabbits were harvested, expanded and some of them were induced into osteoblasts. Porcine small intestinal submucosa (SIS) was converted by a series of physical and chemical procedures into a scaffold. MSCs and induced osteoblasts were seeded separately onto the scaffold, thus fabricating two kinds of tissue-engineered bone membrane. A total of 12 New Zealand rabbits were subjected to a surgical operation; a 15 mm bone segment, including the periosteum, was resected from the radius on both sides of each rabbit to create critical bone defects. The two kinds of tissue-engineered bone membrane and SIS (as control) were implanted randomly into the site of bone defect. The animals had radiographs and were killed after 4 weeks. The specimens were harvested and histological examination performed for evidence of osteogenesis. Bone tissue had formed in defects treated by the two kinds of tissue-engineered bone membrane at 4 weeks. This was supported by the X-ray and histological examination, which confirmed the segmental gap bridged by bone. There was no attempt to bridge in the bone defect treated by SIS. Tissue-engineered bone membrane, constructed by seeding allogeneic cells on an xenogeneic and bio-derived scaffold, can repair critical bone defects successfully

Axial Compressive Behavior of Square Ice Filled Steel Tubular Stub Columns

Concrete has many limitations in the building construction in cold areas. However, there is abundant ice in those regions. Therefore, using ice as a substitute for concrete has been explored by researchers. Inspired by the idea of square concrete filled steel tube (CFT), a new column form termed square ice filled steel tubular (IFT) column is proposed in this study. It consists of a square outer steel tube with the inner space filled with ice. A total of eighteen stub columns were made and tested under axial compression, including three circular plain ice specimens, nine square IFT specimens and six hollow square steel tubes, to demonstrate the advantages of the composite column. The width-to-thickness (B/t) ratio of the steel tubes varies from 39.5 to 77. The test results confirmed that the ice core is effectively confined by the steel tube, and the inward local buckling of the steel tube is suppressed by the inner ice, leading to higher strength and better ductility of the square IFT specimens compared with hollow steel tubes and plain ice columns. A simplified axial bearing capacity equation for square IFT stub columns is proposed and it provides reasonable and accurate predictions of the test results

Structural response reconstruction for non-proportionally damped systems in the presence of closely spaced modes

An approach of structural response reconstruction for non-proportionally damped systems is proposed in this paper, which is a time domain method based on the empirical mode decomposition method with intermittency criteria and modal superposition method. The state space method is employed for decoupling the dynamic system equation to obtain the complex mode shapes. Response reconstruction of the structural system in the presence of closely spaced modes is studied in detail. The key idea is to regard each set of closely spaced modes as an integral part. Two numerical examples are conducted to validate the effectiveness of the proposed method

No spin-localization phase transition in the spin-boson model without local field

We explore the spin-boson model in a special case, i.e., with zero local field. In contrast to previous studies, we find no possibility for quantum phase transition (QPT) happening between the localized and delocalized phases, and the behavior of the model can be fully characterized by the even or odd parity as well as the parity breaking, instead of the QPT, owned by the ground state of the system. Our analytical treatment about the eigensolution of the ground state of the model presents for the first time a rigorous proof of no-degeneracy for the ground state of the model, which is independent of the bath type, the degrees of freedom of the bath and the calculation precision. We argue that the QPT mentioned previously appears due to unreasonable treatment of the ground state of the model or of the infrared divergence existing in the spectral functions for Ohmic and sub-Ohmic dissipations.Comment: 5 pages, 1 figure. Comments are welcom

Effects of Exogenous Melatonin on Body Mass Regulation and Hormone Concentrations in Eothenomys miletus

By regulating the pineal hormone, photoperiods affect many physiological characteristics in small mammals. Thus, melatonin might take part in the thermoregulation of seasonal variations in small mammals. This study determined the influence of melatonin treatment on thermogenic pattern, we measured body mass, thermogenic activities and hormone concentrations of Eothenomys miletus were given exogenous melatonin (MLT) for 28 days. The results shown that body mass was reduced significantly, whereas resting metabolic rate (RMR) and nonshivering thermogenesis (NST) increased at 28 days in MLT group compared to control group as well as the oxidative capacities of mitochondria in liver and brown adipose tissue (BAT) were enhanced; the contents of total and mitochodrial protein increased markedly. Melatonin treatment significantly increased the State 3, State 4 respiration of liver mitochondria, and the activity of cytochrome C oxidase (COX) in liver; but the α-glerocephasphate oxidase (α-PGO) capacity showed no differences during the acclimation in liver. Furthermore, the State 4 respiration, the activities of COX and α-PGO in BAT increased, respectively. The activity of thyroxin 5’-deiodinase ( T45’-DII) in BAT increased remarkably. The serum content of thyroxine (T 4) decreased, and that of tri-iodothyronine (T 3) increased. Moreover, serum leptin levels showed no significant differences in MLT group compared to control group. Together, these data indicate that melatonin enhances thermogenic capacity in E. miletus. Our results suggested that melatonin is potentially involved in the regulation of body mass, adaptive thermogenic capacity and hormone concentrations in E. miletus

Periodic solutions and stability for a delayed discrete ratio-dependent predator-prey system with Holling-type functional response

The existence of positive periodic solutions for a delayed discrete predator-prey model with Holling-type-III functional response N1(k+1)=N1(k)exp{b1(k)−a1(k)N1(k−[τ1])−α1(k)N1(k)N2(k)/(N12(k)+m2N22(k))}, N2(k+1)=N2(k)exp{−b2(k)+α2(k)N12(k−[τ2])/(N12(k−[τ2])+m2N22(k−[τ2]))} is established by using the coincidence degree theory. We also present sufficient conditions for the globally asymptotical stability of this system when all the delays are zero. Our investigation gives an affirmative exemplum for the claim that the ratio-dependent predator-prey theory is more reasonable than the traditional prey-dependent predator-prey theory

Passively mode-locked ytterbium-doped fiber laser with cylindrical vector beam generation based on mode selective coupler

We propose and demonstrate, for the first time to the best of our knowledge, a passively mode-locked ytterbium-doped fiber laser generating cylindrical vector beams (CVBs) using a mode selective coupler (MSC) as the transverse mode converter and splitter, and a semiconductor saturable absorber mirror (SESAM) for mode-locking. According to the coupling mode theory and the phase matching principle, the MSC was fabricated by weakly fused technology, having a low loss of about 0.5 dB and achieving LP11 mode with a high purity of > 96%. The CVB fiber laser operates at a center wavelength of 1042.3 nm, with a 3 dB spectral width of 1.5 nm. The repetition rate of the mode-locked laser pulses is 18.58 MHz. The radially and azimuthally polarized vector beams can be switched by adjusting the polarization controllers in the fiber ring cavity, with a high mode purity measured to be > 95%. The mode-locked CVB ytterbium-doped fiber laser has potential applications in optical tweezers, optical imaging, and so on