Capture Success Rate Research Articles

Enhanced Scratch Detection for Textured Materials Based on Optimized Photometric Stereo Vision and Fast Fourier Transform–Gabor Filtering

In the process of scratch defect detection in textured materials, there are often problems of low efficiency in traditional manual detection, large errors in machine vision, and difficulty in distinguishing defective scratches from the background texture. In order to solve these problems, we developed an enhanced scratch defect detection system for textured materials based on optimized photometric stereo vision and FFT-Gabor filtering. We designed and optimized a novel hemispherical image acquisition device that allows for selective lighting angles. This device integrates images captured under multiple light sources to obtain richer surface gradient information for textured materials, overcoming issues caused by high reflections or dark shadows under a single light source angle. At the same time, for the textured material, scratches and a textured background are difficult to distinguish; therefore, we introduced a Gabor filter-based convolution kernel, leveraging the fast Fourier transform (FFT), to perform convolution operations and spatial domain phase subtraction. This process effectively enhances the defect information while suppressing the textured background. The effectiveness and superiority of the proposed method were validated through material applicability experiments and comparative method evaluations using a variety of textured material samples. The results demonstrated a stable scratch capture success rate of 100% and a recognition detection success rate of 98.43% ± 1.0%.

A Trajectory Planning Method for Capture Operation of Space Robotic Arm Based on Deep Reinforcement Learning

Abstract In order to deal with the complex dynamics and control problems involved in space debris removal, a trajectory planning technique for a spatial robotic arm based on twin delayed DDPG (TD3) in deep reinforcement learning is proposed, and it can accomplish an end-to-end control effect comparable to that of human hand gripping objects. The trajectory planning method for capturing space debris by a floating-base space robotic arm is realized using a space robotic arm task simulation platform built on MuJoCo and using trajectory planners, trajectory trackers, and joint and end-effector control strategies formulated with seven different weighted reward functions. This makes it easier to complete spacecraft in-orbit servicing and maintenance missions. The experiment results demonstrate that the capture strategy can maintain a capture success rate of more than 99%, and debris capture can be mostly finished in three stages when taking the stability of the floating base into consideration by continuously modifying the trajectory.

Efficacy and safety of lumenless leads compared with stylet-driven leads for left bundle branch area pacing

Abstract Introduction Left Bundle Branch Area Pacing (LBBAP) was initially performed with lumenless leads (LLLs). In the last years, stylet-driven leads (SDLs) have emerged as an alternative. However, we are still lacking data comparing these two different approaches. Purpose To compare the efficacy and safety of LLLs Vs SDLs for LBBAP. Methods 116 patients who underwent LBBAP attempt in our institution were prospectively included (mean age 74 ± 9 years, 40 (34%) female). We recorded and analyzed baseline characteristics, procedural findings, LBB capture criteria, lead parameters, success rates and complications. A 6-month remote follow-up data was programmed in every patient. Results We analyzed 75 patients who received LLLs and 41 patients with SDLs. Baseline characteristics were similar in both groups (table 1). There were no significant differences regarding Paced QRS (114 ± 18 ms Vs 117 ± 19 ms, p = 0.36), presence of a LB potential (16 (21%) Vs 9 (22%), p = 0.93), V6 R-wave peak time (V6RWPT) (83 ± 15 ms Vs 82 ± 16 ms, p = 0.71) or V6–V1 inter-peak interval (40 ± 17 ms Vs 37 ± 13 ms, p = 0.37). Time to lead implant was also similar (37 ± 18 minutes Vs 37 minutes ± 13 minutes, p = 0.87). Mean pacing voltage threshold was higher for SDLs after implantation (0.71 ± 0.33 V Vs 0.86 ± 0.30 V, p = 0.02) and also at the 6-month remote follow-up (0.75 ± 0.28 V Vs 0.9 ± 0.34 V, p = 0,04). R-wave amplitude and impedance were also higher in SDLs (table 1). According to 2023 EHRA clinical consensus statement on conduction system pacing, we achieved confirmed LBBP in 63 patients (54%), likely LBBP in 30 patients (26%) and Left Ventricular Septal Pacing (LVSP) in 21 patients (18 %), with no differences between groups (table 1). After the 6-month follow-up, a higher probability of lead dislodgement was appreciated in the SDLs group (3 (7%) Vs 0 (0%), p = 0,01). Conclusions LLLs and SDLs are effective tools to perform LBBAP, achieving similar paced QRS and and success rates. SDLs were associated with slightly higher pacing threshold. After the 6-month follow-up, a higher probability of lead dislodgement was appreciated in the SDLs group.

Research on Vision-Based Servoing and Trajectory Prediction Strategy for Capturing Illegal Drones

A proposed strategy for managing airspace and preventing illegal drones from compromising security involves the use of autonomous drones equipped with three key functionalities. Firstly, the implementation of YOLO-v5 technology allows for the identification of illegal drones and the establishment of a visual-servo system to determine their relative position to the autonomous drone. Secondly, an extended Kalman filter algorithm predicts the flight trajectory of illegal drones, enabling the autonomous drone to compensate in advance and significantly enhance the capture success rate. Lastly, to ensure system robustness and suppress interference from illegal drones, an adaptive fast nonsingular terminal sliding mode technique is employed. This technique achieves finite time convergence of the system state and utilizes delay estimation technology for the real-time compensation of unknown disturbances. The stability of the closed-loop system is confirmed through Lyapunov theory, and a model-based hardware-in-the-loop simulation strategy is adopted to streamline system development and improve efficiency. Experimental results demonstrate that the designed autonomous drone accurately predicts the trajectory of illegal drones, effectively captures them using a robotic arm, and maintains stable flight throughout the process.

Practical, effective and safer: Placing traps above ground is an improved capture method for the critically endangered ngwayir (western ringtail possum; Pseudocheirus occidentalis).

The capture of wild-living animals can provide valuable information that is critical in developing and implementing effective conservation actions. These capture procedures, however, often require direct handling of individuals by researchers, and conservationists should constantly seek to improve capture methods so that the impacts on animal welfare are minimised. The ngwayir (western ringtail possum; Pseudocheirus occidentalis) is a critically endangered arboreal marsupial in need of effective conservation. It is, however, not amenable to conventional trapping, leading to the use of methods such as nest robbing and tranquilisation using dart guns or pole syringes, which involve potentially serious animal welfare risks and longer exposure of animals to humans as compared to conventional trapping. In pursuit of an improved capture method, we investigated opportunistically whether placing traps above the ground would increase the capture success rate of the species, using wire cage traps baited with universal bait and fruit. Between 2010 and 2019, we deployed trapping grids in Locke Nature Reserve and adjacent campsites near Busselton, WA, Australia, with traps placed on the ground for 1,985 trap nights and traps placed on horizontal tree branches, fallen trees or fences, 1-2 m above ground for 694 trap nights. With the above ground traps we trapped 82 ngwayirs out of 694 trap nights, 27 in autumn and 55 in spring. We also captured eleven common brushtail possums (Trichosurus vulpecula; 1.6% trap success rate), 12 King's skinks (Egernia kingii; 1.7%) and five black rats (Rattus rattus; 0.7%). Trapping success rate was higher in elevated traps (up to 18.3%) compared to traps on the ground (0.5%) and using fruit as bait increased the trap success rate. These results suggest that using elevated traps baited with fruit is a practical, effective method to capture the ngwayir.

Imaging high jitter, very fast phenomena: A remedy for shutter lag.

Dielectric breakdown is an example of a natural phenomenon that occurs on very short time scales, making it incredibly difficult to capture optical images of the process. Event initiation jitter is one of the primary challenges, as even a microsecond of jitter time can cause the imaging attempt to fail. Initial attempts to capture images of dielectric breakdown using a gigahertz frame rate camera and an exploding bridge wire initiation were stymied by high initiation jitter. Subsequently, a novel optical delay line apparatus was developed in order to effectively circumvent the jitter and reliably image dielectric breakdown. The design and performance of the optical delay line apparatus are presented. The optical delay line increased the image capture success rate from 25% to 94% while also permitting enhanced temporal resolution and has application in imaging other high-jitter, extremely fast phenomena.

The number of screwing attempt and predictors for the success of left bundle branch area pacing : A multicenter experience with standard stylet-driven pacing leads

Abstract Objectives Although Left Bundle Branch Area Pacing (LBBAP) is emerging conduction system pacing modality, it is unclear which parameters are predictive of procedural success and how many screwing attempts are acceptable. This retrospective observational study sought to assess predictors of successful LBBAP, left bundle branch (LBB) capture, and factors associated with the number of screwing attempts. Methods We performed a multicenter retrospective analysis of 120 patients who underwent LBBAP with stylet driven lead. We analyzed factors affecting the number of screwing attempts and procedural success. Procedural, 12-lead ECG, echocardiographic parameters and clinical variables were used in multivariate analyses. Results LBBAP success rate was 95.8% (115/120), and LBB capture success rate was 86.1% (99/115). Few screwing attempts was associated with procedural success (2.1 ± 1.2, 2.7 ± 1.2, and 3.5 ± 1.3 in LBBAP with LBB capture, LBBAP without LBB capture and failed LBBAP group, respectively) (p for trends=0.03). 4 or more screwing attempt was independently associated with higher complication rate compared to fewer screwing attempt (n≤3) (p<0.05). The larger RA size (B = 1.901, 95% confidence interval [CI] 1.07 - 2.73, p <0.001), smaller RV size (B = -0.995, 95% CI -1.88 - -0.31, p = 0.007), and intraventricular conduction delay (IVCD) at pre-implant ECG were independently associated with more screwing attempts. Larger RA size (4th quartile) was associated with larger final sheath size and frequent sheath size change to larger sheath when compared to others. Conclusions More screwing attempts was associated with failed LBBAP procedure and failed LBB capture, and 4 or more screw attempts was associated with higher complication rate. Larger the RA size, smaller the RV size, and IVCD in pre-implant ECG are predictive of more screwing attempt.

Switching by cuttlefish of preying tactics targeted at moving prey

Previous studies have demonstrated that the size of the prey relative to the cuttlefish is important to the choice between tentacular strike and jump-on tactics. In the present study, we investigated the decision-making in the cuttlefish's tactical switch when preying on the same size prey. A servomotor system controlling the movement of a shrimp was used to elicit the cuttlefish's preying behavior. The success rate of prey capture and the kinematics of visual attack were examined systematically. The results showed that the jump-on behavior appeared mostly after a miss attack by previous tentacular strike on a moving shrimp. Compared with a visual attack with tentacles, the jump-on tactic has over a shorter attacking distance and wider attacking angles. Thus, these two different preying tactics have different operating ranges relative to the prey. More importantly, the cuttlefish can adjust their preying tactics adaptively depending on their prior preying experience.

Transverse curvature characterization of rectangular bistable CFRP laminates with a satellite capturing continuum robotic application

The geometry of a bistable unsymmetric cross-ply carbon fiber reinforced polymer (CFRP) laminate impacts the observed stable configuration curvature. Continuum robotic systems can leverage the multi-stable nature of bistable CFRPs to contort to resemble continuous-bodied appendages observed in nature. The compliance of continuum robots facilitates grasping and manipulating objects such as non-cooperative, tumbling targets encountered in an on-orbit servicing operation. This work investigates large-scale bistable CFRP rectangular laminates previously unexplored in the literature to demonstrate the feasibility of scaling the laminates to meet the needs of potential applications. A numerical parametric study explored the relationship between aspect ratio, thickness, and stable configuration curvature. Non-dimensional parameters enabled the creation of a bifurcation diagram to characterize the stable shapes and bistability. Polynomial regression and machine learning delivered curvature prediction tools. Experiments using an air-bearing zero gravity spacecraft simulator evaluated the feasibility of incorporating rectangular bistable CFRP laminates in an on-orbit servicing continuum robotic system. The initial system resembled a crab claw to grasp target boxes, and the orientation and size of the target significantly contributed to the capture success rate. Future investigations of bistable CFRPs, especially from an application perspective, can benefit from predictive tools like ML to quantify the bistable characteristics.

Estimating energetic intake for marine mammal bioenergetic models.

Bioenergetics is the study of how animals achieve energetic balance. Energetic balance results from the energetic expenditure of an individual and the energy they extract from their environment. Ingested energy depends on several extrinsic (e.g prey species, nutritional value and composition, prey density and availability) and intrinsic factors (e.g. foraging effort, success at catching prey, digestive processes and associated energy losses, and digestive capacity). While the focus in bioenergetic modelling is often on the energetic costs an animal incurs, the robust estimation of an individual's energy intake is equally critical for producing meaningful predictions. Here, we review the components and processes that affect energy intake from ingested gross energy to biologically useful net energy (NE). The current state of knowledge of each parameter is reviewed, shedding light on research gaps to advance this field. The review highlighted that the foraging behaviour of many marine mammals is relatively well studied via biologging tags, with estimates of success rate typically assumed for most species. However, actual prey capture success rates are often only assumed, although we note studies that provide approaches for its estimation using current techniques. A comprehensive collation of the nutritional content of marine mammal prey species revealed a robust foundation from which prey quality (comprising prey species, size and energy density) can be assessed, though data remain unavailable for many prey species. Empirical information on various energy losses following ingestion of prey was unbalanced among marine mammal species, with considerably more literature available for pinnipeds. An increased understanding and accurate estimate of each of the components that comprise a species NE intake are an integral part of bioenergetics. Such models provide a key tool to investigate the effects of disturbance on marine mammals at an individual and population level and to support effective conservation and management.

A trapdoor spider, Latouchia typica (Araneae: Halonoproctidae), uses vibrational cues as a trigger for predatory behavior

AbstractSpiders are one of the most dominant predators in terrestrial ecosystems. Although cues triggering predatory behavior in web‐building and wandering spiders are well investigated, studies concerning burrowing species, the most ancestral group of spiders, are relatively limited. To clarify critical cues affecting the predatory behavior in burrowing species, we conducted vibration‐reducing experiments with the trapdoor spider Latouchia typica (Araneae: Halonoproctidae) and nymphs of the speckled cockroach, Nauphoeta cinerea (Blattodea: Blaberidae), as prey. Spiders achieved a high success rate of prey capture even when blinded (with paint on the eyes). However, the use of a rubber mat to reduce vibrations significantly decreased predation success rate. In addition, the presence or absence of the blindfold did not affect the predation rates under the reducing vibration condition. These results indicate that substrate vibrations emitted from prey are critically important to trigger the predatory behavior in L. typica, but visual and chemical stimuli are not used even in the case when vibration cues are unavailable. This is the first study to use vibration‐reducing experiments to experimentally demonstrate the critical cues for predation in trapdoor spiders.

Fishing behavior in the red fox: Opportunistic-caching behavior or surplus killing?

Fishing behavior in the red fox: Opportunistic-caching behavior or surplus killing?

Research on Multi-Object Sorting System Based on Deep Learning.

As a complex task, robot sorting has become a research hotspot. In order to enable robots to perform simple, efficient, stable and accurate sorting operations for stacked multi-objects in unstructured scenes, a robot multi-object sorting system is built in this paper. Firstly, the training model of rotating target detection is constructed, and the placement state of five common objects in unstructured scenes is collected as the training set for training. The trained model is used to obtain the position, rotation angle and category of the target object. Then, the instance segmentation model is constructed, and the same data set is made, and the instance segmentation network model is trained. Then, the optimized Mask R-CNN instance segmentation network is used to segment the object surface pixels, and the upper surface point cloud is extracted to calculate the normal vector. Then, the angle obtained by the normal vector of the upper surface and the rotation target detection network is fused with the normal vector to obtain the attitude of the object. At the same time, the grasping order is calculated according to the average depth of the surface. Finally, after the obtained object posture, category and grasping sequence are fused, the performance of the rotating target detection network, the instance segmentation network and the robot sorting system are tested on the established experimental platform. Based on this system, this paper carried out an experiment on the success rate of object capture in a single network and an integrated network. The experimental results show that the multi-object sorting system based on deep learning proposed in this paper can sort stacked objects efficiently, accurately and stably in unstructured scenes.

Optimal Adaptive Control and Backstepping Control Method with Sliding Mode Differentiator

In order to improve the success rate of space debris object capture, how to increase the resistance to interference in the space robot arm has become an issue of interest. In addition, since the space operation time is always limited, finite-time control has become another urgent requirement needed to be addressed. Considering external disturbances, two control methods are proposed in this paper to solve the control problem of space robot arm. Firstly, a linear sliding mode control method is proposed considering the model uncertainties and external disturbances. The robot arm can track the desired trajectory, while a trade-off between optimality and robustness of the solved system can be achieved. Then, in order to reduce conservativeness and relax restrictions on external disturbances, a novel backstepping control method based on a finite-time integral sliding mode disturbance observer is developed, which compensates for the effects of both model uncertainties and infinite energy-based disturbance inputs. Finally, simulation examples are given to illustrate the effectiveness of the proposed control method.

Kinematics of prey capture and histological development of related organs in juvenile seahorse

The seahorse is a typical suction feeder with an elongated, tubular snout and a small terminal mouth. It is important to determine the details of this unique prey-capture behavior to improve the survival rate during seahorse breeding, especially for juveniles. In this study, we described the sucking process and characterized the kinematics in juvenile lined seahorse (Hippocampus erectus) at different ages (1–30 days after parturition; DAP) using a high-speed video system, and also investigated the histological basis of the feeding-related organs, including snout, eye, and intestine. The sucking of juvenile seahorses can be divided into four steps: searching, locating, capturing, and swallowing. Seahorses capture prey mainly based on the vision system, and histological results revealed a developed visual acuity in the newborn seahorses, so that they were able to prey once after releasing from the male seahorse's brood pouch. The attack distance, maximum snout width, capture success rate, and daily food intake of juvenile seahorses increased with maturation. A remarkable inflection point, in the snout expansion rate, successful predation rate, and growth rate, occurs at about 10 DAP, when calcification of the snout bones was completed. In addition, the intestines of newborn seahorses were short and quite simple, but developed rapidly during the first 20 DAP. These findings provide a better understanding of prey capture kinematics and nutritional physiology, and will be beneficial for improving the feeding strategies for juveniles during large seahorse breeding.

Improved Trapping and Handling of an Arboreal, Montane Mammal: Red Panda Ailurus fulgens.

Simple SummaryCapture and handling is essential to study some biological and ecological properties of free-ranging animals. However, capturing an arboreal and cryptic species such as the red panda is challenging due to the difficult terrain, their elusive nature, and potential risks to human and animal safety. We developed and successfully tested a protocol for tracking, capture, immobilization, and handling of red pandas. This method could also be used, with some modifications, for other arboreal species. This study extends the known range of body weight and length of free-ranging red pandas. We also report some new morphometric data that could serve as a guide for field identification.It is sometimes essential to have an animal in the hand to study some of their ecological and biological characteristics. However, capturing a solitary, cryptic, elusive arboreal species such as the red panda in the wild is challenging. We developed and successfully tested a protocol for tracking, trapping, immobilization, and handling of red pandas in the wild in eastern Nepal. We established a red panda sighting rate of 0.89 panda/day with a capture success rate of 0.6. We trapped and collared one animal in 3.7 days. On average, we took nearly 136 (range 50–317) min to capture an animal after spotting it. Further processing was completed in 38.5 (21–70) min. Before capture, we found it difficult to recognize the sex of the red panda and to differentiate sub-adults above six months from adults. However, body weight, body length, tail length, shoulder height, and chest girth can be used for diagnosis, as these attributes are smaller in sub-adults. Our method is a welfare-friendly way of trapping and handling wild red pandas. We report new morphometric data that could serve as a guide for field identification.

Multi-face recognition and dynamic tracking based on reinforcement learning algorithm

Aiming at the problem that the current low accuracy rate of face detection and target tracking, a reinforcement learning algorithm is proposed, which integrates face detection technology and target tracking technology organically, adopts the face detection algorithm based on Multi-Task Convolutional Neural Network (MTCNN) and target tracking algorithm based on Kalman filtering, so as to realize face detection, multiplayer face recognition and dynamic tracking of personnel movement. In this paper, the configuration environment is Anaconda, the operating platform is PyCharm, the video-based face detection and dynamic capture and rapid identification system has been designed and developed. The system consists of two modules: face detection module and target tracking module. The optimized face detection and dynamic capture algorithm improved the detection success rate by about 11.5%, the face detection success rate by about 15.2%, the dynamic capture success rate increased by about 12.0%, and the optimized system has a wider practicality.

A variable structure pneumatic soft robot

In this paper, a variable structure pneumatic soft robot is proposed. Its structure is variable in that when it grasps irregular objects, it can adapt to different sizes by active expansion or contraction. Its expansion range is from diameter 200 to 300 mm, its four soft pneumatic actuators (SPAs) can be rotated independently to adapt to different shapes, and it has high flexibility. The active compliant grasping method enables it to capture at the best position, which can improve the success rate of capture and reduce damage to the object being grasped. The experiment proves the effectiveness of the variable structure mechanism, and the proposed soft robot has low cost and a simple manufacturing process, so the mechanism has great application prospects.

Design and testing of a centrifugal fluidic device for populating microarrays of spheroid cancer cell cultures

BackgroundIn current cancer spheroid culturing methods, the transfer and histological processing of specimens grown in 96-well plates is a time consuming process. A centrifugal fluidic device was developed and tested for rapid extraction of spheroids from a 96-well plate and subsequent deposition into a molded agar receiver block. The deposited spheroids must be compact enough to fit into a standard histology cassette while also maintaining a highly planar arrangement. This size and planarity enable histological processing and sectioning of spheroids in a single section. The device attaches directly to a 96-well plate and uses a standard centrifuge to facilitate spheroid transfer. The agar block is then separated from the device and processed.ResultsTesting of the device was conducted using six full 96-well plates of fixed Pa14C pancreatic cancer spheroids. On average, 80% of spheroids were successfully transferred into the agar receiver block. Additionally, the planarity of the deposited spheroids was evaluated using confocal laser scanning microscopy. This revealed that, on average, the optimal section plane bisected individual spheroids within 27% of their mean radius. This shows that spheroids are largely deposited in a planar fashion. For rare cases where spheroids had a normalized distance to the plane greater than 1, the section plane either misses or captures a small cross section of the spheroid volume.ConclusionsThese results indicate that the proposed device is capable of a high capture success rate and high sample planarity, thus demonstrating the capabilities of the device to facilitate rapid histological evaluation of spheroids grown in standard 96-well plates. Planarity figures are likely to be improved by adjusting agar block handling prior to imaging to minimize deformation and better preserve the planarity of deposited spheroids. Additionally, investigation into media additives to reduce spheroid adhesion to 96-well plates would greatly increase the capture success rate of this device.

COMMENSAL SMALL MAMMAL SPECIES AND BAIT PREFERENCES IN URBAN AREAS OF PENANG ISLAND

Physical trapping is an important first step in controlling pest populations and species identification; and bait preferences are crucial information for effective management. This study was conducted to explore species diversity and bait preferences of commensal species in urban areas on Penang Island. Live trapping was carried out in eight sampling sites on Penang Island in commercial and residential areas. Eight different type of baits were used; apple and peanut butter (APB), white bread and peanut butter (BPB), salted fish (SF), salted fish and peanut butter (SFPB), white bread and fish extract (BFE), fried chicken leftover (FCL), vegetables and peanut butter (VPB) and sausages (S). The most successful bait was the high protein bait, fried chicken leftover (FCL), with a capture success rate of 35.56%. We also analysed the bait preferences for the different species of small mammals captured in our study. Five species of small mammals were captured in our study sites: Rattus norvegicus, Rattus rattus, Mus musculus, Bandicota bengalensis and Suncus murinus. Norway rats, R. norvegicus was the most trapped species in commercial areas whereas lesser bandicoot rats, B. bengalensis was the most captured species in residential areas.