65 research outputs found

    Read-only Prompt Optimization for Vision-Language Few-shot Learning

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    In recent years, prompt tuning has proven effective in adapting pre-trained vision-language models to downstream tasks. These methods aim to adapt the pre-trained models by introducing learnable prompts while keeping pre-trained weights frozen. However, learnable prompts can affect the internal representation within the self-attention module, which may negatively impact performance variance and generalization, especially in data-deficient settings. To address these issues, we propose a novel approach, Read-only Prompt Optimization (RPO). RPO leverages masked attention to prevent the internal representation shift in the pre-trained model. Further, to facilitate the optimization of RPO, the read-only prompts are initialized based on special tokens of the pre-trained model. Our extensive experiments demonstrate that RPO outperforms CLIP and CoCoOp in base-to-new generalization and domain generalization while displaying better robustness. Also, the proposed method achieves better generalization on extremely data-deficient settings, while improving parameter efficiency and computational overhead. Code is available at https://github.com/mlvlab/RPO.Comment: Accepted at ICCV202

    Automatic Search for Photoacoustic Marker Using Automated Transrectal Ultrasound

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    Real-time transrectal ultrasound (TRUS) image guidance during robot-assisted laparoscopic radical prostatectomy has the potential to enhance surgery outcomes. Whether conventional or photoacoustic TRUS is used, the robotic system and the TRUS must be registered to each other. Accurate registration can be performed using photoacoustic (PA markers). However, this requires a manual search by an assistant [19]. This paper introduces the first automatic search for PA markers using a transrectal ultrasound robot. This effectively reduces the challenges associated with the da Vinci-TRUS registration. This paper investigated the performance of three search algorithms in simulation and experiment: Weighted Average (WA), Golden Section Search (GSS), and Ternary Search (TS). For validation, a surgical prostate scenario was mimicked and various ex vivo tissues were tested. As a result, the WA algorithm can achieve 0.53 degree average error after 9 data acquisitions, while the TS and GSS algorithm can achieve 0.29 degree and 0.48 degree average errors after 28 data acquisitions.Comment: 13 pages, 9 figure

    Arc-to-line frame registration method for ultrasound and photoacoustic image-guided intraoperative robot-assisted laparoscopic prostatectomy

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    Purpose: To achieve effective robot-assisted laparoscopic prostatectomy, the integration of transrectal ultrasound (TRUS) imaging system which is the most widely used imaging modelity in prostate imaging is essential. However, manual manipulation of the ultrasound transducer during the procedure will significantly interfere with the surgery. Therefore, we propose an image co-registration algorithm based on a photoacoustic marker method, where the ultrasound / photoacoustic (US/PA) images can be registered to the endoscopic camera images to ultimately enable the TRUS transducer to automatically track the surgical instrument Methods: An optimization-based algorithm is proposed to co-register the images from the two different imaging modalities. The principles of light propagation and an uncertainty in PM detection were assumed in this algorithm to improve the stability and accuracy of the algorithm. The algorithm is validated using the previously developed US/PA image-guided system with a da Vinci surgical robot. Results: The target-registration-error (TRE) is measured to evaluate the proposed algorithm. In both simulation and experimental demonstration, the proposed algorithm achieved a sub-centimeter accuracy which is acceptable in practical clinics. The result is also comparable with our previous approach, and the proposed method can be implemented with a normal white light stereo camera and doesn't require highly accurate localization of the PM. Conclusion: The proposed frame registration algorithm enabled a simple yet efficient integration of commercial US/PA imaging system into laparoscopic surgical setting by leveraging the characteristic properties of acoustic wave propagation and laser excitation, contributing to automated US/PA image-guided surgical intervention applications.Comment: 12 pages, 9 figure

    Scar folding for the treatment of nostril stenosis after open rhinoplasty: a case report

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    A 25-year-old woman was referred for discomfort when breathing through her left nose. The patient had undergone augmentation rhinoplasty 5 years ago, after which hypertrophic scarring occurred in the left nostril. Several corticosteroid injections were administered as the first line of treatment, but with no symptom improvement. Therefore, we proceeded with surgical scar removal, with the use of a nasal conformer. However, scarring in the left nostril recurred. Accordingly, we proceeded with further surgical treatment using the scar folding technique. After scar folding, neither scarring nor nostril stenosis recurred during 1 year of postoperative follow-up. To summarize, herein, we report a case of hypertrophic scarring in the nostril that was successfully treated with the scar folding technique

    Thermoregulation of Capsule Production by Streptococcus pyogenes

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    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface

    Acquisition accuracy enhancement of high-speed storage interface signals

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    Study on a Shooting Device to Support a Wire-Driven Bridge Inspection Robot

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    In recent years, the deterioration of many bridges built during the period of rapid economic growth has become a problem. As a solution of it, preventive measures such as visual inspections and repairs by humans have been taken, but these methods have problems in terms of cost and safety. If inspection by robots becomes possible, both of these problems will be improved and it is expected to contribute greatly to the maintenance and management of bridges. Therefore, a number of robots have been developed for the purpose of bridge inspection. The among such inspection robots, wire-driven robots, which have less risk of falling and can perform close proximity or contact inspection, are attracting attention. However, one of the problems with this type of robot is that it is difficult to place the wire under the bridge when there is a river or road underneath it, or when it is very high. Thus, in this study, a shooting device for shooting arrows with attached strings was developed to solve this problem. We then conducted a shooting experiment and confirmed that the device aimed at the target automatically and shot the arrow. In addition, we created a simulation model of an arrow with a string attached to it to obtain information such as the shooting angle of the arrow in advance. Then, the flight trajectory and horizontal flight distance of the arrows were compared between the actual and simulated data, and the consistency was confirmed

    Simulation Design of Incremental Leg Tapered Birdcage Coil for Head Imaging at 4.7T MRI

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    This study analyzed asymmetrical designs of birdcage (BC) coils, for which the conventional shape of the BC is modified in order to improve field intensity and uniformity in the brain region for magnetic resonance imaging (MRI) at 4.7T. Typically the BC coil has insufficient field uniformity when operating at higher frequencies such as 200 MHz, corresponding to the Larmor frequency at 4.7T, due to the interaction between the electrical properties of body tissue and the propagated magnetic field wavelength. We propose a new design of BC coil, which consists of different ring diameters and leg width. The performance of proposed designs was compared to that of a head-size BC coil. Using finite-difference time-domain simulations to obtain the |B1+| fields for a human model, we demonstrate that the proposed designs can achieve better field intensity and uniformity compared with other BC coil designs

    Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials

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    We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of –3.2 V vs. SCE, which can be used to activate substrates with very high reduction potentials (Ered ~ –1.9 to –2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.<br /
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